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July 3

Camera with built in selfie stick

Why don't camera manufacturer create a point and shoot camera with a built in selfie stick and a shutter button on the selfie stick itself? 220.239.43.253 (talk) 01:09, 3 July 2015 (UTC)[reply]

(1) How do you know they don't? (2) Why don't you contact some major manufacturers and present them with your idea? ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:51, 3 July 2015 (UTC)[reply]

I thought most cameras had the standard tripod thread (not on cell phones). If it doesn't make it smaller, it's prbably not cost effective. A lot of feature decisions are based on differentiation and what people will pay for differentiation. If "built-in selfie stick" is a cool feature but not something people will pay more or at the same price allow market share growth, it won't get added because it adds to the BOM without an ROI. 3D TV's and 3D cameras are products that had higher BOM with little ROI and they tend to disappear from the market. --DHeyward (talk) 03:14, 3 July 2015 (UTC)[reply]

BOM = bill of materials (effectively manufacturing cost), ROI = return on investment (effectively profit). Smurrayinchester 08:23, 3 July 2015 (UTC)[reply]

Are selfie sticks used for cameras? I know they CAN be used with a camera, but the only people I see that use a selfie stick are people who use their cell phone as a camera. 199.15.144.250 (talk) 16:36, 3 July 2015 (UTC)[reply]

We do have an article on selfie stick. Apparently there are some specifically designed to use with non-phone cameras. I don't know if anyone has bothered (yet) to gather statistics on usage with cameras that have phones compared to cameras that do not have phones. SemanticMantis (talk) 17:12, 3 July 2015 (UTC)[reply]

One caveat could be that non-phone cameras tend to be heavier than phone cameras, which could make the leverage more difficult. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:08, 3 July 2015 (UTC)[reply]

I wouldn't suggest that the selfie-stick be truly built in, as that would add weight and bulk when you don't need it. They could make one as an accessory that has a shutter button, maybe using Bluetooth to send that signal to the camera/cell phone. I'd use the standard tripod connection. Hopefully the camera/cell phone and selfie-stick could also be replaced independently of each other. StuRat (talk) 22:26, 3 July 2015 (UTC)[reply]

Googling "digital camera selfie stick" indicates that there are selfie sticks for non-iphone cameras. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:14, 3 July 2015 (UTC)[reply]

Measuring displacement, velocity, acceleration, jerk, etc.

Hi, we can measure the displacement of a body, we can also measure its velocity, but can we measure the derivatives of displacement wrt time of any order? Thanx! 5.29.9.245 (talk) 10:03, 3 July 2015 (UTC)[reply]

Displacement and velocity can be measured but only after we have defined the reference frame in which the measurements will be taken. This dependence on reference frame means these two measurements are always arbitrary - a person using a different reference frame will achieve different measurements. In contrast, force, mass and acceleration are not dependent on our choice of reference frame (at least in Newtonian mechanics). Different persons using different reference frames for the measurement of these things will all measure the same acceleration (and force and mass).

For example, a traveler in space or in orbit can turn on an accelerometer and read his acceleration (by comparison with zero acceleration he experienced when calibrating the accelerometers) but there is no similar device that will display displacement or velocity. Dolphin (t) 10:58, 3 July 2015 (UTC)[reply]

If we fix a reference frame (and we don't know whether or not it is an inertial frame of reference) then we can measure the (vector) displacement of an object in that reference frame at various points in time. If we make two measurements in a small enough time interval then we can *approximate* the instantaneous velocity of the object, and if we make more measurements in a small enough time interval then we can *approximate* its instantaneous acceleration, jerk etc. But I don't know of any way to actually *measure* instantaneous velocity, acceleration, jerk etc in a general reference frame. We can only use F = ma to measure acceleration if (a) we know the mass of the object - which requires a reference mass unless maybe our object is a fundamental particle - and (b) we know that our reference frame is inertial. Gandalf61 (talk) 11:24, 3 July 2015 (UTC)[reply]

See accelerometer. However, the acceleration due to gravity is included in that measurement, so you would need to do some vector math to remove that component, if near a massive body (like Earth). StuRat (talk) 16:04, 3 July 2015 (UTC)[reply]

... but to calibrate the accelerometer you need some independent means of measuring acceleration. Gandalf61 (talk) 16:19, 3 July 2015 (UTC)[reply]

