You are here:

Careers: Physics/zero point particle production

Advertisement

Expert: Daniel Mazur - 9/14/2009


Question
Hello sir, I am a non-scientist adult but very curious about quantum physics.
I read that quantum theory predicts particles and their anti-particles are constantly being produced in the quantum vacuum as a result of the Heisenberg Uncertainty principle. These particle pairs then immediately annihilate, producing photons of various frequencies, thus maintaining the conservation principle of energy. If that is so, then why are we not surrounded by light (photons) of various frequencies? Is it because we somehow cannot see them, or is there another reason? Thanks!

Answer
Hi Edward,

the way I understand it - being an experimentalist and not a theorist - the particle pairs do not spring out of nothing. Vacuum is (!) full of photons and the generation and annihilation of particle pairs is something that is necessary to make the description of vacuum complete. The pathway is: photon -> particle+antiparticle -> photon (of the same energy as the original one). The underlying fact is that we actually ARE surrounded by photons at various frequencies. Some small part of those we can see (that's how vision works, by photons exciting electrical pulses in eye retina), and many other frequencies we can detect by machines.

Cheers,
Daniel

Careers: Physics

All Answers

Answers by Expert:

Ask Experts

Volunteer

Daniel Mazur

Expertise

Questions anyone (teenager, undergrad, graduate, professional) may ask on physics, mathematics or inorganic chemistry. Questions may concern subjects themselves or a possible future career in them, if you need advice on a school or hobby project, or you just came across a question that is beyond your current curriculum. I answer bare textbook problems sometimes, but I reserve the the right to redirect you to Physics-Physics section. The kind of questions I like to answer: I just started having science classes at school and they seem difficult, but I enjoy them. Where do I find more information on this, which is not in textbooks but still comprehensible to me? Just leaving high school, and I feel science is really the thing for me. Can you recommend a school and an undergrad program suitable to my inclinations? I am in my second undergraduate year in Physics. We learned the basics of universe expanding this year, the Hubble constant and all that, but invited speakers that gave talks on astrophysics in our department seemed not to agree with this model at all. Is it of any use at all? I am building a [materials research] experimental device for my masters/doctorate thesis and I have the following problem:... I have tried ..., but it still doesn't work. Where might the problem be?

©2012 About.com, a part of The New York Times Company. All rights reserved.