Bertrand's Postulate and Erdős' Proof

[Gear300]

Hello.
Is there a quick proof for showing that the next prime is within twice the current prime?

Edit:
Never mind. Erdős had given a proof of this (of Bertrand's postulate to be precise) at a fairly young age.

http://www3.nd.edu/~dgalvin1/pdf/bertrand.pdf

 

[jedishrfu]

Thanks for sharing this.