Monthly Archives: October 2010

Q: What is the probability that two randomly chosen people will have been born on the same day?

Physicist: 0.0035% or about 1 in 28,500. The most recent, complete information I could find is the 2000 American census.  There they have the number of people of a particular age sorted into five year blocks, so I assumed a … Continue reading

Posted in -- By the Physicist, Probability | 4 Comments

Q: Which is a better approach to quantum mechanics: Copenhagen or Many Worlds?

Physicist: The Copenhagen interpretation requires that new laws be created that, in addition to being impossible, are completely unnecessary, physically unfeasible, and utterly unjustifiable.  The basic laws of quantum mechanics, when applied at all scales, give you the Many Worlds … Continue reading

Posted in -- By the Physicist, Paranoia, Philosophical, Physics, Quantum Theory, Skepticism | 53 Comments

Q: Why is our vision blurred underwater?

Physicist: The speed of light depends on the medium it moves through.  So as light moves from air to glass, for example, it slows down.  Because light is a little spread out, speeding up or slowing down can make it … Continue reading

Posted in -- By the Physicist, Biology, Physics | 9 Comments

Q: In the NEC “faster than light” experiment, did they really make something go faster than light?

The original question was: I was reading an article by Lijun Wang the experiment I think is called the NEC experiment.  Basically what the guy does is speed up light so that it goes faster than the than the speed … Continue reading

Posted in -- By the Physicist, Physics, Relativity, Skepticism | 14 Comments

Q: How does a Tesla coil work?

Physicist: Stripped down to it’s most essential parts, a Tesla coil is a wire sticking out of the ground. To get sparks to fly out of the top the rest of the machine “sloshes” electrons up and down the wire. … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 45 Comments

Q: What are Feynman diagrams, how are they used (theoretically & practically), and are there alternative/competing diagrams to Feynman’s?

Physicist: Feynman diagrams are primarily a way to keep track of what you’re doing.  Physicists aren’t geniuses or anything, and they get distracted pretty easily. When you’re trying to calculate the probability of a particular particle interaction you’ll find yourself … Continue reading

Posted in -- By the Physicist, Combinatorics, Equations, Particle Physics, Physics, Quantum Theory | 10 Comments