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Author | Topic: Stars and a 6000 year old universe. | |||||||||||||||||||||||
PaulK Member Posts: 17826 Joined: Member Rating: 2.3 |
quote: Without additional hypotheses YEC precludes us SEEING stars that are more distant. If the universe is 6000 years old we could not see light from stars more than 6000 light-years away - unless some other factor is involved.
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
Sure, they bring out many scenarios. One that's been popular here is that before the fall, light was faster, near instantaneous. Then, at the fall, it slowed down.
Another popular idea is that light was created in transit. Even though the star is further away than 6000 light years, the light traveled a shorter distance since it originated at a distance appropriate to reach the earth at the right time. The question I have regarding either of those scenarios concerns the photon after the Fall. It would seem that the first photon after the Fall would be one just as those we currently see, limited to the speed of light. Wouldn't that mean that at the moment of the Fall, all the stars would wink out of view, only to gradually reapear in the skies as the first of the normal photons reach the earth? If so, there are no records of such events, and we do know that ancient civilizations kept pretty good records. It's likely they would notice that new stars showed up every night. Aslan is not a Tame Lion
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Chiroptera Inactive Member |
I also fail to see the need for faster-that-light light. (Or whatever I mean.)
Why would there be a problem with the creator just creating the universe as it is, without the theatrics of changing laws of physics? Why shouldn't the first distant star, Proxima Centauri, become visible to Adam a little over 4 years after the creation week? And then further stars gradually come into view as enough time passed for the light to have finally arrived. Just think about it -- if the allegedly omnipotent creator just creator the universe all at once, without speed-of-light gimmicks or radioactive-decay-rate nonsense, all of the obvious evidence that would then exist that the universe was no more than 6000 years old. Imagine if all the stars we see are only withing 6000 light years. And all the stars in the star catalogues compiled 1000 years ago were all within 5000 light years of the earth. And a clear record of new stars coming into view, consistent with the light from more distant stars finally reaching the earth, continuing even now. It would appear that this allegedly omnipotent creator, instead of leaving us some clear proof that the universe is only 6000 years old, bungled the job so bad that he makes it appear that the universe is about 13 billion years old, complete with nearly isotopic cosmic background microwave radiation.
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
Imagine if all the stars we see are only withing 6000 light years. And all the stars in the star catalogues compiled 1000 years ago were all within 5000 light years of the earth. And a clear record of new stars coming into view, consistent with the light from more distant stars finally reaching the earth, continuing even now. Okay, very close to the question in the OP, Currently there are something over a billion objects catalogued. If all of those objects are actually within a radius of 6000 light years, what can we say about them, and about our knowledge of stars? Aslan is not a Tame Lion
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Chiroptera Inactive Member |
Hi, jar.
I did a quick calculation yesterday when I first read the OP. There are about 100 bilion stars in our own galaxy, and about 100 billion known galaxies. If all that were crammed into a sphere 6000 light years across, that would be not quite 100 billion stars in a cubic light year. That is, each cubic lightyear, on average, would contain an entire galaxy. Certainly not likely. If all those objects were within 6000 light years away, then all of astronomy (and physics!) would be way, way wrong. I suppose we would have to start considering the possibility that the stars and galaxies are actually lanterns attached to a large dome (or sphere, I guess) of some finite (if huge) size.
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
To fit such a large number of shining objects (and can we demonstarate that they are shining by their own light and not just reflecting other light), what would the actual physical size of a body be?
Aslan is not a Tame Lion
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Chiroptera Inactive Member |
Well, I just did a quick google search, and it appears that the core of our own galaxy has a density of about 10 million stars per cubic parsec. Already, even at that relatively low density, we see signs of some very energetic phenomena occuring, although that may be the end result of 10 billion years of evolution at this high density. Perhaps if the creator really did create all the stars only 6000 years ago it would be possible for them all to exist within a 6000 light year radius sphere without having yet formed a super massive black hole.
