Subatomic Particles From Nothing?

[Nugso]

Hello everyone. I once read an article saying subatomic particles can exist from nothing in a vacuumed space( or something like that). Is that even possible? Or does the energy vacuumed space has turn into mass/matter, hence we thing it exists from nothing?

 

[kith]

Statements like that are sloppy popularizations of quantum field theory. It is misleading to talk about "nothing" here because these effects occur because of the presence of quantum fields.

 

[hilbert2]

A simplified explanation is that according to energy-time uncertainty relation, a virtual particle-antiparticle pair of total energy ΔE can be created in vacuum for a time interval of approximately $\Delta t = \frac{\hbar}{\Delta E}$

 

[Nugso]

Thanks for the replies kith, hilbert. But I still want to ask a question regarding it;

@hilbert2

It can be created in vacuum. But doesn't vacuum have an enegry?

@kith

I don't get the last sentence. Would you please explain?

 

[kith]

You asked if particles can be created from nothing. I said no because all statements claiming so require quantum fields and quantum fields are not nothing.

 

[Nugso]

Oh, so those so-called subatomic particles exist within the realm of quantum field.

 

[hilbert2]

It can be created in vacuum. But doesn't vacuum have an enegry?

Vacuum is a state where all quantum fields are in their ground state (state of minimum energy). In principle, the fields have an infinite number of "Fourier modes", all of which have a finite zero-point energy even in the ground state. Therefore, vacuum has an "infinite energy", but this zero-point energy is not a quantity that can be measured, and therefore it can be ignored.

 

[Nugso]

Vacuum is a state where all quantum fields are in their ground state (state of minimum energy). In principle, the fields have an infinite number of "Fourier modes", all of which have a finite zero-point energy even in the ground state. Therefore, vacuum has an "infinite energy", but this zero-point energy is not a quantity that can be measured, and therefore it can be ignored.

I see now! Do you also know that the vacuum state before big bang and the vacuum state we see now are different from each other?

 

[kith]

Oh, so those so-called subatomic particles exist within the realm of quantum field.

Yes. On the most fundamental level, all elementary particles are excitations of their corresponding quantum fields.

 

[Nugatory]

I see now! Do you also know that the vacuum state before big bang and the vacuum state we see now are different from each other?

No such thing

 

[Nugso]

No such thing

I see where you're coming from but I think something had to happen before Big Bang.(though time didn't exist before Big Bang)

 

[Vanadium 50]

We can't discuss "I once read somewhere". If the OP has a link or a reference, we can reopen this thread. Otherwise, we have to guess at what we are trying to explain.

 

[Nugso]

Krauss's A universe from Nothing. I don't think I'm allowed to copypasta though.

 

[Darryl]

Opinion: and from a doco (David Suzuki I think) he talks about 'nothing' and 'nothing', one is what we think of nothing in our known universe, but that nothing contains all sorts of things like, light, energy, gravity, dimensions, and time.

And there is the other nothing which is a compete absence of everything, no space, no time, no light, no energy.
By that definition I would think there is nothing in our Universe that is nothing.

 

[bhobba]

I see where you're coming from but I think something had to happen before Big Bang.(though time didn't exist before Big Bang)

Mind numbing isn't it.

One modern view is it started out from what is known as the false vacuum:
http://en.wikipedia.org/wiki/False_vacuum

For an interesting discussion check out:


Been meaning to watch it for a while now so guess what I am going to do for the next hour or two.

Thanks
Bill

 

[Nugso]

@Darryl, that's why I was trying to figure out what happened before. Thanks!

@bhobba, Thanks for the link and the video. There're still some doubts on my mind about the multiverse theory. Hope the video will answer them.

