Alvin Toffler wrote back in 1970 in his book Future Shock that the world then was as different from the world of 1923 as the world of 1923 was from Julius Caesar's day. Until the 20th Century, the changes in technology and industry were hardly discernable during a lifetime, but since then change has been traveling at light speed.  And since Toffler wrote, change has been traveling at the speed of neurtrinos – ghostly subatomic particles.