Radius of initial singularity?

Radius of initial singularity?

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AJI

Original Poster:

5,180 posts

218 months

Wednesday 18th September 2013
quotequote all
Not sure if its been asked before on PH Science! or not, but the theory of the big bang is well established although parts of it I still find hard to comprehend.
My question this time is what is the theoretical radius of the big bang singularity?

Now I think some may reply with a point that space-time, mass, physical laws of measurements etc. did not exist at the initial singularity so therefore I will amend my question.....

What would be the 'relative' radius of the big bang singularity if comparing to objects familiar with human knowledge?
(ie. similar to the size of a marble?, a grain of sand?, a football?, the earth?, the sun?)


mu0n

2,348 posts

134 months

Wednesday 18th September 2013
quotequote all
If I imagine it, I think of it as being a speck similar to an elementary particle, possibly smaller. Impossible for anyone to say given that the Big Bang is just a theory.

mu0n

2,348 posts

134 months

Wednesday 18th September 2013
quotequote all
A proton's radius is I think 0.000000000008 millimeters; so the singularity of the Big Bang would be smaller than that I'd imagine. smile

MiseryStreak

2,929 posts

208 months

Wednesday 18th September 2013
quotequote all
All of space is within the singularity so it has no external dimensions. That is a really unsatisfying answer I know but I think its the correct one. Anyway, at t=0 there are no dimensions but at any time after there is, so the singularity was dimensionless for no time at all in fact.

This is one of the coolest things on the internet (if you're a nerd like me anyway):

http://htwins.net/scale2/

Edited by MiseryStreak on Wednesday 18th September 11:01

mu0n

2,348 posts

134 months

Wednesday 18th September 2013
quotequote all
MiseryStreak said:
All of space is within the singularity so it has no external dimensions. That is a really unsatisfying answer I know but I think its the correct one. Anyway, at t=0 there are no dimensions but at any time after there is, so the singularity was dimensionless for no time at all in fact.

This is one of the coolest things on the internet (if you're a nerd like me anyway):

http://htwins.net/scale2/

Edited by MiseryStreak on Wednesday 18th September 11:01
What about the internal dimensions? wink

AJI

Original Poster:

5,180 posts

218 months

Wednesday 18th September 2013
quotequote all
I can see why modern science is attempting to run away from the big bang theory and its singularity beginning.
wink


I've just stumbled across this :
http://www.youtube.com/watch?v=q3MWRvLndzs&fea...

Suggesting that the big bang doesn't actually mean there was a point singularity.... interesting.

Gandahar

9,600 posts

129 months

Wednesday 18th September 2013
quotequote all
AJI said:
Not sure if its been asked before on PH Science! or not, but the theory of the big bang is well established although parts of it I still find hard to comprehend.
My question this time is what is the theoretical radius of the big bang singularity?

Now I think some may reply with a point that space-time, mass, physical laws of measurements etc. did not exist at the initial singularity so therefore I will amend my question.....

What would be the 'relative' radius of the big bang singularity if comparing to objects familiar with human knowledge?
(ie. similar to the size of a marble?, a grain of sand?, a football?, the earth?, the sun?)
A singularity wouldn't have any radius at all as space no longer exists.

So you cannot even ask the "relative" radius either I am afraid as it is like comparing something with a radius to something that is, well obviously smaller. Smaller than any radius you can imagine, because it does not have one.

Why are you wondering about this would be a more pertinent question?

Also modern science does not work on "trying to run away" from something if it is true, no matter how weird. That is the whole point of science, not running away or making things up or wanting to believe something because it looks right. Just ask a quantum physicist.


Edited by Gandahar on Wednesday 18th September 14:00

AJI

Original Poster:

5,180 posts

218 months

Wednesday 18th September 2013
quotequote all
Gandahar said:
A singularity wouldn't have any radius at all as space no longer exists.

So you cannot even ask the "relative" radius either I am afraid as it is like comparing something with a radius to something that is, well obviously smaller. Smaller than any radius you can imagine, because it does not have one.

Why are you wondering about this would be a more pertinent question?

Also modern science does not work on "trying to run away" from something if it is true, no matter how weird. That is the whole point of science, not running away or making things up or wanting to believe something because it looks right. Just ask a quantum physicist.


Edited by Gandahar on Wednesday 18th September 14:00
OK I guess I wondering how to imagine something so small containing all the energy in order to create the mass and dimensions we view/record in modern science today.
I know the maths and laws of physics break down and its 'just' a theory but if the 'singularity' was maybe not just an infinitesimally small point then I could maybe comprehend it a little easier.
The vid link I posted above that I found after posting the initial question has got me thinking a bit more about it. As it suggests the idea of it being a single point may be missleading? (Is this correct?)


I realise that the term 'run away' may not fall happily with science and it was intended to be used loosely wink ... but would it be correct to say that as modern maths and laws of physics break down at a certain point in the history of the universe it has lead to other theories such as membrane and multi-verse etc. (ie.moving away from the 'simplistic' big bang theory - in comparison of course)

hairykrishna

13,185 posts

204 months

Wednesday 18th September 2013
quotequote all
AJI said:
OK I guess I wondering how to imagine something so small containing all the energy in order to create the mass and dimensions we view/record in modern science today.
I know the maths and laws of physics break down and its 'just' a theory but if the 'singularity' was maybe not just an infinitesimally small point then I could maybe comprehend it a little easier.
The vid link I posted above that I found after posting the initial question has got me thinking a bit more about it. As it suggests the idea of it being a single point may be missleading? (Is this correct?)


