Wikipedia:Reference desk/Archives/Science/2015 December 5

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December 5

What's the cheapest fully automatic car that has a clutchless manual mode?

Sagittarian Milky Way (talk) 00:28, 5 December 2015 (UTC)

It's difficult to know whether there is an even cheaper car, but Ford Fiesta, at $17,500 including the clutchless option, might be one candidate. It has a standard 6-speed manual, with the option of a "PowerShift", which is a clutchless manual. --Denidi (talk) 01:27, 5 December 2015 (UTC)

@Denidi: That's a manual with a clutchless option. Our OP is asking for an automatic with a clutchless manual.

From what I've seen, a bunch of full automatics have the option to push the stick off to the side and force the computer to shift up or down - which is essentially a "clutchless manual" - or an "overridable automatic" - depending mostly on how your mind works! Some go so far as to add paddle-shifters to the steering column. My wife's bottom-of-the-range Kia Soul had that - and the 2015 Soul starts at just $15,190.

With any car where there is a computer controlling the automatic shifter - it's just a matter of adding a couple of $1 switches and a $0.10 spring to the shifter mechanism to add this capability - so I'd expect even the cheaper automatics to include it - so this may boil down to "what is the cheapest automatic?"

Personally, nothing short of a full manual will do - so I may be missing something here. SteveBaker (talk) 03:10, 5 December 2015 (UTC)

How would I know that you could override the shifting computer?, I don't drive. I thought they just went PRNDL. They go PRN1234L, too? Was it always like that? As for why everyone doesn't use a manual, there's too much stuff to do. Pay attention to the engine sound/foot off gas/press clutch/move stick/ease off clutch slowly/wait for the right engine sound/foot off gas/press clutch/move stick/remove clutch slowly/listen for rpm signal/foot off gas/press clutch/move stick/remove clutch slowly/gas pedal just to get on the freeway? And I might even die if I screw up cause the engine stalled or I broke gears? I'm sure it's more fun than a semi-manual if you rented a racetrack or have zero traffic but I'd probably hit a car far frequenter than in an automatic cause I'm trying to not press the clutch too long or do a step 0.1 seconds too soon. Sagittarian Milky Way (talk) 03:57, 5 December 2015 (UTC)

The cars I've seen have PRND - maybe PRND1 - but also a way to push the shifter sideways from the 'D' position where there is a "+" and a "-" position marked next to the shifter. Nudging the stick forward causes it to up-shift by one gear and nudging it back causes it to down-shift. Multiple nudges get you multiple shifts. It's kinda like a manual - but without having a clutch - but the computer will still take over and override your gear selection if it thinks you'll overrev the engine or cause it to stall...so you don't quite have the same level of control as with a true manual. The lack of a clutch still removes some degree of control - and because you can't feel what gear you're in from the position of the shifter, you either have to remember or glance down at the instruments (which generally show which gear you're in)...that wouldn't be so bad if the computer didn't ever override you - but I find it all to easy to get flustered and not know which gear I have selected. Hence I never really use the manual override on my wife's automatic - even though I prefer driving a manual transmission car. SteveBaker (talk) 04:42, 6 December 2015 (UTC)

Why would I ever want to breach the redline or stall the engine though? If it automatically upshifts at redline then I guess there might be times where one would rather have it keep it at redline with the throttle but redline is less efficient (both mpg and thermodynamic % and auto parts life) so one might want a higher gear then anyway. So the overrevving/stall override part doesn't seem that bad to me. Sagittarian Milky Way (talk) 01:52, 7 December 2015 (UTC)

The software override is generally *way* too conservative. Its' choices are fine for fuel-efficient daily driving - but if I want to really push the engine hard to pass a truck on the freeway, I may well want to downshift and then floor it. I don't want the stupid computer up-shifting, robbing me of acceleration and preventing me from passing the truck before the next corner. On my stick-shift car, the computer will limit engine power as I reach redline - so it won't let me damage the engine - but it won't jump an entire gear, which is a huge reduction in torque right when I needed it.

However, if I'm really honest with myself, it's not a matter of performance - I just take pleasure in having that degree of control. If I want to drive home in 5th gear instead of 6th and feel the increased responsiveness and drop to 4th to get a bit of an adrenaline rush on the on-ramp - then I can. If I do it every day, I'll be buying a lot more gas and killing the planet - but the automatic version of my car gets about 5% worse MPG than the manual - so I feel entitled to a bit of 'va-voom!" once in a while.  :-) SteveBaker (talk) 04:07, 7 December 2015 (UTC)

What's the point of a mode that's clearly for those who can shift that still won't let you? I wonder if a regular Joe programmer could reprogram it? 5 gear shifts just to get up to speed? Good God. Sagittarian Milky Way (talk) 04:48, 7 December 2015 (UTC)

Now that you mention it - yes, that's another issue. I frequently skip gears when accelerating or braking hard - but with the nudge-the-stick or paddle-shifters, you have to go strictly through each of the intermediate gears...although you can do it quite rapidly. Doubtless the mechanical systems could handle that - but the controller you're using to tell the computer what to do is inherently serial in nature - so it would need more than just software changes to "fix" this. SteveBaker (talk) 16:22, 7 December 2015 (UTC)

