Quantum fluctuations

[Buket]

Are quantum fluctuations physical?

[swansont]

I assume you mean virtual particles popping into and out of existence. They are virtual particles, not real ones.

[MigL]

They can be, in that they lead to measurable effects.

[swansont]

They can be, in that they lead to measurable effects.

 

 

We have lots of things that aren't real in physics that lead to measurable effects. Many of our models describe that very situation.

[StringJunky]

 

 

We have lots of things that aren't real in physics that lead to measurable effects. Many of our models describe that very situation.

Are they defined as 'not real' because the measurements are not direct but inferred from indirectly associated/directly associated effects that they produce?

Edited August 29, 2016 by StringJunky

[Strange]

I always think of "holes" as charge carriers in semiconductors when this comes up. I don't know if they are real or not.

[StringJunky]

I always think of "holes" as charge carriers in semiconductors when this comes up. I don't know if they are real or not.

I think I see what you mean: a hole in that scenario is considered an artifact and not just a lack of something. Virtual particles are treated the same way?

Edited August 29, 2016 by StringJunky

[swansont]

Are they defined as 'not real' because the measurements are not direct but inferred from indirectly associated/directly associated effects that they produce?

 

 

Yes. You can't measure the particle itself. So it could be something else that behaves the same way.

[StringJunky]

 

 

Yes. You can't measure the particle itself. So it could be something else that behaves the same way.

Right.

[Cynic]

Isn't Lawrence Krauss in his talk about a Universe from Nothing making the case that virtual particles have mass, since he is saying that "nothing weighs something". Therefore shouldn't they be physical?

 

https://m.youtube.com/watch?v=-EilZ4VY5Vs

[swansont]

You have to add energy to them in order to detect the particles.

[Cynic]

You have to add energy to them in order to detect the particles.

But does that negate the possibility of them being physical? He says in his talk, correct me if I misconstrue him, that the major portion of the mass of a proton is contained in the "empty space" between the subatomic particles. So it would seem there's mass, regardless of whether we try to detect it. Have patience, you're dealing with a biologist.

Edited September 22, 2016 by Cynic

[StringJunky]

But does that negate the possibility of them being physical? He says in his talk, correct me if I misconstrue him, that the major portion of the mass of a proton is contained in the "empty space" between the subatomic particles. So it would seem there's mass, regardless of whether we try to detect it. Have patience, you're dealing with a biologist.

You need to absorb this, what swansont said here, then you will realise the question whether they are physical is moot:

 

 

 

Yes. You can't measure the particle itself. So it could be something else that behaves the same way.

Edited September 22, 2016 by StringJunky

[swansont]

But does that negate the possibility of them being physical? He says in his talk, correct me if I misconstrue him, that the major portion of the mass of a proton is contained in the "empty space" between the subatomic particles. So it would seem there's mass, regardless of whether we try to detect it. Have patience, you're dealing with a biologist.

With protons, the issue is that you can't pull the quarks out to measure them. The mass is due to the interaction between them. But we can scatter other particles off of them, which is one way how we know they exist. They aren't virtual particles.