What is Mersenne's Law and its connection to Pythagoras?

[SkyeLilly]

Can someone please explain what Mersenne's Law is?

 

[mathman]

mechanics) The fundamental frequency of a vibrating string is proportional to the square root of the tension and inversely proportional both to the length and the square root of the mass per unit length.
Above from a google search - you can get a lot more by doing it yourself.

 

[Bob S]

How about a Mersenne prime? See
http://www.mersenne.org/

 

[Cantab Morgan]

Interesting that Mersenne gets the credit for that. Pythagoras said something very similar if I recall.