It's not really much different from riding a bicycle - it becomes second-nature very quickly. The quickest way to screw up is to actually think about what you're doing. Bazza (talk) 11:00, 5 December 2015 (UTC)

I don't know how to ride a bike either. Sagittarian Milky Way (talk) 01:52, 7 December 2015 (UTC)

And in Europe, the large majority of people do use a manual (see Manual Transmission: Section 9). As a driver, I regard it as much easier than riding a bicycle (see also Section 8.1), but that's because I never learned the latter :-). {The poster formerly known as 87.81.230.195} 94.11.50.58 (talk) 23:32, 5 December 2015 (UTC)

I'm with Steve — I prefer a full manual, because it makes you feel in control, and there's a special satisfaction in physically moving the gearbox around, not just touching a paddle on the steering wheel. That said, it's a satisfaction that wears a bit thin in stop-and-go traffic, especially on hills. --Trovatore (talk) 23:43, 5 December 2015 (UTC)

Absolutely - a manual gearbox is a pain in stop/go traffic. The problems on hills has largely been fixed in my car where the computer holds the footbrake on for 5 seconds after you take your foot off the pedal or until you move the gas pedal (whichever happens first)...but in slow traffic, it's a real pain. The inability to control engine-braking in an automatic is what bothers me - also that no matter how clever the computer is, it can't know that I want to down-shift to get more RPM's to spin up the turbo prior to accelerating hard...it can only react to a command I've already given. I feel very "out of control" when I'm forced to drive an automatic transmission car. That said - automatics are getting better every year - and here in the USA, it's getting harder to find cars with a manual transmission option. SteveBaker (talk) 04:42, 6 December 2015 (UTC)

Making human males female

Can we make human males female by adding and deleting DNAs and making Y chromosome X, and extending the effects to all the body?, for example, making original sperm (I don't know the words for it) ovum, making body cells female-wise, letting metabolize, originating vargo from original cells (I don't know the words for it either)? --Like sushi49.135.2.215 (talk) 01:39, 5 December 2015 (UTC)

Even if that might work, removing an entire chromosome in every single cell of the body and replacing it with another one is far *FAR* beyond what science can currently do. If you could somehow do that, you'd be replacing a large percentage of the person's DNA - so the question of whether this would really remain the same person would be kinda tricky. If you duplicated the existing X and deleted the Y, you'd end up with someone with two identical X chromosomes - and that could easily result in some dangerous genetic diseases cropping up. If you added an X from someone else and deleted the Y then you'd have added a ton of new genetic material - possibly changing the person in many more ways than just altering their gender.

But this is all very hypothetical. Once large-scale body structures are in place, simply switching chromosomes wouldn't immediately create a complete gender change in that sense. When gender reassignment is done right now, merely changing the hormone balance doesn't do all the work - and surgery is needed. Even after that, there are residual effects that don't change - one example being the vocal chords - transgender people often have trouble sounding like their new gender.

SteveBaker (talk) 03:28, 5 December 2015 (UTC)

I don't see how it could work, unless such a switch were made immediately after the egg was fertilized and before it divided. And such experiments might well be illegal anyway, never mind unethical. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:51, 5 December 2015 (UTC)

We could inactivate SRY throughout the body by some means or other, or at least knockdown (though this would be a technical masterpiece slightly beyond our current competence). But this approach would have most of the limitations of ordinary transgender hormone treatment, chemical castration or whatever - it wouldn't erase an Adam's apple or broaden the pelvis or change the bones of the face, etc. Neither would a more thorough chromosomal replacement. The body doesn't have any Doctor Who style regenerations built in - it came to be what it is by gradual development over time, with a cumulative result.

The main use of chromosomal manipulation would be to make eggs for reproductive purposes - this is reasonably feasible by stem cell transplantation into someone else's ovary, with the added convenience of a bona fide womb close at hand. There was a paper about it (in mice) something like a decade ago ... I could go hunt if you're interested. Wnt (talk) 05:12, 5 December 2015 (UTC)

Imagine the psychological aspect. As somebody was born as male and the society does not respect him as male and having him (ab)used for his work power only, it might be discriminating. The issue was asked as a biological question changes to a political one. A scrotum or uterus has never been created by surgery, but an uterus has been transplanted from woman to woman, sometimes form mother to daughter due cancer or similar issues. In some countries on this planet, parents killed their female babies to have their families a better financial condition. As more families did it the same way there were no women for the men. Today, those men say "thank you" to their parents an their governments who a trying to solve their tolerated crime by war, gender politic or prostitution. --Hans Haase (有问题吗) 11:06, 5 December 2015 (UTC)

Well, now you're getting into social issues of gender, which is a great mystery. I mean, [1] When I was a kid, it was embarrassing for a boy to get an erection in the boy's locker room. today it would be embarrassing for a girl to get an erection in the girl's locker room. Wnt (talk) 11:18, 5 December 2015 (UTC)

