How to pronounce “erato” in English

Now Eratosthenes would have known that you could walk around the world in about 1,000 days if you had a road, of course.

Now that's not Eratosthenes.

- Take the traditional sieve of Eratosthenes again, when we're sieving with just one prime, we just have an over two.

What's cool about both what Eratosthenes did and what his contemporaries did when they figured out the distance to the moon, and the sun, and so on

- So, Eratosthenes, has this idea that you only need to sieve out the primes that are at most square root, the size of the number.

Yeah. So Eratosthenes around 40,000.

It was probably what's called the sieve of Eratosthenes which was the algorithm to try and find all the prime numbers under a certain number.

We're going to use the sieve of Eratosthenes to try and find all the prime numbers.

There was a really brilliant Greek scientist called Eratosthenes, and Eratosthenes noticed that there was a town called Syene, and on a certain date the sun would actually shine

Now the normal version of this tool is called the sieve of Eratosthenes, and it works something like this.

Well, there's your ancient Greek Eratosthenes.

As we zoom out, when Eratosthenes, over 2,000 years ago, first figured out the size of this great ball, Earth, that we live on,

That's Carl Sagan. But he's showing you the technique Eratosthenes used.

The sun was not directly overhead, it was a slight angle, and all that Eratosthenes did was he measured the difference in the angle of the sun.