Monthly Archives: March 2012

Q: The information contained in a big system isn’t the same as the amount of information in its parts. Why?

The original question was: Information doesn’t behave like any other quantifiable property. For example, to describe something which can be in any of 8 states, I would need 3 bits of information. To describe something which can be in any … Continue reading

Posted in -- By the Physicist, Entropy/Information, Math | Leave a comment

Q: Is the quantum zeno effect a real thing?

Quick aside: “Zeno’s paradox” was originally proposed (probably) by Zeno, who was basically trying to show that movement is impossible.  His idea was that in order to get to where you’re going you need to cover half of the distance, … Continue reading

Posted in -- By the Physicist, Physics, Quantum Theory | 6 Comments

π day!

We suddenly got hit with a barrage of π questions today.  Turns out it’s not a coincidence. π is defined, very humbly, as the ratio of the circumference of any circle to its diameter.  From that definition alone it’s managed … Continue reading

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

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 | 11 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 | 5 Comments