On Saturday, January 25, 2020 at 1:51:10 PM UTC-7, Alan Grayson wrote: > > > > On Saturday, January 25, 2020 at 6:23:09 AM UTC-7, John Clark wrote: >> >> On Fri, Jan 24, 2020 at 5:50 PM 'Brent Meeker' Everything List < >> [email protected]> wrote: >> >> >> I would say a infinite amount of information would be needed to >>>> adequately >>> >>> >>> > *Nobody asked about the amount of information. * >>> >> >> Well you certainly didn't ask about it, you ignored information entirely >> and I would say that was the fundamental reason your analysis failed. >> >> >>> * > That's a red herring that LC threw in. * >>> >> >> A red herring?! Lawrence is wise enough to know that if you're >> developing a cosmological model while pretending information does not exist >> then you're heading for trouble. >> >> *> The question was about the expansion and size of the universe.* >>> >> >> No, the question was if the universe was infinite or finite. Yes if the >> position space (aka plain ordinary space) is infinite then it would be safe >> to say the universe is infinite, but that's just one attribute the universe >> can have, there is also momentum space and informational content; if either >> of those was infinite I would say that regardless of whether position space >> was infinite or not it would be misleading at best and dead wrong at worse >> to say the universe was finite. >> >> >>> * > As in my analogy, in a finite universe there are a finite number of >>> intervals of finite distance that can link any two points in the universe. >>> Of course this refers to it being finite at a given time, and you raised >>> the problem of defining what counts as "at the same time". The answer is >>> that it is at the same time if it is at the same degree of >>> expansion...operationally it means that two distant events are "at the same >>> time" if the isotropic temperature of the CMB looks the same to them.* >>> >> >> Even if we ignore Quantum Mechanics any finite level of precision used to >> measure the current position and momentum of those two particles or of the >> temperature of the CMB will soon (very soon because the universe is >> accelerating) prove to be insufficiently precise to predict their future >> position and momentum because phase space keeps getting larger at an >> accelerating rate. The fundamental reason you can't make a good prediction >> is you don't have enough information, an infinite amount is required and >> you don't have that. >> >> John K Clark >> > > I don't think coordinate arguments will solve your problem. Suppose we > have an observer at the origin of a one-dimensional space. If you consider > a 1 meter line starting at the origin and increasing in length at an > accelerating rate at its end point, then obviously, at any observer time t, > the length of the line is finite and can be easily calculated. Now consider > an expanding 4 dimensional space-time continuum. For any observer, and > therefore for all observers, the volume of this space is obviously finite > regardless of how fast it's expanding. So it's conceptually easy to > distinguish finite from infinite volume when comparing an expanding > hyper-sphere (finite) from an expanding plane (infinite). Your doubt seems > to depend on the inability of observers to make the measurements when, due > to expansion, both geometries have non-observable regions. So, does the > distinction between finite and infinite volumes really depend upon what > observers can measure? IMO, this is where the rubber hits the road. AG >
You keep referring to *accelerating* expansion. I explained several times that acceleration has nothing to do with this issue. A constant rate of expansion will ALSO create non-observable regions. Do you accept this or not; and if not, why? AG -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/e3a70c1c-81dc-4a19-a228-c8ab40640827%40googlegroups.com.
