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

Rich wrote:
> Robi replied:
>> 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!
> 
> SSSSSSSSSssssssCCCCCCCccccccccRRRRRRRrrrrrrrEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
> EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
> EEEEEEEEEEEEEeeeeeeeeeeeeeeeeeeeeeeCCCCCCccccccccccccHHHHHHHHHhhhhhhhhhhhhhhhh.

nice brakes ;o)

>> replace "never happens" with "doesn't happen yet"
> No, it will never happen.

I'll leave that for the future ;o)

>>>Rather than
>>>showing an infinity, you've shown something that can never happen. Your
>>>singularity can never happen.
>> 
>> again, "doesn't happen yet"
> 
> What do you think the work "infinite" in 'an infinite amount of time' means?

'infinite amount of time' in "real life" translates to 'as much time as you want/need'
IOW, I'll finish it, even if it takes forever. Ok, this example proves that it will
never be finished, but then again, with some patience it will eventually be finished.

>>>>> 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.
> 
> If it's a number it is not infinite.

what is an "infinite amount"?
I'll give you an infinite amount of guesses to find out what number I am thinking of.

>>>>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 division by zero is an undefined operation.
> 
>> because you have an infinite "number" of results ;o)
> 
> Rather any result is as good as any other.

and that's why some claim it undefined.

>>>>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 :)
> 
> I'll give you an infinite amount of time.

thank you, I was hoping for that ;o)
but trust me, it won't take forever...
But from the reply, you're giving me as much as I need?

-- 
Robi