And lo on Mon, 28 Jul 2008 23:20:44 +0100, andrel  
<a_l### [at] hotmailcom> did spake, saying:

> On 28-Jul-08 23:27, Warp wrote:
>> andrel <a_l### [at] hotmailcom> wrote:
>
> And what exactly does this all prove? I haven't seen anything in those  
> links that I did not know (but I admit I did not read everything) and  
> nothing that even remotely supports your '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.' but I might have missed it.
> Unless you are in a roundabout way referring to the problem that you can  
> not define the 'now' for which you are computing the size.

Imagine standing in a circle of light and all around you is darkness. If  
the light increases in diameter and the floor increases in size (i.e. not  
revealing new areas of floor) and the increase is such that you cannot  
reach the circumference by any means; does the floor you're standing on  
extend beyond the light?

-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

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On Mon, 28 Jul 2008 20:20:59 EDT, "triple_r" <nomail@nomail> wrote:

>moderately large integers, e.g. the sum of the digits in 100!.

Reminds me of how I was quite surprised at the number of unique sorts that can be
obtained from a deck of cards, 52!, or 8.0658175170943878571660636856404e+67.

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On 29-Jul-08 1:26, Warp wrote:
> andrel <a_l### [at] hotmailcom> wrote:
>> And what exactly does this all prove? I haven't seen anything in those 
>> links that I did not know (but I admit I did not read everything) and 
>> nothing that even remotely supports your '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.' but I might have missed it.
> 
>   Uh? I said that the current widely agreed consensus is that the universe
> not only can expand faster than c (which you don't seem to disagree with),

Oh, but I do. Two points may move from one another faster than c, making 
it impossible for one point ever to see the other one. That does not 
imply, however, that the universe itself expands faster that c. I think 
that is also the point that 
http://en.wikipedia.org/wiki/Metric_expansion_of_space is trying to make.

> but most probably has done so (because that would explain many observed
> phenomena). I gave links to wikipedia pages where you could find references
> to more material.

No you gave a website that discusses the 'observable universe' which is 
a totally different beast than the size of the universe at some moment 
in time.

>   Of course there's no absolute *proof* of this. By the very definition
> of cosmological horizon it's *impossible* to have an absolute proof of
> this (ie. that the universe is larger than the observable universe).
> However, currently science most agrees that this is very likely.

What is in the page you referred to seems to me to be a standard 
relativistic approach of the concept of what the observable universe is. 
'Currently' would then seem to mean 50+ years or so.

>   Your way of writing seems to imply something like "you have not given
> me any proof about this, and thus I don't believe you". In other words,
> you still state that the size of the universe is at most the size of
> a sphere with a radius of the age of the universe itmes the speed of
> light (although you don't seem to deny that the universe *can* expand
> faster than c).

I think that the size of the universe (at least from some time, say, a 
million years, after the big bang) is expanding with at most c. I have 
not followed cosmology really closely over the last 20 years or so, so I 
am not really familiar with any recent theories on the early years of 
the universe. Yet, the couple of hundred thousand years that span that 
era are dwarfed by the nearly 14 billion years when normal physics 
applies. What I do know is that I studied special and general relativity 
and some cosmology when I was at the university and that your claim that 
the real size of the universe may be 'staggering larger' than the 
observable universe does not seem to fit what I remember. Although I 
moved to applied physics for my masters, I have still some links with 
the physics and astrophysics community and I tend to think that I would 
have noticed a theory that would imply that.

Please also note that even if someone comes up with a new cosmological 
theory that does not mean that from now on that is the accepted theory. 
Not even when it is reported on discovery channel. Science journalists 
have a habit of suggesting that (and not only for cosmology), but 
science does not work that way.

>   Well, where's your proof? Or any serious references, for that matter.
> At least I gave you *something*.

Yes, a page that was about something else and if anything was 
contradicting your claim. ;)

BTW the concept of the universe having a size at one point in time is 
rather useless, indeed because of relativistic reasons. Observable 
universe is a more useful concept, I grant you that one.

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andrel wrote:
> No you gave a website that discusses the 'observable universe' which is 
> a totally different beast than the size of the universe at some moment 
> in time.

Two fallacies: (1) "observable universe" technically is the same as 
"universe".  (2) "moment in time" is a meaningless term, even for things 
fairly close together, let alone separated in a spacelike way.

In other words, define "universe" first. This gets you into Clinton 
areas, of trying to define what "is" is.

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

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Invisible wrote:
> Does anybody know of a list anywhere that gives examples of really large 
> numbers? 

I don't know about "really big", but here's a start for moderately large.

http://www.kokogiak.com/megapenny/

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

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On 29-Jul-08 22:09, Darren New wrote:
> andrel wrote:
>> No you gave a website that discusses the 'observable universe' which 
>> is a totally different beast than the size of the universe at some 
>> moment in time.
> 
> Two fallacies: (1) "observable universe" technically is the same as 
> "universe".  

why? For many people God is part of this universe, yet not part of the 
observable universe. (I know you did not mean that).

> (2) "moment in time" is a meaningless term, even for things 
> fairly close together, let alone separated in a spacelike way.

yes. I am aware of that. Here informally meant to mean every point in 
space time that has the same value for the time component. So rather 
undefined indeed.

> In other words, define "universe" first. This gets you into Clinton 
> areas, of trying to define what "is" is.

Hmm, I did not know he once tried to define the universe. I know that 
his definition of sex was peculiar, so I assume you refer to that.

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andrel wrote:
> why? For many people God is part of this universe, yet not part of the 
> observable universe. (I know you did not mean that).

