I was thinking earlier today about the following question:
If the Big Bang and the universe originated from a singularity of infinite mass and energy, wouldn't the law of conservation of mass/energy suggest that the current universe, which many consider finite, also contains an infinite amount of mass and energy?
I'm an AS student so I've probably just completely misinterpreted a fundamental facet about the Big Bang theory or the law of conservation, but I'd be grateful if someone with more knowledge on the subject could explain this?
x
Turn on thread page Beta

IchiCC
 Follow
 3 followers
 2 badges
 Send a private message to IchiCC
 Thread Starter
Offline2ReputationRep: Follow
 1
 04022010 23:51

+ polarity 
 Follow
 97 followers
 20 badges
 Send a private message to + polarity 
 Visit + polarity 's homepage!
Offline20 Follow
 2
 04022010 23:57
Did it have infinite mass and energy?

IchiCC
 Follow
 3 followers
 2 badges
 Send a private message to IchiCC
 Thread Starter
Offline2ReputationRep: Follow
 3
 05022010 00:02
(Original post by + polarity )
Did it have infinite mass and energy? 
little pixie
 Follow
 0 followers
 12 badges
 Send a private message to little pixie
Offline12ReputationRep: Follow
 4
 05022010 00:18
My understanding is that it was considered to be incredible density (could probably word that better), but not infinite.

 Follow
 5
 05022010 05:20
(Original post by IchiCC)
Well I've seen it defined in books as a point of infinite density and temperature, so that's what I assumed.
Whether there actually was a singularity at the big bang is debatable. 
 Follow
 6
 05022010 05:21
Also we don't know that the universe is spatially finite.

mathperson
 Follow
 3 followers
 16 badges
 Send a private message to mathperson
Offline16ReputationRep: Follow
 7
 05022010 05:40
(Original post by TableChair)
Suppose I took all the observable matter in the universe (a finite amount) and compressed it to a point. That point would have infinite density, but would still have finite mass.
Whether there actually was a singularity at the big bang is debatable. 
 Follow
 8
 05022010 10:22
(Original post by IchiCC)
I was thinking earlier today about the following question:
If the Big Bang and the universe originated from a singularity of infinite mass and energy, wouldn't the law of conservation of mass/energy suggest that the current universe, which many consider finite, also contains an infinite amount of mass and energy?
I'm an AS student so I've probably just completely misinterpreted a fundamental facet about the Big Bang theory or the law of conservation, but I'd be grateful if someone with more knowledge on the subject could explain this?
http://www.astronomycafe.net/qadir/q1326.html 
 Follow
 9
 05022010 14:49
(Original post by mathperson)
Whether or not the big bang happened is also debatable. 
mathperson
 Follow
 3 followers
 16 badges
 Send a private message to mathperson
Offline16ReputationRep: Follow
 10
 05022010 15:24
(Original post by TableChair)
Not really. All observations of the universe concur that there was a big bang (i.e. approximately 13.7 billion years ago, the universe was in a hot, dense state). To claim otherwise is pretty ludicrous, but I'd like to hear what evidence you have?
I know I can't word this without sounding somewhat rude, but I don't intend it that way , however when you say it is 'ludicrous to question it because of evidence' is typical of what a scientist would say. 
teachercol
 Follow
 108 followers
 8 badges
 Send a private message to teachercol
Offline8ReputationRep: Follow
 11
 05022010 18:11
so I guess you reject all science.
What about mathematical axioms? 
 Follow
 12
 05022010 18:19
A perfect singularity is only a mathematical model, and so far, there has been no evidence to suggest that it has a perfectly corresponding counterpart in physical reality (much like the idea of a perfect circle which is a mathematical model for the imperfect physical circles we see in real life).
For example, consider a collapsing star. Theory tells us that under its own gravity, the star will get smaller and smaller in volume, and hence will get larger and larger in density. This process is in positive feedback, which means that every time the volume decreases, the density increases, the gravity gets stronger per unit volume, the volume decreases, the density increases, etc, etc. Of course, this feedback process would have to go on for an infinite amount of time before it became a singularity  a point mass of infinite density and 0 volume. However, infinite time doesn't exist in the universe, and so it is probably that many collapsing stars may APPROACH a singularity as time TENDS towards infinite, but will never actually get to that point. However, it will get very close, and so we can accurately model our "ALMOST" singularity in real life with a perfect singularity in the mathematical model.
The same could be true of the singularity which set off the expansion of the universe. 
 Follow
 13
 05022010 18:22
I think the ratio of mass to size of the universe is infinite but not the mass. Because as size turns to 0 the mass/size will turn to infinity.

