Roger, I'm sorry but I think you're completely wrong. I know nothing about primes, and only a little about the Universe. But, let me suggest, you're not even within 0.000...0001% of the right answer.
If you're assessing the maximum capacity of our Universe, I defer to your calculations regarding volume, acknowledging that this is something we can speak of loosely, but always, nervously, contemplating GR over our shoulder. However, once the volume is established, I suggest that the Bohr atom is not a good choice. If the Universe ever gets anything like full there will not be atoms around. Gravitation will have squeezed everything down to nuclei. There will be something like a sea of particles, some will be recognizable as nuclei (of hydrogen, helium, ... iron etc), but much may just be a mush of protons, neutrons and electrons. As far as I can follow, the process could lead further: for example, a sea of quarks, or string soup. From my reading, those that study these things are contemplating matter in its ground quantum state. Things don't get much denser than that. So, even by the most relaxed estimate, I suggest that you're out by about a factor of 2000^3 (the cube of ratio of the diameter of the Bohr Hydrogen atom to the size of its nucleus). For a man of science, Roger, I think you have badly underestimated here. But, of course, you'll probably start arguing that a completely dense Universe has lost its capacity to store information. On that question, I defer to Mr. Hawking. Mike Powell On 24-Apr-09, at 4:00 PM, Roger Hui wrote: > These types of "back-of-the-envelope" calculations > http://en.wikipedia.org/wiki/Fermi_problem > keeps the old ticker sharp, and helps in detecting > egregiously erroneous statements like grains of rice > on a chessboard (2^n grains on square n) covering > the earth to great depth, http://keiapl.org/anec/#rice > or 2^60 being larger than the # particles in the universe. > http://preview.tinyurl.com/cunwsm > > For example, having done the calculation > (which I probably could have done in my head), > I know that the number of particles in the universe > is not 10^1000. > > > > ----- Original Message ----- > From: Jonathan Lettvin <[email protected]> > Date: Friday, April 24, 2009 10:42 > Subject: Re: [Jprogramming] table of primes to 1,000,000,000 or more > To: Programming forum <[email protected]> > >> I guess my sense of humor is too dry. >> I know the godaddy server idea is useless. >> But then, calculating a universe >> hexagonal close-packed with Hydrogen >> struck me as being a bit overboard too. >> Just thought I would join in the fun. >> >> On Fri, Apr 24, 2009 at 12:44 PM, Zsbán Ambrus >> <[email protected]> wrote: >> >>> On Fri, Apr 24, 2009 at 6:40 PM, Zsbán Ambrus >> <[email protected]> wrote: >>>> The point is, an average home computer can easily test the >> primality> > of any one really huge number in a few moments (and >> does too when >>>> doing public-key cryptography), >>> ... >>>> The same is true for factorization, >>> >>> I'm being a bit imprecise here though, because while a usual home >>> computer does do primality tests for public-key cryptography, >> I do now >>> think it performs prime factorizatoin often. >>> >>> Ambrus > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
