Mass can neither be creater nor destroyed..true?

[Sci-Fi]

Its a basic Physics law that mass can neither be created nor destroyed.But the BBT(Big Bang Theory) defies this law.Big Bang created mass and as a result we are here.That means Big Bang defies the very basic law of Physics.So one thing has to be incorrect.Either the BBT or the basic law of Physics!Thats what confuses me.

What do you guys think?

Edited August 2, 2011 by Sci-Fi

[Cap'n Refsmmat]

Mass and energy are two sides of the same coin, so they can be converted into each other. (This is why nuclear bombs can convert mass into incredible amounts of energy, for example.)

 

Hence one hypothesis is that the gravitational potential energy, which is negative, balances out all the positive energy and mass, making the net energy zero. The big bang didn't have to create anything.

 

But a more realistic answer at the moment is that we simply do not yet understand the very first moments of the universe, and so until we collect more evidence and develop better theories, we can't know how the conservation of mass/energy applied or if it even did.

[math-helper]

Big Bang Theory didn't create any new mass but spread it all around from a point.

[Dishmaster]

What is wrong is your imagination of the Big Bang paradigm. But you are not alone. It is misconception that it says something about the creation of energy or matter. It doesn't say anything about how the universe came into existence. It only covers the evolution of the universe after it somehow was formed. In addition, you are forgetting that matter is produced all the time.

 

The correct law is that energy can neither be produced or destroyed. Mass and energy are equivalent and can be transformed from one form into the other. However, the BBT doesn't say anything about how energy came into the universe either. The problem is that nearly all popularisations tend to suggest that it does.

[Cap'n Refsmmat]

What is wrong is your imagination of the Big Bang paradigm. But you are not alone. It is misconception that it says something about the creation of energy or matter. It doesn't say anything about how the universe came into existence. It only covers the evolution of the universe after it somehow was formed. In addition, you are forgetting that matter is produced all the time.

 

The correct law is that energy can neither be produced or destroyed. Mass and energy are equivalent and can be transformed from one form into the other. However, the BBT doesn't say anything about how energy came into the universe either. The problem is that nearly all popularisations tend to suggest that it does.

That's just shifting the question of "where did the mass come from?" from the Big Bang to some as-yet-unnamed preceding event, without actually answering the question. What that event was called is significantly less important than how it happened and how matter came into existence.

[MigL]

At time t=0 we have an asymmetry in time, ie you can only go foreward not backwards ( into negative time ). This means the action is not invariant under a continuous transformation in time and Noether's theorem is violated. In effect, at t=0, the law of conservation of mass/energy is not valid.

 

If certain physical laws are not valid at t=0 ( or approaches t=0 ), then they are all invalid. You cannot pick and choose.

Edited August 2, 2011 by MigL

[timo]

That [not counting a step from "no universe" to "universe is there" as part of the big bang] just shifting the question of "where did the mass come from?" from the Big Bang to some as-yet-unnamed preceding event, without actually answering the question.

That is not completely fair. The original premise of this thread was that "the BBT(Big Bang Theory) defies conservation of mass energy" (correction to energy by me, because mass may be a complicated concept in this context). And as Dishmaster correctly says this is not the case. It is a common misconception people get from hearing the term big bang and reading popular scientific texts, or even reading scientific texts but without having the background to understand them.

 

Saying that excluding the creation step from the big bang is just a trick is problematic: you are assuming that there is a kind of creation step. This is not assumed in the standard big bang scenario, where you trace backwards in time from today until you reach a point where you expect that your physics breaks down and that you cannot make any physical statements at and beyond this point. And there is also no scientific evidence for the existence of a creation step (that I knew of). Assuming that a creation step must have preceded the existence of the universe may seem natural to you, but comes with a few inherent assumptions that are not scientifically justified. I could name a few, but they all boil down to the same issue: you are using your intuition to extrapolate beyond the point where you expect your known physics to break down (and where you don't have a good intuition on, because early-universe conditions are probably a bit different from the Newton world you live in). There is, as far as I know, neither a logical nor a scientific reason to assume an event in which the universe came into being, even though I admit that it is not excluded and also very imaginable.

[swansont]

At time t=0 we have an asymmetry in time, ie you can only go foreward not backwards ( into negative time ). This means the action is not invariant under a continuous transformation in time and Noether's theorem is violated. In effect, at t=0, the law of conservation of mass/energy is not valid.

 

If certain physical laws are not valid at t=0 ( or approaches t=0 ), then they are all invalid. You cannot pick and choose.

 

I thinks that's "may have" an asymmetry in time. If you don't know the physics before t=epsilon, you really can't say what happens one way or another.

