::Meh, who cares where it points, as long as it's clear from that page which one that page is talking about. And provides a route to "the other one". I just added a dablink for that last bit. [[User:DMacks|DMacks]] 20:39, 15 November 2006 (UTC)
::Meh, who cares where it points, as long as it's clear from that page which one that page is talking about. And provides a route to "the other one". I just added a dablink for that last bit. [[User:DMacks|DMacks]] 20:39, 15 November 2006 (UTC)
I restored the redirect target to [[bicarbonate]]. I have never seen ''hydrogen carbonate'' refer to carbonic acid, though if someone has a good source I would like to see it. There is plenty of documentation that hydrogen carbonate refers to the same ion as bicarbonate. See, for instance, this [http://www.answers.com/hydrogen%20carbonate answers.com search] (in particular, the Columbia University Press encyclopedia), [http://www.answers.com/topic/hydrogen-carbonate another search], [[IUPAC_nomenclature_of_inorganic_chemistry|our own nomenclature articles]] (see point five), and a [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pccompound&term=hydrogen+carbonate PubChem] search (and the [http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=769 PubChem listing]. — [[User:Knowledge Seeker|Knowledge Seeker]] [[User talk:Knowledge Seeker|দ]] 22:07, 15 November 2006 (UTC)
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November 12
Standard voltages
Where does the five-volt TTL operational voltage figure come from? Is it from the parts originally used in the first TTL circuits (and hence somewhat arbitrary), or is there a more physical/practical engineering reason for it? VirogIt's notmy fault!04:41, 12 November 2006 (UTC)[reply]
Ah, I did read those already, and am quite familiar with digital logic. I was just curious as to how 5V was chosen - was it due to the parts used to prototype the first TTL circuits, or for a physical reason? VirogIt's notmy fault!
I think Light current did answer the question, if somewhat obliquely. Remember, for reasons of minimising power consumption, you want the lowest operating voltage that will still let your logic circuits operate reliably and quickly. I think that 5V was about the lowest voltage that ordinary TTL logic gates (with multi-emitter inputs, so-called "totem-pole" outputs, etc.) could utilize and still produce an adequate noise margin.
Similarly, you'll recall that the older RTL tended to use 3.6 volts.
I know how you feel; when TTL first came out, I know that I said "5 volts? Why 5 volts? Why not good-old 6 volts? Why 5?" But nowadays, of course, we're used to all sorts of odd voltages, and lower with each succeeding CMOS generation.
How does one build a capacitor? This is not for another half-baked idea like using human fat as an alternative fuel source. This is for a home project; don’t ask for the details. -- THL05:23, 12 November 2006 (UTC)[reply]
You'd need some sort of dielectric between them unless they were far apart.
Would that work with AC current? Also, would copper plates work better? I need to build up a fair amount of voltage for this, and I need to minimize resistance. I have access to large amounts of rubber, so the insulator won't be a problem. -- THL11:12, 12 November 2006 (UTC)[reply]
If it matters, I'm wiring this from a generator that I made myself, so it won't be out of a plug. I will be hooking the wires up directly to wherever they need to go. I have already built the generator and it works, but I need way more power than it generates. I only need it for an instant, however, so a capacitor would be perfect. -- THL11:26, 12 November 2006 (UTC)[reply]
From the questions you asked, it seems you might have some misunderstanding about how capacitors work. People here may be able to help you better if you provide more details about your project. I am not an expert in electrical power, but capacitors are not the only way to provide a power reserve. Would a flywheel be an option for what you want to do? --71.244.101.615:52, 12 November 2006 (UTC)[reply]
AC current will flow through a capacitor as if it doesn't exist. The capacitor will charge up, but you can't access the charge unless you isolate the capacitor and connect it to an electric device. Is that what you want? --Bowlhover22:55, 12 November 2006 (UTC)[reply]
I have looked at the page on capacitors. My father and brother both work for major electric companies, and they said that capacitors are often used to dam electricity and build up voltage in the same way that a dam blocks water and pressure builds up behind it. That is what I need to do. I need a fair amount of voltage for a very short time, and they said a capacitor would be the best choice for that purpose. Basically, I need around 500 volts of electricity for less than a second, and I would like to use a capacitor to do this. If you all know of a better alternative I'm listening, but if not I need to know of the best way to build a capacitor, and how to use it to dam electricity. My family doesn't know how to build them, or how to use it for that purpose, but they know that they are used for that purpose. Cheers, -- THL04:35, 13 November 2006 (UTC)[reply]
Indeed, as you would basically be generating an RC circuit, with the thing you need to apply voltage to becoming your resistor. The easiest way to get a capacitor is to buy them; it's hard to build a capacitor with a dielectric constant high enough for it to be small. If size is not a constraint, though, use two aluminum (or any other metal) plates, and wax paper in between, and allow it to charge for a long time before discharging.
Also, remember that your capacitance is inversely proportional to the separation between your plates; so, you can put some weight on it and make your capacitor stronger. Titoxd(?!?)04:44, 13 November 2006 (UTC)[reply]
Sweet, thanks. One last question, aside from precious metals what would be the best metal for me to use? I must build this thing from scratch; I have no choice. I'm not doing anything illegal, but the parts that I would have to buy would look very suspicious. A metaphor so this can make more sense, I have a cold and I'm going to have to clean a house. I need certain ratios of certain cleaning products, and large amounts of Sudafed; what I'm doing is totally innocent, but the cashier at the store will think I'm running a meth lab and turn me in. That is the position I'm in. -- THL05:07, 13 November 2006 (UTC)[reply]
Use kitchen foil (aluminium). Maybe greaseproof paper or (better) polyethylene or polycarbonate sheet as the dielectric (insulator). Please be very careful when you have connected the capacitors to your generator as at 500V they may hold enough charge to kill you (depending on the capacitance ).
I'm going to take the appropriate precautions. Actually, I forgot to ask the most important question. How would I set it up to dam the electricity, and then release it? I couldn't understand the RC current page. I'll be hooking the capacitor up to my generator, and releasing the electricity into a nail. I'll be running wire to the nail. Cheers, -- THL05:34, 13 November 2006 (UTC)[reply]
Well to large extent this depends upon the sort of generator you are using. If its a Wimshurst machine or Van de Graaf generator these will have a high output resistance and so the capacitor should be connected from the output to earth forming the RC circuit to store up the energy. You are also going to need a high voltage switch to release the energy from your capacitor into the nail. THis is going to be rather tricky cos you want it to be safe to operate. You might consider a relay but I suppose you dont have any lying around! It is just possible that you may get a spark gap to operate at around 500 V dc but the gap will have to be very small. Are you tring to melt the nail?--Light current07:09, 13 November 2006 (UTC)[reply]
The questions sound like you have only a vague idea of the physics of electricity. If you know nothing about capacitors and very little about electricity, then you should not be working with capacitors charged to 500 volts, since they are quite capable of killing a person. When you say you will take precautions, I wonder how you would know what the proper precautions are. They are likely more severe than you would suppose. A capacitor of large capacitance connected across AC voltage will conduct a large displacement current and may fail or damage the generator. The capacitive reactance which limits the flow of AC current is where omega (ω)is equal to 2*pi*the frequency. A capacitor connected in an AC circuit might retain some unpredictable amount of voltage if the AC source were suddenly disconnected. DC could be obtained from an AC source by a bridge rectifier circuit. A capacitor connected actoss DC will charge up to the supply voltage, and will discharge across any available conductive path, or back through the generator winding if the generator stops. Diodes can control the direction of flow and resistors can limit the maximum current. A high school physics book can make a lot of things clear to you without going too deeply into the complex mathematics of how the circuits work. That said, a capacitor such as described would have one sheet of conductor attached to the positive supply and one to the negative supply, with an insulator (dielectric) between them. The dielectric must be thick enough to withstand the applied voltage with a sizeable safety margin. Books such as the "Handbook of Chemistry and Physics" or physics textbooks list the dielectric constants of various materials, and the thickness needed to withstand a certain applied voltage. A thinner dielectric means higher capacitance but lower voltage withstand. A thicker dielectric means a higher voltage withstand, but lower capacitance. Different dielectrics (plastic, glass, mica, waxed paper, oil, electrolytic chemicals) have different insulating abilities and dielectric constants. A larger area means a higher capacitance. A home made capacitor might fail by arcing between the conductors as a hole is burned through the dielectric, or by arcing between metal portions where the wires connect to the conductors. The dielectric between the conductive surfaces must not have any gaps or cracks or pinholes or thin spots. Remember that stored energy is inherently dangerous: it can shock and cause burns or cardiac arrest leading to injury or death. It can arc and catch fire, or it can explode. Commercially made capacitors are likely to work out better than a home made unit. Edison16:59, 13 November 2006 (UTC)[reply]
This is an experiment tailor made to kill people. Please do not do this without adequate profesional supervision. 500 volts, if it can be sustained for even a 1/10 of a second across any reasonable resistor is enough amps to kill. Unless you have enough capacitance, you're playing with a giant generator, which given that you're asking these questions, is enough wattage to start serious fires. I have significant and strong safety concerns. JBKramer17:10, 13 November 2006 (UTC)[reply]
I don't understand much about the physics of electricity, but my father and brother will be the ones doing the work. I'm just building it. They are paid to work with wires that are carrying 500,000v of electricity while they are hanging upside-down on a daily basis. They can handle themselves with 500v of electricity ;) They'll be inspecting my connections, how well I wired it, ect. They just don't know how to build capacitors, so they told me to do it. Anyway, all I have to do is get a charge around 500v to the nail, and they are taking care of the rest. We are not trying to melt the nail; we would just use a torch for that. My generator is a large, large coil of copper wire, surrounded by magnets. Like the kind a lot of high school physics teacher build for demonstrations, but it weighs around 50 lbs. I need to wire that up to the capacitor, dam the electricity to build the voltage, and connect the capacitor to the iron nail. My brother said he would wire the switch for releasing it himself, so I don't have to worry about that. At this point all I need to worry about is wiring the generator to the capacitor, and then the capacitor to the nail in such a way that the capacitor can dam the electricity. By the way, I've been forgetting to thank you all. Thanks for everything, and thanks in advance for this. Cheers, -- THL22:54, 13 November 2006 (UTC)[reply]
If you connect one capacitor to one generator, the voltage on the capacitor will only be as great as the voltage produced by the generator. One way around this is to charge several capacitors wired in series, disconnect the generator, then throw switches to connect the capacitors in series. --Gerry Ashton02:54, 15 November 2006 (UTC)[reply]
I think you mean connect them for charging in parallel (10 caps each at 10v) and then discharge them in series (10 caps in line makes 100v). Not that I encourage 'playing' with hazardous voltage, so DON'T TRY THIS AT HOME! In reference to the topic at large, to do what you are describing simply and effectively you need to use an inductor in a charging circuit. This can take a relatively low voltage over a period of time and turn it into a very brief period of very high voltage. To accomplish this from scratch, you will need a generator, a rectifier, a capacitor, and an inductor. I will leave the details to you hoping you will realize the potential hazards during construction. --Jmeden200020:23, 15 November 2006 (UTC)[reply]
Alright. I have trouble understanding articles that are mostly equations with minimal explanation, so I may be back with new questions. Cheers, -- THLCCD21:58, 15 November 2006 (UTC)[reply]
Graphs
Hello all. I have an exam tomorrow and this just came to me now.
(edit) the graph looks real stilted. it goes diagnol up, straight horizontal, diaganol down. im just looking for rough shapes.
Here's a quick rundown on linear motion to help you for your exam. Before we can do anything, we need to decide on an axis. This is the straight line that we will be moving along. It might be forewards/backwards, east/west, up/down, whatever. Once we've got our axis, we choose an origin (a "zero" point), and a direction to call "positive". As an example, if I'm considering the motion of a train rolling along a straight strack over the course of 30 seconds, my axis would be along the track, a good origin will be the spot where the front of the train was at the start of the 30 seconds, and a good positive would the direction the train is moving.
Now that we have set up a way of measuring things, we can analyse motion. Remember that as things move, their displacement (position, with respect to the origin) will be changing. Their velocity is the rate of change of their displacement. So if our object's displacement is remaining constant (not changing at all), then it must have zero velocity. If the displacement is getting higher, then the object is moving in the positive direction, so it must have positive velocity. If the displacement is getting lower, then the object is moving in the negative direction, so it must have negative velocity.
Remember that positive velocity means "moving towards the positive end", not "moving away from the origin", and similarly for negative. An object which starts with displacement -10, and then over a few seconds moves through -9, -8, -7, etc, has a positive velocity, because it is travelling towards the positive numbers. Hopefully this helps you understand what you're looking at with these graphs. Maelin (Talk | Contribs) 12:14, 12 November 2006 (UTC)[reply]
With lack of figures I can't do the calculations involved in order to have the correct gradients and positions, but this image shows the general shape your graph should look like:
The first part shows a constant velocity since the first part of the displacement graph is straight. The middle part shows no velocity, because the displacement graph shows no change in displacement. The end part shows a negative constant velocity since the displacement graph shows the vehicle travelling back to the origin (so must be going in an opposite direction, hence opposite velocity, to the way it went in the first part). RevenDS12:28, 12 November 2006 (UTC)[reply]
I should also add that since velocity has both magnitude and direction, you must indicate the third part of the graph to be below the x-axis. If you are asked to draw a speed-time graph, then your original guess is correct. RevenDS13:03, 13 November 2006 (UTC)[reply]
Psychology
Like to find out 2 main questions that i concern now...
1) How does psychology affect us?
2) Each and every part of a living thing has muscles which are linked to the brain, but how does it work to tell us something?
I am wondering as to the effect a different type of sugar,mainly, glucose, fructose, lactose and sucrose, have on the amount of carbon dioxide, produced by the process of fermentation and the physiological explanation for this. Thank you in advance for your comments and suggestions. —Preceding unsigned comment added by 81.156.30.13 (talk • contribs)
Isn't it a bit far fetched to suggest that a natural climate condition could have been affected so quickly by human actions? A few people driving around in modern SUVs isn't exactly going to affect a thousand year old cycle of climate change on the earth, I mean there used to be an ice age, and it's been getting warmer since, and now it's dry and arid, obviously there haven't been human beings living there the whole time doing it, so why attribute it to human actions? It seems like this was more of an excuse for Al Gore and the Bill Clinton / Howard Dean crowd to get the federal government involved in the personal affairs of Americans, then a serious study in climate change. So the question, in light of current science, does Gore's theory of 'Global Warming' still hold water?--Dusty Bowls20:02, 12 November 2006 (UTC)[reply]
You're basing your conclusion on intuition, not science. A subjective feeling of far-fetchedness is not a proper tool for evaluating the likelihood that a theory explains some phenomenon. I'm sure someone from the Biblical times would find it far-fetched to imagine a machine capable of doing calculations a billion times faster than a human can and yet takes up no more space than an apple. --71.244.101.621:18, 12 November 2006 (UTC)[reply]
CO2 concentrations over the past 400,000 years.
