On 12/19/2012 11:58 AM, Richard Ruquist wrote:

On Wed, Dec 19, 2012 at 2:30 PM, meekerdb<meeke...@verizon.net> wrote:On 12/19/2012 8:34 AM, Roger Clough wrote: Hi meekerdb and Stephen, If information is stored in quantum form, I can't see why the number of particles in the universe can be a limiting fsactor. Information has to be instantiated in matter (unless you're a Platonist like Bruno). No particles, no excited field modes -> no information. Also there are ways of storing information holographically, so size gets a bit ambiguous. The holographic principle says that the information that can be instantiated in spherical must be less than the area of the bounding surface in Planck units. So there's a definite bound. If we looks at the average information density in the universe (which is dominated by low energy photons from the CMB) and ask at what radius does the spherical volume times the density equal the holographic limit for that volume based on the surface area we find it is on the order of the Hubble radius, i.e. the radius at which things are receding at light speed. This suggests the expansion rate of the universe and and gravity are entropic phenomena. BrentBrent, Perhaps you or somebody can help me out. I always believed that the Hubble radius was much larger than the age of the universe times the speed of light. To my surprise the Wiki-Hubble Volume says that the age is 13,7 Byrs as expected , but that the Hubble radius divided by the speed of light is 13.9 Byrs, which is rather close.

`They would be the same except that the expansion rate has not been constant (it has been`

`slightly increasing).`

Does that mean that in 200 Myrs (minus 380,000 years) the Cosmic Microwave Background will disappear outside the Hubble bubble and that 400 Myrs later the now detected light from the first stars will also disappear, even though the universe right now is many times larger than 13.7 billion light-years?

`I don't understand the significance of 200Myrs? The CMB isn't going to disappear, ever.`

`It's just going to be more and more redshifted by the expansion of the universe. There's`

`an excellent tutorial on these questions by Ned Wright at UCLA`

http://www.astro.ucla.edu/~wright/cosmo_03.htm

And if information can be instantaneous as has been suggested here, shouldn't we use the present size of the universe holographically. I think that's where the Penrose limit of 10^124 comes from whereas the Lloyd limit of 10^120 is based on the age of the universe.

I don't know where 10^124 comes from, but 10^120 is what I get for the holographic limit. Brent -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.