Category Archives: — By the Mathematician

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 | 18 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 | 11 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 | 65 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 | 41 Comments

Q: If two trains move towards each other at certain velocities, and a fly flies between them at a certain constant speed, how much distance will the fly cover before they crash?

The brain teaser comes in a many variations. For example: Trains A and B, 700 miles apart, are heading toward each other on a straight piece of track. Train A is going 85 mph while train B is going 55 … Continue reading

Posted in -- By the Mathematician, Brain Teaser, Math | 13 Comments

Q: What are the Intersecting Chord and Power of a Point Theorems?

Mathematician: The Intersecting Chords theorem asks us to consider two intersecting line segments inside of a circle (such that each line segment starts and ends on the edge of the circle). Each line segment can be thought of as being … Continue reading

Posted in -- By the Mathematician, Geometry, Math | Leave a comment