If you look at the graph on the right you will see that the concentration has increased very much over the past 200 years. Of course CO2 isn't the only gas contributing to global warming, but I wouldn't say that humans have nothing to do with it. - Dammit21:47, 12 November 2006 (UTC)[reply]
Al Gore doesn't have a theory of global warming as he is a politician not a scientist. Politics is much more interested in redistributing or protecting wealth so all of the research is tainted (both for and against global warming). --Tbeatty21:50, 12 November 2006 (UTC)[reply]
I regularly read scholarly articles in Science et al. that do provide ample evidence, using dozens of different metrics & techniques, that there is a global warming trend. The most dramatic warming has occurred since the industrial revolution and seems to be causally linked to the great increases in greenhouse gas production via the burning of fossil fuels. It's a pretty established scientific consensus that
1. global warming is real
2. humans play a significant role in its progress
3. the consequences could be drastic and may be irreversible
The debate over #1 is largely closed, with essentially only right-wing thinktanks and such denying it is real, although there are some scientists with arguments against anthropogenic causes worth noting. #2 is a big question as to the proportion of "blame" to lay on us (IMO, it's too much finger pointing & too little action--what does it matter if we're responsible for 95% of the warming or 40%? It's still a significant amount...). #3 is where the real energy should be spent: what are the consequences of the trend & what can (reasonably) be done to slow/stop/reverse the trends. -- Scientizzle21:53, 12 November 2006 (UTC)[reply]
Hmm? I regularly read scholarly articles in Science et al. that do provide ample evidence using dozens (more) of different metrics & techniques, that there is a global warming trend. Assuming a time frame, this is indebatable (no snide comments!). It's for sure. The debate is, and is centered around a few vital questions: how much?what is the cause?how strongly does CO2 as a GHG's affect (logarithmic) the global mean temperature? Most disagreements not dripping science are either politically-, or economically-based and we should kill them we should not give them that much respect for those reasons. X[Mac Davis] (DESK|How's my driving?) 08:15, 13 November 2006 (UTC)[reply]
"A few people driving around in modern SUVs isn't exactly going to affect a thousand year old cycle of climate change on the earth" A few SUVs aren't going to affect the Earth, but how about millions of people driving millions of SUVs? Let's not forget the factories that release huge amounts of carbon dioxide. Carbon dioxide is a greenhouse gas that's very effective in keeping Earth warm; imagine what would happen if the amount currently in the atmosphere is doubled.
Let's imagine, shall we? Oh, it's making me giddy! But we can't. How about don't imagine, and we use data? I like that idea even better.
CO2 is growing exponentially[1][1] Agree? I'm not about to go fetch the data and stick it in Mathematica at 2 am. Let's just eyeball it and it'll be a secret. ;) Wait, you believed me? Maybe I was wrong. Maybe it's a linear trend[2] eh? Or maybe we could just take into account that the relation of CO2 and it's GHG effect is a logarithmic correlation, not linear. That greater the ppm value, the less effect you add on. In fact, the graph looks like this. Take for instance, the very high estimate of Charnock & Shine— rounding, from 0-20 the y coordinate is 6, Δy=6! From 20-40 y=8, or Δy=2. From 40-60, y=8.2? Δy= 0.25 You get the idea. The potential planetary warming from a doubling of atmospheric carbon dioxide from pre-Industrial Revolution levels of ~280ppmv to 560ppmv (future guess to the way we're going) is generally estimated at less than 1 °C. The point is, yes the more CO2 you add the greater the GHE if you don't change anything else (then again, conservation of mass) but it isn't as scary as it sounds, because the more you add the less it counts. X[Mac Davis] (DESK|How's my driving?) 08:15, 13 November 2006 (UTC)[reply]
"The potential planetary warming from a doubling of atmospheric carbon dioxide...is generally estimated at less than 1 °C" Really? Have a look at our climate sensitivity article. The Earth's temperature will rise by 1.5 to 4.5 degrees if CO2 levels are doubled. The average of 1.5 and 4.5 is 3.
"it isn't as scary as it sounds, because the more you add the less it counts" So what? As you yourself admitted, pretty soon the amount of CO2 in the atmosphere is going to be doubled. Isn't a 3-degree rise in the temperature bad enough? Right now the average temperature has only risen half a degree, yet we're already noticing some of the effects. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
Two millennia of mean surface temperatures according to different reconstructions, each smoothed on a decadal scale. The unsmoothed, annual value for 2004 is also plotted for reference.
"I mean there used to be an ice age, and it's been getting warmer since, and now it's dry and arid, obviously there haven't been human beings living there the whole time doing it, so why attribute it to human actions?" Because, as the graph on the right shows, the temperature has been increasing drastically over the past century and a half. Now, Earth is warmer than it has ever been in the past two millenia. Do you think it's a coincidence that this warming started when human CO2 emissions started increasing rapidly?
"It seems like this was more of an excuse for Al Gore and the Bill Clinton / Howard Dean crowd to get the federal government involved in the personal affairs of Americans" But the vast majority of scientists around the world (not only in the U.S.) believe human activities are causing global warming. Unless you believe Bill Clinton can force every scientist in the world to believe in something that goes against the evidence, I don't see how global warming can be an "excuse" concoted by the U.S. government.
"that's quite a loaded question, and I suspect you wont find a unanimous answer." If Dusty Bowls asks scientists rather than us, I'm sure he will get a very nearly unanimous answer: humans are causing the Earth to heat up. --Bowlhover22:53, 12 November 2006 (UTC)[reply]
The idea that "scientists know what is going on and we don't" makes me think appeal to authority, credentialism, and bastardization. And, as shown in our last discussion, paleoclimatology is a very rough field. There is a lot of guessing and we aren't exactly sure what is going on because we're dealing with quite a bit of stuff. Every possible tiny little biological and chemical cycle, quantum physics, the Earth's albedo, solar insolation, cosmic rays... it is all rather crazy. X[Mac Davis] (DESK|How's my driving?) 08:23, 13 November 2006 (UTC)[reply]
Right. But it seems that this time, Mac Davis (the main supporter of the "global warming isn't due to humans" position) doesn't want to debate with us anymore. --Bowlhover05:34, 13 November 2006 (UTC)[reply]
Whoa whoa whoa! What are you talking about? I'm on wikibreak and have got a lot of work to do. That's a low blow man. One day late... why I oughta! I'll see what I can do for you though. ;) And I think you've mischaracterized my position, if I have one. I'm just a guy that likes to read paleoclimatology and has formed my own conclusions after of course speaking with experts on the subject rather frequently. If you were to put me into a camp, although sometimes it seems like "faction" is better for this subject, I would advise you to make it "skeptical of an anthropogenic CO2 global warming (AGW)." Thanks for putting me in quotes though to make me sound silly! X[Mac Davis] (DESK|How's my driving?) 05:57, 13 November 2006 (UTC)[reply]
The difficulty is not in proving that the changes are happening, but in pin-pointing whether that cause is by humans or not. A graph showing a rise in the past 200 years (or so) is not proof that the affect is CAUSED by humans, rather proof that changes are happening.
Additionally science is not a consenseus community, it is a community in pursuit of evidence to proof/disprove their claims. Of course the more scientists that agree on something the more likely that theory/argument is accurate, but by virtue of numbers alone this again is not proof.
All this is, however, an aside. The question with regards to climate change is whether we try to stop it, or whether we try and prepare to live through it. Nobody seems to produce in the media any benefits to global warming, yet with such vast change being undertaken there will be winners and losers. The question of human influence is down to the weight of human influence (is it all humanity's fault or has natural change had an impact too?). The technical questions are where scientists come in, but the world-impact questions are not the remit of science, they do not have the sufficient expertise in population management/technological development/world politics etc. etc. to work. ny156uk23:17, 12 November 2006 (UTC)[reply]
Why do we need proof that the recent rise in temperature has been caused by humans? Strong evidence is good enough. I know science is not a consensus community, but there has been no evidence suggesting that the recent rise in global temperatures isn't due to human activities. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
If the average global temperature starts rising at the same time as the amount of human-produced carbon dioxide starts rising, I would consider that as pretty strong evidence that the former is due to the latter, since carbon dioxide is a greenhouse gas. Of course this is not a proof; nothing in science can be conclusively proved. But if you add wood to a fireplace, and you feel hotter, wouldn't you assume that you feel hotter because of the extra wood? --Bowlhover00:13, 13 November 2006 (UTC)[reply]
If an event, A, happens directly after another event, B, then this provides evidence that B causes A. I know it doesn't prove it, but what if you know for sure that B can cause A, because you've seen it happen before? Adding to the example I gave in my previous post, let's say you add more wood to a fireplace than you've ever added before. You know that your room will get warmer, because it got warmer all the previous times you've added wood. Also, the best scientific theories predict that your room will get warmer. Sure enough, you feel much hotter after a while. Will you assume that your heated up because of the extra wood, or will you assume that it's simply a coincidence that your room gets unbearably hot right after you add a ton of wood to the fireplace? What if a Wikipedia editor came to you and insisted that you're commiting the "cum hoc ergo propter hoc" logical fallacy? Will you listen to him? --Bowlhover17:12, 13 November 2006 (UTC)[reply]
Whether or not humanity has caused the changes to happen is in the past. What matters now is what is making the problem worse. We know that vehicles emit CO2. We know that factories emit CO2. We know that global warming is getting worse, has the potential to change the world as we know it, and is currently in the process of doing so. We know that CO2 makes global warming worse. We know that global warming has the potential to become self sustaining, assuming that it hasn't already. All of this we know. What matters in the here and now is what we should do about it. Lowering CO2 emissions will slow the problem down, and that is better than not doing anything, but the real question is can/how do we reverse global warming. -- THL05:50, 13 November 2006 (UTC)[reply]
"We know that CO2 makes global warming worse." This implies global warming is a problem, a problem in which we will all die (or suffer horribly). If I'm not mistaken, global warming should have been happening since CO2 started going up, somewhere around a hundred years ago (and it probably has). In fact, there should have been a ΔT spike in the 40s[2]. Since we haven't gone through a global warming like this before, or in a high enough state of development to realize what is going on, I don't think we could nail down the cost-benefit analysis very close at all (although there have been a few crazy ones, most notably the most recent one from Britain), and definitely won't be able to think up the effects of any mean change in global temperature. Richard Muller at Berkeley doesn't think global warming is bad at all.[3]X[Mac Davis] (DESK|How's my driving?) 08:15, 13 November 2006 (UTC)[reply]
Just because mankind has never been through a global warming before, it doesn't mean that nobody knows what's going to happen. (As an example, even if no hurricane has ever hit a particular city before, we can be sure that there will be damaged buildings, flooding, power outages, etc. if one does hit.) The weather can be forcasted accurately, and weather forcasting uses roughly the same science as global-warming-forecasting. For example, Antarctic ice melting will increase the sea level, which will cause flooding in low-lying areas. Is flooding a good thing? You decide. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
There is a 30 year lag in climate behaviour from CO2 changes. It's been well established. Just wait til we start experiencing the weather 30 years down the track that we're creating today. Climate change from human sources was predicted, and now it's clearly happening. —Pengotalk · contribs14:13, 13 November 2006 (UTC)[reply]
Well established 30 years eh?[4] So there was an enormous CO2 spike in 1910 then? If, in the 40s there was a CO2 spike, why exactly does the temperature keep going down? Your mentioning of lag brought up an interesting possibility I just thought of. If CO2 ppm goes up why does ΔT wait? Observe[5] Can you read that graph and infer anything? I would say Perhaps ΔT, ΔCH4 ppm, and ΔCO2 ppm are all related, and one or more influence each other. What if temperature influenced CO2? I know that right now we're kind of talking about the around doubling of CO2 (eyeballing) from the pattern in the last 650,000 years. Also, the solar insolation graph stuck on top looks pretty suspicious... X[Mac Davis] (DESK|How's my driving?) 20:37, 13 November 2006 (UTC)[reply]
"If CO2 ppm goes up why does ΔT wait?" Because it takes a long time to warm up the whole planet. If you erect a greenhouse and close the door, does the temperature increase immediately after you close the door? No, it will take a while. Releasing huge amounts of CO2 can increase the temperature because it traps heat. But the trapped heat has to warm up the land, and then it has to warm up 1.3 billion cubic kilometres of water (so that the ocean doesn't keep the global average temperature down). How long do you think this will take? One day?
"What if temperature influenced CO2?" I don't get what you mean. Are you trying to say that 200 years ago the temperature started rising for absolutely no reason, which then caused humans to pollute the atmosphere? If you're saying that a rise in temperature will cause more CO2 to be released by nature, which process would be reponsible for this? Carbon dioxide is, for certain, a greenhouse gas that can warm the planet up. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
If your models predict that the normal state of affairs will change, and then it does, in the way they predicted, then that is usually a pretty strong support for the models. And it isn't Gore's theory. It's a scientific theory. Gore merely refers to it. And he isn't quite the only one. From a scientific point of view there may not be absolute certainty, but then there never is. From a political point of view, if scientists say there is a possibility that things are going to go horribly wrong, then one should at least stop and think. Risk is chance times effects. If the effects are potentially disastrous, then even if there is a small chance, one should take action. If the chances come close to certainty then one should take action really fast. Especially if there are longlasting after-effects. DirkvdM10:28, 13 November 2006 (UTC)[reply]
To come back to a few points... That X happens and then Y happens is not evidence that X caused it without taking into consideration many other factors. To use your wood-example, if at the same time as you were putting wood into the fire someone was turning up the thermostat, you would see a rise that in temperature caused by more than one factor, but on reading purely the wood and heat you would link the wood and not consider other factors that may have added to the issue.
"even a small chance, one should take action". This is quite wrong. In a risk-averse society maybe, but in our world we take actions that have a 'small chance' of catastrophe everyday. We drive a car and risk a crash, we cross the street and risk a crash, we smoke and risk lung disease. The cure to global warming lies in more than just prevention, but in alteration too. It is nigh on stupid to claim that global warming will be the end of civilisation as we know it - too many idiots in the past have proclaimed things will get worse - and the further respectable science goes down this doom-sayer route the more it sounds like religion.
All of this, agian, leads to nothing. The problem is there - we have a wealth of evidence showing change and predicting future change. Until it is seen that the solution has to balance social-allowance, economic-viability and scientific recommendations we will get nowhere. Tell people he world will end tomorrow if they don't stop driving and most will sit waiting for the end of the world. Tell them they can help make a simpler and perhaps better tomorrow by reducing their mileage, or switching fuel type and maybe, just maybe, they'll change. Add in tax-incentives and regulation and what do you have? A coherent policy on how to overcome the problem of climate change. The end of the world isn't scary, losing what advancement has brought me is. ny156uk17:58, 13 November 2006 (UTC)[reply]
"To use your wood-example, if at the same time as you were putting wood into the fire someone was turning up the thermostat..." But you're sitting in the room that has the fireplace. If someone turned up the thermostat, you would know. There is no evidence that anyone touched the thermostat, just like there's no evidence that anything other than human CO2 emissions have been warming up the planet. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
That isn't true. There are indications that the world would have been warming up without human intervention. But the rate at which the climate is changing is way off the scale. What normally happens in at least thousands of years is now happening in decades. Such a fast change is unprecedented (afawk).
ny156uk, I said even if there is a small chance. Not a minute chance. The chances of getting killed when crossing the road are negligible. Even in a whole lifetime, the chances of getting killed in a car accident are about 0.5%. The chances of global temperature rising several degrees is considerable higher. A one or two degree rise is even close to certainty. Also, individually we have no choice but to cross the road if we want to get on with our lives. But, say, driving a car with a much smaller engine will barely affect our quality of life. As will voting for a climate-friendly party (if that is an option where you live). DirkvdM06:18, 14 November 2006 (UTC)[reply]
The addition I made to the wood example is, I feel, correct: See correlation implies causation. That A (wood added) occurs in correlation to B (heat output) does not definitively mean A causes B. The caveat is this - you need further evidence to show that other factors are not at play.
In the real world this is a different matter. I have no idea whether nature has an impact on global warming alongside human-input, but I believe that as many potential avenues must be explored before we can call the explanation to be coherent.
Dirkvd...Sorry it was a poor example, though it does open up questions about risk-management and everybody has their own idea of cost/benefit analysis. Voting for a climate-friendly party is your choice, but a single-issue party is not able to run a government until it matures - it can, however, influence how the major parties operate. ny156uk17:31, 14 November 2006 (UTC)[reply]
Please reread all my previous posts; I've argued against the "correlation implies causation, therefore we can't assume anything from the temperature record" argument two times already. --Bowlhover00:36, 15 November 2006 (UTC)[reply]
The fire-wood example is a bit better if one doesn't know if putting wood on a fire will produce more heat, but has a theory about it, tries it and finds that indeed it does. That may not gove one certainty, but it's a bloody good indication. Sientifically speaking, yes we have to explore all possibilities before we can say for certain. Well, that's not quite right because in science there is never any certainty. But we must make sure we don't die in our ivory tower and in practise act long before we have any certainty. And why would a climate friendly party have to be a one-issue party? DirkvdM08:15, 15 November 2006 (UTC)[reply]
Winners from global warming ?