[csmyth3025]

...If certain physical laws are not valid at t=0 ( or approaches t=0 ), then they are all invalid. You cannot pick and choose.

The standard model of big bang cosmology begins with the inflationary epoch at ~t=10^-36 seconds and lasted until about 10^-32 seconds. It doesn't extend to any time earlier than that. Even for this very early period the actual physics is not very well understood:

 

Inflation is a period of supercooled expansion, when the temperature drops by a factor of 100,000 or so. (The exact drop is model dependent, but in the first models it was typically from 10²⁷K down to 10²²K.^[11]) This relatively low temperature is maintained during the inflationary phase. When inflation ends the temperature returns to the pre-inflationary temperature; this is called reheating or thermalization because the large potential energy of the inflaton field decays into particles and fills the universe with Standard Model particles, including electromagnetic radiation, starting the radiation dominated phase of the Universe. Because the nature of the inflaton is not known, this process is still poorly understood, although it is believed to take place through a parametric resonance

(ref. http://en.wikipedia....logy)#Reheating )

 

You're saying that the physical laws that we are familiar with existed at t=0. I believe that the scientific consensus is that this is not true.

 

Chris

[swansont]

You're saying that the physical laws that we are familiar with existed at t=0.

That's not how I read it. I believe the argument is that they don't exist at that point and the conservation laws begin at that point.

[MigL]

Thanks Swansont, my premise was that we can prove that at t=0 the law of conservation of mass/energy is not valid because of time asymmetry. And I'll go out on a limb and state that all our other physical laws are also invalid.

 

As for your argument about the asymmetry, if we make the assumptin that space/time is 'created' at time t=0, since that was the original question ( if space/time is created then how is mass/energy conserved ??? ), then there is no time before t=0. I don't see how that wouldn't mean a time asymmetry of the physics.

[doG]

Thanks Swansont, my premise was that we can prove that at t=0 the law of conservation of mass/energy is not valid because of time asymmetry...

OK, prove it. Prove that time even started at t=0. Is it possible that time didn't start at the Big Bang, that the Big Bang was just an event in time that redistributed mass/energy into the Universe as we know it? Is it possible that even this event obeyed the law of conservation of mass/energy as we know it even if we don't understand the mechanics that took place during the Big Bang? I personally don't think we can draw any conclusions about where the current mass/energy of our Universe came from.

[MigL]

Re-read my post and the original question.

 

I didn't say I could prove that time started at t=0.

What I said was, given the original question ' if space/time is created at t=0 how is mass/energy conserved ', we can prove, using Noether's theorem, that the asymmetry in time at t=0 invalidates the law of conservation of mass/energy.

[csmyth3025]

That's not how I read it. I believe the argument is that they don't exist at that point and the conservation laws begin at that point.

My appologies to MigL. I re-read his post and realize that I mis-understood the point he was making. In a sort of upside-down logic I mistakenly thought he was saying that if our physical laws are valid, the must also be valid at t=0. As I now understand his post, he's actually saying that at t=0 our physical laws have no predictive power - including the law of conservation of mass/energy.

 

This question does raise a related interesting question: How close to t=0 can we apply the laws of physics as we know them?

 

As far as I know, we're not sure why there was an asymmetric annihilation of matter and anti-matter during the hadron epoch (~10^-6 seconds to ~1 second after t=0) and the lepton epoch (~1 second to ~10 seconds after t=0). Does this make the beginning of the photon epoch (~10 seconds after t=0) the first period of time when our physical laws can be quantitatively applied to the early universe based of what we see today?

 

[i purposely left out the preceding inflationary epoch since the physics of the subsequent matter and anti-matter annihilation aren't yet clear]

 

Chris

 

Deited to correct spelling errors

Edited August 6, 2011 by csmyth3025

[IM Egdall]

 

This question does raise a related interesting question: How close to t=0 can we apply the laws of physics as we know them?

 

 

I believe we can apply the currently understood laws of physics all the way to t = 10^^-43 seconds or "Planck time". At this time, space and time begin to behave as we see them today. Before this time, all known science fails us. To quote link below:

 

"In the era around one Planck time, 10^-43 seconds, it is projected by present modeling of the fundamental forces that the gravity force begins to differentiate from the other three forces. This is the first of the spontaneous symmetry breaks which lead to the four observed types of interactions in the present universe. Looking backward, the general idea is that back beyond 1 Planck time we can make no meaningful observations within the framework of classical gravitation."

