Darren New wrote:
> Possibly something to do with renormalization in the QM 

To be a little more clear:

The way you calculate if particle P goes from place X to place Y is to 
calculate first the probability of oging there directly, then the 
probability of going there by going X->A->Y, then X->A->B->Y, then 
X->A->B->C->Y, for all possible A, B, C, etc.

In QED (quantum mechanics of photons and electrons), the -> bit multiplies 
by a rather small number, so the infinite summation comes to a total pretty 
fast, so you don't have to do too many before you get numbers that match 
experiements.

In QCD (quantum mechanics of nuclear reactions), the -> bit multiplies by a 
much larger number, so you have to trace out the possibilities eight or ten 
deep to get decent numbers.

In either case, you really have to add up an infinite number of 
possibilities (including where B is a spacelike distance from both X and Y) 
to get the 100% correct answer, but the formula diverges. If you stop at any 
given distance, then divide the result by that length (for some meaning of 
the word "divide"), you get the answer that agrees with experiment. (That 
step is "renormalization".)

So it *seems* like there's a lower limit to the number of times you can 
divide a space up and come up with the right numbers in QM. And the 
mathematics of GR are (I'm led to believe) don't work without continuous 
differentiability.  So ... there ya go.

-- 
   Darren New, San Diego CA, USA (PST)
   Why is there a chainsaw in DOOM?
   There aren't any trees on Mars.

Post a reply to this message