Tag Archives: Prime Numbers

An ancient Greek algorithm could reveal all-new prime numbers


FIONA MACDONALD is a Journalist and digital media specialist with 10 years experience across print and online media.
Looks after content strategy and partnerships for ScienceAlert.com, and occasionally freelances when she should be sleeping.
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In Science Alert, 28 SEP 2016

In case you missed it, mathematicians are pretty obsessed with prime numbers – the limitless ‘atoms’ of the mathematical world that are only divisible by themselves and one.

People are so into them, in fact, that there’s a continual push (and even financial incentive) to compute larger and larger new prime numbers.

But one of the world’s top mathematicians thinks the key to taking things to the next level could come from an ancient Greek algorithm, called the sieve of Eratosthenes.

The sieve of Eratosthenes is pretty much what it sounds like – a mathematical sieve that helps people filter out prime numbers.

Developed by Eratosthenes of Cyrene, a Greek mathematician and astronomer (and former director of the famed Library of Alexandria) back in around 240 BC, the sieve allows people to determine all the primes between a certain set of numbers.

It works by having you write all the numbers out (say 1 to 100) and then you start crossing numbers off in a particular order – the multiples of 2 (other than 2) are first to go, then the multiples of 3, etc. starting from the next number that hadn’t been crossed out.

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