I don't really understand this comment, or your previous one. One second is 9192631770 ticks of a cesium clock, without reference to any standard timepiece in France. The kilogram is still a physical object, but only because of practical engineering difficulties. One m/s² could likewise be defined by the behavior of a particular kind of solid-state accelerometer, practical difficulties aside. -- BenRG (talk) 23:02, 3 July 2015 (UTC)[reply]

Perhaps for acceleration he means that the acceleration due to gravity isn't always exactly 9.81 m/s², as it varies a tiny amount by location (on the surface of the Earth) and elevation (and of course quite a bit more in space). So, for extremely accurate readings, you would want to calibrate it for your current location. The direction of acceleration would also be quite critical, so you would need a way to accurately measure the angle, relative to the pull of gravity in that location. StuRat (talk) 23:39, 3 July 2015 (UTC)[reply]

Indeed. An accelerometer does not measure local acceleration - it measures displacement which it translates into force, and then it translates that force into acceleration. To show local acceleration the accelerometer has to be calibrated for a specific location to compensate for gravity and other non-inertial forces. Take an accelerometer calibrated for the Earth's surface and put it on the surface of the Moon and it will tell you that it is accelerating downwards at 5/6 g because it now measures a downwards force that is less than when it was calibrated. And to calibrate an accelerometer correctly you have to ensure it has zero local acceleration. And you cannot measure the local acceleration of an object directly, you can only estimate it from multiple measurements of displacement. Gandalf61 (talk) 08:27, 4 July 2015 (UTC)[reply]

If clocks measure local time, then accelerometers measure local acceleration. The reason they show an upward acceleration when sitting on a table is that the table is accelerating upward. There is only one correct (generally covariant) concept of acceleration in a general relativistic world, and that's what accelerometers measure.

The important thing is that "velocitometers" and "positionometers" don't exist, at least not as self-contained memoryless devices like accelerometers. The original question has it backwards in some sense. You can figure out an approximate spacetime velocity and position using inertial navigation, but you do that by integrating the acceleration, and you have to supply the boundary conditions (initial position and velocity) from outside because they're not intrinsically measurable like acceleration is. Jerk and higher derivatives can be calculated internally as time derivatives of the acceleration (with respect to an internal cesium clock). Velocity and position are the only problematic ones. -- BenRG (talk) 10:03, 4 July 2015 (UTC)[reply]

Obviously the OP is asking about measuring position, velocity, acceleration etc. relative to a local co-ordinate system which will, in general, be non-inertial. So an answer that tells them that the table that they think is stationary has a proper acceleration of approximately 9.8 ms^-2 upwards and this is the only covariant way to definie acceleration is factually correct but completely useless as an answer to their question. Gandalf61 (talk) 14:54, 4 July 2015 (UTC)[reply]

I can think of at least a couple of exceptions where we do measure position and velocity absolutely, and not as the integral of acceleration with respect to time. For example, an ultrasonic pinger (ranger), a gray coded position or rotary encoder, a Doppler RADAR, an altimeter, and a vertical speed indicator each measure absolute linear or angular position, or absolute velocity, directly - and not as a time derivative or as an integral of anything. These machines only work within certain limits, and depend on certain assumptions about natural physical properties; some of these properties are hardly universally true and it would be foolish to think that the measurements are valid outside of the intended range of operation; but the same can be said of any machine that measures any physical property - even if we are trying to think in a way that is consistent with general relativity! Atomic clocks are only accurate if we can disavow thermal noise; accelerometers usually do measure displacement, either by assuming some material property that defines a spring constant or electrostatic relationship; and so on. It's quite easy to say that a General Relativistic model is absolved from all such practical details... but try to build a device that is relativistically correct and has no dependence on any empirical assumption at all! It can't be done. Even if we look at famous tests of measurement of General Relativity - like Gravity Probe A - the precise measurements did not take place in a Platonic-idealistic world. When we test measurements of general relativity, we are still constrained by imperfections and assumptions that simply do not apply everywhere in the universe, and sometimes, our pure physics is even tainted by practical engineering details! Nimur (talk) 04:04, 6 July 2015 (UTC)[reply]

I'm not quite sure what type of question this is. Is it a tool question about measurement (i.e. do we have accelerometers, do we have displacement meters like the Plimsoll line on ships that calculate in time)? Or is it a relativity question regarding reference frames? Or is it a quantum mechanics question regarding Heisenberg uncertainty? The answer depends on which of the three (or possibly which combination) the poster is seeking. Displacement of a ship, for example is a pretty simple static calculation, but when under power and acceleration, displacement is compoinded by those forces in addition to things that affect mass per unit volume of water such as salinity and temperature. --DHeyward (talk) 00:58, 4 July 2015 (UTC)[reply]

