Category Archives: Physics

Q: Are there examples of quantum mechanics that can be seen in every-day life, or do they only show up in the lab?

Physicist: The weird effects that show up in quantum mechanics (a lot of them anyway) are due to the wave-nature of the world making itself more apparent.  What we normally think of as “particle behavior” is just what happens when … Continue reading

Posted in -- By the Physicist, Experiments, Quantum Theory | 33 Comments

Q: Why does it take thousands of years for light to escape the Sun?

Physicist: The original statement is often something like, “It takes tens of thousands of years for a photon to get from the core to the surface of the Sun, but only eight minutes to get from the Sun to the … Continue reading

Posted in -- By the Physicist, Math, Particle Physics, Physics, Probability | 15 Comments

Q: What does it mean for light to be stopped or stored?

Physicist: We’ve gotten a handful of questions since this was published and led to articles like this, this, and, this.  In a nutshell, some dudes in Germany (Georg Heinze, Christian Hubrich, and Thomas Halfmann) have found a method to shoot … Continue reading

Posted in -- By the Physicist, Computer Science, Entropy/Information, Experiments, Physics, Quantum Theory | 14 Comments

Q: What are quasi-particles? Why do phonons and photons have such similar names?

Physicist: Prefixes like “quasi-“, “psuedo-“, and sometimes “meta-” are basically used to mean “sorta like… but different… you know?”.  Quasiparticles behave like particles in a few fairly important ways, but aren’t actual particles at all.  The most important way, and … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics, Quantum Theory | 13 Comments

Q: How do you prove that the spacetime interval is always the same?

The original question was: Here’s my current dilemma: how does one rigorously prove the invariance of the space-time interval?  In Taylor & Wheeler’s Spacetime Physics, they basically show one very good example of the invariance, then they instruct the reader … Continue reading

Posted in -- By the Physicist, Geometry, Math, Relativity | 19 Comments

Q: If time were reversed would things fall up?

Physicist: Reversing time seems to reverse how things work.  Instead of growing, plants shrink.  Instead of going forward, airplanes fly backward.  And, “intuitively”, instead of falling down, things fall up.  If you have a video of someone jumping into water, … Continue reading

Posted in -- By the Physicist, Physics | 21 Comments