Wikipedia:Reference desk/Archives/Science/2017 March 13

= March 13 =

Objects in Earth's orbit
The Pluto article says that "Earth's mass, by contrast, is 1.7 million times the remaining mass in its own orbit". Meanwhile, the Moon infobox gives its mass as 7.342×1022 kg, and its statement that this equals approximately 0.012300 of Earth's mass is compatible with the Earth infobox's claim of a mass of 5.97237×1024 kg. Am I missing something, or is Earth's mass less than 100 times the remaining mass in its own orbit? Nyttend (talk) 01:47, 13 March 2017 (UTC)


 * I don't believe they are including the Moon as being "in the Earth's orbit" (that is, while it orbits Earth, it does not orbit the Sun in the exact same orbit as Earth), but they should state so clearly. StuRat (talk) 01:51, 13 March 2017 (UTC)


 * The article has a link to Clearing the neighbourhood which explains this in detail.   D b f i r s   12:53, 13 March 2017 (UTC)

Why not replace sodium by potassium?
From table 4 on page 149 of this article we can deduce that the Yanomamo Indians have a salt intake of about 60 mg a day (the sodium intake is 23 mg) and a potassium intake of about 6 grams a day. Their salt intake is more than 100 times less than that of most of us, while their potassium intake is higher.

This combination of (by our measure) extremely low salt intake and a higher potassium intake is what all people were subject to until a few thousand years ago when we started to use salt as a preservative. Since that time we have gotten used to extremely high levels of salt, but at the price of doing severe damage to our cardiovascular system. Life expectancy was not long enough to notice the problems and when about a century ago life expectancy started to increase, the heart attacks and strokes due to high blood pressure were wrongly blamed on old age (the blood pressure of Yanomamo Indians does not increase with age, as the article shows).

So, why don't we just dump sodium and replace it with potassium? There are people who use certain types of diuretics who must avoid potassium, but they can just stick to low potassium foods. Count Iblis (talk) 02:21, 13 March 2017 (UTC)
 * NB — a big reason for recent increases in life expectancy is improved care on the other end of things, reducing deaths in childbed (thus increasing the percentage of adult women who lived to menopause) and slashing infant mortality (thus increasing the percentage of children who became adults). I suppose the life expectancy of individuals at age 50 has increased (penicillin and organ transplants have surely contributed to this), but increases in average lifespan for people who reach "old age" is probably less of a factor than increases in the percentage of people who reach "old age".  Nyttend (talk) 02:56, 13 March 2017 (UTC)


 * Don't forget sewage treatment and water treatment, together making huge improvements in life expectancy. StuRat (talk) 02:58, 13 March 2017 (UTC)


 * Have you tasted potassium chloride ? It's OK in small doses, but nasty in concentration.  It's also somewhat radioactive (not enough to be a real concern, but people get all upset about eating anything radioactive). And it's also used to execute people, adding to potential resistance from the uneducated. StuRat (talk) 02:58, 13 March 2017 (UTC)


 * Personally I think the main reason we get such an overdose of sodium is that it makes you thirsty, and beverages are a high-profit item in restaurants, leading them to pack in as much sodium as they can get away with. People then get accustomed to that level of sodium and replicate it in food they prepare themselves.  Until you remove the profit motive, say with laws fining restaurants (enough to make the difference) for high sodium levels, there won't be much change.  StuRat (talk) 03:04, 13 March 2017 (UTC)


 * Both Na+ and K+ are necessary electrolytes and dumping the former is a good way to get hyponatraemia. Na+ is the dominant one outside cells and K+ is dominant inside cells, and the balance between them is regulated by ion transporter proteins to allow the cell to generate an action potential. KCl injections work by disrupting this balance irreversibly, giving a lot of K+ outside cells. (Yes, their chemistry is different enough for this to work, even in this model example of group trends. Rb+ can partially replace K+ in some systems, which Cs+ cannot do at all, but even that is still inadequate as a total replacement.)
 * The taste of KCl varies with concentration. Generally cations and anions with higher atomic masses cause a more bitter taste; LiCl is very salty, while KCl, RbCl, and CsCl are bitter at all but the highest concentrations. Double sharp (talk) 04:32, 13 March 2017 (UTC)


