Latest Approved Revision on: Tue. 06/03/2003
Tin crystals promenade across copper, stopping now and then to trade places with a counterpart, using choreography akin to the "camphor dance"--a phenomenon first observed in 1686.
The discovery of dancing tin, reported 24 November 2000 in Science's Nanotechnology Issue, may promise surprisingly efficient nanomotors, if researchers can harness this chemical locomotion system.
By manipulating the surface energies that drive tin crystals to move across copper, it might also be possible to control such movements, thereby forcing alloys to form desired nanoshapes, according to researchers with the Sandia National Laboratories in Livermore,…
Latest Approved Revision on: Wed. 09/18/2002
A high tech "tomb rider" robot helps scientist to find out about one of the biggest mysteries. But it has unlocked one mystery only to reveal another. The Great Pyramid (the Pyramid of Khufu, or Cheops in Greek) at Gizeh, Egypt, demonstrates the remarkable character of its placement on the face of the Earth.
Latest Approved Revision on: Mon. 08/12/2002
In a drafty shed in rural northern California is perhaps the rarest Macintosh ever made: an electronically shielded Mac used by a spy or military agency. The machine appears to be unique, and is so secret, no one knows anything about it.
Sitting on a dusty shelf in an old Boulder Creek, California, barn owned by programmer and author Bruce Damer, the Macintosh SE 30 1891 T at first appears to be a standard all-in-one Mac from the mid-1980s.
Latest Approved Revision on: Fri. 12/06/2002
Abacus is an instrument used in performing arithmetic calculations. It's a mechanical aid used for counting; it is not a calculator in the sense we use the word today. The person operating the abacus performs calculations in their head and uses the abacus to keep track of the sums, the carrys, etc.
The device evolved from a simple need to count numbers. Merchants trading goods not only needed a way to count goods bought and sold, but also to quickly calculate the cost of those goods. Until numbers were invented, these counting devices were used to…