On 18 October 2014 00:35, Richard Ruquist <[email protected]> wrote: > On Fri, Oct 17, 2014 at 2:17 AM, John Clark <[email protected]> wrote: > >> On Thu, Oct 16, 2014 at 5:18 PM, LizR <[email protected]> wrote: >> >>> >>> > there was no one around in the big bang that we know of, yet it would >>> appear any maths that might be involved in physical processes managed to >>> work OK. >>> >> >> Yes, but to math make the Big Bang or did the Big Bang make the math? I >> don't know and I'm not going to pretend that I do. >> >> > By the way, what is the "recent discovery that information is physical"? >>> >> >> 1961 is pretty recent and in that year Landauer discovered that the >> absolute minimum energy it takes to erase one bit of information is >> ln(2)kT , k is Boltzmann's constant 1.381 X10^-23 J/K, and T is the >> temperature of the computer in degrees Kelvin. In 1972 Bekenstein >> discovered that the maximum amount of information you can put inside a >> sphere is proportional not to it's volume as you might expect but to it's >> surface area, and it's 2PI*R*E/h*c*ln2 where R is the radius of the sphere, >> E is the mass-energy inside the sphere h is Planck's constant and c is the >> speed of light. >> > > Here is something I do not understand. The Bekenstein formula for max > information is proportional to the radius of the sphere and not its area. > Only when you put in a black-hole's mass-energy dependence on the radius of > the event horizon does one get a dependence on surface area of the event > horizon. For example the information content of a spherical volume of > vacuum would appear to contain at most zero information. Is this correct? >
I thought the BB was proportional to the surface area of the sphere, and identical to the entropy of a back hole of that size? Or something similar. A spherical volume of vacuum presumably contains quantum foam, which may have a structure. I suppose one could also say it contains a few bits of information specifying the laws of physics (although that is true regardless of the size and contents of the sphere). -- 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 post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