 * Oh shit, you mean my eating calcium chews (I prefer cheese) and potassium- and magnesium-citrate has all been a big scam, and my sodium levels (from .5 to 1.5x normal) have all been a huge mind fuck (fuck)? I see my endocrinologer this coming 3/16.  Please try not to die until I can report advice meant only for me personally. μηδείς (talk) 07:08, 13 March 2017 (UTC)


 * Hyperkalemia. -- Jayron 32 12:09, 13 March 2017 (UTC)


 * The claim that KCl is bitter really surprises me. I've long used a "salt lite" that is half KCl because I prefer the taste to straight NaCl, and because I think a craving for "salt" is often a craving for potassium.  (I think our ancestors evolved to seek crude mixtures from the earth, rather than purified sea salt)  Honestly I still use it despite taking some lisinopril, which is a theoretical no-no but the potassium level on a blood test is still no where near the top of the normal range - I'm not recommending others do that, but when you want potassium the other sort of salt doesn't really satisfy.  I keep both around.  Between straight KCl and straight NaCl I'd prefer KCl by taste, but straight KCl has a noticeable coldness from dissolution and actually costs enough to notice, and doesn't taste quite as good as the mixture.
 * Though while I'm at it, I should mention that even Epsom salt isn't always bitter to me. Usually it is, though not tremendously so even though I typically just pour a little in my palm and wash it down with diet soda or water.  Maybe one time in ten it has a pleasant sweet flavor - same stuff, same bag, same way - and I really have no idea why.  (I eat a bit of now and then for energy and also to "antidote" the unpleasant effects of ham and other preserved meat on my heart - that's just a subjective sensation, which if left unopposed might lead to a skipped beat/"palpitation", but it seems worth a moment's opposition) Wnt (talk) 13:29, 13 March 2017 (UTC)
 * It could very well vary between observers, as a cursory Googling of various people's reports on the taste of KCl reveal. (It is already known to vary with concentration, after all.) Maybe pure KCl would taste more bitter, though; it is not clearly salty until about 0.1 M, according to the reference I gave. Double sharp (talk) 16:37, 13 March 2017 (UTC)
 * There is also the possibility that depending on bodily needs, the taste varies. This reminds me of over-salted meals prepared by first-term pregnant women, to the point of being nearly unpalatable to others present.  PaleoNeonate (talk) 18:20, 13 March 2017 (UTC)
 * Hmm Life expectancy was not long enough to notice the problems is a lol statement that I love to hear when people complain about diet. --DHeyward (talk) 18:53, 13 March 2017 (UTC)


 * Shouldn't the title of this section be, "Why not replace sodium with Potassium?" All one can do is Kackle. μηδείς (talk) 20:34, 13 March 2017 (UTC)
 * Indeed. The problem is that the OP's assumptions are wrong. The extreme demonization of NaCl salt was based on poor science, as with many (most?) other mainstream nutritional recommendations of the past few decades. If you aren't a Yanomamo, you may not have much to fear from salt, and slowly and quietly the mainstream is dumping and qualifying the defective science. Including such now rare populations in studies making recommendations for the vast modern majority descended from people using salt for millennia was one technique of this poor science. That being said, as suggested above, lite salt can be a good idea as it provides both major electrolytes in rough balance. Needs for electrolytes can vary between people and their living conditions. For instance, it is not uncommon that insufficient potassium intake can lead to the body breaking down muscles to obtain potassium, so sufficient potassium can cause instant muscle growth.John Z (talk) 00:52, 14 March 2017 (UTC)
 * I know that Dr. Alderman disagrees, but as pointed out here, he doesn't have good arguments. Count Iblis (talk) 02:06, 14 March 2017 (UTC)


 * There is sodium sensitive hypertension, which can be a serious problem for those who have it. StuRat (talk) 20:40, 15 March 2017 (UTC)
 * As I said, there is a tradition of crappy research and disputes in nutrition. Often one side has had a lock on public opinion, institutional recommendations and research money, while unknown to the general public, disputes continue in serious research. See for instance Intersalt study and references for distortion due to overweighting rare populations. Or from Health effects of salt - "Studies found that excessively low sodium intake, below about three grams of salt per day,[8] is associated with increased mortality[10] and higher risk for cardiovascular disease." As above, it depends on the person and their heredity and their living conditions. What is right for a Yanomano or a Japanese person may not be right for you. Sodium, potassium and magnesium are essential electrolytes. Completely replacing one of them with another is impossible. For reasonable intakes, the effects of excessive intakes are even hypothetically mostly long-term, while insufficient intake can be very dangerous. That's why there is such a thing as Oral rehydration therapy and why athletes drink things like Pedialyte. For instance, if you engage in heavy physical activity in a hot climate, many people (example, myself) may need extra Na, K & Mg.John Z (talk) 04:01, 17 March 2017 (UTC)


