Greatest Equations Ever

sgant writes "What is your favorite equation? This was the question asked by Physics World in a recent poll. This is also covered in a New York Times article about the same poll. Some of the equations mentioned were the simplistic 1+1=2 and Euler's equation, eⁱ + 1 = 0. What are some of your favorite equations?"

Comments

V=IR

[oddbudman]

Gotta Love V=IR. Works pretty well, I use it daily, well that and P=VI.

Re:V=IR

[djdead]

When I was taking physics for the first time in high school, a EE from MIT taught me the following:

twinkle twinkle little star
power equals I squared R

I remembered it.

Re:sum of cubes

[themusicgod1]

I mean, you're right it does. But man, was I skeptical.

I say, that until I saw the sum of cubes I internally denied the existance of negative numbers. I mean I could work with them and all, I just didn't believe in them. If you deny the existance of negative numbers, you cannot have an expression 0-1, because -1 is meaningless, so therefor the result is meaningless. It's circular reasoning, and this is why[according to my youthful very non-standard way of thinking of things]:

there is a number -1
there is a number 0
if you have two numbers, there is a third number which represents their sum. :.
there is a number -1 + 0

if there is a number -1 + 0 there must be a class of numbers known as negative numbers
[the direction you were going in?]
but if you cannot prove there is a number -1 + 0, you cannot even get that far.

a^3+b^3 = (a+b)(a^2 - ab + b^2 ), on the other hand, shows quite clearly that no matter what numbers a and b you pick, you end up, in your equation, with a negative number.