 

[Maui]

It seems superposition of states are fundamental and the known macroscopic concepts from experience(matter, time, space, life...) arise via decoherence and observation/world-splitting. In this fully consistent with all qm experiments view, there is no before and no after at the most fundamental level. There was an attempt at keeping objective reality fundamental in the Bohmian interpretation but it's no longer fully consistent as superpositions have been indirectly observed/employed and will continue to be utilized in the computing of tomorrow and in that interpretation superpositions were not part of the theory. One of the top physicists once said that if a question seems interesting, it likely has an answer(although per the rules your question on events 'before' the BB falls outside the scope of the forums).

 

[Crazymechanic]

Well quite honestly speaking "before the Big Bang" kinda falls out of everything not only on this forums but on this world...
As till this point physics and the level of knowledge has showed us that we have no actual physical way of knowing before the beginning or in other words the BB.So I believe that it will always be left as a matter of what is most believable and scientifically accurate scenario.

About the nothing nothing , well the one which is the real nothing I believe we have nothing to say about that.One just simply can't say something about nothing.This is actually a philosophical matter.

You got to have faith to believe in nothing... :)

 

[Darryl]

@Darryl, that's why I was trying to figure out what happened before. Thanks!

@bhobba, Thanks for the link and the video. There're still some doubts on my mind about the multiverse theory. Hope the video will answer them.

One possibility I watched on another documentary it think the idea was proposed by Penrose or at least explained by him, considered what happens AFTER the Universe, not before it.

If you consider that everything will eventually degrade to photons, when that occurs you have a universe with nothing but photons, you have no gravity, no dimensions, no distance, and no time.
Sounds a lot like it could have been before the BB.

the moment the last bit of matter ceases to exist, the size of the universe becomes zero, time stops, or starts as the new universe is BB'ed into existence.

That would seem to me that there was time before the BB, and it was the 'stopping of time' that caused the BB to happen at the instant time stopped before the BB, it might be a fundamental that time has to past. If it tries to stop a BB will occur to make it continue !

Sounds like as good a theory to me as any other ..

 

[Nugso]

One possibility I watched on another documentary it think the idea was proposed by Penrose or at least explained by him, considered what happens AFTER the Universe, not before it.

If you consider that everything will eventually degrade to photons, when that occurs you have a universe with nothing but photons, you have no gravity, no dimensions, no distance, and no time.
Sounds a lot like it could have been before the BB.

the moment the last bit of matter ceases to exist, the size of the universe becomes zero, time stops, or starts as the new universe is BB'ed into existence.

That would seem to me that there was time before the BB, and it was the 'stopping of time' that caused the BB to happen at the instant time stopped before the BB, it might be a fundamental that time has to past. If it tries to stop a BB will occur to make it continue !

Sounds like as good a theory to me as any other ..

Thanks, but how could that be possible? If there are going to be protonos can't we as well say that there're going to be dimension(distance between protons that is), gravitiy(the force acting at each other and the force that curves the space and time, though very weak force)?

 

[Nugso]

Well quite honestly speaking "before the Big Bang" kinda falls out of everything not only on this forums but on this world...
As till this point physics and the level of knowledge has showed us that we have no actual physical way of knowing before the beginning or in other words the BB.So I believe that it will always be left as a matter of what is most believable and scientifically accurate scenario.

About the nothing nothing , well the one which is the real nothing I believe we have nothing to say about that.One just simply can't say something about nothing.This is actually a philosophical matter.

You got to have faith to believe in nothing... :)

And I hope we'll someday figure out what happened before the BB.

 

[Crazymechanic]

only theoretically and even then not with a 100% certainty.

 

[ZapperZ]

Hello everyone. I once read an article saying subatomic particles can exist from nothing in a vacuumed space( or something like that). Is that even possible? Or does the energy vacuumed space has turn into mass/matter, hence we thing it exists from nothing?

I'm a bit disappointed with the responses in this thread. It seems that whenever a question like this occurs, the FIRST thing that often gets brought up is the "big bang" or how it came into being due to such vacuum fluctuation. I know the OP later on brought up Krauss's book as the "source", but really, we need to keep in mind two things here:

1. vacuum fluctuation came out of the concept of quantum criticality, which is a consequence of quantum field theory.

