Monthly Archives: December 2013

Q: What is radioactivity and why is it sometimes dangerous?

Physicist: Here’s every particle you’ve ever interacted with: protons, neutrons, electrons, and photons*.  Dangerous radiation is nothing more mysterious than one of those particles moving crazy fast. The nucleus of some kinds of atoms are unstable and will, given enough … Continue reading

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

Q: How do we know that π never repeats? If we find enough digits, isn’t it possible that it will eventually start repeating?

Physicist: In physical sciences we catalog information gained through observation (“what’s that?”), then a model is created (“I bet it works like this!”), and then we try to disprove that model by using experiments (“if we’re right, then we should … Continue reading

Posted in -- By the Physicist, Geometry, Logic, Math | 25 Comments

Q: Why does carbon dating detect when things were alive? How are the atoms in living things any different from the atoms in dead things?

Physicist: As far as carbon dating is concerned, the difference between living things and dead things is that living things eat and breathe and dead things are busy with other stuff, like sitting perfectly still.  Eating and breathing is how … Continue reading

Posted in -- By the Physicist, Biology, Particle Physics, Physics | 1 Comment

Q: What role does Dark Matter play in the behavior of things inside the solar system?

Physicist: To a stunningly good approximation: zero. The big difference between dark matter and ordinary matter is that dark matter is “aloof” and doesn’t interact with other stuff.  Instead, it cruises by like “ghost particles”.  Matter on the other hand … Continue reading

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