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View Full Version : Cosmologists' greatest blunder?



JohnMartin
2003-Sep-20, 12:25 AM
Perhaps one day most cosmologists will say that their greatest blunder was believing that the processes involving gravitation relate only to attraction which leads to the conclusion that the universe will eventually collapse if its mass density exceeds a certain amount. However, if one examines what is happening in the universe, especially in view of recent findings, one might be wise to consider other possibilities.

One such possibility is the premise that the more massive that the universe is, the more swiftly it will expand. The universal gravitational constant, G, has the value of 6.67E-11 cubic meters per kilogram per second per second. As applied to the universe as a whole, that constant might mean that 6.67E-11 cubic meters of space is added to the universe per second per second for each kilogram of matter in the universe.

Assuming that the foregoing premise is correct would mean that the mass of the universe is increasing if its rate of increase in volume is increasing. If the mass of the universe is indeed increasing, that increasing mass might originate in accordance with E=mc^2 from electromagnetic radiation that is being redshifted to lower energy levels. Understanding how that can happen might be gained through knowing the nature of one or more forms of nonbaryonic matter. Possibly it is a repository of the lost energy of redshifted radiation.

Most of the above ideas have been covered by me in previous postings.

wedgebert
2003-Sep-20, 01:10 AM
Except that the mass of the universe isn't increasing as that would violate the laws of conservation of matter/energy.

As it stands right now, we have no direct evidence of a repulsive gravitational force. We have possible indirect evidence in the form of the acceleration of expansion, but nothing direct as of yet.

russ_watters
2003-Sep-20, 05:31 AM
Most of the above ideas have been covered by me in previous postings. Here? Under what name?

The thing about assumptions is for some reason people think you can assume anything. You can't. There has to be some basis for it - you can't just pull anything out of thin air and assume it to be true. Your particular assumption violates one of the stronger laws of physics.

beskeptical
2003-Sep-21, 07:40 AM
If volume increases, mass does not increase. Density decreases.

It is an interesting idea though, to look at the Universe from another direction or point of view: The volume of the Universe increasing as a function of time and mass, rather than just as a function of time.

I'm not sure where you would go from there though.

Rich
2003-Sep-21, 03:52 PM
I always just assumed that the volume or "size" of the universe was constant, not expanding. It's simply that all its constituent pieces are shrinking. Space isn't expanding, everything is just getting farther apart because the volume of every particle in the universe is shrinking at an ever increasing rate, thus giving the appearance that any two objects in the universe are getting farther apart.

We just can't notice this "Castanza" affect, as I dub it, because as everything shrinks at the same rate in relation to every other particle subjective or relative size appears to be stable. It is only when compared to the stable volume of the universe that this effect is even noticeable. 8-[

Go ahead, prove me wrong... lol! :P

Cougar
2003-Sep-21, 09:36 PM
I always just assumed that the volume or "size" of the universe was constant, not expanding. It's simply that all its constituent pieces are shrinking. Space isn't expanding, everything is just getting farther apart because the volume of every particle in the universe is shrinking at an ever increasing rate, thus giving the appearance that any two objects in the universe are getting farther apart.... Go ahead, prove me wrong... lol! :P

Sorry, Rich. The math doesn't work out. Suppose two galaxies, each 100,000 LY across, have 1 billion LY of space between them. The galaxies can only shrink so much before they essentially become "points", whereafter they would not get any further apart (since your imagined universe is otherwise static). But from everything we've seen, distant galaxies continue to get farther apart indefinitely. It must be the space between them that's expanding.

Besides, very distant objects are much younger objects, so according to your idea they should be less shrunk, but this is not observed. Very distant objects are observed to have higher redshifts, but they're not observed to be particularly bigger.

kilopi
2003-Sep-21, 11:04 PM
I always just assumed that the volume or "size" of the universe was constant, not expanding. It's simply that all its constituent pieces are shrinking. Space isn't expanding, everything is just getting farther apart because the volume of every particle in the universe is shrinking at an ever increasing rate, thus giving the appearance that any two objects in the universe are getting farther apart.... Go ahead, prove me wrong... lol!
Sorry, Rich. The math doesn't work out. Suppose two galaxies, each 100,000 LY across, have 1 billion LY of space between them.
Are you sure? What if--in the last hundred years--we've been shrinking at a constant rate. Since we'd be smaller than we were a hundred years ago, the relative rate would be greater. Our "yardsticks" would have shrunk (I know mine has), and the distance between galaxies would not only be seen to be increasing, but also accelerating.

beskeptical
2003-Sep-22, 07:55 AM
I can't comment on the math of a shrinking mass universe but things further away would still be older because it's the light from them that took time to get here. So if distances were increasing between all the objects in the Universe because they were shrinking rather than because they were moving away from eachother we would still see more distant objects as they were further back in the past.

But isn't there at least one galaxy in the local group that is blue shifted not red shifted? So how would the shrinking violet model account for that?

Rich
2003-Sep-22, 09:48 AM
I always just assumed that the volume or "size" of the universe was constant, not expanding. It's simply that all its constituent pieces are shrinking. Space isn't expanding, everything is just getting farther apart because the volume of every particle in the universe is shrinking at an ever increasing rate, thus giving the appearance that any two objects in the universe are getting farther apart.... Go ahead, prove me wrong... lol!
Sorry, Rich. The math doesn't work out. Suppose two galaxies, each 100,000 LY across, have 1 billion LY of space between them.
Are you sure? What if--in the last hundred years--we've been shrinking at a constant rate. Since we'd be smaller than we were a hundred years ago, the relative rate would be greater. Our "yardsticks" would have shrunk (I know mine has), and the distance between galaxies would not only be seen to be increasing, but also accelerating. =D>

That's right, everything, including the Planck length, shrinks due to the Castanza effect. And though the Castanza effect causes the distance between objects to increase in a general sense, there is nothing preventing relative motion between objects. So, two shrinking galaxies could still be moving towards one another resulting in a blue shift.

This whole concept came upon me one day and I've been telling it as a total joke... most of my friends don't get it. Still, it's fun to have everyone here parse stuff like this out.

dgruss23
2003-Sep-22, 08:46 PM
beskeptical wrote: But isn't there at least one galaxy in the local group that is blue shifted not red shifted? So how would the shrinking violet model account for that?

There are also a fair number of galaxies in the Virgo cluster with blueshifts.