 Follow
 14
 05022010 18:25
(Original post by mathperson)
I don't have any evidence, you see I'm a mathematician and I don't deal with 'evidence' as scientists/engineers do, I deal in absolute proof. Now I don't have mathematical proof that the big bang didn't happen, because if I did have mathematical proof then it is unquestionable, however whether or not the big bang did happen will always be up for debate until absolute proof is found.
I know I can't word this without sounding somewhat rude, but I don't intend it that way , however when you say it is 'ludicrous to question it because of evidence' is typical of what a scientist would say.
Of course, I would never stop someone from questioning it, because you never know where an alternative hypothesis might lead... it may just be successful enough to acquire more evidence than the previous hypothesis.
However, it is still quite ludicrous to question something for which the evidence is substantial, to the point that it is self evident.
And yes, as someone else has already mentioned, your beautiful subject of Mathematics is founded, regardless of what field you are in, on a set of axioms. Axioms being "selfevident" starting points which, themselves are not proven. And then, from these axioms, all other theorems are proved. However, it can be seen as debatable that these axioms are "selfevident beyond reasonable doubt". You might be ludicrous to suggest so, but there is room for debate in all mathematics that springs from unproven axioms. Especially when we consider Gödel's theorems of incompleteness... we can see that the realm of the Mathematical can be deeply flawed in its basic premises.
Of course, I presume that you have never heard of "axioms" or Gödel's theorems, and are still under the schoolboy illusion that all of mathematics is conceptually perfect, and that every question has a "right" answer. When you undoubtedly wiki these concepts, you will either have to accept the "beyond reasonable doubt" rule of thumb, or you will be forced to lose your faith in your favourite subject, because it is not the image of perfection and purity that you think it is.Last edited by Phugoid; 05022010 at 18:30. 
 Follow
 15
 05022010 18:27
(Original post by buckett)
I think the ratio of mass to size of the universe is infinite but not the mass. Because as size turns to 0 the mass/size will turn to infinity. 
paddyman4
 Follow
 2 followers
 14 badges
 Send a private message to paddyman4
Offline14ReputationRep: Follow
 16
 05022010 18:30
The laws of physics that we know and love completely break down at singularities.

mathperson
 Follow
 3 followers
 16 badges
 Send a private message to mathperson
Offline16ReputationRep: Follow
 17
 05022010 18:34
(Original post by Phugoid)
In science and engineering, there is a thing called "beyond reasonable doubt". That is, we may never be able to acquire an absolute proof for a hypothesis, but there can be SO much evidence supporting the hypothesis that you would be going beyond reasonable doubt into unreasonable doubt to question it.
Of course, I would never stop someone from questioning it, because you never know where an alternative hypothesis might lead... it may just be successful enough to acquire more evidence than the previous hypothesis.
However, it is still quite ludicrous to question something for which the evidence is substantial, to the point that it is self evident.
And yes, as someone else has already mentioned, your beautiful subject of Mathematics is founded, regardless of what field you are in, on a set of axioms. Axioms being "selfevident" starting points which, themselves are not proven. And then, from these axioms, all other theorems are proved. However, it can be seen as debatable that these axioms are "selfevident beyond reasonable doubt". You might be ludicrous to suggest so, but there is room for debate in all mathematics that springs from unproven axioms. Especially when we consider Gödel's theorems of incompleteness... we can see that the realm of the Mathematical can be deeply flawed in its basic premises.
I really hope this doesn't come across as rude, I'm not that sort of person, and I appologise if it does . However to be honest I don't feel I can have a decent conversation with you about this subject.
newton's law of universal gravitation was 'beyond reasonable doubt', however his approach was flawed in that his formula came from experimental observation rather than mathematical derivation. This resulted in, eventually, it being replaced with a mathematically derived theorem (note not theory) called quantum mechanics.
"However, it is still quite ludicrous to question something for which the evidence is substantial, to the point that it is self evident." This is a typical thing that a scientist/engineer would say, and I'm not going to trouble myself to answer it, not because I don't want to assist your understanding, but I believe that unless you find out for yourself why this statement is incorrect, you will not appericiate why it is.
Again, scientists/engineers tend not to have a full understanding of what an axiom is. They are not theorems that need proving, they are quite simply fundemental definitions that define that language that the theorems built upon them are expressed in, they do not need proving. There is no room for debate in mathematics, however as previously mentioned in this post, I shall let you figure out why.
Take care. 
 Follow
 18
 05022010 18:47
(Original post by mathperson)
I really hope this doesn't come across as rude, I'm not that sort of person, and I appologise if it does . However to be honest I don't feel I can have a decent conversation with you about this subject.
newton's law of universal gravitation was 'beyond reasonable doubt', however his approach was flawed in that his formula came from experimental observation rather than mathematical derivation. This resulted in, eventually, it being replaced with a mathematically derived theorem (note not theory) called quantum mechanics.
Newtonian principles were INDEED beyond reasonable doubt, but then something happened independently that brought the possibility of reasonable doubt into the arena  people began to observe things that were not explained by Newtonian physics. Such things were blackbody radiation, optics, the motion of bodies at high velocities, and the physics of the microworld. These were the things that allowed reasonable doubt to be cast upon Newtonian physics, and FROM that doubt the theories of General Relativity and Quantum Mechanics were born.
The vast majority of successful theories which supersede an existing theory only come to centrestage once the previous theory has doubt cast upon it by some observation, and Quantum theory is no different.
Now, the mathematics of quanta are indeed "theorems", but the hypothesis that these theorems accurately depict physical reality is a THEORY!
Newtonian theory, btw, is not "wrong". The only thing that was "wrong" about the Newtonian philosophy was that it was considered to describe all motion in the universe, when in fact it only describes motion within a limited range of velocities, masses, etc.
"However, it is still quite ludicrous to question something for which the evidence is substantial, to the point that it is self evident." This is a typical thing that a scientist/engineer would say, and I'm not going to trouble myself to answer it, not because I don't want to assist your understanding, but I believe that unless you find out for yourself why this statement is incorrect, you will not appericiate why it is.
Again, scientists/engineers tend not to have a full understanding of what an axiom is. They are not theorems that need proving, they are quite simply fundemental definitions that define that language that the theorems built upon them are expressed in, they do not need proving. There is no room for debate in mathematics, however as previously mentioned in this post, I shall let you figure out why.
Take care.
1) Define a set of mathematical axioms and then ASSUME that they have counterparts in the physical world.
2) Observe the physical world and try to determine the axioms, and selfevident truths of reality from there.
Both, of course, have their flaws, and you are a fool if you fail to recognise that. 
 Follow
 19
 05022010 21:42
Ok we're going to get nowhere here. I think I've seen this guy in another thread, just let him be.