As the human brain is doing much by learning and even more people expect. It is still not completely discovered. But some theories are made around it. The scientific way would be find or causes an interactions that made the things like they are. Sometimes we will find ourselves in a small bubble, looking for a truth inside it but still forgot what outside the bubble is. Before focussing on an aspect, see its dependencies to have an answer that covers all occurring conditions and also faces the point where its not applicable. --Hans Haase (有问题吗) 11:59, 5 December 2015 (UTC)

• It wouldn't be possible to do that to an adult, because most of the effects of sex chromosomes play out during development, especially childhood and puberty. There is no way to undo those processes in an adult. It would be possible, in principle, to do that in a single-celled embryo, but there is an easier method than replacing the Y chromosome with an X. All you would need to do is remove or otherwise inactivate the Y chromosome. In a normal human female one of the two X chromosomes is inactivated anyway, so the result should develop just like a normal female. Looie496 (talk) 14:34, 5 December 2015 (UTC)

That's a horrible idea, it leads to Turner syndrome which means a whole list of mental and physical impairments, including sterility, deformities of the neck and jaw, a lack of breast development, and being prone to loss of sight and hearing. Even though one X chromosome is deactivated per cell in XX females, which X chromosome is deactivated is random for each cell. Hence if a vital gene is missing in one X, at least half the body is still producing the necessary protein. μηδείς (talk) 21:17, 5 December 2015 (UTC)

Oh well, you learn something new every day :-(. Looie496 (talk) 22:33, 5 December 2015 (UTC)

Guy on earth looking at a camera inside a spaceship.

Imagine there is a guy X on earth, now imagine ther is a spaceship travelling near the speed of light.
This spaceship has a camera inside it that record what is happening inside the ship, this image is them shown on a monitor that guy X is looking at.
The question is, what would this guy X see
— Preceding unsigned comment added by 201.79.59.44 (talk) 10:28, 5 December 2015 (UTC)

Guy X would not see a thing, as in a millisecond, the screen would be 300km away. Can you see a screen that far away? If the camera is transmitting a signal to a screen stationary with respect to X, there would be a very serious Doppler effect. The video would be nowhere near standard and the screen would likely not sync to it. If it did, the image would appear to be in slow motion, matching the time dilation observed. Note that even trying to transmit a video to or from an aeroplane give synchronisation problems. Graeme Bartlett (talk) 12:36, 5 December 2015 (UTC)

The video might be faster or slower depending on whether the ship is receding from Earth or approaching it. The speedup/slowdown is given by the Doppler shift formula, not the time dilation formula. It's the same if the screen is on the spaceship and the guy on Earth is looking at it from there (ignoring the practical difficulties of doing that). -- BenRG (talk) 17:23, 5 December 2015 (UTC)

Hang on, is the monitor on the spaceship or is the monitor on earth? 110.22.20.252 (talk) 12:49, 5 December 2015 (UTC)

Originally on Earth, but Ben was pointing out that exactly the same speed effect would be visible if X was somehow able to view a monitor on the spaceship (super-telescope, and for a tiny fraction of a second as the ship passes Earth?). Ben will no doubt correct me if I am wrong, but I think there will be a difference -- an additional (blue or red) colour shift if the monitor on the spaceship is viewed from earth (because for a monitor on Earth the true colour will be re-created from the signal in coded form, with synchronisation corrections, of course). Our article on Doppler effect gives the formula only for sound. For the correct formula to use for light and radio (monitor) signals, see Doppler radar or Relativistic Doppler effect. Dbfirs 22:11, 5 December 2015 (UTC)

I understood the question as being about the camera inside the spaceship, transmitting to a monitor on Earth. None of the answers so far seem responsive on that point. I guess the Doppler shift implies that the Earth-based equipment would have to do some juggling merely to render the signal at all (as the carrier frequency would be constantly changing), and at that point, who knows; it depends on the corrections applied by the Earth-based system.

I thought we were all replying about that scenario, except for commenting on the difference. The Doppler formula for light determines the speed change in the video, assuming that the equipment can cope with the synchronisation problems. Dbfirs 23:03, 5 December 2015 (UTC)

I don't think that's clear at all. Let's say the camera records 60 frames/second, and spits them out in a transmission. The Earth-based receiver is able to follow the changing carrier frequencies and reconstruct the frames. Then what do you see? That depends entirely on how the receiver chooses to render the frames. To me, the most natural-seeming possibility is that it would render them at 60 frames/second. Then the viewer would see nothing particularly unusual (well, except insofar as the inside of a relativistic spaceship is unusual). However, it might have to do some caching to be able to do that. --Trovatore (talk) 23:09, 5 December 2015 (UTC)

Oh, I'd assumed that the camera was transmitting live, so each frame would be delayed by the Doppler effect if the ship were moving away. I agree that there are some complications, and if a recording were being transmitted then the receiving equipment might well be adjusted to show the film at normal speed by delaying early frames. Dbfirs 23:15, 5 December 2015 (UTC)

Also, the inside of a relativistic spaceship is entirely normal. These is no distortion "caused" by speed. Dbfirs 23:17, 5 December 2015 (UTC)

