Are Virtual Particles A New Layer of Reality?
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it when explaining that virtual particles are largely a calculational device, in answers about particle exchange, black hole radiation and QFT methods.
Recommended by 2 people across 2 different months, 2018 to 2023.
What it is
A PBS Space Time episode hosted by Matt O'Dowd on virtual particles in quantum field theory. It explains how they began as a mathematical trick in perturbative calculations and asks whether they reflect something real, noting that lattice (non-perturbative) QFT does without them.
What people said
Recommends Torge · 2019-08 · Physics Stack Exchange · on “Black holes and positive/negative-energy particles”
I just watched PBS Space time on this, which also seems to answer your question. [this video] While I have no doubt the accepted answer is the most complete. I still want to try to explain it in the simple terms I understood it from the video. Disclaimer: I am not a physicist and my answer is most likely wrong/incomplete. a) Virtual particles are first and foremost a mathematical trick for us to be able to calculate the constantly wiggling space-time on a quantum scale. In reality it seems like, when we talk about virtual particles we actually talk about small field fluctuations canceling out each other. b) On the event horizon however those fields are suddenly cut of, so the fluctuation can't ca
Recommends frt132 · 2019-11 · Physics Stack Exchange · on “Do protons exchange photons with electrons?”
For all the people looking to know more about particle interactions, you could go to check Matt O'Dowd from PBS Space Time's excellent video about virtual particles: [this video]
Cites Gonenc · 2018-11 · Physics Stack Exchange · on “Heisenberg energy uncertainty”
This is an excellent question, which clearly demonstrated the lie perpetuated by a lot of people, that the Energy time uncertainty relationship has the same meaning as the momentum and position uncertainty relationship. First of all, there is no energy and time uncertainty. Recall that the uncertainty principle for operators $\hat A$ and $\hat B$ have the form $$ \sigma _ { A } \sigma _ { B } \geq \left| \frac { 1 } { 2 i } \langle [ \hat { A } , \hat { B } ] \rangle \right| = \frac { 1 } { 2 } | \langle [ \hat { A } , \hat { B } ] \rangle | $$ Now there is no "time" operator in quantum mechanics thus, it doesn't make any sense to talk about "time" uncertainty. The best you can do is the fol
Cites Mikayla Eckel Cifrese · 2023-02 · Physics Stack Exchange · on “What does it mean that forces are carried by virtual particles, since virtual particles are just math?”
"This force can *only be present if a photon is exchanged*--and the only type of photons that can be exchanged in this manner in a scattering process are virtual." I don't think that's right. I'm not familiar with the math myself, but PBS Spacetime, who generally know what they're talking about, did an entire episode about how virtual particles, while convenient, aren't actually *necessary* to explain anything. [this video]
Cites Mikayla Eckel Cifrese · 2023-05 · Physics Stack Exchange · on “Does the current form of non-perturbative QFT make all the same predictions as perturbative QFT, or is it incomplete?”
For context, I watched PBS Spacetime's video on virtual particles (link goes to relevant timestamp) [this video] where they say that virtual particles aren't mathematically necessary, because the lattice version of nonperturbative QFT doesn't use them, and yet still makes all the same predictions as perturbative QFT. I was satisfied with that, until I had a brief exchange with someone in the comments of this answer [LINK] where he says that, in most cases, it's impossible to actually do computations in nonperturbative QFT, and, when I asked if this was just due to not having sufficiently efficient algorithms, he said Note that in particular that even establishing the existence of a non-perturbati