Monthly Archives: January 2010

Q: Is it possible to choose an item from an infinite set of items such that each one has an equal chance of being selected?

The complete question was: The other day I was trying to explain the difference between “impossible” and “with probability zero” to a friend. I remarked “if you pick an integer, and I pick an integer, the mathematical probability that we … Continue reading

Posted in -- By the Mathematician, Math, Probability | 15 Comments

Q: Do aliens exist?

Physicist: Yuppers.  In as much as the probability that they don’t is effectively zero. The statistics on this are a little weak, since we only have one real data point.  If you define intelligent life as tool-using, then (based on … Continue reading

Posted in -- By the Mathematician, -- By the Physicist, Astronomy, Biology, Evolution, Physics | 6 Comments

Q: Is it true that all matter is simply condensed energy?

The complete question was: Is it true that all matter is simply condensed energy? Does that mean that the Big Bang was pure energy and coalesced into matter? Physicist: Pretty much.  If you can get enough energy into one place … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics, Quantum Theory | 14 Comments

Q: Which is better: Math or Physics?

Physicist: Physics. Mathematician: Math, of course. Can physics do this? Physicist: Lasers, dude. Mathematician: Lasers, shmasers.

Posted in -- By the Mathematician, -- By the Physicist, Math, Philosophical, Physics | 17 Comments

Q: Why is the number 1 not considered a prime number?

Mathematician: Note that when we say that a number is “prime”, all that we are doing is applying a definition that was devised by mathematicians. A prime number is generally defined to be any positive number that has exactly two … Continue reading

Posted in -- By the Mathematician, Math, Number Theory | 10 Comments

Q: If the universe is expanding and all the galaxies are moving away from one another, how is it possible for galaxies to collide?

Physicist: Because the universe isn’t expanding fast enough.  On average all the galaxies are moving apart, but often a given pair will be moving together. Hubble observed that the farther things are away, the faster they’re receding.  Specifically, in the … Continue reading

Posted in -- By the Physicist, Astronomy | 5 Comments