I wasn't talking about distortion caused by speed. I just imagine that the interior of a relativistic spaceship is probably unusual, given that I do not usually encounter relativistic spaceships. Maybe they have seventies-style black velvet paintings and lava lamps. That would be unusual. --Trovatore (talk) 23:23, 5 December 2015 (UTC)

I thought it had just left Earth, but yes, I see what you mean. Dbfirs 23:27, 5 December 2015 (UTC)

Not responsive to the original question, but possibly interesting to people thinking about this stuff: The Visual Appearance of Rapidly Moving Objects. Do we have an article that discusses these effects? --Trovatore (talk) 22:46, 5 December 2015 (UTC)

Ignore where the monitor is. If it is on Earth, the receding space ship needs to transmit the image to the monitor. The transmission happens at light speed, making it equivalent to the monitor being on the ship.

The original question is equivalent to asking "what do you see if you look at a mirror receding at near light speed?" My intuition is you see a normal image of yourself, but intuition can easily fail here. Anyone? 91.155.193.199 (talk) 23:16, 5 December 2015 (UTC)

Intuition isn't always reliable when the speed of light has to be taken into account. If you are talking into your mirror mounted on a moving vehicle on Earth, will you expect to hear the echo of your voice at normal frequency and speed? Dbfirs 23:24, 5 December 2015 (UTC)

Yes, I think I would expect reflection of sound and light to be unaltered, on basis of conservation of momentum. Or would the reflection speed up or slow down the receding reflector? Sourced scholarly discussion of this would be welcome of course. 91.155.193.199 (talk) 06:06, 6 December 2015 (UTC)

You are correct that the reflected sound will travel at the same speed in the opposite direction, but the fact that the reflector is moving away will increase the wavelength (and thus reduce the frequency) of the reflected sound. See our article Doppler effect for details. The same applies to light and all electromagnetic radiation, as illustrated by a Radar gun. Dbfirs 07:49, 6 December 2015 (UTC)

If you're talking about sound reflecting off a wall that's at a constant distance from you, you will hear no Doppler shift. The reflected sound can't be faster because it would eventually overtake your voice, and it can't be slower because there would have to be an ever-larger region of space to buffer the sound that hadn't gotten back to you yet (or a changing speed of sound, which could happen if there was an ever-increasing wind, I suppose). -- BenRG (talk) 20:13, 6 December 2015 (UTC)

Looking at the ship (or a video feed from the ship) and looking at yourself in a mirror on the ship are not quite the same. In the latter case you get a double Doppler shift (the square of the Doppler shift factor). -- BenRG (talk) 20:13, 6 December 2015 (UTC)

transistor as a switch/oscillation

in the common emitter configuration, if I connect the collector to the base (negative feedback), why doesn't the circuit oscillate? In my (undoubtly simplistic) mental model, the collector resistor and the transistor form a voltage divider. Initially, the transistor is open. The supply voltage drops across the open transistor, the base is pulled high, the transistor closes, the base is pulled to ground, the transistor opens, repeat. A similar circuit with a reed relay would oscillate, shouldn't this one, too? Is this because of inertia (in the relay)? Asmrulz (talk) 10:29, 5 December 2015 (UTC)

Beginning work with electronic essentials, an amplifier always becomes an oscillator and an oscillator never oscillates. Similar to mechanic assembly it is to install a spring between two parts. If there's no change, it returns to a condition where it is being forced to. There are many oscillator circuits and You need make Your circuit amplifing the change to make it oscillating. Also see the bikicle, stepping on the pedats the right time an position, makes You ride faster. When stepping the wrong way or time or not releasing the foot when the pedal returns, You need to ride down a hill or stop riding it when the hill ends in the bottom of a valley. In Your case, the capacitor only variates the transistors behaviour on a change in the operating voltage or the base input. When charged in the new condition, it will remain there. --Hans Haase (有问题吗) 10:48, 5 December 2015 (UTC)

As a relay completely turns off and has mechanical inertial mass that shifts the delay for oscillating. A transistor, see its meaning as transfer resistor, can be used as a switch but, it is also working analog as a the volume control on Your stereo. This makes the transistor stay in a definend condition like a voltage regulator. Transistors had a long time the problem not to reach the low resistor value of a switch or relay when turned on. But that is history. --Hans Haase (有问题吗) 11:45, 5 December 2015 (UTC)

See Electronic oscillator for our general article, and Barkhausen criterion and Nyquist criterion for some more mathematical details. As well as providing positive feedback, a working circuit needs to ensure that the overall gain is (exactly) 1, otherwise the output will just drive to the maximum or minimum DC value, and that this gain occurs at a particular frequency, otherwise the circuit will just generate noise. Tevildo (talk) 11:58, 5 December 2015 (UTC)

I just thought that as a relay can be made to oscillate by having it pinch off its own supply current, the same could be done with a transistor. In the classic discrete multivibrator, two transistors pinch off one another in turns Asmrulz (talk) 14:40, 5 December 2015 (UTC)

Yes, that's how a blocking oscillator works. The important thing is the feedback path must contain some components to determine the frequency - it won't operate with just a resistor. Tevildo (talk) 15:19, 5 December 2015 (UTC)

