With the launch of Apple's new MacBook Air this week, "the world's thinnest notebook", it might be worth reminding ourselves of how far technology has come since, say 1935?
The MacBook Air weighs a tiny 1.3 kilograms compared to the 1935 ballistic computer which weighed 3 tons!
Boing Boing published an interesting post citing part of an article published in the 1935 Science and Mechanics magazine, about the "Ballistic computer of 1935: the 3-ton "Big Brain" that could give a "not necessarily physical picture of the movement of one of the heavenly bodies, but a mathematical picture of it", in (eventual!) answer to the following problem: "... three or more heavenly bodies (like Earth, Sun, and Moon) are moving in their orbits at different rates of speed and varying distances, attracting each other. What will be the combined result of their forces, in changing the positions of each, in a given period?"