I am familiar with two types of accelerometer. One uses a strain gauge to measure the deflection of a cantilever with a mass on the end of it. As such it measures down to DC, hence measures the acceleration due to gravity, even if the accelerometer is stationary. The other uses a piezo electric force gauge to measure the forces experienced by a small mass. These are typically used down to 3, 1 or 0.3 Hz (this is an instrumentation decision). Within those frequency limits they both measure the absolute acceleration, ie they are operating in an inertial reference frame.Greglocock (talk) 02:57, 5 July 2015 (UTC)[reply]

Egg Hatching

How long should it take for Dove eggs to hatch? — Preceding unsigned comment added by 2601:581:8400:9D36:CA2A:14FF:FE3F:3730 (talk) 15:34, 3 July 2015 (UTC)[reply]

It will depend on the species, you can easily google for results and add the species name for more specific info. But if your Dove Eggs hatch, you should film it and call the local news. μηδείς (talk) 11:47 am, Today (UTC−4)

[1] lists 15 days, but it might vary by species/subspecies. StuRat (talk) 15:53, 3 July 2015 (UTC)[reply]

It won't very that much though. The shortest dove incubation I can find is 12+/- 0.8 days, here [2], and the common mourning dove takes 13-14 days [3]. Interestingly, the little desert diamond doves in the first link are nearing a fairly absolute limit of about 11 days for any bird. This paper [4] discusses how many birds were reported to have 9-10 day incubation times, but those were probably due to bad methodologies, and not accurate measurements of real incubation. As of 1953, there were no records of any incubation under 11 days. I also couldn't find any good records of a dove species with a 16 day incubation period. SemanticMantis (talk) 16:28, 3 July 2015 (UTC)[reply]

July 4

Is the CMB a baby picture of only the observable universe?

Is the Cosmic Microwave Background a "baby picture" of the entire universe or just the observable universe? If the observable universe is all we're able to see then isn't the CMB picture incomplete? Or can we extrapolate from the CMB how the entire universe appears beyond just what is observable? 184.65.230.52 (talk) 01:59, 4 July 2015 (UTC)[reply]

The observable universe. Dragons flight (talk) 02:17, 4 July 2015 (UTC)[reply]

The CMB light that's just now reaching us has all traveled about the same distance, so its points of origin form a sphere centered on us. That sphere is the boundary of the observable universe. CMB maps like the one to the right are Mollweide projections of the sphere. So not only does the map not directly tell us about the universe outside the boundary, it also doesn't directly tell us about the universe inside the boundary. It does contain information about the interior because the light interacted with matter in the interior on its way to us, and it contains information about the exterior because the state of the plasma that emitted the light (about 380,000 years ABB) depended on the earlier state of the universe in all directions, including the directions that are farther from us than the source of the light. -- BenRG (talk) 03:25, 4 July 2015 (UTC)[reply]

The source of the microwave background is in the observable universe because we're observing it. That said, the concept of the observable universe is full of tricks. The distance back to the Big Bang in years/light years is real, but the later part of it is measured at a time when the universe is very small. Changes in the rate of expansion affect what is observable - to give a simple example, if the expansion slows down enough, then eventually everything becomes observable, even though it isn't now. On the other hand in a Big Rip eventually nothing is observable to anything else anymore. Wnt (talk) 03:32, 4 July 2015 (UTC)[reply]

Hmmm, on second thought, I suppose that a trace of extremely redshifted radiation always exists (the sky before the Big Rip), much like the popularized image that things fallen into a black hole always remain technically visible. The light of the distant stars that has reached within a proton's radius of a nucleus never totally falls away (though a photon almost certainly will not arrive, you would never know it won't, I think) Which makes me wonder now... no matter what cosmic inflation occurred, if the universe was ever entirely observable to itself, I suppose it always remains so, technically? Wnt (talk) 00:57, 6 July 2015 (UTC)[reply]

How interchangeable are injection molding molds?

Plastic injection molding company usually follow the following protocol: give us your design and X dollars and we will design the mold and produce Y parts within Z weeks, at the end of which we will send you the mold. My question is, how interchangeable is the said mold? If I take the mold to a different company will they be able to use it? Will the mold produced for one brand of injection molding machine work with a different brand? Are there industry standards for mold sizes and interfaces, and if so, do they differ across different countries? I'm chiefly interested in making ABS parts. My other car is a cadr (talk) 04:00, 4 July 2015 (UTC)[reply]

For example, Toshiba America publishes a catalog for Injection Molding Machines that specifies clamp and platen dimensions. You can compare to other manufacturers, and check with each vendor to determine what equipment they use, and whether they permit you to supply your own mold.