 * Note that there are products which replace some of the sodium chloride with potassium chloride. Two that come to mind are Campbell's Healthy Request soups and Low Sodium V8 (beverage).  See Campbell_Soup_Company. StuRat (talk) 04:46, 17 March 2017 (UTC)

Is weight a net force?
A person stands on the scale to measure weight. The person has mass, and the mass of cells push on the scale because of the Earth's gravity. The scale has mass and pushes back. Also, what about the person's arms? Are they included in the weight even though they are attached onto the main body by joints? Would a swing set scale take into account of the person's whole body? 107.77.192.34 (talk) 13:53, 13 March 2017 (UTC)
 * Assuming the person is immobile in an inertial frame of reference (the Earth's surface is not, but it is close enough), Newton's first law applies to all parts of their body. The head is pushed down by gravity but up by the neck reaction which exactly compensates it (excluding negligible buoyancy effects). The neck is pushed down by gravity, down by the head (by exactly as much as it pushes the head up, per Newton's third), and up by the chest reaction that exactly compensates it etc.
 * You can decompose the body in your mind in as many parts as you want, the back of the feet are always pushed down by a force equal to the sum of the weights of all that is above, arms included, by a force equal to the total person's weight.
 * Notice also that the scale need not have mass the scale's mass is irrelevant - it merely needs to be able to provide a reaction force that equilibrates the person's weight (to avoid them falling through). The way the scales work is that the reaction force is measured and converted into a weight (by some mechanism). Tigraan Click here to contact me 15:39, 13 March 2017 (UTC)
 * If you have a scale that has no mass, I'd like to see it. -- Jayron 32 15:41, 13 March 2017 (UTC)
 * How about a mass spectrometer? (oh, wait, I guess that has some in the name nyuk-nyuk. And ... oh, phooey, does a magnetic field necessarily have mass (in terms of there being some energy stored in it), or not? Wnt (talk) 23:20, 13 March 2017 (UTC)
 * How do you generate a magnetic field with no mass? The magnets have mass.  The lenses have mass.  The flight tube has mass.  The electron gun has mass.  -- Jayron 32 01:25, 14 March 2017 (UTC)
 * Amended. Tigraan Click here to contact me 15:54, 13 March 2017 (UTC)
 * In September 2010, we talked on the topic of how measurement really works in physics: "The scale can't actually measure a force - we're really measuring a compression of the spring inside the scale! ...we can simply relate spring force to mass; and we could have a standard spring-scale - so we could actually measure a mass in meters - even though mass is not measured meters!"  All that was in response to a question about why physicists commonly describe mass using electron-volts, which sounds like a unit that ought to be better-suited to describing electricity!  Nimur (talk) 18:58, 13 March 2017 (UTC)
 * Yes, it is determined by the mass of the person and the mass of the earth which is a "net" effect. I believe gravity is better described as a tensor field generated by objects with mass.  --DHeyward (talk) 16:15, 13 March 2017 (UTC)


