Why are virtual particles called such?

[StringJunky]

I know , as per the definition mordred gave in another thread: it is that which has less than a quanta of energy, but any idea as to what the thought is behind calling them 'virtual'?

[Velocity_Boy]

Well ive always thought a virtual particle is a transient, very brief fluctuation in a real field of space that, well, might have some of the characteristics of an real particle, but whose existence is limited by the Heisenberg uncertainty principle.

 

And....Virtual particles don't carry the same mass as the corresponding real particle, either, right? But they DO conserve energy and momentum. So The longer the virtual particle exists, the closer it comes to being a real particle.

 

Here's a link you might enjoy. I didn't read it all so it might show some if what I said above to be not exact. I'm no physicist.

 

 

https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

Edited April 30, 2017 by Velocity_Boy

[Mordred]

Correct on all the above and yes virtual particles can have less mass than the real. Also very good descriptive on the VP. +1

 

Now lets look closer at

but any idea as to what the thought is behind calling them 'virtual'?

As there is insufficient momentum of individual VP to cause action. No instrument can measure individual VP. We can detect them under confined regions of a collective quantity to generate measurable action. ie greater than a quanta.

 

For example on confined regions the proton itself. The Prof site link posted above also mentions the 2 up and 1 down quark is only the excess color charge. It is a literal sea of fluctuations/virtual quarks and gluons.

 

Further detail can be found by googling S-Matrix QFT I always add pdf at end you get better results.

Edited April 30, 2017 by Mordred

[StringJunky]

As there is insufficient momentum of individual VP to cause action. No instrument can measure individual VP. We can detect them under confined regions of a collective quantity to generate measurable action. ie greater than a quanta.

 

For example on confined regions the proton itself. The Prof site link posted above also mentions the 2 up and 1 down quark is only the excess color charge. It is a literal sea of fluctuations/virtual quarks and gluons.

 

Further detail can be found by googling S-Matrix QFT I always add pdf at end you get better results.

Right. Cheers Mordred. So, basically, it's because they are not measurable as a single entity but their effects can be measured as ensemble.

Edited April 30, 2017 by StringJunky

[Mordred]

Correct