Obviously many will lose, but who will win ? One country that comes to mind is Canada, who won't suffer as much as many other countries because most of it's major cities (Toronto, Montreal, Quebec City, Ottawa) are not on the ocean (Victoria, BC being a major exception). Canada could also benefit by the opening up of the Northwest Passage, formerly blocked by ice most of the year. Also, the vast northern tundra could change into productive cropland with enough of a temperature increase. Similarly, Russia might benefit. StuRat04:51, 13 November 2006 (UTC)[reply]
Acutally "losers" from current environmental restrictions is perhaps more striking. One example, cheap and efficient refrigeration keeps food from spoiling. Considering there is starvation in the world, their money went to buy more expensive refrigeration instead of more food. I've seen estimates in millions of lives. There are lots of poor choices being made because of the shrill cry of global warming.--Tbeatty05:58, 13 November 2006 (UTC)[reply]
Actually, Canada is losing at the moment, as it has to invest in ships and submarines for patrolling its huge (!) coastline in the north which will be subject of much interest (the famous Northwest passage). -- 85.179.10.10610:00, 13 November 2006 (UTC)[reply]
In a 'globalised world' (sorry if that sounds odd :) ) a country's ecomomy depends to a large extent on other countries' economies. If your trade partners do bad, you will do bad. As to the local effects, two things should be kept in mind. Firstly, the warming is global, but regionally there could be cooling. An extreme example is the shutdown of thermohaline circulation, which could cause Northern Europe to freeze over. Secondly, the change will be unpredictable, so until it 'settles' (if it does) farmers won't know what to grow, resulting in bad harvests (and food shortages and hunger if you can't import from elsewhere because they had a bad harvest too). But what's possibly worse is that what the climate settles into will probably be more extreme. Just like heated water starts to boil (sorry about the slightly lame analogy), a heated atmosphere will result in more violent weather, with greater extremes. Storms will probably be more violent (hurricanes like Katrina will become commonplace) and one year may be too dry, while another year may see heavy downpours. This is probably the greatest threat, alas often ovelooked. Farmers rely on the weather being somewhat predictable. If it isn't, food shortages will result, irrespective if locally there is warming or cooling. Also, global warming means sea levels will rise and that will affect almost all civilisations since humanity largely lives at coastal areas and, again, that's where one finds most agriculture because of the deposited fertile soils. So the land that will disappear will be of the most valuable kind. Unless the thermohaline circulation shuts down and the ice will absorb a lot of water. But then we've got another problem (apart from this not being very nice for Europe). Ports will no longer be at the coast, causing transportation problems. Probably not as serious as the losing of land, but still a problem that will take a long time to overcome and cost a lot of money. Our societies are based on the status quo and if that changes, the way our societies are arranged no longer makes sense. And the change will cost us. DirkvdM10:28, 13 November 2006 (UTC)[reply]
You can both win and lose if your partner does poorly. The question is whether the world economy goes downwards, or your regions. There will be short term difficulties from changes in power, but other nations can win as others lose. Farms wise the growing of harvests/food can be done in virtually all conditions and unless climates are changing rapidly from one year to the next there is no reason change cannot be acted quickly and efficiently (particularly if it is regularly happening they will become more efficient over time). This would mean it is likely that foodstuffs would go up in price though.
Just because the sea-level rises doesn't mean there we cannot cope. Population movement and development of systems to control/react to sea levels are not impossible to create or develop.
The cost to society of major upheaval is evidently large, but if the cost of reducing emissions is higher which do we choose? The world is going to have to come to terms with some big changes I am sure, but it is hardly the first time in history. We had nations almost bankrupt and ruined by 2 world wards in under 50 years. Our technological development will not go backwards, the difficulty will be in keeping the pace of change we have seen. It is far better that we have achieved the things we have in the past 200 years than to have prevented them from happening because of future issues.
The sentiment over global-warming/climate change is depressing reading. Few have faith in humanity, ingenuity and downright resiliance. I tend to believe we have what it takes to get through this, but that it will indeed be one of the toughes dilemmas we have encountered. But a world war that took 60 million lives, and one just before that took what 9 million (or thereabouts) our world is truely well adjusted to horrific atrocities occuring. Lets hope that we can minimize/eliminate it this time round. ny156uk18:13, 13 November 2006 (UTC)[reply]
So your idea is to not reduce CO2 emissions and watch what happens. But reducing the emissions is definitely not more expensive than evacuating whole cities and spending more money for food because it's more expensive. The poor polar bears will drown because there's no more ice floes to rest on, and many other species will also have a tough time coping with the changing environment. --Bowlhover00:57, 14 November 2006 (UTC)[reply]
Ny156uk, you say "unless climates are changing rapidly from one year to the next". But that is precisely the problem. (Also note that a rapidly changing climate really means 'no climate'.) And we probably can cope, but there will be a transitional period that may turn out very nasty (possibly around when I am an old man, so maybe I should strive to die young). And unlike the two world wars, this will be truly global. No Marshall plans for any nation because all others will have their own problems. The cost of adapting now or adapting then would have to be weighed against each other, with the problem that the latter will be mere guesswork. But something that is a certainty is that fossil fuels will run out. So we will have to come up with alternatives. So we have no choice to invest in that. So why not do it now and leave the remaining oil for other purposes it might turn out to be handy for in future technologies? I agree that we can solve this, but the problem is that hardly anything is happening so far. The free market will only step in when big profits can be made and it will be too late then. DirkvdM06:42, 14 November 2006 (UTC)[reply]
Dirkvd, Until it is economically viable (or politically necessary) we will not change our behaviours. Fossil fuel will not run out - simplistically speaking the price will go so high that development of alternatives will be viable/lucrative and thus developments will be made, previously unworthwhile finds will become worthwhile investments/etc. etc. The cost of adapting now for the future is no more known than what the cost will be in the future, specifically because you cannot be sure of the exact benefits changes will bring.
This is not a call for non-action this is a call for rational action. Make changes where we can and help make it economic to change for the better and/or tax the habits you want to reduce. Direct funding into development and prevention, focus on ways of improving what we do and also improving the accuracy of the science. Do all these things we will (and to some degree already do), and the world will be better for it. But do not expect people to make their lives measurably worse, because few will regardless of the 'scale' of the potential disasters. In short be realistic about what is achievable and push the boundaries where you can. ny156uk17:31, 14 November 2006 (UTC)[reply]
THC stopping sounds like it could never happen. There will always be change in the differences in temperature, density, and salinity. Through all the ice ages and warm periods in the recent past (myr I'm referring to) there has always been a circulation, it is in the data. Things move, period. The THC will change, and has been changing forever, just like currents in the atmosphere. If you can, prove me wrong. X[Mac Davis] (DESK|How's my driving?) 20:37, 13 November 2006 (UTC)[reply]
I'm not interested in debating this, Mac. Post a new question if you feel the need to disprove global warming so badly. My question was who would benefit from global warming, not whether or not THC will end. StuRat21:01, 13 November 2006 (UTC)[reply]
No luck there either. From the article: "If the Greenland ice sheet were to completely melt away, sea levels would rise more than 7 m [] and Greenland would most likely become an archipelago." The Netherlands, Bangladesh and Florida would have disappeared long before that. DirkvdM06:42, 14 November 2006 (UTC)[reply]
Has it ever completely melted away? Bangladesh, ha! Everytime it's monsoon season or a typhoon comes by they go underwater. The Netherlands is pretty damn good at keeping the water out though :) X[Mac Davis] (DESK|How's my driving?) 16:57, 14 November 2006 (UTC)[reply]
"Bangladesh, ha! Everytime it's monsoon season...they go underwater." And you're using this to argue we shouldn't try to stop global warming? If sea levels rise, even more of Bangladesh will go underwater even more often, killing many more people. --Bowlhover00:36, 15 November 2006 (UTC)[reply]
Funny, if something hasn't happened before, you say "Ha, see, it can't happen" and when it has happened before you say "Ha, see, it has a different cause". DirkvdM08:15, 15 November 2006 (UTC)[reply]
Sorry if it's been mentioned already (I don't have the time/am too lazy to read through everything) but oil companies would probably benefit. I remember recently reading that 1/4 of the world's oil is lying, untapped, in inhospitable places such as Antartica.
With all the ice melting, oil companies could easily begin extracting that oil too, and keep making money. --Saxsux19:24, 15 November 2006 (UTC)[reply]
gastroenterology
is Barrett gastric metaplesia in the esophagus a precancerous lesion?
Barrett's esophagus refers to intestinalization of the esophageal mucosa. We know that (1) Barrett's itself carries a very low rate (but still extant rate) of malignant transformation and that (2) gastric metaplasia carries a lower rate than intestinal metaplasia. Most gastroenterologists recommend surveillance 2-4 years for Barrett's, with increased surveillance or treatment if there is dysplasia. -- Samir धर्म03:54, 14 November 2006 (UTC)[reply]
Gabapentin
I work at a pharmacy and I noticed that a lot of people get benzodiazepines for their anxiety. I was reading the gabapentin article and it mentioned that it was made to mimic the GABA nuerotransmitter, which from what I learned the more you have, the calmer you are. So why aren't more people prescribed gabapentin and are prescribed benzodiazepines? Is it not as effective?
Because Gabapentin (despite it's name) doesn't act on the GABA receptor. Instead it binds to the α2δ subunit of a voltage-dependent calcium channel in the central nervous system and acts as an analgesic used especially in chronic pain. Mmoneypenny10:37, 15 November 2006 (UTC)[reply]
Leaving aside conspiracy theories and pseudoscience, some serious minority theories I have read in recent years (sorry I do not have citations handy): One minority opinion theory is that humans were in North America long before the Clovis culture era dating from Folsom points, like 20,000 years ago versus 13,500 years ago. Another is that North America was first settled by Solutrean people from northern Europe before people came from Siberia. Another is that Neanderthals interbred with modern humans. Another is that a meteor hit the moon during the middle ages and the impact was witnessed by monks in Europe. Another is SETI, that we should be able to detect radio signals from intelligent beings on planets orbiting other stars with present technology. Another is that genetically modified plants and animals pose a great danger to our survival, due to the modified genes making their way into other species, like a gene for herbicide resistance added to a cultivated grain crop jumping to the genome of weeds. Another is that global warming is NOT a threat to our survival and is not caused by human activities. Another is that condoms do not reduce the spread of sexually transmitted diseases, and that abstinence education is the best way to prevent undesired pregnancies and STDs among young people. Edison17:21, 13 November 2006 (UTC)[reply]
I recently saw what the bleep do we know and found it quite disappointing, but it all made sense once I read about who it was produced and directed by. Some of it was entertaining I suppose, but one thing in particular caught my interest. In it one of the 'experts' claims that somewhere in a lab someone has created a something which exists in two places at once, a laser or something, which seems insignificant, but it IS actually the SAME thing in two places at ONCE. My question, is this true and if so what's it called, apologies if this has been asked a million times but I'm not even sure what to google or where to start looking. Vespine00:18, 13 November 2006 (UTC)[reply]
Also, wave particle duality tells us that things we think of as particles are actually "wave packets", with a location described by a "probability function". In other words, these particles exist in many locations at once, in fact, every possible location at once (although they become more localized when observed, which is truly bizarre). StuRat04:35, 13 November 2006 (UTC)[reply]
No no, there is a guy on the show that says they have a box in a lab and it just looks like it has two things in it, but it is actually the same thing, it's in two places at the same time. He literally said you can go up and look at it with your own eyes. Like it's not just some split second thing that they did in a cyclotron that only a scientist can interpret by looking at a screen full of data. Anyway, reading all the articles above, sounds like BS to me. Vespine04:18, 15 November 2006 (UTC)[reply]
Dinosaurs and Oil
Some friends and I are having some disagreement about where oil comes from. I learned when I was in Jr. High School that Oil came from Dinosaurs and other Prehistoric creatures that decomposed over the millions of years. I know that is a simple statement for a very broad subject that I found trying to get a simple answer out of over one hour of reading through much of the information that you have. I found it all very interesting but not simple enough to convience my friends. Then I may be wrong for all these 60 some years since I heard that in a class.
I would appreciate the answer, to satisfy all our curiosity,
Jack Schram
(e-mail removed)
You ought to have a look at the articles you link to. That article doesn't have anything on where oil comes from beyond "formed from decayed plants and animals". A better explanation is at Petroleum#Biogenic_theory: oil is formed from the preserved remains of prehistoric zooplankton and algae which have been settled to the sea bottom in large quantities under anoxic conditions (no dinosaurs mentioned). And the reader may also be interested in Coal#Origin_of_coal, which is slightly more likely to have some dinosaur in it. —Pengotalk · contribs01:34, 13 November 2006 (UTC)[reply]
I did look at the article before I linked to it. The sentence you quoted answered the question, although I admit there is not a lot of detail there. --Ginkgo100talk · e@05:48, 13 November 2006 (UTC)[reply]
The "dinosaurs got turned into oil" thing is a quote from the movie Airplane!. Inexplicably, it's not on our voluminous wikiquote page devoted to that film. I believe the next item in that brief history of the world was "And then the Arabs came!". Matt Deres17:52, 15 November 2006 (UTC)[reply]
The article is crappy, not bothering to explain many of the terms involved. It's not even clear to me whether it's SIRT2 or Sir2 (maybe they're different things, but if so, that too is far from clear). The term "sirtuin" seems to have been created as a name for the group of genes. That would suggest it is pronounced "Sir-two-in". JackofOz23:46, 13 November 2006 (UTC)[reply]
There's a room of almost infinite size. A cable has been suspended from the ceiling, hung straight down. The cable is so long (a length so close to infinite that any but the most pedantic mathematicians would call it so) that it cannot support its own weight.
So the cable breaks not far from the top just a few seconds after it's hung. But nevertheless, the engineers who made the cable know it's perfectly safe to hang a cablecar from the bottom end of it, because the effect of the break, travelling down the cable in a wave (at the speed of sound?), won't be felt in the cablecar for a period of time so long that any but the most pedantic mathematicians would call it so.
There you go: just as a thought experiment, does this work?
sure it works, except for the fact that there is no such thing as "close to infinite"; it's either finite or infinite, there is no "close". Anyway, a finite cable that breaks won't be noticed at the other end for a finite time. Whether that amount of finite time is significant to you, depends on your engineering standards. --GangofOne01:02, 13 November 2006 (UTC)[reply]
Yes, as long as you're prepared to have the cablecar drop and break whenever the "signal" from the top of the rope reaches it. --Bowlhover01:06, 13 November 2006 (UTC)[reply]
Beauty, that's what I wanted. Yes, Gang, you're right, of course, there's no such thing as close to infinite, but I'm fudging the notion of infinity for a sci fi thing I'm writing. Thanks, both of you. Adambrowne66601:10, 13 November 2006 (UTC)[reply]
The "top" of the "infinite" rope would not have much gravitational pull from the Earth, as it's so far up. So, if it can't support its own weight, it's not the top of the rope that would be struggling so much as the "bottom" or middle, or whereever gravity kicks in. —Pengotalk · contribs01:44, 13 November 2006 (UTC)[reply]
That's what I was thinking, the gravity thing. Also, could a rope of almost infinite length have its own gravity? or is its 3 dimensional mass never 'dense' enough? Vespine02:04, 13 November 2006 (UTC)[reply]
Pengo & Vespine: the top of the rope will always experience more tension than the middle or the bottom. Yes, Earth's gravity is not very strong at the top. But the top of the rope will have to bear to weight of all the rope below it, and the lower you go, the stronger gravity gets. --Bowlhover05:28, 13 November 2006 (UTC)[reply]
Try reducing the problem to practical (even if impractical) case. If you posited say a 100 km or 1000 km cable of a given size, say 4cm woven steel, then what length of it suspended from space to Earth would exceed the tensile strength of the cable? How does the answer differ with cable diameter, that is, can a thinner or thicker cable support a greater length before it breaks of its own weight? Then when it breaks at the top, what is the propagation speed, i.e. how quickly does the bottom end respond to the break and drop the cable car? Per the Mythbusters experiment with breaking steel cables to see if the cable slap would slice a pig in half, would the stored energy in the stretched cable come snapping down the cable and hit the end like a rubber band smacking a fly? Edison17:30, 13 November 2006 (UTC)[reply]
The break wouldnt travel as a wave, as it is the weight of the bottom that is the force that breaks the cable' so as soon as it was unsupported it would fall. PhilcTECI19:22, 13 November 2006 (UTC)[reply]
(Ignoring gravity differences) the car would be in free-fall anyway since it would be accumulating slack from above as the cable stretches (the propagation speed being much faster than the falling speed). I think.