The transistor is not a Schmitt trigger. As the relay turns on and of, by the mass of its lever, the Schmitt trigger is triggeres by the charge level of a capacitor when used as oscillator. --Hans Haase (有问题吗) 12:09, 5 December 2015 (UTC)

Will a schmitt inverter oscillate if I short the output to the input? I know non-schmitt inverters (74HC04) just settle at roughly half the supply voltage Asmrulz (talk) 13:22, 5 December 2015 (UTC)

I googled and it seems, it will Asmrulz (talk) 14:18, 5 December 2015 (UTC)

Based on an Operational amplifier its output has a rise time. It will only run between its trigger voltages. It might be possible to use the next faster operational amplifier in comperator mode to change it to a square voltage. Feeding the inverted schmitt trigger over and resistor to capacitor on ints input, You have a simple RC-Oscillator, higher resistor or capacitor lower its frequency. Smaller values rise the frequency. --Hans Haase (有问题吗) 15:48, 5 December 2015 (UTC)

I'm coming to the discussion late because the question and answers were posted while I was asleep overnight. Are you sure that the circuit does not oscillate? According to theory, it should, but the fact may not be readily apparent. When power is applied, current is initially not flowing in the collector-emitter path, but current that flows via the collector resistor into the base-emitter junction causes heavy collector current to flow, pulling down the collector voltage to about 0.6 volts in the case of a silicon transistor. That voltage is not sufficient to keep the base current flowing, so the transistor begins to turn off, whereupon the collector voltage starts to rise again. The process repeats in the same manner. So the OP is correct in assuming that the circuit should oscillate. The problem is that because of the high gain (presuming a silicon device), only a minute rise and fall in base voltage is sufficient to turn the transistor on and off (respectively). It is therefore oscillating at the millivolt level or less, and perhaps OP hasn't noticed that it's doing so. It might appear to him to be in a steady state condition with collector voltage at less than supply voltage (Vcc). Also, because there are no timing components (eg. capacitor and resistor) in the circuit, oscillation will take place at a very high frequency, probably hundreds of MHz, limited only by stray circuit capacitance and the transistor's Hfe versus frequency limit. A DC voltmeter will not show the presence of oscillation at such frequencies. Akld guy (talk) 19:27, 5 December 2015 (UTC)

It seems You created a blocking oscillator. When adding the coils, You might have it operating better or oscillating in an predictable frequency range. The parasitive inductivity of the capacitor You used might have completed the blocking oscillator. See also: de:Kategorie:Elektrischer Oszillator contains more articles as the Category:Oscillators. --Hans Haase (有问题吗) 22:02, 5 December 2015 (UTC)

Exaggerated colour in old movies

I've noticed that the colours in old movies on tv look unnaturally intense. It seems to be particularly noticable in movies from the 1950-60s era. Is this phenomenon related to film chemistry, the age of the film, or perhaps the process of converting to video? I've just looked at "Raintree County" and "Meet Me in St. Louis" that just happened to be on my satellite service right now and the over-intense colour is very noticable in both. Others that show the phenomenon clearly are "Seven Brides for Seven Brothers" and in the case of "Brigadoon" it's so intense that it almost looks like cartoon colouring. Roger (Dodger67) (talk) 10:48, 5 December 2015 (UTC)

I took the liberty of Wikilinking those... the first two mention Technicolor in the articles. Wnt (talk) 11:15, 5 December 2015 (UTC)

I think that Technicolor is the answer. Bubba73 ^{You talkin' to me?} 00:47, 6 December 2015 (UTC)

Companies like Kodak and Agfa rised their business with chemical solutions for color films. But if You are seeing movies from Video, note NTSC and SECAM have no color carrier signal correction. PAL has it by frequently shifting the color carrier signal by 180 degrees. This also causes effects like brown and yellow washed pictures. As old movies are reworked by removing sand and noise, some also have been recolored. It might be done with less manual interaction when understanding how noise is being removed from pictures and 100 Hz oder 120 Hz television is working. It deinterlaces and interpolates the missing information from the previous pictures. It is an industry to rework old movies. --Hans Haase (有问题吗) 11:16, 5 December 2015 (UTC)

Sorry User:Hans Haase, your post is completely incoherent, I'm afraid your English is not fluent enough to help here. Roger (Dodger67) (talk) 11:21, 5 December 2015 (UTC)

Thanks, I have edited my answer above. --Hans Haase (有问题吗) 11:36, 5 December 2015 (UTC)

I still don't understand your post. The pieces of information appear not to be connected.Scicurious (talk) 13:35, 5 December 2015 (UTC)

It is not only caused by the photo chemicals. When receiving it over analog television, NTSC and SECAN also cause a lost of clear red and blue color. Click the links, I added. --Hans Haase (有问题吗) 15:35, 5 December 2015 (UTC)

• Unfortunately I don't know the answer in great detail, but it's basically a matter of technology. When those movies were made the photography industry had just begun to develop color film that responded fast enough for motion pictures, but just barely: it was necessary to use extremely bright light for color filming. The combination of crude chemistry and bright lighting led to substantial color distortion. Looie496 (talk) 14:26, 5 December 2015 (UTC)