2. there are already strong evidence of quantum criticality without having to invoke exotic, still debatable, and still highly unverified idea of "what happened right at or before the Big Bang"!

Quantum criticality, and the existence of quantum critical point, has some of the strongest evidence out of condensed matter. In fact, I can tell you that this might easily be present in the behavior of electrons in metals! How much more "common" and "pedestrian" than that?

The melting of ice is, like most phase transitions, caused by the increase in random thermal motion of the molecules which occurs as the temperature is raised. The ordered arrangement of atoms that exists in the solid cannot be sustained beyond a certain temperature and the crystal melts. Yet research into condensed matter over the past decade has revealed a new kind of phase transition that is driven, not by thermal motion, but by the quantum fluctuations associated with Heisenberg’s uncertainty principle. These quantum fluctuations are called ‘zero-point motion’. According to the uncertainty principle, the more certain a particle’s position, the more uncertain is its velocity. Thus, even when random, thermal motion ceases at the absolute zero temperature, atoms and molecules cannot be at rest because this would simultaneously fix their position and velocity. Instead they adopt a state of constant agitation. Like thermal motion, if zero-point motion becomes too wild, it can melt order, but in this case the melting takes place at absolute zero. Such a quantum phase transition[3] takes place in solid helium, which is so fragile that it requires a pressure to stabilize its crystal lattice even at absolute zero. When the pressure is released, zero-point motions melt the crystal.

The best studied examples of quantum phase transitions involve magnetism in metals. Electrons have a magnetic direction or spin, which when aligned in a regular fashion makes a material magnetic. Iron magnetizes when all the spins inside align in parallel, but in other materials the spins form a staggered, alternating, or antiferromagnetic, arrangement (Fig. 1). These more fragile types of order are more susceptible to melting by zero-point fluctuations. Almost three decades ago theoretical physicist John Hertz, now at Nordita, made the first study of how quantum mechanics would affect phase transitions[4]. Hertz was fascinated by the question of how critical phenomena might be altered by quantum mechanics. Applying quantum mechanics to phase transitions turns out to be very like Einstein’s relativistic unification of space-time. In Hertz’s theory, quantum mechanics appears by including a time dimension to the droplets of nascent order. Normally this produces no additional effect, but Hertz reasoned that if a phase transition took place at absolute zero, then the4 droplets of order that foreshadow the transition would become quantum-mechanical rather than classical. At a zero-temperature phase transition, he reasoned, these quantum droplets would grow to dominate the entire material, changing its properties in measurable ways—and most affected would be the electrons (Fig. 2). Such ‘quantum critical matter’ offers the real prospect of new classes of universal electronic behaviour developing independently of the detailed material behaviour, once the material is driven close to a quantum critical point.

In responding to a question such as this, established first the validity of the idea via results that we already know. Show that this phenomenon is well-known, and that the application of the principle is the only known explanation for these well-established observations. Then show that if this principle works there, then there is a good possibility that it should also work in more "exotic" situations, and that's where someone such as Krauss might apply the concept to the possible beginning of our universe. Jumping straight into the Big Bang gives the impression that this idea has no other evidence to support it, which is patently false! It isn't something that was plucked out of thin air as a crutch to explain the beginning of our universe. It is a concept that has already been known to work elsewhere, and that needs to be established first and foremost!

Zz.

 

[Nugso]

Hello Zz. Sorry for the late reply. I've had hard time translating your post, thanks to my English. :shy: I still don't understand "How much more "common" and "pedestrian" than that?", though.



I'd like to apologize to all those who replied. My apologizes are due to my sidetracking the thread.( From subatomic particles to the BB theory)


Thanks for the article. Reading the whole of it. Will be asking questions as soon as I'm done reading.( Langauge of it seems sort of difficult to me, would take a lot of time)

 

[Nugso]

only theoretically and even then not with a 100% certainty.

Well, you know there's this nice quote; " Quantum theory is a world of possibilities, nothing is certain."