Category Archives: Physics

Q: How can carbon dating work on things that were never alive?

Physicist: It doesn’t. Carbon dating is the most famous form of “radiometric dating”.  By measuring the trace amounts of radioactive carbon-14 (so named because it has 6 protons and 8 neutrons) in a dead something and comparing it to the … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics | 5 Comments

Teleportation! In space!

Physicist: This isn’t a question anybody asked, just an interesting goings-on. A few weeks ago QUESS (QUantum Experiments at Space Scale) began teleporting quantum information to and from the Micius satellite and between ground stations 1200 km apart.  This is … Continue reading

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

Q: If the world is a giant magnet, how come we can’t build a repelling magnet that can float?

Physicist: Three big reasons: 1) The Earth’s magnetic field is hella weak 2) it’s so big and roughly uniform that there’s no reason for a magnet to go one direction or the other 3) floating a magnet in a magnetic … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 2 Comments

Q: How can something have different amounts of energy from different points of view?

The original question was: … in a scenario with two cars driving towards each other, the system could be measured externally to have an energy equal to the sum of the kinetic energy in the two cars. However, if you … Continue reading

Posted in -- By the Physicist, Physics, Relativity | 29 Comments

Q: Where is the middle of nowhere?

The original question was: Is there any location in intergalactic space which is so far away from anyplace that it would be impossible to see anything with normal naked eye vision?  No stars, but no galaxies, no nothing — just … Continue reading

Posted in Astronomy, Physics | 13 Comments

Q: If light is a wave, then what’s doing the waving?

Physicist: In short: nothing.  Light acts like a wave, but unlike sound waves, light isn’t a material that’s moving back-and-forth. Waves are a coordinated movement of atoms.  A wave itself isn’t made of anything, it’s just a propagating motion through … Continue reading

Posted in -- By the Physicist, Experiments, Physics | 33 Comments