I disagree. I think my statements, that number (of hydrogen atoms) is bounded by 10^100, and that the number of particles is not 10^1000 (much less than 10^1000), are more correct than yours, that I am "you're not even within 0.000...0001% of the right answer", implying that that numbers are much larger.
Anyway, this is no longer on topic about J programming, and I will say no more. ----- Original Message ----- From: Mike Powell <[email protected]> Date: Friday, April 24, 2009 19:05 Subject: Re: [Jprogramming] table of primes to 1,000,000,000 or more To: Programming forum <[email protected]> > 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
