Category Archives: — By the Physicist

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

The nuptial effect

Every day, on average, 2-3 physicists get married.  On Saturday I’ll be attempting to push that average to as high as 3-4. So (for our regular readers), there’ll be a longer gap between posts than usual.  The future Mrs. Physicist … Continue reading

Posted in -- By the Physicist, Combinatorics, Evolution | 23 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: Are numbers real?

Physicist: This question usually comes in the form of “are complex numbers real?” or “are negative numbers real?” or something along those lines.  Turns out you can answer all of these questions at once (if you make up a nice … Continue reading

Posted in -- By the Physicist, Math, Philosophical | 11 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