Academic Equivalence of a UK Pilots License
What is the academic equivalence of a UK issued Airline Transport Pilots License ATPL(H). Any references will be much appreciated.—Preceding unsigned comment added by 86.141.223.90 (talk • contribs)
Perhaps I don't understand the question, but what makes you think there is such a thing? It's like asking about the academic equivalent of a driver's licence. Do you mean a degree in aeronautics? Or are you asking what academic qualifications airline pilots need?--Shantavira09:29, 13 November 2006 (UTC)[reply]
Bioenergetics - Cellular energy expended on nucleic acid production?
I want to find information estimating the energy a cell expends producing different nucleic acid forms.
I am interested in:
1. Specific cell lines and a general comparison of Eukaryote, Archerotes, and Bacteria.
2. Different time frames from cycle specific to overall.
3. A comparison of DNA, ncRNA, rRNA, mRNA, etc.
4. Any insights or sources on methods to answer the above.
It seems to me these estimates would give an excellent characterization of the relative influence of various forms of nucleic acid (esp. non coding RNA vs mRNA) on phenoype and evolution.
Ben Haley
--<email removed to prevent spam>--
I'm guessing you'd have to either find a study yourself or do the research yourself. But anyway, the picture is more complex, as a cell also expends energy repairing DNA, and creating the enzymes to help in the formation of DNA, RNA, etc. As well as the histones and things. —Pengotalk · contribs01:52, 13 November 2006 (UTC)[reply]
Is this for real? Not only does this question just sound ridiculous, but isn't DDT not really used commercially in the states and aren't most quails farmed, hence one would not think they had pesticides specific to their (quail) diet? This sounds like secret code for something to me, like "the pigeon has flown the coop, I repeat: the pigeon has flown the coop!" If something big goes down in the next couple of days, I'm onto you two! ;) Vespine04:00, 13 November 2006 (UTC)[reply]
That's an absurd accusation. And furthermore, I'll have you know that the green vampire will eat 27 bananas at midnight. StuRat04:25, 13 November 2006 (UTC)[reply]
Well, I meant environmental levels, attributed to a time and place. DDT is not used for agricultural purposes almost everywhere now. I'm looking for that of a wild quail, and I think 200 ppm is a few orders of magnitude greater than, "normal." Also, some species of mosquito (mostly in the Indian sub-continent) started evolving resistance, so the Indians poured it on, because they were stupid [6]. If the mosquitos are already immune ot it don't spend more money on it!! Also, good point, I don't believe anyone has created a reference frame like in measuring mean surface temperature anomalies. But there has to be a range. You could take levels now, or "then." X[Mac Davis] (DESK|How's my driving?) 05:54, 13 November 2006 (UTC)[reply]
and <gasp> DDT isn't carcinogenic. But it's replacements have been highly toxic to agriculture workers. More people have died from the replacement than would have died from DDT. Tbeatty06:03, 13 November 2006 (UTC)[reply]
It's not accurate to say it's not carniogenic:
The EPA, in 1987, classified DDT as class B2, a probable human carcinogen, based on "Observation of tumors (generally of the liver) in seven studies in various mouse strains and three studies in rats. DDT is structurally similar to other probable carcinogens, such as DDD and DDE." Regarding the Human Carcinogenicity Data, they stated " The existing epidemiological data are inadequate....
The National Toxicology Program (NTP) determines DDT to be "reasonably anticipated to be a human carcinogen" based on the following evidence: "By stomach tube, DDT induced hepatomas in mice and rats of both sexes, and lymphomas and lung carcinomas and adenomas in mice. When administered by subcutaneous injection, DDT induced liver tumors in mice of both sexes (IARC 1974, 1987, 1991)... Administration of technical grade DDT, TDE, and p,p'-DDE in the diet provided no evidence for the carcinogenicity of DDT in mice and rats (NCI 1978)." In a 1567 monograph by Swiss physician Paracelsus, it was observed that "All things are poison and none are without poison," a phrase which is usually said "The dose makes the poison." It might be reasonable to anticipate that pumping large amounts of DDT directly into a human's stomach would be carcinogenic, but it is not reasonable to call DDT carcinogenic because of that (the EPA lists DDT as Class B2 carcinogen, alongside coffee and the profession of carpentry). Early claims of carcinogenicity were based on abnormally high total DDT (DDT and it's broken-down components) in blood serum of patients dying from cancer. However, cum hoc, ergo propter hoc (correlation does not necessarily imply causation), and these were probably a consequence of cancer causing mobilization of total DDT from adipose tissue (body fat). Better designs include the storing of numerous serum samples to wait until some of the subjects develop cancer, then compare total DDT levels in their stored sera with those of matched controls. One such study found a significant excess in breast cancer patients, but an analysis of six such studies yielded no conclusions. DDT's chemical makeup has been claimed to be close enough to that of oestrogen to offset human male hormonal balance. Although the statement is dubious, DDT could be partially responsible for declining sperm counts in European men. However, this decline has continued even though total DDT in sera and adipose tissue have also been declining, and it is very difficult to eliminate variables.
In April 1972, after seven months of testimony, EPA Administrative Law Judge Edmond Sweeny stated:
DDT is not a carcinogenic hazard to man… DDT is not a mutagenic or teratogenic hazard to man …The uses of DDT under the regulations involved here do not have a deleterious effect on freshwater fish, estuarine organisms, wild birds, or other wildlife. …The evidence in this proceeding supports the conclusion that there is a present need for the essential uses of DDT.
I'd ignore anything the EPA says during a Republican administration (1972 was under Nixon), as their purpose changes from "protecting the environment" to "protecting businesses which pollute the environment", under Republican leadership. StuRat20:46, 13 November 2006 (UTC)[reply]
I find it a bit odd that Mac Davis would reply to an old study with an even older non-study (an EPA statement). My point was that DDT's carcinogenic properties are debatable, not that they are or are not significant. Arguing that DDT was not environmentally hazardous is just bizarre, especially quoting a 1972 EPA statement. —Pengotalk · contribs00:22, 14 November 2006 (UTC)[reply]
I'm trying to keep down space. The older non-study would be the Judges final decision after 7 months of hearings on DDT. Afterwards, William Ruckelshaus disagreed and decided DDT was against the law. Don't think you can hate the EPA more than I do Stu! What do you mean arguing that DDT is not environmentally hazardous? X[Mac Davis] (DESK|How's my driving?) 17:08, 14 November 2006 (UTC)[reply]
No, the oil almost never occupies caverns or giant holes -- it occupies the tiny (often microscopic) pore spaces between the grains of sand or limestone or whatever was once other than rock and could therefore hold some fluid. As oil (or natural gas) is pumped, usually water rises to fill the pores. Geologyguy02:42, 13 November 2006 (UTC)[reply]
Damn that means no Oil Well Speluncking, anyways thanks.
However, in the Netherlands areas that lie above the gas bubbles frok which natural gas is pumped have occasionally sunk and many houses have cracks in them. Is it different for gas or what is going on here? DirkvdM11:40, 13 November 2006 (UTC)[reply]
The oil or gas that was originally there was under great pressure (indeed, it was that pressure that helped make it into oil and gas). Even if the space previously occupied by the oil or gas is immediately refilled with water, we've removed a lot of the mass of the overall subsurface oil/gas/water liquid system - so the net pressure is lower (just like opening the lid of a bottle of carbonated water, and resealing it once the gas has escaped). That pressure took part in supporting the layers of material above it, and with the pressure lowered the rocks above will sag a bit as a result. I'd guess that if you can see the difference at the surface, the gas reseve must be fairly close to the surface, and the rocks above the gas reserve not terribly strong. -- Finlay McWalter | Talk11:52, 13 November 2006 (UTC)[reply]
Areas of oil extraction and water injection can have significant earthquake clusters, showing that the process does disturb the rock quite a bit. --Zeizmic13:33, 13 November 2006 (UTC)[reply]
Do sapphires dull?
Do sapphires dull over time? I looked all over the Internet for the answer, but couldn't find it. If they indeed dull with the passage of time (or for any other reason), could someone provide a link where the effects of dulling would be described? Thanks.
Xanon
Don't take my word for it, but I am not aware of precious stones "dulling." Dulling is usually from oxidation or chemical bonding with chemicals in the air, and I don't think sapphires would do that. X[Mac Davis] (DESK|How's my driving?) 03:42, 13 November 2006 (UTC)[reply]
"There are several folklores and legends associated with sapphire . To many religions sapphires blue color was representative of heaven. Sapphire has been a holy stone to the Catholic Church and to ancient Persians. Ancient priests and sorcerers honored sapphire above all gems, for this stone enabled them to interpret oracles and foretell the future. Ancients believed the Ten Commandments were written on a sapphire tablet. Marriage partners put great faith in the stone. If its luster dimmed, one knew his or her spouse had been unfaithful. Sapphire refused to shine when worn by the wicked or impure." http://www.jeweler.com/birthstone_jewelry_info_sapphire.htm
So the sapphires probably do dim, although probably not due to the spouse being unfaithful.
Xanon
I wouldn't be too sure about that. A lot of folklore doesn't have any basis in reality although some does. See Claudius Aelianus for one humorous example involving beavers. Chances are your stone is dirty. On the backside where the stone attaches to the ring it gets dirty often. Taking it to a jeweler would probably brighten it back up. 152.3.74.13605:51, 13 November 2006 (UTC)[reply]
I don't have a sapphire, I am just looking to use that fact in a literary work. On the Internet, I have seen a lot of mentions of jewelry items dulling and needing to be cleaned. Could a sapphire be such an item? If not, could someone please provide an example of a precious stone that does dull over time?
Xanon
I have read of some gemstones, probably sapphires, being irradiated to make the blue color more intense. Could that enhancement possibly fade over time, and the stone return to something closer to its original state? By the way, at first I thought you meant physical dulling, and was going to cite the lifetime for sapphire phonograph needles, which needed replacement less frequently than steel ones and more frequently than diamond ones, all things being equal. Edison17:36, 13 November 2006 (UTC)[reply]
Sapphire is a very hard mineral, so it does not scratch easily (or dull from abrasion). However, it is just crystaline Aluminium_oxide, which it is chemically reactive, especially to acids. I cannot find any information about it dulling chemically, but I'd certainly keep them clean and dry. --Ronz02:41, 16 November 2006 (UTC)[reply]
A bicycle wheel mounted on handles does a much better job for most demos - commercial gyroscopes spin far too quickly for students to really grasp that the concept exists. What are you trying to demo specifically? JBKramer
Do spiders sleep? My boyfriend and I got into a curious debate over the topic. Neither of us could find any information anywhere, so I thought I'd ask here. ♠PMC♠04:56, 13 November 2006 (UTC)[reply]
From article sleep - "Sleep is the state of natural rest observed in most mammals, birds, fish, as well as invertebrates such as the fruitfly Drosophila." If flies can sleep spiders probably can, although I seriously doubt they can dream. It probably is more like a resting state. 152.3.74.13606:02, 13 November 2006 (UTC)[reply]
Scientists still don't know what sleep is or what its purpose is. There is a lot of controvercy over whether any other animals apart from humans 'sleep' in the same way we do. Although a lot of animals rest, there is no way of telling whether they are sleeping. Englishnerd14:46, 13 November 2006 (UTC)[reply]
It is, however, well-known that all mammals sleep. Much of the research about sleep is done on cats, since they sleep ~20 hours/day. howcheng {chat}22:41, 13 November 2006 (UTC)[reply]
I suppose rust (iron oxide) is "biodegradable corrosion", as even the rust will eventually break down and dissolve in the rain. StuRat07:45, 13 November 2006 (UTC)[reply]
Are you sure you have the term right ? Doing Google searches, I've found the phrases "biodegradable corrosion inhibitor" and "biodegradable corrosion protector". In both cases, I take this to mean that the biological agent prevents corrosion. In short, there doesn't seem to be any mention of "biodegradable corrosion". There is "biological corrosion", of course, if that's what you mean. StuRat04:18, 14 November 2006 (UTC)[reply]
tower construction
I've looked at the usual article suspects and can't seem to locate and answer. Towers are used in arid agricultural areas as water pump power, more or less everywhere for radio antennas, and so on. A common construction techniques are mentioned, but not the one I thought I remembered. There is a tower design made of several different sizes of triangles (from the usual materials, steel angle iron, tubing, etc) which looks rather like it was laid out by someone on an LSD flashback. All jumbled impossibly together. They really don't look like they should stay up at all. But I have a tag in my mind that this odd design is least expensive to design, or easiest to erect, or cheapest materials, or lowest mass for a given height, or some such. The trouble is I can't remember anything else about this peculiar sort of tower construction.
I don't remember anything taller than perhaps 40 feet or so, so it may be that the design doesn't scale well. Or not. Anywaya, does anyone have a name, or a reference? An explanation of what's special about the design technique? Anything? ww07:02, 13 November 2006 (UTC)[reply]
There are no pictures in this article, but perhaps you were remembering a Tensegrity tower? These are designs that are based on a distinct separation between compressive and tensile forces, and many certainly fit your description of a deisgn that "was laid out by someone on an LSD flashback". Google probably has images Bute here's one: http://www.kennethsnelson.net/icons/scul.htm
hi
i had scarlet fever as a 5yr old and i was just wondering how rare it actually is, like 1 in how many people get it, i'm just very very curious and i cant find much about it other than the symptoms on the net
thanks
skye
Two measures of how common a disease is are its incidence and its prevalence. "Incidence" is how many new cases are seen, while "prevalence" is how many cases exist. The annual incidence of scarlet fever in the Oxford region of England was 0.3 cases per 1000 per year in 1983 (so that would be 3 new cases a year in a population of 10,000). Peak incidence is in children 4 to 8 years old. 80% of children aged 10 or older have protective antibodies against streptococcal pyrogenic endotoxins. (But of course these need not be due to clinical cases of scarlet fever). - Nunh-huh13:24, 13 November 2006 (UTC)[reply]
Scarlet fever is not rare (as evidenced by the numbers) and is simply the skin's reaction to a common bacteria (the strep in strep throat). It is not a reportable disease and numbers are bound to be unreliable. I know I personally had it and have seen a ton of cases. I generally don't even tell the parents that it's "scarlet fever" because of the connotations and the fact that it's really nothing to fear above and beyond the strep infection. InvictaHOG01:18, 14 November 2006 (UTC)[reply]
Well, enzymes in some fruit, like papaya, do help to break down some foods, so it's not completely impossible that lemons or limes could do something similar. StuRat20:33, 13 November 2006 (UTC)[reply]
Quicklime or Calcium oxide is very nasty stuff, used by the mafia on dead bodies. Organic toilets use bacteria, moisture, heat and oxygen to break down waste. I have one at the cottage. Your whole effort with these things is to keep the little critters happy. If they get sad, the whole place fills up with stink! Every few months, you get a nice pile of clean compost which you throw in the forest. --Zeizmic13:28, 13 November 2006 (UTC)[reply]
Lime was the standard stuff to toss into the pit in an outhouse (well, that and pages from the Sears and Roebuck catalog); I don't know its chemical effects on human waste, though.
