Re: Infinities in Physics: was-> Re: OT: Universe Born in Black Hole Explosion?

Rich wrote:
> Alfred A. Aburto Jr. replied:
>>> Rich wrote:
[...]
>>> As the gravitational field strength increases, time slows. It will literally
>>>take forever for gravitational collapse to result in a singularity (if in
>>>fact this is what happens).
>> 
>> Isn't "forever" infinity?
> 
> This is not an infinity in nature Alfred. Let me translate it for you,
> if something takes infinite time to happen, it never happens.

stop! stop right there!
replace "never happens" with "doesn't happen yet"

> Rather than
> showing an infinity, you've shown something that can never happen. Your
> singularity can never happen.

again, "doesn't happen yet"

>>>So you may have a black hole, and there are many candidates, but you cannot
>>>show that any have yet collapsed into a singularity.

>> Yes, that is the point of infinities ... you'll never see it ... you'll
>> never get there ...
> 
> You'll never get 'where'? You still refer to infinity as if it were a
> number.

It is the concept of inmensely large numbers, therefore pick a number in
infinity ;o) - it will be an infinite number.

>> even when 1/r = 10^(100000) you are still a long ways from infinity ...
> 
> And when r=0, the equation becomes undefined, rather than infinite.

and that is why? because you have an infinite "number" of results ;o)

>> But often in physics when one, conceptually, mathematically, takes something
>> to the limit (let "n" go to infinity say in a series expansion) then there
>> is a residue left that is observable and measurable.
> 
> Methinks you've fallen for Zeno's paradox and confused limits for time.
> 
> http://www.mathacademy.com/pr/prime/articles/zeno_tort/index.asp


I'll read into this later :)



-- 
Robi
(2.9#@ 2.75 yrs)