How big are the stars?

I'm glad that you feel you imagine that you roughly know. So what gravitatational effect do we observe that tells us that a star light years away is big? Not that you don't have an answer, but I think it's a valid question. After all, atoms go around don't they? What exactly is the effect that tells us it's mass. Now luminance is kind of interesting, don't we have to presume a fair amount to arrive at this? Is it possible there could be another explanation?

Gravitational lensing, for one thing. Gravity bends light. When a massive object bends light, we can tell how massive it is by how much the light is bent. I don't understand what you mean by this. Only that the laws of physics are the same wherever you go. Do you have reason to believe that they're not?

I've reformatted your quoted text to make it a bit more readable. Hit the edit button on this post to look at how I added formatting. You won't actually be able to edit, but this is an easy way to see how others used the available tags.If there was enough truth in it then it would be relevant, yes. You gave the problem in your original extract when you called this second link "Art Bell like". That is a good description, and so I did not bother to comment further on that link; I thought you had recognized that it was obviously ridiculous.The first link was sensible, and did not mention anything about speed of light. This is not evidence for a changing speed of light, not remotely.As I said previously, this is about the Pioneer 10 apparent anomalous acceleration; also detected in other craft though with less confidence. I looked into this a couple of years ago in sci.astro. It is an unresolved puzzle, with a number of solutions proposed, none of which is completely satisfactory. It is a genuine puzzle. Your first link gave a fair summary.When there is a genuine and interesting question arising in science, the cranks are always there to point how that their remarkable new physics will solve the problems. That is your second link, quoted above.The association with the speed of light given in the quoted text is nonsense. The papers by John Anderson (mentioned in the article you are quoting) consider many possible solutions, including some which are really outlandish. But speed of light variation is not even raised. It is merely ridiculous. It fails as an explanation because the same anomaly is not observed in other planets. A credible explanation has to explain why the anomalous apparent accleration is seen only in the probes.People familiar with the name Lambert Dolphin may grimace sadly and draw a curtain over the corpse. If the name Dolphin is not familiar to you, you may have heard of Richard Hoagland, whose website you are citing. Art Bell like is being generous; this stuff belongs in National Enquirer next to "Elvis clones from space abducted my baby!", or "Martian artifacts revealed in images from NASA landers!". In fact, that last one is apparently is one of Hoagland's latest notions. Yes, we would know it. Basically, science never proves anything, but we do manage to learn things all the same. We have models which help us understand the material world: quantum mechanics, relativity, physics generally. These models are not based on faith, but on stringent testing. The models may be refined and extended as we make more and better observations; but always it is driven by the empirical world; not a faith based revelation or assumption. We can see and measure nuclear reactions going on in stars at immense distances, and they show the same fundmantal laws of physics in operation. This is enough to make inferences about what we see.If you don't like this method, why worry about "size"? The stars might not be stars at all, but small holes in large crystal domes in the sky, letting in light from a primal fire. Hoagland and Dolphin are much more fun; but the link I gave you is an introduction to how science builds and tests models. You can call it "faith" if you like; I think that is misuse of the word. The FAQ I cited goes into a fair bit of detail as to how the various models are tested.Cheers -- Sylas

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don't we have to presume a fair amount to arrive at this? Is it possible there could be another explanation?

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It is always possible to find another explanation, but you touch on something quite relevant.We have to presume something to make sense of any observation. We presume that there is indeed a person on the other end of a telephone line, and often we presume it is a specific person. We could presume it was a very intelligent machine that just emulated our grandmothers voice - just by talking on the phone we could not tell the difference!But in science - as in out daily lives - we try to use the law of parcimony - or Ockhams Razor404: This page could not be foundOnce it was thought that the earth was the center of the universe. When the study of the sky reached a level that was advanced enough, it was found that the observations did not conform to the theory.The planets did not appear to move arounf the earth in perfect circles, actually ome of them appeared to move in the wrong direction at times. Now some people amended the theory, by assuming that the planet moved in perfect circles round the earth, but their movement included a second movement in which the planet moved in a perfect circle around it self. The center of this circle moved in a perfect circle round the earth. By adding this assumption the observations were once more explained by the theory.But alas each heavenly body seemed to move by different principles. To salvage the theory one would need a new explanation for each object, but with such an explanation, the theory still explained the observations.Now we like to think today that the earth moves around the sun, the sun around the galactic center etc..Newton, Keppler and Einstein are a few of the well known people who has developed the theory we now use to explain and predict the movement of heavenly bodies. We presume that the theory holds not only on earth, or in our solar system, but also throughout our galaxy, and through the universe.By doing this we have a simple (as such) theory, explaining all of our observations.Now we do not know that this is true. It might be possible to amend the old theory with the earth being the center of the universe to explain all of our observations, but such an explanation would have to be amended with each new observation.This is why we so couragously use our presumptions about the laws of nature to make conclusions. We have a strong theoretical foundation, to assume that the speed og light or the gravtational forces should be very different in the far reaches of the universe - without founding these assumptions on observations - would be folly.So to get back to the point. Yes we have to presume a fair amount to reach these conclusions, but we try to presume as little as possible. To presume that the stars we see far away work by different principles than our own star, would be an added presumption, which would have to be founded on something.What you often see with the YEC crowd is that they add presumption on thegrounds of what they want to conclude. Eg that the speed of light was a million times faster earlier in history, or that the evolution rate has been quicker in the past to allow the millions of species we see today to have evolved since the ark.There is no problem in considering a conclusion and trying to find the mechanisms to support this conclusion, but if you cannot support the mechanism then it is just so much hot air!Cheers
/Sren

In addition to the distance ladder already mentioned, there was one unique star at a distance of 169,000 light years; Supernova 1987A, often referred to as SN1987A. When this star exploded it produced a ring of gas, and through a lucky concatenation of circumstances we can measure the distance to the supernova using just basic high school trigonometry. What's even cooler is that the distance would be the same even if the speed of light had changed!. See The Age of the Universe and SN1987A and SN1987A and The Antiquity of the Universe (by a former young-earth creationist).

