Quantum physics
6 questions tagged Quantum physics — spanning every one of the seven Ws.
What is the photoelectric effect?
The photoelectric effect is the emission of electrons from a material when it absorbs light of sufficiently high frequency. It helped establish the quantum nature of light.
Which force gives photons their name as force carriers?
The electromagnetic force is carried by photons. Photons are massless, which is why electromagnetism has an effectively unlimited range.
How does the Casimir effect show that empty space is not truly empty?
Two very close uncharged metal plates attract each other because quantum fluctuations in the vacuum are restricted between them. It is a measurable quantum effect.
Why does radioactive decay happen at random times?
Radioactive decay is a quantum process, so you can predict the chance of decay over time but not the exact moment a single atom will decay. The randomness is built into quantum physics.
Which force is carried by particles with no rest mass?
The electromagnetic force is carried by photons, which have no rest mass. That is one reason it has infinite range.
How does the Casimir effect make two metal plates attract each other?
The Casimir effect comes from quantum fluctuations in empty space. When two plates are very close together, fewer virtual electromagnetic modes fit between them, creating a tiny attractive force.