Nimur (talk) 13:20, 4 July 2015 (UTC)[reply]

Biology: What bird is this? (mp3)

I have heard this Mystery Bird in the media a few times, from the Dark Castle computer game to this recording, taken from the film The Last of Sheila. I thought maybe Whip-poor-will or Loon, but I can't find a match. Thanks! Reflectionsinglass (talk) 18:00, 4 July 2015 (UTC)[reply]

It's an owl hooting. The first bit is caught mid-call, but my guess is that it is a barred owl. Our description of the vocalization is accurate and you can hear the last few syllables fairly clearly at the beginning of the file. Matt Deres (talk) 21:36, 4 July 2015 (UTC)[reply]

I'm afraid I have to disagree, that's definitely not the call. This call is used in multiple media forms and I've heard it since the 90s and it's never sounded like an edited version of a bird call. I appreciate the suggestion though. I went to the Cornithology site and listened to all the samples and it's not the Barred owl. However, it may very well be an owl of some kind! I'll keep my ears out. Reflectionsinglass (talk) 19:01, 5 July 2015 (UTC)[reply]

The "oooooo-d-d-d-d-d" call is most commonly a barred owl. They make many calls, this one being a mating call. When I was young, I'd hear it. Then, the response would be a rising "oo-oo-oo-d-oooooo-d-d-d-d". When I listen to the recording you linked, I don't hear anything that sounds at all different than the barred owls I heard growing up. It just has a bit of echo added to it to make it sound a bit creepy. 209.149.114.69 (talk) 15:00, 6 July 2015 (UTC)[reply]

To me, it sounds just like a male Tawny owl response to a broadcast song by the female. I hear this just about nightly where I live.DrChrissy ^(talk) 15:08, 6 July 2015 (UTC)[reply]

Just as a follow up, I think that the barred owl and the tawny owl have mutually exclusive distributions. If the location of the recording is known, this could rule out one of the owl candidates.DrChrissy ^(talk) 19:45, 6 July 2015 (UTC)[reply]

July 5

Stars

The following is the statement of confusion: In the dense nebulae where stars are produced, much of the hydrogen is in the molecular (H2) form, so these nebulae are called molecular clouds.

Q:

Does this mean population I stars are burning H2 and helium in its core? Done
Which stars turned H into H2? Done
‘A still gaseous body before any star formation has taken place’ & ‘over-dense region of dark matter in the very early universe’ – Does this mean ‘the foggy universe’ time?

Space Ghost (talk) 21:06, 5 July 2015 (UTC)[reply]

H₂ is the normal form of Hydrogen under reasonably cool conditions - e.g. on Earth. In this form, two hydrogen atoms share their electrons in a covalent bond. Under most reasonable conditions, H₂ will form spontaneously. However, the H-H covalent bond is a chemical bond. At the temperature of stars, all chemical bonds break down, and indeed, even the bond between the H nucleus and its electron breaks down. Matter in a star is, nearly without exception, in the form of a plasma. The nuclear reactions that "burn" Hydrogen affect only the nuclei, not the electron shell, of hydrogen. Main sequence stars generally burn Hydrogen, but there are population I stars that have evolved far enough to burn Helium (but not H₂) and have turned into red giants. --Stephan Schulz (talk) 22:08, 5 July 2015 (UTC)[reply]

Thanks

-- Space Ghost (talk) 19:18, 6 July 2015 (UTC)[reply]

Star formation, Evolution & Mass

Does it occur only in a giant molecular cloud? Doesn't it occur in a small/medium molecular cloud? Is it called the cold molecular cloud?
Does a star's mass increase and decrease with its age, like 'temperature' and 'luminosity'? If so, how? - is it from accretion during its complete life time? How does the mass work out anyway? Does it depend on the chemical element?

