Category Archives: Math

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: 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: Why is it that photographs of wire mesh things, like window screens and grates, have waves in them?

Physicist: There are two major effects that generate waves in pictures. The first is called “aliasing”, and it’s caused by “under-sampling”.  It shows up every now and again when you’re using a digital camera, or when you’re trying to express … Continue reading

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

Q: Will the world end in 2012?

Physicist: Firstly, happy new year! So, there’s been a lot of hoopla around 2012 doomsday stuff for a while.  Maybe not as much fuss as there was over the techno-apocalypse of Y2K, but still.  Although there are a variety of … Continue reading

Posted in -- By the Physicist, Paranoia, Probability, Skepticism | 17 Comments

Q: How do you find the height of a rocket using trigonometry?

The original question was: I am a Physics teacher wanting to measure the height of a rocket.  3 measurers are standing at the corners of an equilateral triangle standing on flat ground.  Each of them measures the angle from horizontal … Continue reading

Posted in -- By the Physicist, Equations, Experiments, Math | 2 Comments