Thanks, the Technicolor article Wnt linked contains some fairly good explanations - though the chronology is sometimes unclear. Roger (Dodger67) (talk) 14:46, 5 December 2015 (UTC)

I think User:Hans Haase's explanation may be at least as relevant - I don't know. To this day I still have no idea if Latin American soccer teams really play on yellowish-green grass, either. Haase's explanation above is not badly written as I'm reading it now (did miss "oder -> or", though). Also, according to IMDb "Seven Brides" was promoted as "In CinemaScope in blushing color". Incidentally, you may have encountered yet other films that were colorized, though this seems to be out of fashion lately. Wnt (talk) 15:35, 5 December 2015 (UTC)

Also Agfacolor appeard that way. Today digital video covers all that losts. But a damage causes loosing a number of frames or JPG «squares», the picture is split into. --Hans Haase (有问题吗) 15:38, 5 December 2015 (UTC)

• The high color saturation was a desired effect, not a mistake. They advertised that films would be in Technicolor. See the work of Frank Tashlin for example, and Pedro Almodovar's fascination with his color techniques. Full saturation went out of style in the 60's when realism replaced romanticism. But look at movies like The Fifth Element and What Dreams May Come as well as Amélie where color made a big comeback. μηδείς (talk) 00:13, 6 December 2015 (UTC)

Natalie Kalmus was color supervisor of virtually all Technicolor features made between 1934 and 1949. The article points out that she was in frequent heated disputes with the studios over the unnatural color intensity they insisted on using. The OP refers to the 1950s and 1960s when Kalmus no longer was color consultant, but the studios' desires to over-emphasize color may have persisted into those decades after her departure. Akld guy (talk) 04:01, 6 December 2015 (UTC) Edited for typo in date. Akld guy (talk) 04:16, 6 December 2015 (UTC)

Note that studios also intentionally picked colorful scenes to film in color, much like 3D movies tend to have lots of scenes with things flying "out of the screen". In the original Wizard of Oz, for example, there were ruby slippers, a yellow brick road, and the Emerald City, not all of which were specified to be so colorful in the book. On the other hand, in films where color wasn't seen as a selling point, they kept them in black and white rather than filming with subdued colors. See film noir, for example. StuRat (talk) 19:26, 6 December 2015 (UTC)

Routine blood test draw locations

Why is it that for most routine blood tests, they draw from the inner elbow? Why not go for the hand or another part of the arm? — Preceding unsigned comment added by 2A02:C7D:B901:CC00:193D:96FB:D0D4:9774 (talk) 20:30, 5 December 2015 (UTC)

They want an area with high bloodflow. The crux of the elbow has a large vein, and phlebotomists like the easily accessed vein in my right arm. They will indeed use the veins in the back of the hand, especially for IV drips, if they have to, but the hand is more sensitive, and the patient is more likely to jerk if pricked there. This is OR, but it comes from years of speaking with phlebotomists. μηδείς (talk) 21:08, 5 December 2015 (UTC)

To agree with Medeis, I will add that the hand has a lot of nerve endings, including pain nerves, reflecting the high utility of the hand for motor and sensory activity, and thus the need to protect it (with pain signals). The inner elbow doesn't have nearly as many pain nerves, and it has all of the blood flow of the hand, typically in one vein. Robert McClenon (talk) 21:22, 5 December 2015 (UTC)

Yes. It hurts more to have something inserted into the back of the hand than into the crook of the elbow. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:15, 5 December 2015 (UTC)

If one wants a spot with high blood flow then why not do what phebotomists do when confrounted by a DA. Blood gravitates downwards. Look your own ankles. The inner bony bit (medial malleolus ?) . The long saphenous vein is clearly visible there. One can't miss it -even if one is still hung over from drinking too much retsina the night before (thats providing it is possible to drink too much retsina, which is according to my OR is something I have not yet been able to ascertain – but I will go on trying).--Aspro (talk) 22:59, 5 December 2015 (UTC)

You are kind of going out of your way for no purpose. The phlebotomist doesn't want to get down on the floor, you don't want to get up on the table, then be stabbed in the ankle. Medicine is like cooking and engineering, it's an applied science with standard procedures that make sense because they have been shown to work for a long time. A doctor who needs to draw blood from an armless heroin addict might do all sorts of things, but the bottom line is that the crux of the armpit is convenient a2A02:C7D:B901:CC00:1C9B:DD1F:6D57:E999 (talk) 09:45, 7 December 2015 (UTC)nd reliable. μηδείς (talk) 00:07, 6 December 2015 (UTC)

What's a DA? Double amputee? — I consistently find that a needle in the back of my hand hurts less than one in the elbow. —Tamfang (talk) 04:37, 9 December 2015 (UTC)

What about the upper arm on the outside? I can clearly see veins there and it doesn't seem as sensitive as the hand.

An ionic bounding can occur between metals to metals or nonmetals to nonmetals?

