>> Well, the number of grains of sand on the entire English coastline is 
>> "obviously" a pretty damned big number. And the number of subatomic 
>> particles in the universe is equally obviously *very* much larger.
> 
>   The funny thing about the amount of particles in the universe is that,
> if current theories are right, there's no way of knowing how big the
> universe is and how much material there is. There's a thing called
> cosmological horizon which makes it completely impossible for us to
> observe the entire universe, no matter what the means.
> 
>   That's where the term "observable universe" comes from: It's everything
> inside the cosmological horizon, which is at least in theory possible to
> be observed.
> 
>   The real size of the universe is completely impossible to know. It
> could be just slightly larger than the observable universe, or it could
> be staggeringly larger. There's just no way of knowing.

Well, when people say "number of atoms in the universe", they usually 
mean "number of atoms in the *observable* universe" - since, as you 
point out, the true size of the *entire* universe can never be known to 
mankind.

However, even this (much?) smaller number cannot really be known with 
much accuracy. One has to make assumptions about Dark Matter and Dark 
Energy and so on and so forth. So it's really a wildly approximate estimate.

Even so, if you do a calculation and it says that the amount of storage 
required comes anywhere near to our "estimated" number of particles in 
the visible universe... you *know* you aren't going to find a computer 
anywhere that can run this algorithm. (!)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message