However, many of these stars are pretty effing big and bright. Note that most of the galaxies are too distant to be seen with the unaided eye -- I would expect that if all those stars really were packed into a density of 100 billion stars per cubic light year the night sky would be fairly bright -- at least if the stars were evenly distributed, so that 100 billion stars were packed in the cubic lightyear that surrounds us! My main concern, though, would be obvious gravitational interactions. We should see signs that the galaxies are attracting each other. And noting the intergalactic interactions with clusters of galaxies, which are pretty far apart, can be clearly observed, the lack of obvious graviational interactions between most of the galaxies that we see would seem to show that they are indeed very far apart. Unless they were not massive suns as we understand them. I'm not sure how to answer your question. The color of the stars can be measured -- that gives some indication as to their surface temperature. Now, assuming black body radiation (which should be good to an order of magnitude) this would tell us the brightness per surface area of the star. If we assume that these stars are closer than 6000 light years, this would indeed put contraints on the size of the star. A rough calculation: the brightness we see (assuming a point source) is proportional to the surface area and inversely proportional to the the square of the distance. Since the surface area is (roughly) proportional to the radius of the sphere, that means that a given star's radius is proportional to its distance (very rough estimate). So, take a sun-like star in the Andromeda Galaxy, about, 2 million light years away. If it were only 2000 light years away, that would reduce its actual radius by a factor 1000 -- if we previously assumed that this star is like the sun, with a radius of about 700,000 km, this would mean its actual radius is about 700 km. And of course a "sun-like" star in a galaxy 1 billion light-years away would only be a few tens or hundreds of meters across. And to prevent observable gravitational interactions, their masses would have to be very small, too. It would be an interesting question as to what would be maintaining the surface temperatures that we see! Maybe they are really just very large LEDs? Is this the sort of answer you were looking for, jar?
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
Getting very close. Sure moving in the right direction.
Something with the size and mass of Jupiter does not form a star. Is that correct? Would that set a lower limit on the size? Aslan is not a Tame Lion
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Chiroptera Inactive Member |
Well, it appears that we have two problems here.
For a star to shine with a certain surface temperature due to nuclear fusions would, indeed, require a minimum size. Certainly larger than Jupiter. For any of these stars to be within 6000 light years and exhibit the colors that they do would imply a certain maximum size, which, if my rought calculations are to be believe, smaller than the above minimum size. It would appear that all of these stars being within 6000 light years away would imply that the stars do not shine according to the currently accepted solar-nuclear-fusion model.
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
It would appear that all of these stars being within 6000 light years away would imply that the stars do not shine according to the currently accepted solar-nuclear-fusion model. Very good. So the next step I'd like to explore is "Is there some alternative mechanism, some alternative method that will allow the small size and observed luminosity?" Aslan is not a Tame Lion
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Chiroptera Inactive Member |
Not that I am aware of.
Burning doesn't work -- not only can I not see objects this small burning consistently for the hundreds and thousands of years that we have been observing them, but the composition of their atmospheres can be determined through spectroscopy, and we see mainly hydrogen and helium -- nothing indicative of combustion. Gravitational collapse would not work for these small objects, either. They could have been created very, very hot, but objects this small would have cooled off a long time ago. So, I can't think of any reasonable explanation for objects this small (and close) to be shining so hot and so consistently. (This is, of course, ignoring that models based on large bodies of hydrogen shining through nuclear fusion predicts the distribution of stars that we actually do see, as well as many of their observed characteristics, but I am assuming that we are attempting to do "creation science" here.)
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jar Member (Idle past 420 days) Posts: 34026 From: Texas!! Joined: |
just in case someone might have some idea of how the stars we can see might fit in a 6000 year old universe.
Aslan is not a Tame Lion |
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Maxwell's Demon Member (Idle past 6255 days) Posts: 59 From: Stockholm, Sweden Joined: |
jar writes: Another popular idea is that light was created in transit. Even though the star is further away than 6000 light years, the light traveled a shorter distance since it originated at a distance appropriate to reach the earth at the right time. This, of course, would have some rather silly consequences.Consider for instance the 1987A Supernova, more than 150,000 light years away (if I remember it correctly). If light was indeed created in transit some 6000 years ago, it would mean that God created light in transit showing us events (for instance this supernova) that have never actually happened. So if someone wanted to use this in defense of your 6000 light years large sphere argument (the stars aren't actually within the spheres, light was simply created in transit) they'd still have some 'splainin' to do.
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