Virtual Particles: Creation & Destruction in 10-43 Seconds?

[Bararontok]

Then what term is used for the bosons that make up a static force field such as is the case with the photons of a permanent magnet or the gravitons of the Earth's gravitational field but are not traveling independently of each other and are clustered into a given volume depending on the range of the field?

 

[Vanadium 50]

Bararontok, there is no "bosons that make up a static force field" or "traveling" or "clustered" in any sense whatever. You're coming at this from the very direction that got this thread started. Rather than repeat what has been said, let me encourage you to reread the messages already posted.

 

[Bararontok]

Alright, based on what you have said, virtual particles are not real but are just calculation tools used in some of the mathematical forumlas of quantum physics. The actual bosons that are physically detectable and cause force interaction are not classified as virtual but are real and not just abstract mathematical tools. The distinction will be summarized below:

1.) Virtual Particle - mathematical tool used in some quantum physics forumlas.

2.) Real Particle - the actual bosons.

Since virtual particles are non-existent and abstract mathematical tools, why not just call them Math Particles?

 

[jamjr1979]

Unfortunately popularizations in particular seem to misunderstand that the reason we distinguish between "real" and "virtual" particles is that virtual particles are not real.

Hawking radiation (black hole radiation) is built on the principle that the virtual partner particles are realized. Unless I am misunderstanding it. This is not yet proven because the amount of radiation is so small we currently can not detect it. Correct me if I am wrong.

 

[tom.stoer]

Hawking radiation (black hole radiation) is built on the principle that the virtual partner particles are realized. Unless I am misunderstanding it. This is not yet proven because the amount of radiation is so small we currently can not detect it. Correct me if I am wrong.

This is the most common explanation.

I would try to explain it slightly different: Hawking radiation is due to the fact that in curved spacetime (or in spacetime with horizons) there is no unique choice for a vacuum state. Hawking radiation are "vacuum fluctuations" w.r.t. one vacuum state that "become real" w.r.t. a different vacuum state. So a transformation between vacuum states "creates" "real" particles out of vacuum fluctuations (I don't think that this is a better decription - it's just a different one).

A related effect is the Unruh effect where there is no physical curvature but a horizon due to accelerated motion. The Unruh effect shows that it's not essential to have a physical entity like a black hole; an observer-dependend horizon is sufficient to "create" the radiation.

 

[Boy@n]

Note to moderator(s): I've revised my post so it doesn't include link to “crackpot article” and my own speculation. Please do understand that by being a layman I cannot be the judge to which articles are accepted by current science and which aren’t, that’s why I asked about it. By asking here I certainly don’t mislead any layman readers, on the contrary, they too might find those articles by themselves and THEN be misled, as I was re Tesla/ether, so, asking here can only be beneficial for many readers, since once asked mentors and experts here can set the record straight. (I am now afraid to post that link due to warning I got, but I think it should be posted and labeled as crackpot, so others don't get mislead as well.)


Before posting this I've read most of the posts in various threads and articles regarding virtual particles, and as a layman I'd say that from all the reading I understand that virtual-particles are not real per-se (being just a mathematical tool), but that they do represent something (e.g. a field) which is there for real – do I have a proper understanding of this? For example, https://www.physicsforums.com/showpost.php?p=3018700&postcount=63": "Peskin is simply saying that the momentum of a field is real, and therefore any change in momentum is also real, and if quantised can be considered as a particle."

Regarding existence of virtual particles I find it to be a similar question to ask how many discrete steps are there in a continuous space-time. If space-time is truly continuous it's pointless to ask how many steps are there, since there would be infinite amount of them, and thus, moving my hand from point A to point B would be impossible… Well, I am not sure I got this (understanding/analogy) right either, that’s why I mentioned it... can someone please correct me if wrong?

I would try to explain it slightly different: Hawking radiation is due to the fact that in curved spacetime (or in spacetime with horizons) there is no unique choice for a vacuum state. Hawking radiation are "vacuum fluctuations" w.r.t. one vacuum state that "become real" w.r.t. a different vacuum state. So a transformation between vacuum states "creates" "real" particles out of vacuum fluctuations (I don't think that this is a better decription - it's just a different one).

A related effect is the Unruh effect where there is no physical curvature but a horizon due to accelerated motion. The Unruh effect shows that it's not essential to have a physical entity like a black hole; an observer-dependend horizon is sufficient to "create" the radiation.

So, there is SOMETHING within vacuum itself which enables "creation" (of particles/energy), via transformation between vacuum states due to curved space-time due to gravity? If vacuum were “pure void”, so to say, then I don’t see how anything could be possibly created by transformation between vacuum states?

Isn’t creating something out of void/nothingness a logical and physical impossibility? So, how do physicists here take "creation" into account, if there is only true void and not some kind of field (which we might imagine as virtual particles becoming real particles), since real particles are surely not ever-lasting, not even protons, right?

I'd say "Something must exist since ever, or there would be no existence." And since we do exist, where "I exist", or "I am", is certainly the strongest "evidence of existence" for each of us, then what is that something which exists since ever? As said, it cannot be known fundamental particles of our Universe, right? Is it quantum or say vacuum fluctuations, which are mostly in balance, until they aren’t and Big Bang happens (meaning, out of virtual real happens)?

