Category Archives: Combinatorics

Q: Are some number patterns more or less likely? Are some betting schemes better than others?

Physicist: First, don’t gamble unless you can be sure you won’t get caught cheating or you enjoy losing money. Games of chance come in two flavors: “completely random” and “not quite completely random”.  It’s not always obvious which is which, … Continue reading

Posted in -- By the Physicist, Combinatorics, Entropy/Information, Math, Probability | 8 Comments

Q: What fair dice can be simulated by adding up other dice?

The original question was: The five platonic solids (tetrahedron, cube, octahedron, dodecahedron, and icosahedron) are often used in games to make 4, 6,8,12, and 20-sided dice respectively. However, if you renumber the dice using nonnegative whole numbers you can create … Continue reading

Posted in -- By the Physicist, Brain Teaser, Combinatorics, Logic, Math, Probability | 4 Comments

The nuptial effect

Every day, on average, 2-3 physicists get married.  On Saturday I’ll be attempting to push that average to as high as 3-4. So (for our regular readers), there’ll be a longer gap between posts than usual.  The future Mrs. Physicist … Continue reading

Posted in -- By the Physicist, Combinatorics, Evolution | 22 Comments

Q: How is radiometric dating reliable? Why is it that one random thing is unpredictable, but many random things together are predictable?

The original question was: Suppose there is a set of variables whose individual values are probably different, and may be anything larger than zero. Can their sum be predicted? If so, is the margin for error less than infinity? This … Continue reading

Posted in -- By the Physicist, Combinatorics, Math, Particle Physics, Probability | 8 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 | 8 Comments

Q: What’s the chance of getting a run of K or more successes (heads) in a row in N Bernoulli trials (coin flips)? Why use approximations when the exact answer is known?

The original question was: Recently I’ve come across a task to calculate the probability that a run of at least K successes occurs in a series of N (K≤N) Bernoulli trials (weighted coin flips), i.e. “what’s the probability that in … Continue reading

Posted in -- By the Mathematician, -- By the Physicist, Combinatorics, Equations, Math, Probability | 34 Comments