And thus, it would produce the effect we see. Alright, so then this glimmering, or bending as it seems to be interpreted, or perhaps I could say twinkling-could not even possibly be something totally different? No other theoretical explanation exists, or could exist? On earth of course, we may see a candle burning a mile away, and flicker, because of some wind perhaps, or some reflective effect, etc. But for something far away to 'flicker' I guess there could not be another explanation. Now if the object was actually very small, would the amount of observed bent light appear different from our perspective? well they are small, and to an untrained mind, seem to behave somewhat like larger spheres, in that they go around like an orbit. So, if we stuck a much reduced "solar system" out there, and we assumed it was real far away, could we get a picture that was off? (Now remember, the line of questions is to illicit your explanations more than propose a theory of some kind)
"You do not really understand something unless you can explain it to your grandmother." - Albert Einstein (1879-1955) Well, if there is a metaphsical or spiritual aspect to the universe, then I could see where not everything would respond to the way we think things should work from our tiny perspective.
"Thinking is a momentary dismissal of irrelevancies."
Source: Utopia or Oblivion: The Prospects of Humanity (1969)

Crashfrog,You never should have mentioned lensing. Arkathon now how some serious confusions going on in his head now. Lensing doesn't measure the mass of the lensed object but the lens which is (in microlensing) invisible.Arkathon,I could tell right away from your questions you were trying to get just enough info to cry foul and then trot out some YEC type nonsense. This is why I gave you a list of things to check out. Having said that I think you probably need some high school physics first and then an intro to astronomy.Forget the lensing thing and twinkling is caused by the turbulence in the Earth's atmosphere - stars don't really twinkle.

Atoms are not tiny little BB's the classic model of electrons circling a atom nucleus is no more. The current model I believe is that the electrons are more like a 'cloud' surrounding the atom's nucleus. Although Its been years since I have read about this subject matter and a new model is possible.

why? Good answer. So the planets are moving in the same direction, and we should see the same effects, despite the difference in size? So then if we accept that all forces everywhere act according to our 'empirical world' is that not somewhat of an assumption? This seems to indicate we pretty well know it all, and in all the dimensions anywhere, things that we are limited by, like time, must bind and apply equally. And we are certain in every instance that it is nuclear reactions we are observing, that are producing the effect we see? Would there be any point where the 'cosmic ladder' is relied on heavily to give us the distance and size of the star, and could be way off? So deductions about what we see are made based on perceived reactions, based on empiracal knowledge, all based on the cosmic ladder distances, which in turn tell us the size. Is this basically how it works?
"Synergy is the only word in our language that means behavior of whole systems unpredicted by the separately observed behaviors of any of the system’s separate parts or any subassembly of the system’s parts. There is nothing in the chemistry of a toenail that predicts the existence of a human being." Buckminster Fuller I think that the cosmic ladder to God may be a few rungs short. But it is a good compilation of man's limited knowledge so far.

I still think so, after all, God is moving here Himself soon. So far I haven't assumed that, any more than assuming they may have some real differences. Fine, then I will be impressed by your possible support of your mechanisms.
" The difference between mind and brain is that brain deals only with memorized, subjective, special-case experiences and objective experiments, while mind extracts and employs the generalized principles and integrates and interrelates their effective employment. Brain deals exclusively with the physical, and mind exclusively with the metaphysical." Buckminster Fuller{edited by AdminTL to fix coding--I also put some extra lines (returns) in there so you could see how much nicer it looks.}[This message has been edited by AdminTL, 02-25-2004]

So then they are kind of more like galaxies, or nova etc, than like little solar systems?

No, but for billions of people they do twinkle. They even made a song about it. It goes to show, though, that billions of people's preconceived ideas needed an adjustment. (just trying to make sure it doesn't 'die of improvements') As far as the lensing thing I can forget it if it's not all that important.

They are not at all remotely like anything with which we have direct experience. They are not anything like solar systems, they are not anything like galaxies, they are not anything like novae, they are not like anything you have ever seen or heard of ... except atoms. They are atoms and there's nothing else that's like them. It's useless to say "atroms are like ..." because there's only one thing you can put at the end of that sentence without being wildly wrong: "atoms". Atoms are like atoms.The "clouds" that have been referred to are not physical clouds and are not really anything physical at all. They are graphs of the probability of finding an electron in a particular place if you were to look at that place for the electron.

Sorry, finger stuttered: double post.[This message has been edited by JonF, 02-24-2004]

I guess our experience or empirical world is somewhat limited. Kind of makes you wonder in this big known universe, if there may be other things 'not at all remotely like anything with which we have direct experience', and which could even be misunderstood.
"When the solution is simple, God is answering." - Albert Einstein (1879-1955)