An ionic bounding can occur between metals to metals or between nonmetals to nonmetals or it can occur between metals to nonmetals only? 92.249.70.153 (talk) 22:54, 5 December 2015 (UTC)

See below also regarding telling us your native language so we can direct you to a better place to answer your question. Again, as a "general rule", the kind one learns in a rudimentary chemistry class (usually at the middle or early high school level) one learns that ionic bonds are expected when one has simple binary compounds between metals and nonmetals, whereas covalent bonds are expected when one has simple binary compounds between two nonmetals. --Jayron32 23:19, 5 December 2015 (UTC)

I asked this question because I have read in the book "chemistry for dummies" the following sentence: "an ionic bond occurs between a metal and nonmetal" and it wasn't clear what about ionic bounds between metal to metals or nonmetals to nonmetals. Now I understand that indeed ionic bound occurs between metals to nonmetals only. Thank you. (By the way I'm not English native speaker but I'm learning in English books only)12:08, 6 December 2015 (UTC) — Preceding unsigned comment added by 92.249.70.153 (talk)

An ionic bond forming between a metal and a non-metal is, as Jayron said, a useful generalisation for when first learning chemistry, but it is not always true. Metal to metal ionic bonding is possible (eg caesium auride, CsAu) and ionic bonds do exist in compounds with only non-metals (like ammonium chloride, NH₄Cl, which has one NH₄⁺ cation for every Cl⁻ anion. Please do not mistake a general rule to use when starting as a statement that has no exceptions. A better statement might be something like: An ionic bond is formed by the attractions of opposite charges between a cation and an anion. The most common (simple) cations are metal cations like Na⁺, but there are also cations with multiple atoms which are all non-metals (ammonium above is likely the simplest example) and the hydrogen ion H⁺ is an important cation. The most commone (simple) anions are non-metal anions like Cl⁻, but there are also anions with multiple atoms like OH⁻ and SO₄²⁻ and some anions containing metals like [Fe(CN)₆]³⁻. The ratio in which the cation and anion are present in a compound is determined by their charges, as the overall compound will have zero net charge. So, the compound between K⁺ and [Fe(CN)₆]³⁻ will be K₃[Fe(CN)₆] as 3 x 1+ charges are needed to balance 1 x 3− charge. EdChem (talk) 12:45, 6 December 2015 (UTC)

Can it be an cation in the metals or an anion in the nonmetals?

92.249.70.153 (talk) 22:59, 5 December 2015 (UTC)

I'm not sure I follow your question. As a general rule of thumb, metals tend to form cations and nonmetals tend to form anions. So I think the answer to your question is "Yes". If your native language is not English, there is probably a Wikipedia in your native language; if you tell us what language you speak natively, we can direct you to the correct location where you can ask the question in your native language and get better answers. --Jayron32 23:15, 5 December 2015 (UTC)

As Jayron has said, metal cations and non-metal anions are common, a simple example being table salt, NaCl, with an Na⁺ cation and a Cl⁻ anion. There are, however, non-metal anions like ammonium, NH₄⁺ and metal containing anions. The page on potassium nonahydridorhenate mentions the formation of its tetraethylammonium salt [N(C₂H₅)₄]₂ReH₉ with the cation N(C₂H₅)₄⁺ and anion ReH₉²⁻. This compound was originally thought to contain the rhenide anion. Metal-containing anions like this are not unusual, the hexacyanoferrates like [Fe(CN)₆]³⁻ and [Fe(CN)₆]⁴⁻ are common examples. Compounds with uncoordinated metal anions are known - caesium auride, CsAu, is one example which has an Au⁻ anion, but these are comparatively rare. EdChem (talk) 06:03, 6 December 2015 (UTC)

I asked my question because that I saw in "chemistry for dummies - workbook" (p.194) the following sentence: "The metal is present as a cation (positive ion) and the nonmetal is present as an anion (negative ion)". 12:12, 6 December 2015 (UTC) — Preceding unsigned comment added by 92.249.70.153 (talk)

Ok, thanks for the clarification. As a general rule, compounds made up of one metal and one non-metal, like NaCl, CaO, PbCl₂ have a cation (positively charged species) and an anion (negatively charged species). The ratio in which the two species are present is determined by the charges (a compound will have no charge overall). Metals generally form cations and non-metals anions. So, sodium chloride has one positively-charge sodium cation (Na⁺) for every negatively charged chloride anion (Cl⁻). This 1:1 ratio is seen in the formula NaCl. Calcium oxide (CaO) also has a 1:1 ratio as the charges on the ions are again equal in magnitude but opposite in sign (Ca²⁺ and O²⁻). For a compound like lead(II) chloride, the anion Cl⁻ has only half of the charge of the Pb²⁺, and so two anions are needed for every cation to get a balanced compound, written as PbCl₂.

