The usefulness of useless knowledge

FT.com – Tim Harford [no paywall]: “In the 1970s, some basic ideas in supposedly useless number theory were deployed by Ron Rivest, Adi Shamir and Leonard Adleman. They developed the RSA algorithm, which enables public key cryptography, without which there would be no ecommerce. Cryptography is hardly valueless to the military, either. One never knows ...