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Argos
2002-Apr-05, 05:04 PM
Although it may sound silly, I can’t refrain from telling the Bad Comrades a thing.

The topology of the space-time continuum looks weird for most of us (I humbly suppose). Days ago, the son of a friend, knowing that I am the strange guy who talks about things like cosmology and relativity at weekend parties, came to me with a lovely question: where exactly did the Big bang happen?

I was astounded (though happy) to hear such question from a 10-year youngster. Another soul presenting to me to be saved by the light of science. The years spent under the dew in cold nights trying to understand the universe were worthwhile at last! And I had a hard time trying to explain those bright and inquisitive eyes the secrets of the cosmos. For a moment I feared being stripped of my informal PhD in party cosmology by a furious unsatisfied little mob. Then a light shone on my head and I said: Right here in this place! I reasoned that if all the places were at the same place in the pre-big bang singularity, thence the big bang occurred in all the places!

Ok I had won the first round. The boy looked shocked. The audience froze in a silent moment. After a second that seemed an eternity the gang exploded in questions of how come it could be possible, accusing me of doctoring the answer. I was caught in a dead end. In panic I gave a long off-set answer, full of (misplaced) technical terms and bad examples. That moment I knew how little is my knowledge and how little I can imagine and properly explain the nature of the space-time fabric. The group didn’t seem satisfied, and I had no more tricks in my hat. I grabbed my coat and headed home in the first opportunity. I hope my reputation is still impeccable in that group.

I submit the question to you my fellow Bad Astronomers. Lets have a discussion that can enlighten many of the members who may have had a similar problem, or never thought about the matter. How can I properly explain: Where Did The Big Bang Occur?


<font size=-1>[ This Message was edited by: Argos on 2002-04-07 07:22 ]</font>

Jim
2002-Apr-05, 05:35 PM
Well, to quote from a book I recently read:

(Imagine) you're stuck on the surface of (a) ball, with no real concept of up or down. The center of the ball isn't on the surface, it's inside, removed into the third dimension, which you cannot access. ...

The same can be said for our own 3-D universe. If it has a center, it might not be in our universe at all, but in some higher dimension. (p 149)

So, the universe (the Big Bang) could be centered somewhere in time (the 4th dimension) or simply not centered at all.

However, from a philosophical viewpoint, your answer is a good one. The Big Bang occurred here because all of creation is part of the Big Bang.

Argos
2002-Apr-05, 05:41 PM
On 2002-04-05 12:35, Jim wrote:
So, the universe (the Big Bang) could be centered somewhere in time


That's the easy part, Jim.



(the 4th dimension) or simply not centered at all.


Here the trouble begins.

ToSeek
2002-Apr-05, 06:38 PM
I just got back from an APL Colloquium with Mario Livio of the Space Telescope Science Institute, who literally pulled out a balloon and blew it up to demonstrate some of the various concepts associated with the Big Bang.

Phobos
2002-Apr-05, 07:02 PM
I would have told him that a fraction of a second after the big bang, the place that was to become planet Earth, and the place that was to become the moon were still so close together that you couldn't separate them with the most powerful microscope.

And as you go further back in time, and closer towards the big bang, so all other locations that we are familiar with today were closer and closer together.

Finally we go back to the big bang and all present day locations were at the same place.

Don't know if you would have been more likely to be believed, but it would be more likely to be understood.

Phobos

dx
2002-Apr-05, 07:21 PM
The determination of position (where) depends upon a comparison using a coordinate system. Now to me it would seem that assigning coordinates requires knowledge of what these mean. An example is to say something happened at two o'clock you need to know how time is measured. This seems to depend on known physical principles. At the instant of creation physical theories break down thus no coordinate system can be valid.

Wiley
2002-Apr-05, 07:55 PM
I think the correct answer, if there is one, to the question "Where did the big bang occur?" is, simply, everywhere.

As other people in this thread have mention, all space was compacted into a single point, and, to quote Phobos, "all present day locations were at the same place." Hence the simple answer: everywhere.

Spaceman Spiff
2002-Apr-05, 08:24 PM
The Big Bang happened everywhere at a moment
in time....as you and others have mentioned.

Donnie B.
2002-Apr-06, 12:39 AM
The Big Bang occurred at Alamogordo, New Mexico, on July 16, 1945.

/phpBB/images/smiles/icon_biggrin.gif

Chuck
2002-Apr-06, 01:21 AM
Buy some land with a cave near a highway in the southwest and put up a "see the birthplace of the universe" sign. People are making money with much lesser attractions.

informant
2002-Apr-06, 12:20 PM
Wiley wrote:
I think the correct answer, if there is one, to the question "Where did the big bang occur?" is, simply, everywhere.

As other people in this thread have mention, all space was compacted into a single point, and, to quote Phobos, "all present day locations were at the same place." Hence the simple answer: everywhere.

I think that what confuses people (I know it confuses me) is: "Where was that point?"
But, of course, perhaps the question itself has no meaning.

Argos
2002-Apr-06, 12:30 PM
On 2002-04-05 20:21, Chuck wrote:
Buy some land with a cave near a highway in the southwest and put up a "see the birthplace of the universe" sign. People are making money with much lesser attractions.


Yes. Using 3D technologies and stuff. Good idea. /phpBB/images/smiles/icon_wink.gif

GrapesOfWrath
2002-Apr-06, 01:22 PM
On 2002-04-05 14:02, Phobos wrote:
I would have told him that a fraction of a second after the big bang, the place that was to become planet Earth, and the place that was to become the moon were still so close together that you couldn't separate them with the most powerful microscope.