 * Clarifying the standard terminology: when we say "net force," we mean the sum of multiple forces.
 * When we measure weight for any object that isn't a point particle, we generally just use the total mass of the object and assume it can be well-modeled as a point particle at its center of mass. Weight is simply total mass multiplied by the acceleration due to gravity: typically, the little g constant).  When we use that simplistic model, there's no "summing" of forces, so weight isn't a "net" force.
 * If you wanted to calculate the weight from a stack of point particles that are rigidly attached - and you don't care about the dynamic interactions of those objects, then you can just add up all the individual weights and compute their sum. That would be a net force due to multiple individual masses, and you might choose to ignore any of the complicated details about how they are connected.  As a first step, you might want to consider the net force and the moment arm - the net displacement of the force from the center of mass - so you can determine if the grouping of mass exerts a net weight and a net torque.  This complication is usually one of the first methods taught to aspiring physicists.
 * If the object has a complicated shape, and the weight is supported by more than one point of contact, we could use elaborate and difficult methods from engineering and physics, like rigid body mechanics and D/H parameterization to compute where each element of the force shows up, and how much weight is supported at each point of contact. If you wanted to design a control system for a human, or a bipedal robot, you'd probably have to know how much weight to put on each foot - how much force each muscle needs to exert - else there will be an unbalanced net force and the robot will either jump upward, fall downward, or topple to the side!
 * Nimur (talk) 18:15, 13 March 2017 (UTC)
 * The human probably doesn't have to know. Nature already has done the work. 107.77.193.67 (talk) 22:23, 13 March 2017 (UTC)
 * To maintain balance, those difficult control-equations have to be solved somewhere, even if you're just barely conscious of most of the things that are happening inside of your own nervous system! It's hard to blame you, because a significant amount of that work is done by your spinal cord without ever asking your brain for permission... when it comes to the difficult philosophical problems of sentience, everybody seems to forget about the lowly spinal cord.  It's been doing your most difficult math homework for years, and your brain probably never even really knew it!  Nimur (talk) 23:19, 13 March 2017 (UTC)
 * Isn't the cerebelum technically "doing the math" in this case though? PaleoNeonate (talk) 00:30, 14 March 2017 (UTC)
 * No. -- Jayron 32 03:01, 14 March 2017 (UTC)
 * This somehow reminds me of Sumotori Dreams [[Image:Face-smile.svg|20px]] (example link: ). PaleoNeonate (talk) 20:16, 13 March 2017 (UTC)

Ecological niche of Homo sapiens
1) What is the ecological niche of Homo sapiens?

2) Are they supposed to be fruit eaters and seed spreaders?

3) I have read that avocados were eaten by other animals before becoming human food. Humans bulldoze a lot of trees to make room for farming edibles. And many organisms are made more palatable by selective breeding. How do humans fit in nature?

4) What are they designed to do?

5) How can plants spread their seed when they are tightly controlled by humans? 107.77.193.67 (talk) 22:36, 13 March 2017 (UTC)


 * I added numbers to better answer your Qs. StuRat (talk) 22:40, 13 March 2017 (UTC)


 * 5) "Control" is an interesting question. If an animal or plant we farm spreads because we farm it, are we controlling it, or is it using us ? StuRat (talk) 22:41, 13 March 2017 (UTC)


 * "How can plants spread their seed when they are tightly controlled by humans?". Plants have master the art of manupulating the dumb humans to spread their seeds for them by a very simple trick of making the plant's seed taste yummy for humans. 148.182.26.69 (talk) 22:56, 13 March 2017 (UTC)


 * While not answering everything, I will comment on some of the questions: 3) Not only for farming, but for demand for construction materials, land management and building. You are right that humans are able to keep farming crops, or animals, which may have otherwise become extinct in the wild.  We may also have made some dependent on us over time, which would no longer survive in the wild.  4) That is a tricky question: there was no directed design that we know of (other than various origin myths), but there was adaptation and selection.  Evolution of the brain may possibly answer some of the questions.  PaleoNeonate (talk) 23:10, 13 March 2017 (UTC)
 * I also recommend Anatomically modern human. It may appear contentious, but what humans are doing is part of their nature, even if creating artificial environments and destroying natural ones.  Serious crisis can cause some humans to sometimes go back to an ancestral pre-agricultural hunter-gatherer life if the natural resources for hiding and food are available.  There also have been other circumstances of plants or animals dramaticaly changing their environment, although not necessarily at the same scale.  PaleoNeonate (talk) 23:25, 13 March 2017 (UTC)


 * One answer to question 1 is Apex predator. ←Baseball Bugs What's up, Doc? carrots→ 23:30, 13 March 2017 (UTC)
 * Thanks for this very relevant link. PaleoNeonate (talk) 23:58, 13 March 2017 (UTC)


 * As kind of an aside I should mention with #4 that there is an old discredited idea, the so-called "Aquatic ape hypothesis", which accounts for relative human hairlessness as an adaptation to swimming. The notion that humans were some kind of dugong wannabe does indeed seem far-fetched (especially since polar bears are better at it, with no hair loss) but I think it is striking that in modern national parks humans are sometimes videotaped jumping into mud pits to free trapped animals.  The broad feet of humans also seem like they might be suitable for a little extra advantage in thick mud.  There are places like the Okavango delta that are all mud and standing water for one season, and wildfires to dodge and roast meat to be found from animals that weren't so clever in the other. Wnt (talk) 23:42, 13 March 2017 (UTC)


