

Virtual particles aren't particles (2011) - krohling
http://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

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adekok
The "virtual" particles are intended to avoid the "action at a distance" issue
with fields. The virtual particles are place-holders for calculations.

They came about from looking at the philosophical problem of "What is a
field"? A field between two interacting electrons changes the electrons
trajectory.

OK... but what does it mean for the electrons to "interact"? Saying "there's a
field" is just a circular argument.

The better response is "they exchange a photon". OK, but is the photon real?
No... it's just a place-holder to make calculations easier.

Do two electrons _actually_ exchange virtual photons? No one really knows...
All we can say is that the theoretical calculations match the experimental
ones. What that _means_ is a question for philosophers. :)

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hvs
Is it a question for philosophers, though? Or is it just a current limitation
of our model that we don't understand? They are obviously "communicating"
somehow. The mechanism is simply unknown.

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tfgg
Virtual particles are an artefact of the calculation method usually used,
perturbation theory, and the Feynmann diagrams that produces. They needn't
exist with other methods.

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reagency
Why is physics is not an artifact of the calculation method used?

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jbb555
This is an amazing article that's made a lot of things much clearer for me. To
stop thinking of particles as "things" and start thinking of them as certain
configurations of a field. Perhaps it makes sense to think of them as
configurations that the mathematics ensures are somehow stable.

And then virtual particles and other interactions make a lot more sense. They
are just other configurations.

My new understanding might not be correct but this article has certainly
opened my eyes and suddenly a lot of previous things make a lot more sense!

~~~
JonnieCache
Strassler has a lot of articles of this kind on his site, highly recommended.
Check the articles menu on his homepage. There's a nice series on dark matter.

There's also this page with various links:
[http://profmattstrassler.com/about/about-this-site-and-
how-t...](http://profmattstrassler.com/about/about-this-site-and-how-to-use-
it/)

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ilitirit
Something that I found rather interesting but still don't quite understand is
the effect of the Uncertainty Principle in a vacuum. Apparently the
Uncertainty Principle affects not only particles, but fields as well (which in
my mind is possibly due to the mass/energy equivalence?). This manifests as
disturbances, which is what causes these virtual particles to "appear" in a
vacuum.

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em3rgent0rdr
thanks. Human language seems to be an impediment to understanding here due to
previous definitions of terms. Sometimes, it is better to create a completely
new term than overload an old already-understood term.

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amelius
Didn't read the article, but aren't the "holes" as encountered in
semiconductor physics also virtual particles? Or is this a new concept?

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danbruc
That is something different, holes are quasiparticles [1], phenomena that show
characteristics of and can be mathematically described like particles but are
not particles but for example collections of particles or the absence of a
particles in case of a holes. They really show particle like behaviour while
virtual particles don't.

[1]
[https://en.wikipedia.org/wiki/Quasiparticle](https://en.wikipedia.org/wiki/Quasiparticle)

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reilly3000
Wouldn't "emergent particle" be a better term? The fact that it is a side
effect of multiple particles doesn't make its effects less tangible. It feels
like object orientation is clouding our perception.

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murbard2
Programming analogy:

There are several ways to implement the laws of physics. Virtual particles are
an implementation detail, you can factor them out of the code, but it makes it
a bit more readable.