Space Ghost (talk) 21:06, 5 July 2015 (UTC)[reply]

2. A stars mass will generally decrease with age. Solar wind gradually bleeds off plasma, and mass. This solar wind is driven by the nuclear fusion of the sun, which releases lots of EM radiation. When two nuclei combine to form a third nucleus, that third nucleus will have a mass of less than the sum of the two original nuclei. The difference in mass will result in photons (electromagnetic radiation, light, IR etc.) being given off. The photons leaving the star will also reduce the mass. The only chance of it increasing in mass is colliding with another star, or swallowing a large planet. Big stars burn faster than small stars, e.g. Betelgeuse is a very good example. Early stars with low metallicity burn slower than later starts. Martin451 23:48, 5 July 2015 (UTC)[reply]

Is the reason a star moving through a cloud couldn't pick up mass, that the solar wind would blow the cloud out of the way ? StuRat (talk) 00:49, 6 July 2015 (UTC)[reply]

I would think that wouldn't be significant. The amount of mass lost to the solar wind is tiny/insignificant. If the cloud were much denser than the solar wind, the volume of the solar wind pressure would decrease as the solar wind heats it. I'm not sure what density it would take to move that pressure volume boundary to within the star itself. I would tend to think there simply aren't enough conic solutions that result in the collision with the star. How much mass does the earth gain from the solar wind vs. loss from energetic escapes? I think the loss of solar mass to both fusion and solar wind over the entire lifetime of the sun is about 0.1% or so IIRC (before Red Giant phase). The solar wind doesn't appreciably affect the orbits of planets. --DHeyward (talk) 08:45, 6 July 2015 (UTC)[reply]

Strange things can happen in binary star systems - see cataclysmic variable star. Gandalf61 (talk) 10:13, 6 July 2015 (UTC)[reply]

'Zero age main sequence' (ZAMS)! I forgot, sorry. But I'm still not clear of the issue.

Lets say (for example) when the cloud is fragmenting, its accreting material creating a round object, as its becoming heavy, it went up to 5 solar mass and turned into ZAMS. As it decreases its mass, at what mass does it become a red giant, white dwarf, black dwarf? - (the mass is just an example btw) - I understand that once it fuses all of its hydrogen but at what mass it burns all its hydrogen then goes into helium burning phase?

Mass is not the determining factor, as stars with greatly different masses could all be at the same stage (e.g. Main Sequence G2, like our Sun) at the same time. However they would have started at different times as the mass of a star does greatly influence how fast they progress through the various stages of Stellar Evolution, an article which you should read thoroughly as it should clear up many of your misconceptions and answer most of your questions. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 20:53, 6 July 2015 (UTC)[reply]

Also, I don't understand about the 'early stars with low metallicity burn slower than later starts', I thought the early 'quasars' (not known of its mass) and 'III' stars burnt faster than expected because they had over 100 mass. No information found on 'II' stars mass even though its visible till today. -- Space Ghost (talk) 19:28, 6 July 2015 (UTC)[reply]

Clarification required:

I understand that a Star can accrete, what I forgot i.e. up to what age/time? I assume, even up to the black hole time? Am I right?
When does it become a neutron star, after a white dwarf or it depends on its mass/accreation? I believe neutron star do not accreate as it spins extremely fast...
Is after a 'supernova' where you don't actually see nothing left at all of a star? I mean 'no round ball'?

Space Ghost (talk) 19:20, 6 July 2015 (UTC)[reply]

1) A star could continue to accrete material, if it's surrounded by a dense enough cloud that the solar wind can't push it away. I'm not sure of how dense it would have to be, though. Also, if the cloud was rapidly heading towards the star that would change the calculations. At some mass and/or time a nova or supernova would occur, before it got to a black hole.

2) See neutron star. They can accrete material from a binary system twin.

3) Supernova often do leave a core at the center, perhaps a neutron star, perhaps a black hole, depending on mass, etc. See the chart in supernova#Core_collapse. StuRat (talk) 20:16, 6 July 2015 (UTC)[reply]

July 6

Sleep immobility

Is sleep paralysis the same state when you fall asleep in a potentially unpleasant position (for example, with head pressing against your arm) and later start to feel numbness due to disrupted blood flow, but is unable to move or wake up? I'm healthy, but had at least one such experience in the past, and this is really a nasty thing. Brandmeister^talk 08:51, 6 July 2015 (UTC)[reply]