 * The answer to #4 is "nothing". There is no design to anything in nature, it just happens by chance.  Humans are not designed for anything, from a scientific perspective.  If you want to find purpose in your life, religion may be a valid way to do that for you, but evolution doesn't work by design.  -- Jayron 32 02:21, 14 March 2017 (UTC)
 * We know how evolution works, but it seems a bit silly to say a bombardier beetle isn't designed to hit anything ("it just happens to do it very well"). Hmmm, would you say that a research team that isolates an aptamer to bind a certain protein "designed" it or not? Wnt (talk) 22:12, 14 March 2017 (UTC)
 * The point is that words matter. The bombardier beetle was not designed by anything.  It evolved.  -- Jayron 32 01:29, 15 March 2017 (UTC)


 * Yes, but everyone here knows that, so repeating such a nitpick is just annoying. StuRat (talk) 03:04, 15 March 2017 (UTC)


 * It depends on how you use "designed". Not actively designed by some super-intelligent being, necessarily, but "designed" by random natural forces. Sculpted, as it were. ←Baseball Bugs What's up, Doc? carrots→ 03:18, 15 March 2017 (UTC)
 * A m ore neutral but similar words is "shaped". If you say the beetle was "shaped by natural forces, pressures and interactions", people usually don't complain, and know what you mean. Many of my evolutionary biologist colleagues say things just like that. But when you say a beetle was "designed by natural forces...", that word is unfortunately loaded, and subject to (sometimes willful) misinterpretation, and while many people will know what you mean, others will wonder if you really understand evolution. So it is indeed best to avoid "design" when talking about evolution, unless you're pretty sure you know your audience, and they know you. SemanticMantis (talk) 19:15, 15 March 2017 (UTC)
 * We've got much the same problem with "natural selection". It could imply some conscious action by the forces of nature. In Jurassic Park, the Jeff Goldblum character said about dinosaurs, "nature selected these animals for extinction." Presumably knowing full well that it was just random natural forces, not some deliberate act. But it makes for a good metaphor. ←Baseball Bugs What's up, Doc? carrots→ 23:58, 15 March 2017 (UTC)


 * It is not certain what the original poster really meant by "designed" at 4, so I think that it was still sensible to state the obvious. I also wrote a note on it earlier.  PaleoNeonate (talk) 03:22, 15 March 2017 (UTC)
 * It's pretty clear he was referring to humans. The question also has an agenda, as with other recent IP's who've been asking about vegetables and the like. ←Baseball Bugs What's up, Doc? carrots→ 03:31, 15 March 2017 (UTC)
 * I think there is also an agenda in saying that nothing that evolved can be "designed" or have a "purpose". This is merely atheism masquerading as science.  Scientifically we don't know whether evolution of organisms, like evolution of an aptamer selected by scientists in a lab, had an intended goal or purpose.  There is a widespread religious belief in a "causality" that begins with a few random events in the distant past and proceeds to the present instant without any kind of planning.  But that causality is at most an assumption, and I don't think it's even true.  I think that the proper "causation" of events is more like a Sentience exists, it looks out and perceives a universe, and the universe is ... sculpted ... via the strong anthropic principle or more explicitly religious means to have a past consistent with that first initial cause.  Some of that may be ordinary quantum mechanics, especially in the Copenhagen interpretation.  And that process, whether unconsciously or not, is not merely the creation of logic and mathematics and ideas and natural selection as a tool, but also might require or even specify certain ecological features.  And so the things we see may be random or they may be divine providence and there is no scientific principle I know of to tell us which with any great confidence. Wnt (talk) 13:54, 16 March 2017 (UTC)
 * No intelligent being required for them to form, and no known reliable evidence of any having been found, is indeed very different than everything being useless, or that there were no (at least natural) causes involved. If there's anything intelligent outside the world we know which could have been involved, there are many other new problems to consider, like the reason of suffering, for non-divine interference in the world, the culture-specific aspects and traditions, which are very interesting to study, even scientifically through archeology and other sciences.  It would be right to say that science cannot disprove the existence of the divine, but it also happens that science can only deal with what is evident and palpable, what can be studied and worked with, and is often pushing the divine further away in the gaps of knowledge.  Some people also live spirituality in a way that does not conflict at all with all that science discovered (an example being naturalistic pantheism).  The need for spirituality, personal spiritual experiences and origins of religion can also be increasingly understood by science today, although there is still much more to be learned.  Some proposed that we may live in a simulated universe...  PaleoNeonate (talk) 02:17, 17 March 2017 (UTC)