 Follow
 20
 05022010 21:47
(Original post by Phugoid)
A perfect singularity is only a mathematical model, and so far, there has been no evidence to suggest that it has a perfectly corresponding counterpart in physical reality (much like the idea of a perfect circle which is a mathematical model for the imperfect physical circles we see in real life).
For example, consider a collapsing star. Theory tells us that under its own gravity, the star will get smaller and smaller in volume, and hence will get larger and larger in density. This process is in positive feedback, which means that every time the volume decreases, the density increases, the gravity gets stronger per unit volume, the volume decreases, the density increases, etc, etc. Of course, this feedback process would have to go on for an infinite amount of time before it became a singularity  a point mass of infinite density and 0 volume. However, infinite time doesn't exist in the universe, and so it is probably that many collapsing stars may APPROACH a singularity as time TENDS towards infinite, but will never actually get to that point. However, it will get very close, and so we can accurately model our "ALMOST" singularity in real life with a perfect singularity in the mathematical model.
The same could be true of the singularity which set off the expansion of the universe.
Reply
Submit reply
Turn on thread page Beta
Related discussions:
 Did God or the Big Bang create the universe? (vague title)
 What was before the BigBang?
 Big bang theory problem solved?
 why do the laws of physics break down at the big bang?
 Stop with the "who created God" argument it's bloody ...
 Energy cannot be created or destroyed.
 How could the universe have started from nothing? What ...
 Why do you believe in god?
 Can the universe have existed forever?
 Anyone who loves KPop and lives in London????
TSR Support Team
We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.
This forum is supported by:
 charco
 Mr M
 TSR Moderator
 Nirgilis
 usycool1
 Changing Skies
 James A
 rayquaza17
 Notnek
 RDKGames
 randdom
 davros
 Gingerbread101
 Kvothe the Arcane
 TeeEff
 The Empire Odyssey
 Protostar
 TheConfusedMedic
 nisha.sri
 Reality Check
 claireestelle
 Doonesbury
 furryface12
 Amefish
 harryleavey
 Lemur14
 brainzistheword
 Rexar
 Sonechka
 LeCroissant
 EstelOfTheEyrie
 CoffeeAndPolitics
 an_atheist
 Moltenmo
 Labrador99
 EmilySarah00
Updated: February 5, 2010
Share this discussion:
Tweet