Category Archives: Math

Q: How do you define the derivatives of the Heaviside, Sign, Absolute Value, and Delta functions? How do they relate to one another?

Physicist: These are four standard reference functions.  In the same way that there are named mathematical constants, like π or e, there are named mathematical functions.  These are among the more famous (after the spotlight hogging trig functions). The absolute value … Continue reading

Posted in -- By the Physicist, Equations, Math | 3 Comments

Q: What does “E=mc2” mean?

Physicist: This famous equation is a little more subtle than it appears.  It does provide a relationship between energy and matter, but importantly it does not say that they’re equivalent. First, it’s worth considering what energy actually is.  Rather than … Continue reading

Posted in -- By the Physicist, Equations, Philosophical, Physics, Relativity | 8 Comments

Q: If you flip a coin forever, are you guaranteed to eventually flip an equal number of heads and tails?

The original question was: Lets say we have a fair coin that is flipped a hundred times and at the end of the trial there have been 40 tails and 60 heads. At this time there have been 20 more heads than … Continue reading

Posted in -- By the Physicist, Math, Probability | 13 Comments

Q: How do we know that π never repeats? If we find enough digits, isn’t it possible that it will eventually start repeating?

Physicist: In physical sciences we catalog information gained through observation (“what’s that?”), then a model is created (“I bet it works like this!”), and then we try to disprove that model by using experiments (“if we’re right, then we should … Continue reading

Posted in -- By the Physicist, Geometry, Logic, Math | 12 Comments

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: How do we know that atomic clocks are accurate?

Physicist: It turns out that there is no way, whatsoever, to look at a single clock and tell whether or not it’s accurate.  A good clock isn’t so much accurate as it consistent.  It takes two clocks to demonstrate consistency, … Continue reading

Posted in -- By the Physicist, Experiments, Logic, Philosophical, Physics | 2 Comments