 * 5)See seed dispersal, e.g. zoochory, myrmechory, frugivory, wind dispersal,ballistic dispersal, and links therein. gene escape and hybridization are also relevant. SemanticMantis (talk) 19:19, 15 March 2017 (UTC)

Black dwarf atmosphere
The black dwarf article mentions that the atmosphere would be very thin, but with a citation needed tag. Considering the high mass of these objects, would it be likely to attract a lot of nearby gas but to also cause it to compact as a solid on the surface? If so, how could any gaseous carbon atmosphere persist? Perhaps that some particular gas could still persist as a thin atmophere? Any relevant source would also be appreciated. Thanks, PaleoNeonate (talk) 23:45, 13 March 2017 (UTC)


 * I can find no sources of any kind discussing the hypothetical atmosphere of a black dwarf, and I also doubt the unsourced statement that the atmosphere would be mostly carbon. Looking at White_dwarf, the precursor to a black dwarf, though it has a mass of mostly carbon and oxygen, will have a primarily hydrogen/helium atmosphere, with heavier elements having sunk to the degenerate interior region due to gravitational separation. I can fathom no reason a hot object could retain this atmosphere for billions of years, but a cold one of the same mass and composition would be expected to lose it. Maybe a black dwarf is expected to lose its atmosphere to space in arbitrary time, but that means time scales matter, and the "carbon atmosphere" is only expected to exist after a certain point of time. Our article also refers to the atmosphere as "thin", but that needs clarification. A white dwarf's atmosphere is "thin" in that it forms a small portion of the star's mass, and is thinner than that of a yellow dwarf, and a black dwarf's atmosphere, being cold, would be thinner still. But what does that mean? So tldr, I can't find any sources on this, and the statement in our article, even if it's true, is too vague to convey any useful information. Someguy1221 (talk) 02:25, 14 March 2017 (UTC)


 * I'll leave the article as-is for now, but it's unfortunate that those claims cannot be reliably sourced or better explained at current time. Thank you very much.  PaleoNeonate (talk) 03:45, 14 March 2017 (UTC)
 * Because a black dwarf is cold, the atmosphere would condense on the surface. If oxygen is in excess then an atmosphere of oxygen and nitrogen and inert gasses may exist like on earth.  But if it is cryogenically cold, it may be more like the atmosphere of Pluto.  It would not be thick due to the high gravitational field about 1,000,000 times Earth's, perhaps 10 cm thick. Graeme Bartlett (talk) 04:45, 14 March 2017 (UTC)


 * Hmm it makes sense, yes. Thanks, PaleoNeonate (talk) 03:17, 15 March 2017 (UTC)


 * From reading the article, the term "black dwarf" is not precise: it's just a white dwarf that has cooled. Two temperatures are mentioned: 5 K and .06 K, and the article states that the universe is nowhere near old enough for any white dwarf to have cooled down to 5 K yet, so there are no black dwarves. If we assume a definition of 5 K, I think that all gases except hydrogen will have condensed. But you can have fun thinking about warmer "almost black" dwarves and compute (guess) what the surface gravity will be, and therefore what gasses would be present. -Arch dude (talk) 04:17, 15 March 2017 (UTC)
 * Exactly. The article tentatively gets there, yet only barely (and so far without sufficient references, unfortunately).  A fascinating topic, though.  PaleoNeonate (talk) 05:30, 15 March 2017 (UTC)


 * This unreferenced section of the article has been cleaned out by Someguy1221 for now, so unless we find a good reference and rewrite it, this issue is now solved. Thanks to all.  PaleoNeonate (talk) 09:16, 15 March 2017 (UTC)


 * The atmosphere is going to be "very thin" (width) in the sense that the scale height is ridiculously small. It is also going to be "very thin" in the sense that at a high multiple of the scale height few atoms will be present, and that at lower multiples any hydrogen present won't be atmosphere but metal or something, eventually electron degenerate matter as you go deep enough.  But it should be very thick in the sense that no matter how much hydrogen you dump on that star the atmosphere shouldn't get any thicker -- the hydrogen should keep condensing to something else as fast as you put it on. Wnt (talk) 14:03, 16 March 2017 (UTC)


 * Kewel! μηδείς (talk) 02:25, 18 March 2017 (UTC)