There are two kinds of lime mentioned in relation to outhouses, not sure of the details, but one is quicklime and the other isn't. I've read that it keeps down the smell but actually delays and interferes with the biological breakdown of the waste. It was probably the same lime used to correct excess acidity in fields on farms, because that would have been handy. Edison17:40, 13 November 2006 (UTC)[reply]
A solution of lime (actually CaOH when hydrated) will hydrolyze protein if it is concentrated enough. It will also convert fats to the calcium salts of fatty acids. No idea what it will do to carbohydrates. Seems reasonable that it would help breakdown most types of biological waste, but as mentioned above, also inhibit microorganisms that could also help with this. ike989820:42, 15 November 2006 (UTC)[reply]
Magnets
A bar magnet is a rectangular parallelopiped and its 2 ends are the north pole and the south pole. So what are the other 4 sides?
They are the sides. If you look at the image at Magnet, you can see how the field lines go for a bar magnet. By the way, the cross section of a bar magnet does not have to be a rectangle; it could as well be a cylinder with a circular cross section. --LambiamTalk11:52, 13 November 2006 (UTC)[reply]
Or any other shape for that matter. It could also be a bar with the poles at the sides in stead of at the ends. But that would have the magnetic force spread over a larger surface, so it would generally be less useful. DirkvdM11:57, 13 November 2006 (UTC)[reply]
Every part of a magnet is also a magnet, so if you'd cut a piece out of a magnet that would also be a magnet, but I'm not sure if that's what you mean. Are you referring to the direction? In the sense that at one side you've got one pole, at the opposite side the other pole and what do you have at the four remaining sides? I don't think there is a name for that. DirkvdM11:54, 13 November 2006 (UTC)[reply]
FYI re composite refrigerator magnets: The flat refrigerator magnets (that are used as advertisers and souvenirs, e.g., "Wikipedia: your place to be bold!") are often constructed with alternating north and south poles on the same surface of the plane; you can feel this if you take two similar (or identical) refrigerator magnets and slide them against each other with the "magnetic" sides facing each other: the magnets will alternately repel and attract as you move a few millimetres. This construction is more effective at keeping the large planar magnet uniformly stuck onto the steel 'fridge than a uniformly-polarized magnet would be. But this tends to make these magnets less useful for hacking.
Why do the really huge gulls have eyes located on the sides of their heads?
Doesn't that mean that evolution has designated them as prey animals? Was there something around in the past that could take the really big gulls on the wing? That's quite scary if you consider how violent they are. --84.68.125.12212:45, 13 November 2006 (UTC)[reply]
the eyes on the side are to help the more vulnerable young look out
evolution hasn't had time to move the eyes forward, as the larger gulls are still closely related to the smaller ones. Or there simply isn't the evolutionary pressure to do so.
even eagles appear to have their eyes pointing in fairly different directions. Are you sure larger gulls eyes are the same as the smaller ones?
Just a guess: gulls and eagles have relatively narrow heads. This helps to reduce air resistance in flight. It makes no evolutionary sense to have eyes pointing forward on a narrow "face" - the eye base is too small. Owls have forward pointing eyes, but (for the same body weight) owl heads are much broader than gull heads. A hypothetical gull "design" with eyes pointing forward would probably be inferior to fish owls. Again, this is just a guess. --Dr_Dima.
(After edit conflict) Anyone know how closely related the large gulls (e.g. the herring and great-black backs) are to the small ones, e.g. black-headed gulls (which do have lots of predators)? It'd be interesting to find out which evolved from which and how recently - therein probably lies the answer. Humans have also removed or reduced the numbers of many of the predators capable of taking the big ones in the last few hundred years too (the large raptors for example) - not really long enough for evolution to give them the forward-facing eyes of a top predator. --Kurt Shaped Box16:43, 13 November 2006 (UTC)[reply]
Here's another big old physics question. There's some formula for gravitational attraction force between two object (Kepler's doing?), equivalent to... G(m1+m2)/R^2 (if my memory serves me well).
My question: at some point, does gravity just go away? If we put two equal point masses with a mass of 1 kilogram 100 light years apart, will they eventually collide? Lets make this some ideal universe, i.e. no radiation, other gravitational sources, etc.
General Relativity says they eventually collide - the math is left as an exersize for the reader. If gravity is quantized, they may not collide, read Quantum gravity, though I believe that article may suffer from POV innacuracy, so tread lightly. JBKramer16:55, 13 November 2006 (UTC)[reply]
Note that there is a gravity-related formulat that has m1+m2 in it rather than m1 m2, but it's the formula for orbital period as in Kepler's Third Law.
Thinking about this, I became curious enough to see what the behavior of those two 1 kg masses would be in Newtonian physics. Their initial situation is a degenerate case of an elliptical orbit; they will complete 1/4 orbit before colliding. If I compute correctly, Kepler's Third Law gives a period of 5.006e32 seconds for the full orbit, so the time to collision would be 1.251e32 seconds or just under 4 septillion (American style) years. Their gravitational potential energy would be 7.05e-29 joules, half of which would go into kinetic energy for each object, so their speed on impact -- if "impact" is the word I want -- would be5.93e-15 m/s or a bit over 7 inches per million years. If I compute correctly. --Anonymous, 06:10 UTC, November 14.
About a month after this was written, it was called to my attention that the while the motion in Newtonian physics is indeed a degenerate case of elliptical orbit, it's not the same elliptical orbit I had in mind. The bodies actually complete 1/2 orbit before colliding -- the apoapsis is their original separation and the periapsis is zero. This reduces the time by a factor of sqrt(2), so if my calculation was otherwise correct, the actual time is 8.85e30 seconds or a mere 2.8 septillion years. --Anonymous, note added to archive December 18, 2006, 18:25 (UTC)
If they are moving away from each other fast enough, they will never collide. If both are at rest, they will.
While all of these answers are definitely right for standard newtonian and einsteinian gravity, given the large distance and small size of the masses, some branches of Quantum gravity theory (unproven) argue that gravity is quantized and that the quantum is too large for there to be any force at all between the objects given the distance and the mass. JBKramer20:29, 13 November 2006 (UTC)[reply]
I lack the appropriate background to speak intelligently about Quantum Gravity, which is an advanced theoretical possibly garbage theory that has not been experimentally tested. It would take extensive post-graduate theoretical physics knowledge to even start thinking intelligently about QG. I lack such. JBKramer21:23, 13 November 2006 (UTC)[reply]
Actually it's an entire class of theories which share the common feature that we won't be able to test them for a very long time, because gravity is very weak. An interesting exception is theories of large extra dimensions (no article... there should be!) in which only gravity propogates; in these cases gravity looks week at macroscopic distances, but becomes quantum mechanical at much lower energies, leading to testable theories of quantum gravity. -- SCZenz22:54, 13 November 2006 (UTC)[reply]
Can this also go to say that I am (or any other mass in the universe) currently being attracted by every other mass in the universe? I know that the Earth is pulling on me, the moon is pulling on me, and the Sun is pulling on me, but does that go for every other mass in the universe?Ed Dehm05:26, 14 November 2006 (UTC)[reply]
According to the currently-accepted best theories of gravity, yes. Other bodies actually do have a measurable effect on you, and in fact on the solar system (or galaxy!) as a whole. See for example the Great Attractor. -- SCZenz05:30, 14 November 2006 (UTC)[reply]
Identical "non-twins"
What are the chances of 2 brothers or sisters, born at different times, i.e. not twins as such, having the same genetic information? I know it is slim but has it ever been recorded to happen and what are the consequences/results of this?
The chances are 2^46, if you don't start by assuming they are the same sex, and 2^45, if you do. That ignores gene cross-linkage, mutation, etc. which would make the chances even lower. Since that's 1 in 70 trillion or 1 in 35 trillion, which are both far more than the number of people who ever lived, it's quite unlikely to have ever happened. However, if the parents are related (share chromosomes), the chances become much better. StuRat20:19, 13 November 2006 (UTC)[reply]
I think it's possible for the egg to be fertilised and split into two embryos, then you take out the second one and deep freeze it, let the first one be born normally, then reimplant the second one into a surrogate mother. I'm not sure though. --WikiSlasher11:20, 14 November 2006 (UTC)[reply]
Not if using cryopreservation, "[Human] embryos that are 2, 4 or 8 cells when frozen ... pregnancies have been reported from embryos stored for 9 years. ... Many studies have evaluated the children born from frozen embryos (“frosties”). The result has uniformly been positive with no increase in birth defects or development abnormalities."Vespine22:05, 14 November 2006 (UTC)[reply]
if i were to light a fire and put a cast iron pot into the flames, then place copper into the pot would the copper melt? as so i could pour it into a mould? thankyou. lwnicklin
According to Copper copper melts at 1084.62 °C, and Iron at 1538 °C. However, that's hotter than wood burns, so you'll need to use something hotter, like a blowtorch (I think). But, yes, you could melt copper in an iron pot. However, this experiment is dangerous. Do not attempt it without a traned professional metalurgist around. JBKramer19:18, 13 November 2006 (UTC)[reply]
Coal would probably burn hot enough. Maybe charcoal briquets?
You shouldn't need "white heat"; it's not for nothing that the ancients smelted copper before iron; see Bronze Age. I think a charcoal fire is probably sufficient. I know for a fact that the coals of an ordinary fireplace-style wood fire will melt the tin that forms the core of modern American pennies although I can't remember ever successfully melting an older bronze penny using just a fireplace fire.
A few years ago I visited a small town in Sichuan province of China.That town was called Renshou.Could anybody tell me the exact geographic coordinates(latitude and longitude) of that town so that i could search it in GoogleEarth
Thank You
amrahs19:26, 13 November 2006 (UTC)[reply]
Is there a statistical correlation between peanut butter sales and throat cancer? Not asking if there's a direction of causality, just if there's a statistical correlation between the two? Anyone know? 19:31, 13 November 2006 (UTC)64.12.116.74
A quick view of pubmed results seems to show most research is geared toward peanut butter (really Aflatoxin) and liver cancer. I'm no where near an expert, however, and have no idea about throat cancer. --TeaDrinker19:45, 13 November 2006 (UTC)[reply]
Welcome to Wikipedia. You can easily look up this topic yourself. Please see Skin. For future questions, try using the search box at the top left of the screen. It's much quicker, and you will probably find a clearer answer. If you still don't understand, add a further question below by clicking the "edit" button to the right of your question title. X[Mac Davis] (DESK|How's my driving?) 20:09, 13 November 2006 (UTC)[reply]
How is this name spelled?
Wverm? wervm? verm? werm? wevrn? Its another name for a dragon. Wikipedia links are prefered. IP
Evolutionary seeding or illness leading to differences in psychology?
We seem to consider certain types of mental "wiring" to be abnormal or an illness but is this correct in all cases? Is it not possible that different types of mental processing as brought out in a species as part of evolutionary seeding? I can imagine that depending on the environmental state some types of behavior would be more successful than others. An example may be the way that some people are considered to be highly valued during a violent conflict such as a war and then spurned or even incarcerated during peace time. Assuming there is no observable physical anomaly, what is mental illness and what is natural diversity? Is it a matter of divergence from the perceived societal norm? --150.101.153.11021:30, 13 November 2006 (UTC)[reply]
Evolution has led to some rather evil behavior, like genocide. So, I'm not sure it's valuable to classify people as "normal" and "abnormal" so much as "contributes to modern society" and "is a detriment to modern society". StuRat22:46, 13 November 2006 (UTC)[reply]
For some genetic predispositions towards mental illness there may no real benefit from the pathology in any environment (Psychosis: a costly by-product of social brain evolution in Homo sapiens). However, I suspect that there has been positive selection for diversity in human brain functions, particularly for genetic diversity that results in valuable behaviors at young ages. For example, genes that provide a predisposition towards creativity might be retained in a population even if they also cause a predisposition to mental illness and death in the third or fourth decade (Schizotypy, creativity and mating success in humans). The effects of genes and environment on Schizophrenia seems to be very complex. --JWSchmidt03:41, 14 November 2006 (UTC)[reply]
in general, variation is highly liked by evolution. Even 'extremes' can be useful, since natural selection can't happen if there's no variation to begin with. The thin line between "mental illness" and "natural diversity" is mostly a cultural/society thing. Of course, some things are obviously just 'diversity', where as some things are obviously an 'illness' or 'abnormality', but there is a large fuzzy grey area in between. Check out Autism rights movement for an example - where autistic people are demanding for 'understanding' rather than a 'cure', claiming that their condition is not an illness, but merely a different way of being. --`/aksha03:52, 14 November 2006 (UTC)[reply]
More gravity (sorry)
I was thinking about how long it would take for an object's gravitational waves to effect something. Since there is that handy law of conservation of matter, no object with mass can be created and suddenly have gravity. Therefore, it would be silly to regulate gravity 'waves' to the speed of light since there is always a continuous presence (stars continuously generate light, but that's different, since light can be created or not created, while gravity is just a property of mass).
Since I couldn't give gravity a 'speed', it occured to me: is there a constant center of mass/gravity for the entire universe?
Say I wanted to communicate with another planet that was pretty darn far away. If they had some sensor that was extremely sensitive to gravity, is there anything that I could do on my planet that would register a change in that sensor if we were the only two objects in the universe? Assume ideals, i.e. no radiation, no orbits, everything is just perfect.
The followup question would be: what is the 'speed' of gravity?
I believe the center of mass is everywhere. I think a two dimensional analogy is the surface of an inflating baloon. Every point moves away from every other point but there is no center. I believe the speed of the effect of gravitational changes due to movement is the speed of light. --Tbeatty23:08, 13 November 2006 (UTC)[reply]
As far as I understand it, and I am far from an expert, pretty much any, and all information is limited to (near) the speed of light. Even purely 'observation' can only happen at the speed of light. Vespine00:02, 14 November 2006 (UTC)[reply]
Why can't we give gravity a speed? E=mc^2, so it is possible to create mass from energy. Particle accelerators do it all the time. I know that the particles created will have very little gravity, but it isn't absurd to say "what might the speed of gravity be if we could measure it?" I agree with the other editors that gravity travels at the speed of light.
As for the second question (how to communicate with another planet): how about detonating a few hydrogen bombs, to destroy a few kilograms of mass? --Bowlhover02:42, 14 November 2006 (UTC)[reply]
Gravity works on energy, not just mass. Destroying mass won't change the gravitational pull of something at all, except insofar as it makes it "spread out," which will only be visible from short distances. -- SCZenz05:31, 14 November 2006 (UTC)[reply]
If the aliens had an extremely sensitive sensor, then simply moving a large mass towards and away from them would be detectable. Naturally, the speed of that communication would be limited to the speed of light. — Knowledge Seekerদ03:01, 14 November 2006 (UTC)[reply]
Possibly, but a pubmed search reveals no articles written about it. If someone has done it, they haven't told the medical community through the usual channels. InvictaHOG01:11, 14 November 2006 (UTC)[reply]
one atmosphere of pressure??
I was reading an article that claimed that a reaction caused one atmosphere of pressure, how much is this in grams or pounds etc???? can it be quantified this way?
