Category Archives: — By the Physicist

Q: Is there an intuitive proof for the chain rule?

Physicist: The chain rule is a tool from calculus that says that if you have one function “nested” inside of another, , then the derivative of the whole mess is given by .  There are a number of ways to … Continue reading

Posted in -- By the Physicist, Equations, Math | 12 Comments

Q: How do you write algorithms to enycrypt things?

Physicist: There are several algorithms, but almost all of them are all based on “trap-door encryption”.  The idea is that you find some kind of mathematical process that’s easy to run forward, but effectively impossible to run backward, unless you … Continue reading

Posted in -- By the Physicist, Computer Science, Math, Number Theory | 8 Comments

Q: Satellites experience less time because they’re moving fast, but more time because they’re so high. Is there an orbit where the effects cancel out? Is that useful?

The original question was: I read that due to time dilation from both gravity and speed, GPS satellites need their clocks adjusted to match Earth’s time or else the whole idea would fall flat on its face. So my question … Continue reading

Posted in -- By the Physicist, Physics, Relativity | 11 Comments

Q: Is it possible to objectively quantify the amount of information a sentence contains?

The original question was: It seems to me that it’s impossible to measure the information content of a message without considering the recipient of the message. For example, one might say that a coin toss generates a single bit of … Continue reading

Posted in -- By the Physicist, Entropy/Information | 3 Comments

Q: If you are talking to a distant alien, how would you tell them which way is left and which way is right?

Physicist: Assuming this question isn’t about interstellar political leanings, the answer is: it’s tricky, but it can be done. This is worth trying out just once in your life.  Try to define left and right for someone using only physical … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics | 26 Comments

Q: Would it be possible in the distant future to directly convert matter into energy?

Physicist: You hear about nuclear devices taking advantage of “E=mc2” to turn matter into energy, so nuclear power seems like it might be a good way to go.  But it so happens that everything that releases energy loses mass in … Continue reading

Posted in -- By the Physicist, Mistake, Particle Physics, Physics | 27 Comments