 

[tiny-tim]

Isn’t creating something out of void/nothingness a logical and physical impossibility? So, how do physicists here take "creation" into account, if there is only true void and not some kind of field (which we might imagine as virtual particles becoming real particles), since real particles are surely not ever-lasting, not even protons, right?

Boy@n, you're missing tom stoer's point …

he put ' "create" ' in quote marks to emphasise that nothing is created …

(the radiation is simply vacuum fluctuations with a different name)

there are two different ways of looking at the same thing, related by a very simple transformation …

if something is in one but not in the other, then the transformation has "created" it …

but transformations can't actually create anything, they only provide a different way of looking at the same things …

if they weren't there the first time, they're not there the second time, even if they appear to be

if reversing the transformation appears to destroy something, then was it ever there?​

 

[Boy@n]

Boy@n, you're missing tom stoer's point …

he put ' "create" ' in quote marks to emphasise that nothing is created …

Makes sense - nothing really “new” is created, just something changed in form, so to say. Well, nice to know that, since something cannot be created out of nothing(ness).

Though, this alone still doesn’t help me to understand basics of our physical existence…. We can have transformations going on for eternity, but they for themselves are like non-existent, if they have nothing to transform… Fundamental physical particles, as we know them, are not eternal, right?

So, what’s that which is being transformed (changed in form) since ever? Are quarks eternal? Would string theorist say “strings”?

(the radiation is simply vacuum fluctuations with a different name)

If true it makes me even more puzzled/confused… I imagined radiation to be in domain of observable/measured physical reality, and vacuum fluctuations in domain of unknown/immeasurable virtual reality (e.g. virtual particles pairs popping in existence and almost instantaneously annihilating themselves). Wrong?

there are two different ways of looking at the same thing, related by a very simple transformation …

if something is in one but not in the other, then the transformation has "created" it …

but transformations can't actually create anything, they only provide a different way of looking at the same things …

if they weren't there the first time, they're not there the second time, even if they appear to be

if reversing the transformation appears to destroy something, then was it ever there?​

Is this a riddle? ;) J/K, makes perfect sense, but then again, what’s that “something” which transformation keeps transforming?

P.S. Tiny-tim, I really like your posts, I think they are clear in communicating difficult topics, or let's say, in putting them into quite understandable terms for lay people.

 

[tom.stoer]

The first problem is that "vacuum" and "nothing" are not the same "thing", they are not on the same "ontological level"; "vacuum" means something physically, i.e. something in the context of quantum field theory, whereas "nothing" means something in the context of philosophy.

Second Hawking's (and Unruh's) results show that "physical vacuum" is not "nothing" - which we know since decades - and that there is no unique definition of "nothing" in physics.

 

[Boy@n]

The first problem is that "vacuum" and "nothing" are not the same "thing", they are not on the same "ontological level"; "vacuum" means something physically, i.e. something in the context of quantum field theory, whereas "nothing" means something in the context of philosophy.

Second Hawking's (and Unruh's) results show that "physical vacuum" is not "nothing" - which we know since decades - and that there is no unique definition of "nothing" in physics.

Nice clarification regarding vacuum and nothing(ness), thank you Tom! I hope my next questions will not sound too ignorant or too speculative, I'd just like to make a clearer picture of our existence via the "eyes" of currently prevailing science theories. I hope that you, and others too, can help me out...

Would it be proper to say, that (physical) vacuum, which is and always was filled with fluctuations, "created” our physical reality as we know it (by some kind of powerful vacuum collapse)?

But then, what fluctuates? I guess not quarks, and not Higgs bosons (if proved to exist), right? Is it simply energy, being eternal? Would string theorists call it “strings vibrating”?

Is radiation also present within vacuum or is it just an emergent property once matter is "created"? Similarly, only when matter is present gravity and electromagnetism appear as well, true?

(I’ve put “created” in parenthesis because it seems that “converted” and “transformed” are better words to describe it more properly, since “nothing new” gets really created, just something already existing changes...)

So, in a sense it could be said that "virtual existence (particles)" created the “real existence (particles)”? Well, this would be probably true if we consider “virtual” that which “potentially exists” but it’s simply something which we cannot directly observe and measure… (Thus, “virtual existence” would be “existing” in realm where “everything” in it is smaller than Plank constants.)

Even if vacuum fluctuations do all that, it looks though like that "creation" doesn't happen in our "normal" space-time (if we don't count “creation” of real particles out of virtual particles near the Black Hole horizon, because it's practically impossible to measure that for real, since even background radiation is stronger).

So, true “creation” only happened once, which we call the Big Bang… it surely looks as if something really "unusual" happened at that moment. What could be the possible scenario? What if just before the Big Bang there was the Big Crunch? There being another Universe before ours, which collapsed into itself, which was then immediately followed by birth of our Universe? Simply put, existence of Universe cycling. What are other potential (realistic enough) scenarios in today science? (BTW, I don't think that the Multiverse theory answers "births".)