 

In other words, general relativity (classical gravitation) theory breaks down below this Planck time. We need a so-called theory of quantum gravity to go beyond Planck time to time zero. No such theory has been substantiated by empirical evidence.

 

See link:

 

http://hyperphysics.phy-astr.gsu.edu/hbase/astro/planck.html

 

 

 

[questionposter]

At time t=0 we have an asymmetry in time, ie you can only go foreward not backwards ( into negative time ). This means the action is not invariant under a continuous transformation in time and Noether's theorem is violated. In effect, at t=0, the law of conservation of mass/energy is not valid.

 

If certain physical laws are not valid at t=0 ( or approaches t=0 ), then they are all invalid. You cannot pick and choose.

 

What if matter and energy appeared because they existed by having the potential to exist? I don't know how it works exactly, but sometimes when I see a diagram of the big bang, the first thing in the line is "quantum fluctuations", and in the quantum level, aren't things really indetirmined and chaotic? And isn't what scientists predicted the big bang to be the result of this super small singularity-like thing? Given its not science because its not testable, but its an educated guess. So I guess the universe, like those hawking radiation particles, were created out of the nothingness of space from improbability.

Edited August 12, 2011 by questionposter

[questionposter]

Wait, one other thing. How can the conservation law be true when matter and energy are being created and destroyed all the time? You have those virtual particles that appear in vaccum space then destroy each other.

Edited August 13, 2011 by questionposter

[Cap'n Refsmmat]

Wait, one other thing. How can the conservation law be true when matter and energy are being created and destroyed all the time? You have those virtual particles that appear in vaccum space then destroy each other.

Mass and energy can be converted into each other according to the famous law [math]E=mc^2[/math].

[questionposter]

Mass and energy can be converted into each other according to the famous law [math]E=mc^2[/math].

 

So then matter and energy CAN be created or destroyed, because when you destroy mass, you create energy, and when you destroy energy, you create mass.

[Cap'n Refsmmat]

Individually, yes, matter or energy can be destroyed, but taken together, they are conserved. The theory of relativity suggests that matter is just a form of energy.

[questionposter]

Individually, yes, matter or energy can be destroyed, but taken together, they are conserved. The theory of relativity suggests that matter is just a form of energy.

 

But can't energy just be a form of matter? What if particles are actually tiny vibrating strands of matter rather than energy?

[IM Egdall]

But can't energy just be a form of matter? What if particles are actually tiny vibrating strands of matter rather than energy?

 

I guess you are talking about string theory, which postulates that all fundamental particles are extremely tiny one-dimensional strings. However, unlike relativity, string theory is still hypothetical -- no substantive experimental evidence has been found to confirm (or deny) its predictions.

 

But in either case, E=mc^^2 holds. In the case of string theory, I believe the energy of vibration of a string indicates that string's mass (using the E=mc^^2 equation).

 

Take the atom bomb, for example. Say we weigh the bomb before it explodes. Then say we somehow collect all the mass of the bomb materials after the explosion; gases, dust, etc. and weigh that. We find the weight after is less than the weight before the explosion (by about one percent).

 

Where is this missing mass? It has been converted to energy(radiation) according to E=mc^^2. So mass can be converted to energy. And energy can also be converted to mass. Both are common occurrences in particle accelerator experiments.

Edited August 13, 2011 by IM Egdall

[questionposter]

I guess you are talking about string theory, which postulates that all fundamental particles are extremely tiny one-dimensional strings. However, unlike relativity, string theory is still hypothetical -- no substantive experimental evidence has been found to confirm (or deny) its predictions.

 

But in either case, E=mc^^2 holds. In the case of string theory, I believe the energy of vibration of a string indicates that string's mass (using the E=mc^^2 equation).

 

Take the atom bomb, for example. Say we weigh the bomb before it explodes. Then say we somehow collect all the mass of the bomb materials after the explosion; gases, dust, etc. and weigh that. We find the weight after is less than the weight before the explosion (by about one percent).

 

Where is this missing mass? It has been converted to energy(radiation) according to E=mc^^2. So mass can be converted to energy. And energy can also be converted to mass. Both are common occurrences in particle accelerator experiments.

 

Well energy can be converted into mass, but whenever that happens, matter seems to appear. Why can't energy just turn into "mass" particles? Why does matter always have to be associated when energy turns into mass? What about just free mass from energy?

[Cap'n Refsmmat]

"Mass particles" are by definition matter, since matter is any particle with mass and volume (in a simple definition).

[questionposter]

"Mass particles" are by definition matter, since matter is any particle with mass and volume (in a simple definition).

 

Well then how come physicists slap you over the head when you say "energy is converted into matter" instead of "mass"?