Of course, your microscope would still be somewhere down there in the mix between Earth and moon. /phpBB/images/smiles/icon_smile.gif

Argos
2002-Apr-07, 11:16 AM
Excuse me you all for the dreadful "where didthe big bang ocurred(!). An unforgivable Lapsus Memoriae. I hope BA will edit the title.

Hat Monster
2002-Apr-08, 03:37 AM
Simple analogy:
Put some dry ice in a balloon, tie the neck, the balloon will slowly inflate, then ask "Where inside the balloon did the balloon inflate from?"
It's the same question.
The answer is everywhere.

jkmccrann
2005-Oct-22, 08:42 AM
Everywhere and nowehere all at once. I think your reputation will remain intact Argos, is there anyone else to really replace you in that group? I daresay not. :)

iantresman
2005-Oct-22, 01:02 PM
Where Did The Big Bang Occur?

Since we're in the Against the Mainstream section, the cynical answer is that...

...the only thing we know for sure, is that the Big Bang occured in the 20th century, in the minds of a small number of scientists on Earth, a couple of thousand of years after the analogous Creation occured to a number of believers who forgot to qualify it with some maths and submit it for peer review. Ironically that makes the Earth the centre of the Universe.

Regards,
Ian Tresman

gzhpcu
2005-Oct-22, 04:52 PM
Well, if M-theory is correct, the question makes sense, since there was perhaps a pre-existing, empty brane/universe, and after a collision with another brane a Big Bang occured, populating the empty brane/universe with matter... but where?

bigsplit
2005-Oct-22, 05:06 PM
The best answer would have been.....we are not sure yet.

Bathcat
2005-Oct-22, 05:48 PM
I think bigsplit is right.

Given the Standard Model, since space was a product of the big bang, isn't it a little like asking where a violet's smell was before the violet existed?

Which doesn't help when answering questions from earnest young chaps, I know.

Cougar
2005-Oct-22, 06:34 PM
...the only thing we know for sure, is that the Big Bang occured in the 20th century, in the minds of a small number of scientists on Earth....
Well, it's true there's not a lot we (humans) know for sure. But I think we might appreciate the advances in understanding the universe around us in the last several hundred years of observation, experimentation, and theorization. The advance of science is not a random walk. The fact that these understandings are only held by "a small number of scientists" is indeed a tragedy. But it may be more than you think.
....a couple of thousand of years after the analogous Creation occured to a number of believers....It's a bad analogy.

NanC
2005-Oct-22, 09:03 PM
I like the idea of it occurring in the minds of those who thought it up because its still possible a new theory could replace it. Thats the joy and strength of science. But it is not very good for explaining to children. I think the best answer would have been

We are not sure yet, which is why we need young, fresh scientific minds to do well in school so they can help us figure that stuff out later :)

More important to get them interested in learning than to get them impressed by you.

(edit to add I dont mean anything bad to you by saying that last line. I hope you are not hurt.)

RussT
2005-Nov-26, 02:51 AM
I believe the real problem here is...Not one of these answers included the word "IF" the Big Bang happened, where did it happen? It is still a Theory, isn't it?

cjl
2005-Nov-26, 11:57 AM
Yes it is, as a matter of fact.
Kind of like the theory of gravity
Or the theory of magnetism
Or the theory of relativity
...

Sam5
2005-Nov-26, 05:41 PM
How can I properly explain: Where Did The Big Bang Occur?


You're not supposed to ask that question, because from our viewing position it looks as if it occurred right here and as if the universe expanded outward from here.

Sam5
2005-Nov-26, 06:07 PM
Well, to quote from a book I recently read:

(Imagine) you're stuck on the surface of (a) ball, with no real concept of up or down. The center of the ball isn't on the surface, it's inside, removed into the third dimension, which you cannot access. ...

The same can be said for our own 3-D universe. If it has a center, it might not be in our universe at all, but in some higher dimension. (p 149)


This legend comes from some 19th Century speculations about 4-D geometry.

But, we don’t live on the surface of a sphere. We don’t live ON the universe, we live INSIDE it.

What you are quoting comes from Arthur Cayley’s 1883 analogy of the little 2-D creatures living on the surface of a sphere. See his essay about this on pages 177-188 (go to page 183 for the original story, in English, about the 2-D creatures living on the surface of a sphere; Helmholtz apparently was the first to publish the analogy, a decade or so earlier):

http://cdl.library.cornell.edu/cgi-bin/moa/moa-cgi?notisid=ABR0102-0159-5

But that analogy works (as a poor one) only if we live in a 4-D universe, but there is absolutely no evidence that we live in a 4-D universe. The little 2-D creatures on a sphere analogy came out of the 19th Century speculations of geometry theorists who speculated about what 4-Ds of space would be like. But they never actually found any evidence of 4-Ds of space. Einstein used the analogy briefly before the expansion of the universe was discovered, but a 4th D of space wasn’t needed after the expansion was discovered.

Here is Richard Proctor’s 1884 response to Cayley’s silly idea. See pages 228-234 and the article "Dream Space":

http://cdl.library.cornell.edu/cgi-bin/moa/moa-cgi?notisid=ABR0102-0160-6

Cayley’s idea was turned into the humorous 1884 fairy tale titled “Flatland - A Romance of Many Dimensions”, by Edwin Abbott. The text is here:

http://www.eldritchpress.org/eaa/FL.HTM