Because "universe" means "everything there is". Define "is" in a way 
that includes things that do not and never will have any chance of 
affecting any sort of causality in your observations.

>> (2) "moment in time" is a meaningless term, even for things fairly 
>> close together, let alone separated in a spacelike way.
> 
> yes. I am aware of that. Here informally meant to mean every point in 
> space time that has the same value for the time component. So rather 
> undefined indeed.

It's the informality that kills you, tho. There's no such thing as "the 
same time component". The same point in spacetime has many values for 
the time component. You can have two things that happen "at the same 
time", and I experience A happening before B, and you experience B 
happening before A, and Andrew experiences them both happening at the 
same time. There isn't any universal clock you can use to determine the 
"time component" for a place in space, any more than there's any 
universal clock you can use to determine the Y component of a parabola.

>> In other words, define "universe" first. This gets you into Clinton 
>> areas, of trying to define what "is" is.
> 
> Hmm, I did not know he once tried to define the universe. I know that 
> his definition of sex was peculiar, so I assume you refer to that.

No, I was referring to his arguing over what "is" is. Does something 
completely outside your causality exist? Is there an actual definition 
you could come up with that would make "the universe" bigger than "the 
observable universe"?

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

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andrel <a_l### [at] hotmailcom> wrote:
> What I do know is that I studied special and general relativity 
> and some cosmology when I was at the university and that your claim that 
> the real size of the universe may be 'staggering larger' than the 
> observable universe does not seem to fit what I remember.

  You might find this article interesting:

http://www.sciam.com/article.cfm?id=misconceptions-about-the-2005-03

  A quote:

"Notice that, according to Hubble's law, the universe does not expand
at a single speed. Some galaxies recede from us at 1,000 kilometers
per second, others (those twice as distant) at 2,000 km/s, and so
on. In fact, Hubble's law predicts that galaxies beyond a certain
distance, known as the Hubble distance, recede faster than the speed
of light. For the measured value of the Hubble constant, this distance
is about 14 billion light-years."

  And btw, I didn't say the universe *is* staggeringly larger than the
observable part of it (observable by us, that is). What I said is that
it's perfectly *possible* for it to be enormously larger. We simply have
no physical means of knowing. However, AFAIK, current consensus is that
it's probable that the size of the universe is significantly larger than
the observable part, because that's one good explanation of some observed
phenomena related to the big bang theory.

-- 
                                                          - Warp

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On 29-Jul-08 23:35, Warp wrote:
> andrel <a_l### [at] hotmailcom> wrote:
>> What I do know is that I studied special and general relativity 
>> and some cosmology when I was at the university and that your claim that 
>> the real size of the universe may be 'staggering larger' than the 
>> observable universe does not seem to fit what I remember.
> 
>   You might find this article interesting:
> 
> http://www.sciam.com/article.cfm?id=misconceptions-about-the-2005-03
> 
>   A quote:
> 
> "Notice that, according to Hubble's law, the universe does not expand
> at a single speed. Some galaxies recede from us at 1,000 kilometers
> per second, others (those twice as distant) at 2,000 km/s, and so
> on. In fact, Hubble's law predicts that galaxies beyond a certain
> distance, known as the Hubble distance, recede faster than the speed
> of light. For the measured value of the Hubble constant, this distance
> is about 14 billion light-years."

That is what I said also. So given the time of day, I skip that one for 
tonight.

>   And btw, I didn't say the universe *is* staggeringly larger than the
> observable part of it (observable by us, that is). What I said is that
> it's perfectly *possible* for it to be enormously larger. We simply have
> no physical means of knowing. However, AFAIK, current consensus is that
> it's probable that the size of the universe is significantly larger than
> the observable part, because that's one good explanation of some observed
> phenomena related to the big bang theory.

AFAIK that is not the consensus. I.e. if significant means a couple of 
times. If it means a P<.05 that is probably true.

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On 29-Jul-08 23:26, Darren New wrote:
> andrel wrote:
>> why? For many people God is part of this universe, yet not part of the 
>> observable universe. (I know you did not mean that).
> 
> Because "universe" means "everything there is". Define "is" in a way 
> that includes things that do not and never will have any chance of 
> affecting any sort of causality in your observations.

There may be things that you know existed or must have existed once but 
now are outside of your observation forever.

>>> (2) "moment in time" is a meaningless term, even for things fairly 
>>> close together, let alone separated in a spacelike way.
>>
>> yes. I am aware of that. Here informally meant to mean every point in 
>> space time that has the same value for the time component. So rather 
>> undefined indeed.
> 
> It's the informality that kills you, tho. 

I think I acknowledged that already.

> There's no such thing as "the 
> same time component". The same point in spacetime has many values for 
> the time component. You can have two things that happen "at the same 
> time", and I experience A happening before B, and you experience B 
> happening before A, and Andrew experiences them both happening at the 
> same time. There isn't any universal clock you can use to determine the 
> "time component" for a place in space, any more than there's any 
> universal clock you can use to determine the Y component of a parabola.
> 
>>> In other words, define "universe" first. This gets you into Clinton 
>>> areas, of trying to define what "is" is.
>>
>> Hmm, I did not know he once tried to define the universe. I know that 
>> his definition of sex was peculiar, so I assume you refer to that.
> 
> No, I was referring to his arguing over what "is" is. 

Ok, never heard that one before.

> Does something 
> completely outside your causality exist? Is there an actual definition 
> you could come up with that would make "the universe" bigger than "the 
> observable universe"?

As said, I think you can.

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