ELI5: Explain Like I'm 5

Calculus of finite differences

Okay, imagine you have a bunch of numbers written down in a row. Let's say they're 2, 4, 6, 8, 10.

Now, if you know how to count, you can tell that the difference between 2 and 4 is 2, the difference between 4 and 6 is 2, and so on. Those differences are always the same because the numbers are going up by the same amount each time. In fact, you could say the difference between any two consecutive numbers in this row is always 2.

That's basically what calculus of finite differences is all about - looking at patterns in the differences between numbers. But it gets more complicated than just counting.

Let's say you have a row of numbers like this: 2, 5, 10, 17, 26.

If you take the differences between these numbers, you'll get 3, 5, 7, 9. There's a pattern there too - the differences are going up by 2 each time.

But now, things get even more interesting if you take the differences of those differences. That gives you 2, 2, 2. And it turns out that if you keep taking differences of those differences, you eventually get to a row of all zeroes.

This might seem like a weird thing to do, but it's actually really useful in some areas of math and science. It can help you find patterns and make predictions.

So that's the basics of calculus of finite differences - looking at patterns in the differences between numbers. And if you keep taking those differences over and over again, you might be able to discover some really interesting things!