There are many ions which consist of multiple atoms and, as I described above, there are cases where anions may contain metals and cations non-metals, but as a general rule and a starting point for understanding ionic compounds, the sentence you quote is a reasonable start. Note that this is a generalisation and there are exceptions, in that there are compounds with metals and non-metals where there is little or no ionic bonding and an understanding of covalent bonding (like is present in water) is needed. For example, the anticancer drug cisplatin [Pt(NH₃)₂Cl₂] does not consist have a platinum cation but rather a platinum atom convalently bonded to the N and Cl atoms in the compound. EdChem (talk) 12:25, 6 December 2015 (UTC)

The one thing that can't vary is there has to be an equal amount of positive and negative charge. Even a one-part-per-billion excess of one or the other would explode the substance with some kind of force that I could calculate as an exercise, but won't, but would guess to be remarkable. My feeling though is that compounds with two nonmetals tend to be thought of as covalent (HCl, for example) even if they can dissociate in water. And if you have two metals together you think of that as an alloy. But EdChem gave some good exceptions above! Wnt (talk) 20:11, 9 December 2015 (UTC)

Kidney Stones / Hernia prior modern medicine

So whilst I was having a good play with myself, I had this disturbing thought.

Say I was a typical person in 7853 BC, and didn't have a car. I also happened to have Kidney Stones. Or a Hernia. Or pretty much anything that's extremely unpleasant and requires modern medical intervention to resolve. Am I screwed? Should I just find the nearest Dinosaur to kill me? It's both terrifying and morbidly intriguing. — Preceding unsigned comment added by 92.241.130.120 (talk) 23:55, 5 December 2015 (UTC)

While suspecting that this question is not being asked in 100% seriousness, see History of surgery, Lithotomy, and Truss (medicine). 7853 BC is going a bit too far back (you're still technically in the Neolithic at that point), but you'd have been (comparatively) OK in the Egyptian Old Kingdom, and other Bronze Age societies. Tevildo (talk) 00:41, 6 December 2015 (UTC)

There were no dinosaurs in 7853 BC. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:32, 6 December 2015 (UTC)

No non-avian dinosaurs. SteveBaker (talk) 04:22, 6 December 2015 (UTC)

IIRC, when Cleopatra needed a dinosaur by which to commit suicide, she exposed herself to a pair of venomous coconut swallows. μηδείς (talk) 16:46, 6 December 2015 (UTC)

Yeah, those venomous coconuts are a menace. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:58, 7 December 2015 (UTC)

Oh - I thought "Coconut crab" - the worlds' largest terrestrial invertebrate..."cases of coconut crab poisoning have occurred". SteveBaker (talk) 16:18, 7 December 2015 (UTC)

African, or European? μηδείς (talk) 01:37, 9 December 2015 (UTC)

If something "requires modern medical intervention" (bolding, mine), and you are not in the modern era, there is no possible solution. Untreated, an ailment can develop differently. However, according to History of alcoholic beverages, there are some indications that alcohol already existed back then in 7853 BC. So, they could hypothetical treat pain with it.--3dcaddy (talk) 02:43, 6 December 2015 (UTC)

You don't have to look back into pre-history for this. There are plenty of people in the world today who live out of reach of modern healthcare. The answer is that they suffer greatly and often die from easily treatable conditions. Even a relatively small injury can become infected - and without antibiotics, you can die. There are probably 'herbal remedies' that may or may not help much - possibly pain relievers of some degree of effectiveness - but generally not much that would come close to modern medicine. We know that Trepanning was a common practice in neolithic times - we know that "Out of 120 prehistoric skulls found at one burial site in France dated to 6500 BC, 40 had trepanation holes." - so if they were capable of such drastic surgical procedures - it's possible they could have tried other desperate measures in all manner of life-or-death situations. How successful this might have been is unclear - but it's unlikely such procedures would have been so common if they didn't work at least occasionally.

SteveBaker (talk) 04:22, 6 December 2015 (UTC)

Ancient medicine was a real phenomenon, and while modern treatments are usually better, on occasion the ancients had equivalent or even superior treatments. (For example, artemisinin was discovered by consulting an ancient Daoist text, or looking forward, I can't help but note that lanosterol, which has been reported as a method to clear cataracts once it is all duly developed, patented and monopolized, seems to be closely related to abundant triterpenes in cyclamens, the eye salve the Romans would have prescribed for the condition) In the case of kidney stones already causing pain, there are some things like chanca piedra that are alleged to help ease the passage of the stone ... but they're not really sufficiently studied. The literature is full of herbal remedies with one or two papers giving encouraging results that haven't been studied since. So it's hard to say that this or that would have saved you back when, but in aggregate, there would have been physicians who (as today) sometimes would help a little, sometimes a lot, often not at all. Even Neanderthals collected healing herbs, so I think even in Neolithic times you'd have had a chance, not necessarily a good one though. (note that long distance trade improves the power of herbalism ... even the separation of Europe from Middle East during the Crusades was sufficient to badly damage the utility of herbal medicine there) Wnt (talk) 11:24, 6 December 2015 (UTC)

I should also note that trepanation still works, and is still used on occasion ... the biggest difference is simply that people don't get their heads bashed with clubs and such as often. You don't need a trepan for a gunshot wound! The fact that physicians can see if there is a hematoma or not also, of course, greatly reduces the tendency for unnecessary procedures. Wnt (talk) 11:27, 6 December 2015 (UTC)