Rob
Google has a pretty neat trick that it seems too few people are aware of - search for a unit conversion and it will calculate it for you. For example, try Googling 1 atm in psi and see what you get. So far, I've found it capable of handling most commonly used units. Confusing Manifestation08:15, 14 November 2006 (UTC)[reply]
Afix two sterile clamps to the cord at about 10cm and about 20cm, cut with sterile shears. After a few hours it will dry out, and it will fall off after a day or two. Don't pull it, don't remove the clamps once they are clamped. Tuckerekcut01:07, 14 November 2006 (UTC)[reply]
Typically we use clamps in the delivery room to stop the flow of blood in the cord and then cut just above (away from the baby) the clamp. This leaves a small stump and the clamp attached to the baby. The clamp generally comes off before you leave the hospital and the cord dries up and falls off in the next week or two. There is no reason to mess with the cord once you are out of the delivery room - no cleaning, pulling, picking, or cutting of the stump is required! InvictaHOG01:09, 14 November 2006 (UTC)[reply]
On kittens it remains as a little dried up stick looking thing that falls off aftr a few days. But one wonders how they survive without nurses and doctors to apply sterile clamps. Edison01:55, 14 November 2006 (UTC)[reply]
I don't have children yet and never witnessed childbirth, is there ever any reaction from the infant when the cord is clamped or cut? I imagine there wouldn't really be any nerves in the cord itself, does the child seem to even notice? I found the article on Lotus Birth quite interesting. Vespine01:18, 14 November 2006 (UTC)[reply]
When I was little my mother told me that the doctor ties a knot in the end of the umbilical cord that stays attached to the baby, and that's what forms a person's navel. So that's not true? The funny knot-looking part inside a navel is not really a knot, but just forms naturally as the navel heals? (I am serious, until reading the above answers, I believed my mother about the knot!) 192.168.1.1 7:15PM, 13 November 2006 (PST)
Are "innie" and "outie" navels the result of umbilical cord clamping/cutting practice, or else why are there such marked differences in navel appearance later in life? Edison14:24, 14 November 2006 (UTC)[reply]
I was told (when I was a child and I asked my mum this question) that 'outies' result from the doctors clamping the umbilical cord too far from the baby's body. I don't know if this is actually true or not. --Kurt Shaped Box20:38, 14 November 2006 (UTC)[reply]
It's not common practice to tie knots in the cord; I've never seen it, at least in America. It would be difficult to do, though anything which places pressure on the cord vessels would work to stop the bleeding. The belly button scar results from the natural scarring process after it falls off. Innie and outie happen naturally. InvictaHOG14:33, 14 November 2006 (UTC)[reply]
Cool, thanks for all the answers! I never knew I'd ever find out that Mom was just pulling my leg all those years! Okay, next question: What does the umbilical cord connect to inside the baby? I assume the vein & artery in the umbilical cord join a vein and an artery inside the fetus in a "T" configuration... what other structures or things are behind the navel, so to speak? 192.168.1.1 6:50 pm, 14 November 2006 (PST)
November 14
Bismuth-213
When the isotope bismuth-213 emits an alpha particle, what new element results? what if it emits a beta particle? Thanks!!
You're gonna have to make this homework question less obvious if you want it answered. Consider: Bismuth is element 83, yours has a mass of 213, find out how many neutrons and protons it has, then subtract the number of neutrons and protons in an alpha particle, and recalculate the element number of the result. Repeat for a beta particle. Tuckerekcut01:03, 14 November 2006 (UTC)[reply]
I've been very careless lately; I looked at the list of 3 isotopes in the Bismuth article, and assumed that they were the only ones. I don't think I saw the "isotopes of bismuth" link. --Bowlhover04:34, 14 November 2006 (UTC)[reply]
Isotopes never really become "fictitious", they just become more and more unstable. You might say oxygen-24 is the heaviest isotope of oxygen, but my colleague Calem Hoffman is writing a paper on oxygen-25. It's unbound to neutron decay, so its lifetime is so short that its energy has a large range because of the uncertainty principle between energy and time. Still, it's a legitimate state that has objective reality. —Keenan Pepper06:08, 14 November 2006 (UTC)[reply]
Only the central part of a neutron star is made up entirely of neutrons, not all the star, AFAIK. However, that depends to a significant extent on how you define a surface of a star (not a trivial task). Anyway, I don't think that you would find O-9999 at any depth inside a neutron star; rather, just a "soup" of neutrons, protons and electrons. However, if a catastrophic event involving a neutron star would happen (for example, a collapse to a black hole if the mass exceeds the limit, or collision with another star / black hole), some of the matter will be ejected. Most of it would still be neutrons I suppose, at least for an hour or two (neutron, when left alone, has a lifetime of about 15 minutes; it can be longer if it still has other particles to strongly interact with). Then maybe there is a chance to find something like a highly excited O-9999 nucleus, namely, a nucleus of a stable Oxygen isotope with a cloud of neutrons around it. --Dr_Dima.
irradiated food
When food is irradiated with gamma rays from a cobalt-60 source, does the food become radioactive? why is this?
Probably the easiest way to explain this is to think of atoms as tiny bombs. Radioactive atoms are bombs which are liable to blow up at any moment, whereas most atoms are relatively stable unless hit in exactly the right place and with exactly the right amount of energy. So consider Co-60 a insidious bomb. When this bomb explodes, it sends a shard of shrapnel hurling through space. Chances are, that shrapnel will never hit anything (space is actually pretty empty), but a very small percentage of the time, the shard will hit something. When the shard does hit something, a few things can happen: most of the time, everything probaly just snaps back into place, no harm done. Sometimes, however, a molecule will get knocked out of whack. If, by some wild chance, that molecule happens to be DNA, and that part of the DNA happened to have two cysteine residues next to each other, then the DNA will end up pretty messed up at that point, and if this dimer in the DNA happens to cause a mutation, and if that mutation happens to be bad (you see where this is going), then death or some other pathology can result (please note that death and pathologies can result from a lot of other molecular bombardment mishaps, but this is a popular one). This is how the radiation kills whatever is in the food. However, very rarely, the bomb shard hits another molecule in such a way that that molecule becomes "armed" up to blow up itself. The reason irradiation doesn't tend to make other things radioactive is because this secondary "explosion" is very unlikely in the first place, and exposure is limited in such a way to decrease this possibility even furthur, ensuring that irradiated food is no more radioactive than, say, brazil nuts (actually, probably much less so...).Tuckerekcut00:53, 14 November 2006 (UTC)[reply]
No. Gamma rays are high energy light. It doesn't change atomic structures. It can change chemical bonds and that kills bacteria but to be radioactive the atomic structure changes. Usually, neutron radiation is required to make something radioactive IIRC. --Tbeatty03:01, 14 November 2006 (UTC)[reply]
Can you tell me how many types of atoms can you expect to find in a pure sample of any element?
Depends on your definition of "pure", and "type", which element you're talking about, and where you got your sample from.
In the real world, most samples of elements, no matter how pure, contain very small traces of contaminants. Ignoring that, for the moment, most elements come in more than one isotope, though the number varies greatly between the different elements. Gold, for instance, has only one stable isotope, whereas tin has 10. --Robert Merkel03:26, 14 November 2006 (UTC)[reply]
A have a feeling this is a high school chem question. In which case, the answer is 1. "pure sample" of any one element means it contains only atoms of that one element. --`/aksha03:49, 14 November 2006 (UTC)[reply]
Right. In high school you learn that a sample of each chemical element consists of atoms of only one type (namely, atoms of that chemical element). If you are preparing for a chemistry exam, follow `/aksha's advice.
In college or university you learn that atoms of a chemical element are actually not all alike. the electric charge of the nucleus of all the atoms of a given chemical element is the same, and the chemical properties of all the atoms of that chemical element are very, very similar. However, the number of neutrons in the nucleus of an atom need not be the same, look at isotopes in Wiki.
Another year passes, and you learn that the protons and the neutrons in the nucleus may be arranged in different quantum states. Again, even in a single-element single-isotope sample not all atoms are the same. You open Wiki, and here it is, an article on nuclear isomers.
A few months go by, and you suddenly learn that when you put a magnet to your sample, for elements/isotopes with net electron and/or nuclear magnetic moment, some atoms have higher energy than the others. Again, even in single-element single-isotope single-nuclear-isomer sample not all atoms are the same. Fascinating, as Spock used to say. Wait, there is more.
Now you take a basic plasma science course. You heat up your atoms to a few thousand Kelvin or more, and - surprise surprise - again, not all atoms are the same. Some have excited electrons in them, some have lost one or more electrons altogether and became positive atomic ions. Now you have a variety of atoms in your single-element single-isotope single-nuclear-isomer sample!
The punchline is simple. If you want good grades at school, know what the teacher expects you to say. If you want to succeed in science, read books and talk to scientists. And, using Wiki ref desk also helps ;-) --Dr_Dima
Molecule
How many atoms are there in one molecule of H3PO4 ? and how many atoms of each element are there in this molecule?
Are there Infinite Possible Futures? or just a lot?
A piece of semi-spiritual philosophy hold "We live in a universe of infinite possibilities". But is this actually true, according to our best guesses of the laws of physics? Are there an infinite number of states this galaxy could be in 10 minutes from now? or just some arbitrarily large yet finite number? --Alecmconroy03:57, 14 November 2006 (UTC)[reply]
Since there are a finite number of particles in the universe we inhabit, I would say that the number of possible futures is finite. However, there may be an infinite number of universes... Clarityfiend07:55, 14 November 2006 (UTC)[reply]
There are, however, apparently an infinite number of possible positions and momenta for each particle, unless space is quantized. So the answer, really, is that we just don't know. -- SCZenz16:17, 14 November 2006 (UTC)[reply]
Earliest sound recording (possibly pre-Edison)
Is anyone familiar with any attempts to record sound prior to Edison's famous 1877 invention of the phonograph? Our article on Sound recording and reproduction says "the first practical sound recording and reproduction device ..."
The reason I ask is this: Talk:Frédéric_Chopin#The_First_Recording_Ever. It was posted by a new user earlier today, and you can see my answer to him there. While I know quite a bit about Chopin, I know less about early attempts at sound recording. Is what this user suggests even possible? (You can tell from my reply what I think.) Yet perhaps there were attempts to record sound before Edison which we haven't covered in Wikipedia. Thanks! Antandrus (talk)04:44, 14 November 2006 (UTC)[reply]
No one before Thomas Edison is known to have even made the attempt to record and play back sound. Scott built the phonautograph whcih had all the elements needed to record sound: a diaphragm to respond to sound waves, a stylus to record them, and a smoked glass plate to receive the tracing. But obviously you could not operate a playback stylus from the smoked glass. In theory, such a smoked glass tracing could have been photographically copied and used to etch a playable record. The technology to practically do that did not exist in the 1860's. That was the basis of the Chopin recording hoax. Yet there exist a few pre-Edison sound wave tracings, by Scott, and from 1868 by the physiologist Donders (Donders, F. C. (1868/1969).On the speed of mental processes. Acta Psychologica, 30, 412-431.) These are clear black and white photo reproductions of words and phrases recorded by Donders with a phonautograph while doing reaction time experiments. I know of no one having done the obvious task of translating these phonautograph traces to wave files. There would be a need for equalization of different parts of the frequency spectrum, and perhaps controlling for geometric distortions but I would expect some sound could be recovered. Ideally, the phonautograph would be modelled and its resonant frequencies and distortions "subtracted out" in the reproduction, but it would be cool to hear at least a raw playback of the tracings. Edison14:37, 14 November 2006 (UTC)[reply]
It's not particularly meaningful to look at monocyte percentage as an isolated number, because (obviously), if something (like a bacterial infection) increases your neutrophil count, your monocyte % will decrease, and that won't really mean anything, it's just the result of the increase in polys, which is the significant thing. The WBCdifferential count provides the greatest amount of information when it is looked at as a pattern, in terms of both changes over time, and the relative quantities of the various cells. A low monocyte count in isolation isn't usually particularly significant - though of course if this occurs in a clinical situation, it should be reviewed by the clinician and clarified by him or her with the patient. - Nunh-huh07:21, 14 November 2006 (UTC)[reply]
I am attempting to name of the following product of a Diels-Alder reaction: [9]. I have found the name of a similar molecule[10], but cannot determine exactly how to translate the change from O to N. Thank you in advance; any help is greatly appreciated.
Chemical Abstracts names it as cis-3a,4,9,9a-tetrahydro-2-methyl-4,9[1',2']-benzeno-1H-benz[f]isoindole-1,3(2H)-dione and lists as an alternate name cis-9,10-dihydro-N-methyl-9,10-ethanoanthracene-11,12-dicarboximide. --Ed (Edgar181) 19:10, 14 November 2006 (UTC)[reply]
microalgal bioreactors
hello,
ive been doing some research and i cant find anything on microalgal bioreactors. i need to know what a microalgal bioreactor is, what its used for, whats its uses and its effects on the surrounding envionment? And who uses microalgal bioreactors such as organisations etc...
thanks heaps guys,
graham
Have you read Biochemical engineering? It's primarily composed to material related to bioreactors. I'm only familiar with tissue-related bioreactors, but I'd assume a microalgal one would be used to grow algae, with primary uses by whomever would be studying algae. I don't think the reactor has an effect on the surrounding environment, since it's designed to be a completely in-vitro system. 16:27, 14 November 2006 (UTC)
alternating magnet
Is there a permanent magnet that alternates its poles withut any supply of energy
It is not likely that you'll find one. If this exists, all you need to do is to wind a coil of wire around it. The changing magnetic field would produce alternating current without spending any energy ! -- Wikicheng11:07, 14 November 2006 (UTC)[reply]
Erm, not quite. You need a power source. There won't be any alternating current if you don't put any current in the wire to start with. You can't get energy from nothing. - Mgm|(talk)11:17, 14 November 2006 (UTC)[reply]
A changing magnetic field passing through a wire creates electrical current. You don't need to put current in the wire to get it going. You can try it yourself. Attach the ends of a coil to a volt meter and wave a magnet back and forth past all the coil. You'll see the volt meter bounce. --Kainaw(talk)14:00, 14 November 2006 (UTC)[reply]
Well, if we get a permanent magnet which changes it's polarity without using any energy (wow !), the we can get AC from the magnet by simply winding a coil of wire around it ? If effect, such a magnet does not exist.-- Wikicheng13:15, 14 November 2006 (UTC)[reply]
But wait! That means that if the earth were surrounded by a giant coil of wire, then every time it flipped its magnetic pole (every few million years) it would generate a half cycle of electricity. Cool! 14:42, 14 November 2006 (UTC)Edison
Yes but the frequency would be rather low beacuse the flipping actually seems to take thousands of years. THe induced voltage would therefore be very low. 8-)--Light current16:23, 14 November 2006 (UTC)[reply]
I didn't know that earth flips its magnetic poles (albeit once in a million years). I am assuming that the change would not be instantaneous but would be gradual. So does it mean that in the middle of this cycle, there will be a period when there are no North and South poles ?(because the N pole is slowly becoming S pole and vice versa) -- Wikicheng11:32, 15 November 2006 (UTC)[reply]
To some degree yes (though the other non-magnetic sets of poles would still exist in their same location, see e.g. North pole), but it's not as if the Earth's magnetic field is as simple as that of a bar magnet. It fluctuates quite a bit and during the course of a flip (if I recall correctly), it's sort of a general weaking of the polar poles compared to fluctuations all over the Earth and eventually the magnetic poles re-establish themselves, potentially reversed. That is a very simplified version of the story, of course. digfarenough (talk) 20:34, 15 November 2006 (UTC)[reply]
organ transplantation
What are the sources available for organ transplantation?Are such sources effective?Are they ethical?How may the government improve its healthy system to make organ transplantation more effective?— Preceding unsigned comment added by 210.195.36.143 (talk • contribs)
I believe they were asking if the sources were ethical. On top of stolen organs, some question the ethics of paying for organs, for example. Skittle22:36, 14 November 2006 (UTC)[reply]
Anomalous compounds/substances
What are the examples of such compound which show anomalous behaviour?
Why do water show anomalous behaviour?Explain in short.