No, these are quite distinct phenomena. Sleep paralysis involves a more or less complete (though typically very brief) loss of volitional motor function for the whole body, usually occurring during either hypnagogia or hypnopompia (the transitions between full wakefullness to sleep and between sleep and wakefulness, respectively). It results from irregular function in the neural pathways which regulate these states of consciousness and restrict volitional movement when we sleep, lest we act upon mental stimuli while we sleep; sleepwalking, accordingly, is in some sense the inverse of this condition in which those circuits do not operate appropriately while asleep, allowing movement. Sleep paralysis is therefore more or less completely the product of the central nervous system. By comparison, a limb "falling asleep" from pressure on a nerve or the surrounding tissue (with the experience being clinically known as obdormition with regard to the numbness, and parathesia with regard to the telltale "pins and needles" sensation) does not usually involve significant impairment of motor function or proprioception and is best defined as a matter of physiological disruption of the relevant area of the peripheral nervous system (though similar numbness in limbs can, in rare instances, result from brain tumors or other CNS dysfunction). We all, of course, have experienced the sleeping limb phenomena every so often. Most people also have a memory of experiencing sleep paralysis once or twice in their life -- these events (or at least the fully conscious variations which one can later recall) are usually highly transient and exceedingly rare, but there is also a chronic version of the condition in which episodes can last longer and occur more frequently. I do agree, it can be an unsettling experience, even when not fully awake. Snow ^{let's rap} 10:20, 6 July 2015 (UTC)[reply]

@Snow Rise: I've always read that sleep paralysis affects motor function without mention of the sensory, and certainly people are sensitive to touch when asleep... yet I've had the personal experience during gout attacks of intentionally maintaining sleep paralysis in the lower part of my body for close to an hour (I think) after reaching wakefulness, during which there was no pain. It was only after "breaking" the sleep paralysis that the pain started. I'm still not sure of the explanation for this. Wnt (talk) 13:57, 6 July 2015 (UTC)[reply]

I think you're referring to something unrelated, but I can confirm that I've experienced it as well. For example, if I'm suffering from a cold, I may wake up feeling quite well only to suddenly feel worse after I begin moving. Or, as in your example, a painful or itchy appendage seems to quiet down during the night only to come roaring back as soon as I start moving. I'm curious about the mechanism; I've just assumed that it was due to laying still. Matt Deres (talk) 19:39, 6 July 2015 (UTC)[reply]

Interrupted blood flow would mean limb death, not just tingling. It is sometime possible to tell which nerve is compressed or trapped by part of the limb is tingling. For example, it is sometimes possible to compress the nerve on the outside of the elbow through flexion. The middle finger, ring finger and pinky will go numb. A different posture compresses the nerve for the index finger and thumb and they will "fall asleep" in that position. A lot of people don't remember which finger and just remember "hand is tingling." The specifics are good for determining carpal tunnel syndrome or what type of sleeping posture fixes it. --DHeyward (talk) 11:28, 6 July 2015 (UTC)[reply]

Looking for research study paper on Fibromyalgia

Hello, I had come across an article on Fibromyalgia and wanted to read the study paper that was related. Unfortunately http://guardianlv.com/2013/06/fibromyalgia-mystery-finally-solved/ did not point to where to get the paper on painmed.org and I am having difficulty trying to find it on this site, as it doesn't seem to host a database (pay or otherwise. Dr. Rice is the name of the senior researcher. Is there a place I can find this paper? Thank you. 67.234.207.4 (talk) 19:56, 6 July 2015 (UTC)[reply]

@@ Line 132: / Line 132: @@
 {{=2|doh}} 'Zero age main sequence' (ZAMS)! I forgot, sorry. But I'm still not clear of the issue.
 Lets say (for example) when the cloud is fragmenting, its accreting material creating a round object, as its becoming heavy, it went up to 5 solar mass and turned into ZAMS. As it decreases its mass, at what mass does it become a red giant, white dwarf, black dwarf? - (the mass is just an example btw) - I understand that once it fuses all of its hydrogen but at what mass it burns all its hydrogen then goes into helium burning phase?
+::Mass is not the determining factor, as stars with greatly different masses could all be at the same stage (e.g. Main Sequence G2, like our Sun) at the same time. However they would have started at different times as the mass of a star ''does'' greatly influence ''how fast'' they progress through the various stages of [[Stellar Evolution]], an article which you should read thoroughly as it should clear up many of your misconceptions and answer most of your questions. {The poster formerly known as 87.81.230.195} [[Special:Contributions/212.95.237.92|212.95.237.92]] ([[User talk:212.95.237.92|talk]]) 20:53, 6 July 2015 (UTC)
 Also, I don't understand about the 'early stars with low metallicity burn slower than later starts', I thought the early 'quasars' (not known of its mass) and 'III' stars burnt faster than expected because they had over 100 mass. No information found on 'II' stars mass even though its visible till today. -- [[User:Russell.mo|Space Ghost]] ([[User talk:Russell.mo|talk]]) 19:28, 6 July 2015 (UTC)
 ----
 Clarification required: