25 JUN 2013 by ideonexus
T T T=<em>N</em>
Occasionally he made a comment similar to Archimedes' "Eureka!" about a discovery, as he did when he wrong T T T=N. This is part of number theory, the field that Gauss called the Queen of Mathematics. A triangular number T is a number that you can get by adding up a string of consecutive whole numbers beginning with one. The number 6 is triangular because you can get it by adding 1 2 3, and 15 is triangular because you can get it by adding 1 2 3 4 5. The number 5,050, the sum of the first 100...Folksonomies: mathematics
Folksonomies: mathematics
Gauss' beautiful mathematical discovery.
22 JUN 2013 by ideonexus
A Brief History of Signals
Prior to the advent of practical electrical communication, human beings had been signaling over a distance in all kinds of ways. The bell in the church tower called people to religious services or “for whom the bell tolls”—the announcement of a death. We knew a priori several things about church bells. We knew approximately when services were to begin, and we knew that a long, slow tolling of the bells announced death. Thus we could distinguish one from the other, namely a call to relig...Folksonomies: communications signals
Folksonomies: communications signals
From church bells, speech, body language, semaphores, fires, and smoke signals.