The caffeine article mentions, in the "effects" section, that caffeine is sometimes used in conjunction with painkillers; I've heard elsewhere that caffeine enhances the action of analgesics. My question is, which classes of analgesics does caffeine enhance? Does it affect NSAIDs, narcotics, gabapentin, and/or local anesthetics? Thanks. -- Creidieki 13:42, 14 November 2006 (UTC)
Caffeine is matabolized by cytochrome P450, and thus may potentiate any other drug which is metabolized through this pathway. You'll have to be more specific for the other compounds (these things you have listed are grouped by mechanism of action, not mechanism of catabolism), but I will tell you that gabapentin isn't even metabolized in the body (and get this: the bigger a dose you take, the less of it is bioavailable, isn't that weird?), so it is not contraindicated with caffeine. However, there are other interactions (because a certain isoform of cytochrome p450, CYP2A6, is slightly inhibited by gabapentoin) in your list. Gabapentoin should not be taken with naproxen (an NSAID), hydrocodone or morphine (these are narcotics), unless your doctor specifically is aware of the interplay between these drugs (its, um, complicated, and needs vigilant monitoring). Gabapentoin has other contraindications too, but not, as far as I remember (which is not very far), in the drug classes listed above. This is not medical advice, see your physician if this question is anything but hypothetical, mixing drugs can have potentially lethal effects. Tuckerekcut19:28, 14 November 2006 (UTC)[reply]
Thank you for your response; I've been bouncing around between physicians a bit. I'll corner one of them about some questions I have now. -- Creidieki 21:20, 14 November 2006 (UTC)
Some unorganized, general info...Excedrin & other brands of headache medicine contain acetaminophen, aspirin & caffeine -- which apparently provides "significantly superior efficacy and speed of onset compared with" ibuprofin. Codeine is often given with caffeine, according to this site, but it's not clear that it helps with the opiate effects or the acetaminophen that often accompanies it. This paper suggests that caffeine consumption increases headache risk. According to this paper, "acute, but not long term, caffeine intake reduced neuropathic pain state in nerve-injured rats, but only at very high doses." -- Scientizzle19:41, 14 November 2006 (UTC)[reply]
The last abstract I linked to explains "The potential hyperalgesic effect of chronic A(1) adenosine receptor blockade [by caffeine] may have been compensated for by an antinociceptive effect of caffeine through antagonism of A(2A) receptors and tolerance development." Drugs that work through adenosine receptor systems may be particularly affected by caffeine. -- Scientizzle19:45, 14 November 2006 (UTC)[reply]
An innovative application of laser?
Hi all! Could you help me out and give me a really innovative thing you could/would like to do with lasers? Thanks in advance. PS: This aint for school. And I need it as fast as possible.--202.88.231.14714:11, 14 November 2006 (UTC)[reply]
I heard on the radio yesterday that the only reason supermarkets still put plastic wrap onto cucumbers is that the label doesn't stick to the cucumber properly. So I'd laser-etch the label info (including the barcode) into the skin of the cucumber. Hopefully some tweaking of the laser frequency and power could produce a mark that noticeably changes the colour of the cucumber skin (ideally bleaches it white) without really damaging the skin (affecting its shelf life and customer acceptability). As cucumbers are mostly eaten in little slices, the mark shouldn't be off-putting to the final consumer. -- Finlay McWalter | Talk14:48, 14 November 2006 (UTC)[reply]
Believe it or don't it's been done! I read a blurb about laser-etched food items a few years ago; sorry, no link.
A means of propulsion for spacecraft. A powerful stationary laser in Earth orbit aims a laser at the spacecraft. The beam then reflects off the craft, accelerating it away from the laser. StuRat15:01, 14 November 2006 (UTC)[reply]
Make three lasers: red, blue, and green. Each one will be fine-tuned to a specific frequency. Use them to project HD television on a screen. Then, make the screen out of three fibers: red, blue, and green. When meshed together, they will appear to be nearly black. But, the fibers are made so that they reflect one and only one frequency of light - the one the lasers produce. So, when all 3 lasers hit the fabric, it produces crisp and clear white light. When they don't, it is black - even in a completely lit room. So, you can have super-mega-huge projection television without having to shut off all the lights. --Kainaw(talk)15:07, 14 November 2006 (UTC)[reply]
It's not precisely related, but this might interest you: Tunable crystals] 16:14, 14 November 2006 (UTC)
Sinc the current best focussed lasers produce a spot one mile wide at the moons surface, the power density would probably not be enough to boil a cup of tea!--Light current21:43, 14 November 2006 (UTC)[reply]
I think the problem is one of the atmosphere tending to defocus the beam due to turbulence; so the power is a secondary issue-- Its how fine you can focus it on the moons surface. --Light current22:00, 14 November 2006 (UTC)[reply]
Wouldn't a wide beam be the most suitable choice for carving a message into the moon anyway? If you wanted to be able to see it from earth, this is... --Kurt Shaped Box22:54, 14 November 2006 (UTC)[reply]
Yes, if you give him a blowtorch and a rocket to get to the Moon. And a $9.99 laser pointer to apply to the freshly burnt surface, as it must be an "application of laser" after all. --Dr_Dima.
That's just great. The first grafitti on the Moon. Speaking of which, does anybody actually "own" or have any legal rights to any part of our neighbor (somebody who could sue you for defacing his or her property)? Clarityfiend00:32, 15 November 2006 (UTC)[reply]
The Outer Space Treaty says that the Moon or anywhere else outside earth can't be claimed by any particular country. Until there is actually an attempt to economically exploit some extraterrestrial body, however, it's really not an issue. --Robert Merkel00:39, 15 November 2006 (UTC)[reply]
the liver
To whom this may concern,
I tried to get a clear copy of your "view from below" the liver and I am unable to. It down loads fuzzy and prints illegible. Is there any possible way that you can send me a clear copy or fix the one on the page so that it is more functioning. As a user of your site I am always excited to see all your wonderfull illustrations but when they are unreadable, it is frustrating. I am a homeschooler doing a unit on the digestive system with my two children so this particular illustraion would be wonderful to have since it labels all the liver parts.
Thank you in advance for your help.
With much appreciation
Christine Blamire
I had some free time, so I emailed her a response, which I've included below:
Hi! I'm Creidieki (please excuse the weird name), and I'm one of the volunteers answering questions at Wikipedia's Reference desk.
I should note first that we don't usually reply via email. In general, putting your email in a public place on Wikipedia is an easy way for spammers and other impolite folk to find it. We've hidden your email address on the page. For the reference desk, you should check back at the same reference desk page you asked on to see answers to your question.
It looked like you hadn't realized that, so I thought I'd send you an email; other people may also respond to your question on the reference desk, and you should look for those responses over the next several days, at http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#the_liver . (Or you could go to Wikipedia, type "Wikipedia:Reference desk" into the search box, go to "science", and then scroll down to find your question).
Anyway, on to answering your question. Wikipedia is a free encyclopedia, which means a couple of things. It's put together by volunteers, and we only accept material that can be freely redistributed (under a license called the GFDL). That's really good, because it means that schools and universities and people can use Wikipedia's material under very generous terms. Unfortunately, it's also difficult to find trained medical illustrators who want to draw complicated diagrams for free. It looks like the liver picture you were asking about was scanned from a 1917 book copy of Grey's Anatomy; it's probably accurate, but we're not going to be able to find a better copy of that specific diagram for you.
So, if you want a good image of the liver, you're probably going to have to look elsewhere. I searched google for a bit, and came up with a few candidates for better images. Frankly, I have no idea how authoritative these images are; all I can say is that they claim to be diagrams of the liver. You may want to go to a local library and see if they have an updated copy of Grey's Anatomy, or other similar books.
What is the meaning (purpose) of the hands in the closing posture of Yang style Tai Chi. Right fist in palm of left hand or left fist in palm of right hand.
Thank You Mike Woodside
It's a salute. It's typically found at the end of wushu sets, though its origin probably predates competitive kung fu.
If I understand you correctly, you are basically covering your fist with the other hand (usually the left covering the right). I was taught that this is symbollically "covering your weapon" and saying that you mean no harm, although since your fist is still there, it means that you will defend yourself as necessary. We use it as a sign of respect at the beginning and end of class and forms (Shaolin Wushu Kung Fu). At least that's what we were told, I have no idea if it is correct. But it sounds reasonable. --Bennybp01:45, 15 November 2006 (UTC)[reply]
The claim seems somewhat unlikely given the ingredients, and after having eaten Kashri cereals I've never noticed any untoward effects. A radical change of diet may initially cause extra gas as the flora adapts to it; perhaps that is the origin of the complaint, but then it is not specific to Kashri. The anon's IP address has no history of vandalism and is assigned to the Detroit Medical Center, but the statement is depreciative of a commercial product, completely unsourced, and in this form ("may") unfalsifiable. Altogether I've found it best to remove this claim. --LambiamTalk20:28, 14 November 2006 (UTC)[reply]
There might be a basis for the claim in that high fiber foods can cause gas, and Kashi cereals tend to have a higher dietary fiber content than more mainstream cereals.--Mabris21:24, 14 November 2006 (UTC)[reply]
Mathematical functions do not change units. Taking the log of a number is no different than multiplying by a constant. For example: 10 * 10m = 100m. Your example of proving it wrong would be: 10 * 10m = 10 * 10 + 10 * m. That makes no sense, just as ln(m) makes no sense. --Kainaw(talk)20:31, 14 November 2006 (UTC)[reply]
Thanks for the reply, although I think you might be mistaken here. Mathematical functions frequently change units, provided they are not linear functions. As an example, consider (10m)2 = 100m2. I believe a simplified version of the 'correct' answer here is that the natural log function results in a unitless number. Comments? --132.194.13.12120:40, 14 November 2006 (UTC)[reply]
The issue here is that the natural logarithm only takes unitless numbers as arguments. Thus physical quantities that involve natural logs of numbers with units always have some "scale" in the argument to cancel out the units. Otherwise there would be exactly the problem you describe. -- SCZenz20:42, 14 November 2006 (UTC)[reply]
(after edit conflict) A more appropriate spot for this question is the Mathematics reference desk, but in any case the statement is false. If 0 < m < 1/10, ln(10m) < 0, while 2.3m > 0. When you graph ln(10m) against m you get a curve that has the same shape as the green curve in the article Logarithm, whereas graphing 2.3m gives a straight line. There must be a relationship between the "2.3" in the question and the fact that ln(10) = 2.302585..., so someone may have mistakenly thought that log(a×b) = log(a) × b for the case a = 10. --LambiamTalk20:44, 14 November 2006 (UTC)[reply]
(after another edit conflict) Now I understand the question, the "m" is supposed to be metres, and not a variable. Then indeed ln(10m) is meaningless. (By convention, units are not set in italics.) --LambiamTalk20:51, 14 November 2006 (UTC)[reply]
Thanks for all the responses. This came up in a Chem lab project measuring vapor pressures at various temperatures. (Hence the post in the Science desk.) When this is done, a plot of lnP vs. 1/T yields a straight line, the slope of which is of interest. Now, the average slope of this plot would be m = Δ(lnP) / Δ(1/T). So in this sense the unit for pressure isn't important as it is subtracted out as I showed above. In other words, what SCZenz said above. Sorry for the confusion Lambiam - I did mention "When taking the natural log of a number in a given unit". --132.194.13.12121:03, 14 November 2006 (UTC)[reply]
Right, the slope will be independent of the "scale" (i.e. unit) of pressure being used in the argument, so it often isn't specified. -- SCZenz21:06, 14 November 2006 (UTC)[reply]
If you treat the log of a unit as an unspecified constant, then they should all cancel out at the end. By itself, ln(10 m) is meaningless, but ln(10 m) – ln(5 m) = ln(10) + ln(m) – ln(5) – ln(m) = ln(10) – ln(5) = ln(2) = 0.693. It works out that way because the difference of the logs is the log of the ratio, which is dimensionless. If you end up with the log of a unit in your final answer, that means you made a mistake. —Keenan Pepper21:15, 14 November 2006 (UTC)[reply]
For instance consider the problem of changing nepers into dBs. THe bases are different but the net difference between the two units is only one of multiplication by a certain constant that relates the two bases (base e and base 10 -- cant remember what it is and too lazy to work it out). Is this comment relavant?--Light current21:54, 14 November 2006 (UTC)[reply]
I think the best answer is there is a unit ln(P) where P is in pascals, but there is no special name for this unit. Indeed, I can't think of any unit with a special name that is the result of taking the natural or common logarithm of a quantity expressed in some other unit. --Gerry Ashton02:41, 15 November 2006 (UTC)[reply]
Sorry, that doesn't work either. In dimensional algebra, the numbers are conceptually multiplied by their units of measure. Thus 2 m × 3 m = 6 m²: you're just multiplying the 2, the 3, and the two instances of "meters" all together. In fact it works just like 2m × 3m = 6m² where m is a mathematical variable instead of being meters. But if it was meaningful to take ln(20 Pa), you would get ln(20) + ln(Pa), not ln(20) times anything. It simply is a fact that taking the logarithm is something you can only do with a pure, dimensionless number.
What may confuse the issue is that something like "pressure in pascals" is a dimensionless number, and so it's safe to take its logarithm if you want. Think of the word "in" here as indicating division. You are dividing the actual pressure, 20 Pa, by the unit Pa to get the pure number 20. So as soon as you work with something like "pressure in pascals" or "length in meters", you are using dimensionless numbers.
--Anonymous, 07:05 UTC, November 15.
Logarithmic scales always have an implicit reference value - the value of the underlying that corresponds to a value of 0 on the logarithmic scale. For example:
The reference value for the decibel scale (in the acoustics definition) is 20 µPa.
The reference value for the decibel watt scale is 1 W.
The reference value for the pH scale is 1 mol/litre.
The reference value for the Krumbein scale of grain size is 1mm.
By assigning a value of ln(10) to "ln(10m)" you are implicitly using a reference value of 1m. If you use a different reference value, you add or subtract a constant amount from the values in the logarithmic scale. Gandalf6113:02, 15 November 2006 (UTC)[reply]
I used to use a program called body works 4.0 to learn about human body, anatomy, etc.
I see this software, even the newest version, is outdated. Does anyone have any recommendations for an easily accessible program geared towards physiology / anatomy?
I'm doing my science homework and I've been learning about Polyatomic Ions in class and now we're practicing writing formulas and nomenclature. I had to write a formula for Hydrogen Carbonate. I know that there is some controversy weather or not it is the same as Bicarbonate. I thought that the formula for Bicarbonate was HCO3 and that Hydrogen Carbonate would be H2CO3. If anyone knows the answer, this would be very helpful. Thank You -- Jesusfreak01:51, 15 November 2006 (UTC)[reply]
The prefix 'Bi' is sometimes (always?) used to indicate the presence of hydrogen as in sodium bicarbonate (NaHCO3??)
Ahh! look what I found!
The bicarbonate ion is a polyatomic anion with the empirical formula HCO3− and a molecular mass of 61.02 daltons; it consists of one central carbon atom surrounded by three identical oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens. The bicarbonate ion carries a negative one formal charge and is the conjugate base of carbonic acid, H2CO3; it is the conjugate acid of CO32−, the carbonate ion.