I realise that the term 'run away' may not fall happily with science and it was intended to be used loosely wink ... but would it be correct to say that as modern maths and laws of physics break down at a certain point in the history of the universe it has lead to other theories such as membrane and multi-verse etc. (ie.moving away from the 'simplistic' big bang theory - in comparison of course)
The point is that saying it was infinitesimally small is meaningless. There were no dimensions so ascribing it a size, small or otherwise, makes no sense.

AJI

Original Poster:

5,180 posts

218 months

Thursday 19th September 2013
quotequote all
Interesting replies. Thanks guys.

I do struggle to visualize or comprehend the size differences and shear scale of things when looking at the big bang theory.
I understand that a huge amounts of energy are involved in 'mass' in that only 0.6 grams of mass where converted to energy in the first nuclear bomb dropped on Japan in WWII for example.
And that over 99% of an atom is just 'empty space'.

These two acknowledgements can allow my understanding that there is a huge amount of energy in the universe and also the matter that is in the universe can be compressed down to over 99% of its space before protons/neutrons are being forced to occupy the same place.

But then going back in time to when protons and neutrons were not in existence and 'stuff' was even closer together is where my understanding sort of breaks down.
I don't think I fully grasp the idea of what the big bang singularity is about. (Especially after watching that vid I linked earlier).

Russian Rocket

872 posts

237 months

Thursday 19th September 2013
quotequote all
if spacetime is infinatley curved at a singularity so nothing can get out how come the universe got out?


hairykrishna

13,185 posts

204 months

Thursday 19th September 2013
quotequote all
ash73 said:
The universe is quantised; at the smallest scale everything is reduced to irreducible counting units, or natural numbers. A singularity can be no smaller than the Planck length, which in metres is a decimal point followed by 34 zeros and then a one. It's equivalent to a single pixel in the context of the cosmos.
Nobody knows if spacetime is quantised.

Engineer1

10,486 posts

210 months

Thursday 19th September 2013
quotequote all
Russian Rocket said:
if spacetime is infinatley curved at a singularity so nothing can get out how come the universe got out?
We are in the realms of well as the universe exists it must have got out so something we currently don't understand must have happened.

Gandahar

9,600 posts

129 months

Thursday 19th September 2013
quotequote all
AJI said:
Gandahar said:
A singularity wouldn't have any radius at all as space no longer exists.

So you cannot even ask the "relative" radius either I am afraid as it is like comparing something with a radius to something that is, well obviously smaller. Smaller than any radius you can imagine, because it does not have one.

Why are you wondering about this would be a more pertinent question?

Also modern science does not work on "trying to run away" from something if it is true, no matter how weird. That is the whole point of science, not running away or making things up or wanting to believe something because it looks right. Just ask a quantum physicist.


Edited by Gandahar on Wednesday 18th September 14:00
OK I guess I wondering how to imagine something so small containing all the energy in order to create the mass and dimensions we view/record in modern science today.
I know the maths and laws of physics break down and its 'just' a theory but if the 'singularity' was maybe not just an infinitesimally small point then I could maybe comprehend it a little easier.
The vid link I posted above that I found after posting the initial question has got me thinking a bit more about it. As it suggests the idea of it being a single point may be missleading? (Is this correct?)


I realise that the term 'run away' may not fall happily with science and it was intended to be used loosely wink ... but would it be correct to say that as modern maths and laws of physics break down at a certain point in the history of the universe it has lead to other theories such as membrane and multi-verse etc. (ie.moving away from the 'simplistic' big bang theory - in comparison of course)
Hopefully I was not to in your face with my reply. Yes, it is hard to think about, it really is scrabbling at the boundaries, I have no real answers of course either.

I still cannot even imagine how big the Universe is now, on an experience point of view, so trying to imagine it at the very beginning might be just completely impossible.

It seems to me that you have to start with maths rather than English. How good is your maths? If it is poor like mine I doubt you will ever get a good descriptive sentence in English to put it in your mind. You would need to "read" the maths and understand it to see if it is a "beautiful" description that makes sense.


maffski

1,868 posts

160 months

Friday 20th September 2013
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The singularity wasn't infinitesimally small at all - it was the size of the entire universe.

davepoth

29,395 posts

200 months

Friday 20th September 2013
quotequote all
maffski said:
The singularity wasn't infinitesimally small at all - it was the size of the entire universe.
I was just about to post this exact same thing. Damn you!

biggrin


Thorodin

2,459 posts

134 months

Tuesday 24th September 2013
quotequote all
The trouble with untrained minds trying to understand ununderstandable theories is we can't get to the root.

Seems to me a visionary thinker formulates a fantastic (in the true sense) guess and then spends years devising a mathematical "proof" (which of course it isn't). It is then necessary to imagine (invent) parallel guesses/explanations to support the original idea.

Given the Scientific establishment requires rigorous experiment to accept development, it is surprising how many luminaries support these theories, the veracity of which is unprovable. The benefits of such ponderings are of course the resulting expansion of the brain, maybe ultimately to understand considerably more than we do. For me, fascinating.

Simpo Two

85,590 posts

266 months

Tuesday 24th September 2013
quotequote all
Which reminds me, what happened to Gene Vincent?

Thorodin

2,459 posts

134 months

Tuesday 24th September 2013
quotequote all
Simpo Two said:
Which reminds me, what happened to Gene Vincent?
Given his choice of clothes, maybe a black hole had something to do with his demise?
(I met him once by the way, great bloke - very friendly and oh so cool).

AJI

Original Poster:

5,180 posts

218 months

Wednesday 25th September 2013
quotequote all
Simpo Two said:
Which reminds me, what happened to Gene Vincent?
Yeah, I used to enjoy reading his comments.