# Monthly Archives: December 2009

## Q: Why does the leading digit 1 appear more often than other digits in all sorts of numbers? What’s the deal with Benford’s Law?

Mathematician: Benford’s Law (sometimes called the Significant-Digit Law) states that when we gather numbers from many different types of random sources (e.g. the front pages of newspapers, tables of physical constants at the back of science textbooks, the heights of … Continue reading

Posted in -- By the Mathematician, Math | 1 Comment

## Q: How does the Monty Hall Problem work?

For those of you who aren’t familiar with The Monty Hall Problem: You’re on a game show where there is a prize hidden behind one of three doors (A, B, or C), and the objective is to guess the correct … Continue reading

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

## Q: How/Why are Quantum Mechanics and Relativity incompatible?

Physicist: Quantum Mechanics (QM) and relativity are both 100% accurate, so far as we have been able to measure (and our measurements are really, really good).  The incompatibility shows up when both QM effects and relativistic effects are large enough … Continue reading

## Q: What the heck are imaginary numbers, how are they useful, and do they really exist?

Mathematician: Imaginary numbers arise quite naturally when you start asking certain basic mathematical questions. Probably the best example is the following: Once we know how to multiply and add, we might ask ourselves “are there any numbers x that satisfy … Continue reading

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

## Q: What’s that third hole in electrical outlets for?

Physicist: Ground. The zero volt, large-slit wire is called the “return” or “neutral” line.  If it seems strange that the power company would supply you with a wire that has no voltage, keep in mind that what you really need … Continue reading

Posted in -- By the Physicist, Engineering | 7 Comments

## Q: Do physicists really believe in true randomness?

Physicist: With very few exceptions, yes.  What we normally call “random” is not truly random, but only appears so.  The randomness is a reflection of our ignorance about the thing being observed, rather than something inherent to it. For example: … Continue reading