Yes, bicarbonate and hydrogen carbonate are synonymous (HCO3−). In fact, I believe hydrogen carbonate is the IUPAC recommended term (so, for instance, sodium hydrogen carbonate instead of sodium bicarbonate), which is logical: using bi- to indicate the hydrogen is not intuitive. It’s more awkward, though, and in practice the bicarbonate terminology seems to be well-entrenched. — Knowledge Seekerদ03:31, 15 November 2006 (UTC)[reply]
Um, this may be out-of-date terminology for all I know, but I think "hydrogen carbonate" is H2CO3. "Carbonic acid" is hydrogen carbonate dissolved in water. The pure substance, with no water to make it dissociate, is not particularly an acid. --Trovatore03:40, 15 November 2006 (UTC)[reply]
The orinal question was about ions, not full compounds. You're correct that H2CO3 would be "hydrogen carbonate", but it would not be "a hydrogen carbonate ion". DMacks03:47, 15 November 2006 (UTC)[reply]
Well just to quote from our page again,
The bicarbonateion is a polyatomic anion with the empirical formula HCO3
But it doesn't mention hydrogen carbonate. Our hydrogen carbonate was a redirect to bicarbonate; this seems to have been the clamorous error of some idiot user who calls himself Trovatore. What was he thinking? I guess we'll never know. Anyway, I've redirected it to carbonic acid; I think this is more correct, though technically speaking the pure substance H2CO3 (which, I think, can't exist at standard temperature and pressure, but can exist under other conditions) should be called hydrogen carbonate rather than carbonic acid. --Trovatore04:34, 15 November 2006 (UTC)[reply]
i think it should point to bicarbonate, since someone is far more likely to be wondering about sodium hydrogen carbonate etc than something else. my two cents. Xcomradex05:15, 15 November 2006 (UTC)[reply]
Meh, who cares where it points, as long as it's clear from that page which one that page is talking about. And provides a route to "the other one". I just added a dablink for that last bit. DMacks20:39, 15 November 2006 (UTC)[reply]
I'd like to bone up on exoskeletons...why exactly can't they grow, leading animals to shed the old before growing a new one ? Mammal bones can grow, including the skull, which is pretty much a portion of exoskeleton. Is there some inherent reason why other animals with full exoskeletons can't do this, or have they just failed to evolve that ability ? StuRat02:32, 15 November 2006 (UTC)[reply]
"This structure makes cuticle extremely strong, as well as highly effective at keeping the spider from drying out, but the material does have one serious drawback. While it's flexible enough for movement, it can't expand like human bones and tissue -- in other words, it can't grow. In order to increase its size, the spider has to form a new, larger cuticle exoskeleton and shed its old one (this is called molting)." Got it from http://science.howstuffworks.com/spider1.htm Hope that helps! (too lazy to sign in) User:Sifaka152.3.72.5003:15, 15 November 2006 (UTC)[reply]
If you look at this site http://www.cals.ncsu.edu/course/ent425/tutorial/integ.html it has a nice diagram of the exoskeleton cellular layers. The outermost and exposed layers that form the hard inflexible parts of the exoskeleton called sclerites are formed from individual protein molecules that are linked together by quinone compounds. This is a pretty exothermic reaction so these are very stable bonds that are forming and are energetically difficult to reverse. However that isn't enough to explain it. First of all since the sclerites are not composed of living cells and they are on the outside of the insect exposed to air, modifying them, which would take place in an aqueous environment by appropriate enzymes would be difficult. If the insect were to dissolve portions of the whole cuticle at once, it will lose water quickly and open itself to disease vectors. One could imagine an insect sloughing off pieces of its exoskeleton at a time. Human skin which has a similar pattern of layering, but is different in that dead cells take the place of the cuticle. These cells are sloughed off rather quickly and allow a human to grow. An insects exoskeleton can't slough off in tiny pieces like human skin because it is one big interconnected mass. Instead it has to get rid of the whole thing and harden a whole new layer that is big enough for it. That is why newly shed insects are very soft to the touch. Their cuticle hasn't hardened yet. Procuticle has some more information with lots of jargon. Ecdysis, the scientific term, describes the cellular actions behind molting. That is about the best I can do without consulting an entomologist. Sifakatalk05:04, 15 November 2006 (UTC)[reply]
Random guess time! Your skeleton is inside you, therefore your bones can grow by adding layers on. For an exoskeleton to grow, the dry outer layer which is not in contact with the useful fleshy parts of the animal would have to have another layer laid down. This is rather hard to arrange. It's possible that I'm in fact saying what Sifaka is saying ("...they are on the outside of the insect exposed to air..."). Skittle21:15, 15 November 2006 (UTC)[reply]
Non-Standard Sleeping Pattern Name
Is there a name for the patter of sleeping 12 hours, staying active for 24 hours, sleeping for 12, and so forth? If so... what is it? Thanks in advance ^^ kaiti-sicle02:43, 15 November 2006 (UTC)[reply]
I don't think enough people could follow that schedule that there is a name for it. Many biological rhythms are close to 24 hours. Even when external cues are removed, the drift of rhythm is smaller that that. The system you describe would shift sleep alternately between day and night. In the 1970s, some medical or surgical residencies required every-other-night call, which was essentially 36 hours awake, followed by 8-10 asleep, for 1-3 years with occasional breaks. It was grueling. Currently, residency rules mandate going home after being at work for 24 hours, and people may then sleep for 12 hours, but do not then stay awake another 24 hours-- it is a stressful, unnatural rhythm that cannot be sustained. alteripse11:45, 15 November 2006 (UTC)[reply]
Just a slight nitpick: current residency rules mandate going home after 30 hours, it's just that no new patients can be started in the last 6 hours.Tuckerekcut15:29, 15 November 2006 (UTC)[reply]
I would think that every time an exhausted resident makes a mistake that kills somebody, the hospital would be sued for millions, and this idiotic practice would end. Why doesn't this happen ? StuRat18:32, 15 November 2006 (UTC)[reply]
They don't, although many of them do. The definition of a Lewis acid is a compound that likes to collect a pair of electrons. A better known non-hydrogen containing one is Aluminum trichloride. Electrophiles are by definition Lewis acids.
"Lewis Acids All species have a vacant orbital and/or an available LUMO (Lowest unoccupied molecular orbital)
and all species with full or partial positive charge behave as Lewis Acids.
Lewis Acid behaviour is found amongst:
• Metal cations
• Electrophiles (attacking Lewis acids)
• Electrofuges (Lewis Acid leaving groups
• Lewis acid "ligands" around and anionic centre (H+ and R+)
• Classic electron deficient species such as boron trifluoride, BF3
• Cationic spectator counter ions
• Electron deficient pi-systems which take part in multicentre interactions
"
Some of the above are kind of complicated if you haven't taken organic chemistry yet. The short answer is many acids have hydrogen because the corresponding thing the hydrogen is attached to is perfectly happy replacing the hydrogen bond which it has to share with the hydrogen with a pair of electrons that it gets to keep for itself.
One reason that many acids (for some definition of "acid" that is more restrictive than the Lewis definition) contain active hydrogen is because that essentially is the standard more-restrictive definition. See Acid#Definitions of acids and bases for more definition info. It began as a descriptor of materials that had a common property...only later was is ascribed to "has active hydrogen". DMacks06:04, 15 November 2006 (UTC)[reply]
High specific heat of water relating to exothermic reaction (simpler question on paragraph 3)
Because water has a high specific heat will an exothermic reaction such as, heat escaping to the atmosphere after heating or more specifically to a calorimeter, progress slowly compared to the progression of the endothermic reaction taken place during the actual heating. If yes would a measurment of heat capacity be calculated wrong if temperature is measured before exothermic reaction is complete? or would it not matter when you measure the water during the exothermic reaction. 69.150.209.1305:31, 15 November 2006 (UTC)[reply]
Um, what reactions are you talking about? Transfer of heat, by itself, isn't a chemical reaction at all; it's neither exothermic nor endothermic. If you're trying to measure the heat capacity of water by adding a known amount of heat energy and then measuring the temperature, you should do so immediately. If you wait until all the heat escapes and the water is back to its original temperature, you'll get a heat capacity of infinity, which is obviously wrong. —Keenan Pepper06:41, 15 November 2006 (UTC)[reply]
During a chemistry lab, we were told to get the heat capacity of a calorimeter. By heating one beaker of 50mL of water and leaving another 50mL in a styrophome cup. Then to measure both temperature: cool (22 C) hot (42 C) - my results. Then we were told to mix the water. the temperature of the new warm water was 35 C. The hot water seemed to lost only 7 degrees. amd the cool seemed to gain whole 13 degrees. Ideally it was said the heat transfer is supposed to be moderatly equal. I do not understand why I got these reuslts. I apologize for my errors in the first question. I wanted to make it simpler but made it more complex 69.150.209.1308:24, 15 November 2006 (UTC)[reply]
That doesn't sound that far off. Did you use a fancy digital thermometer or a regular liquid thermometer? Probably the 22 and 42 measurements happened to be a little low and the 35 to be a little high. —Keenan Pepper15:56, 15 November 2006 (UTC)[reply]
Was the transfer done such that the cold water was added to the warm water in the beaker? If that's the case, it could be that the beaker was warmer than the water, and was still transferring heat to the water when the cold water was added.--Mabris16:46, 15 November 2006 (UTC)[reply]
Hydrocarbon fuel cells with proton-conducting electrolytes
This question is about fuel cells that run on hydrocarbon fuel rather than H2. If the electrolyte conducts O2− ions, I can write down the half-reactions and everything makes sense, but if the electrolyte conducts protons, I'm not sure what goes on. Is CO2 formed at the anode? If so, it seems like some electrons are wasted, because carbon is oxidized and oxygen is reduced at the same place, and the electrons from that redox couple don't flow through the circuit. Is that accurate? —Keenan Pepper05:53, 15 November 2006 (UTC)[reply]
The applicable half-reactions are in the article Direct-methanol fuel cell. The electrolyte conducts protons, C is oxidized at the anode (producing CO2 as you had guessed) but the reduction of the oxygen occurs at the cathode. --Mabris17:06, 15 November 2006 (UTC)[reply]
Oh, I see where I went wrong. I had the hydrocarbon reacting with O2 at the anode, but really it reacts with water and makes more protons and electrons, so the total number of electrons is the same no matter the electrolyte. Thanks! —Keenan Pepper21:09, 15 November 2006 (UTC)[reply]
redox potential
Generally NAD is said to be having more negative redox potential than FAD.......and also NAD is capable of donating electrons to FAD but not in a reverse manner ie from FAD to NAD in normal conditions...My question is in what conditions FAD can donate elecctrons to NAD?{i know one example of this kind that is formation of acteyl Coa from pyruvate.here FAD accepts electrons and donates them to NAD...enzyme acting here is pyruvate dehudrogenase complex. how is this possible?)--hima 09:19, 15 November 2006 (UTC)
Since FAD is covalently bound to a protein the amino acid side chains can signifiantly change the chemical environment. This context is the critical factor. David D.(Talk)12:20, 15 November 2006 (UTC)[reply]
The energy to overcome this reaction which seems to work against the redox potentials comes from the oxidization of the Coenzyme A to acetyl-CoA and CO2. The pyruvate dehydrogenase coordinates the reaction to make this thermodynamically feasible.--Mabris16:53, 15 November 2006 (UTC)[reply]
Power (in watts) = Voltage (in volts) x Current (in amps), i.e., P = VI. You can substitute in Ohms Law (V = IR) to get other variations on this. (edit conflict)--jjron12:17, 15 November 2006 (UTC)[reply]
Power=Current times voltage =Current squared times resistance=Voltage squared divided by resistance assuming direct current or alternating current with unity power factor (resistive load). If the circuit contains inductance or capacitance, then consult power factor. Edison15:32, 15 November 2006 (UTC)[reply]
Magnetism
I recently had a question on a test for MRI. The question was "What is not a characteristic of a magnet? The answers where a. attracts, b. holds iron, c. dipoles, d. resistive. I need to know if a characteristic of a magnet is that it holds iron? I was confused because I answered resistive. But after looking up resistive in the dictionary (which is a term used normally when talking about electronics) I found that resistive can also mean repel..I think the question was worded badly. Can anyone share some insight?
I'd say the most probable answer is d. All the others are certainly characteristic of a magnet, but only d is questionable. And when the word resistive is used in science, it can safely be assumed (at least I would) to refer to electrical resistance, which isn't characteristic of a magnet. –Mysid☎14:07, 15 November 2006 (UTC)[reply]
I've heard there was a way to clean and plate iron such as found in old hammer heads by leaving them in molasses and then putting them in some kind of electrolyte with copper pennies. How this work and what would the setup be? 71.100.6.15217:13, 15 November 2006 (UTC)[reply]
I'd use quick-hard instead of the molases, and you can electroplate things at home with reasonable materials - sulfuric acid (WEAR KITCHEN RUBBER GLOVES BE NEAR RUNNING WATER HAVE A SAFETY MASK OR GOGGLES), copper, distilled water, CuSO4, wires and a battery. More info for home electro-platers findable at [11]. READ THE SAFETY NOTES BEFORE ATTEMPTING ANYTHING AND HAVE COMPOTENT PROFESSIONAL SUPERVISION. JBKramer17:43, 15 November 2006 (UTC)[reply]
I have a 'guiness book of records' type question - is this ok?
What is the largest nut? On a swing bridge I have observed hex nuts appox 2ft diameter, 1ft depth and approx 1ft bolt diameter - does anyone know of much larger nut and bolt combinations. Thank you.
how to test out reactolite (photochromic) spectacle lenses?
i just bought a pair of prescription specs with reactolite lenses - but
after 8 hours of use i haven't noticed them go dark! this included
walking around outside in a cloudy uk november day for several hours,
and staring up at my kitchen fluorescent lamp for a few minutes.
neither of them had any noticeable darkening affect!
how can i test if they are working and be sure they're ok once and for
all? obviously its a bit difficult finding bright sunshine in the uk in
november.86.31.114.9720:12, 15 November 2006 (UTC)[reply]
A flashlight might do the trick. I suspect there is not too much difference in luminescence between a cloudy day and a fluorescent lamp. --HappyCamper20:14, 15 November 2006 (UTC)[reply]
These types of glasses only change color when exposed to certain frequencies of light. I suspect that light filtered through clouds is just not bright enough and light from a bulb or fluorescent lamp doesn't contain the right frequencies (ie why would you want your glass to go dark inside a building?). You could try a full spectrum bulb or just wait for a sunny day to test them. --Cody.Pope21:14, 15 November 2006 (UTC)[reply]
You need real UV light, since I have a pair. Usually the stores that sell them have a little display that has UV light. Failing that, the local donut shop has a counterfeit money detector... --Zeizmic21:21, 15 November 2006 (UTC)[reply]
About a year ago, I had my gallbladder removed because of gallstones. The gallbladder is one of those body parts that you can live without just fine, but I'm curious about how the body changes to accomodate the lack of one. I haven't found any answers to that, either online or in the articles on gallbladder, liver, and bile. Basically, the gallbladder stores bile from the liver and then releases it into the small intestine when it is needed. Where does the bile go if you don't have a gallbladder? Does it get stored in the liver, or does it get released directly into the small intestine? —Cswrye21:25, 15 November 2006 (UTC)[reply]
I think you should ask the surgeon who removed it what they did with the connecting pipes - that should give you the answer..
Making magnets
Rently, I purchased a pair of magnets (I think that they were made of neodymyum or something that sounded like that) which were gold plated, from [[12]] and I was wondering, how do they make them if they are so magnetic? If they use machines, which they probably do, are the machines' "hands" or grabbers or whatevers made out of plastic so the magnets don't stick to them? How do they manufacture them without them sticking to the machinery and ruining it? Thanks for your answers. Ilikefood21:37, 15 November 2006 (UTC)[reply]
^A. Neftel, H. Friedli, E. Moor, H. Lötscher, H. Oeschger, U. Siegenthaler, & B. Stauffer (1997). Historical carbon dioxide record from the Siple Station ice core. http://cdiac.ornl.gov/trends/co2/siple.htm
^http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=4512&posts=4&start=1Economic recovery from a world wide depression, leading into increased industrial output in the run up to second world war, followed by combustion of cities in Asia and Europe as a result of warfare. Warfare ends in 1945, and there is a fall in C02 concentations during 1950's as industrial output declines. C02 concentrations only begin rising during late 1950's as industrial output recovers to prewar levels.
![[1]](http://cdiac.ornl.gov/trends/co2/graphics/siple-gr.gif){kind=link}
![[2]](http://img166.imageshack.us/img166/5919/co2ub9.jpg){kind=link}
![[3]](http://muller.lbl.gov/pages/IceAgeBook/Image2.gif){kind=link}
![[4]](http://www.junkscience.com/Greenhouse/GHCN-ERSST.gif){kind=link}
![[5]](http://www.niwa.cri.nz/pubs/wa/09-1/ice-graph.jpg){kind=link}
![[6]](http://timlambert.org/img/chapinfig2.png){kind=link}
![[9]](http://www.sherwoodxc.com/personal/molecule.JPG){kind=link}