These curious objects work together very amusingly. If you place the set of 3 solids on a flat surface and place a book on top of them, you will be able to slide the book in any direction completely smoothly, without any up or down movement. Onlookers might think that only 3 spheres would be able to do this, but solids of
constant width can behave in the same way.
5. Take Home Mirage $56.86
Mirage was originally discovered over 30 years ago, when a member of staff at the University of California at Santa Barbara was cleaning around a stack of searchlight reflectors (which are parabolic reflectors of course!) when he noticed that he was trying to clean off some 'dust' that turned out not to actually be there! He showed this to one of the physics professors, and the two of them started making a commercial product, based around the phenomenon that they had accidentally discovered.
4. The Beta Pen $26.84
The solid metal 'nib' consists of a metal alloy, that leaves a mark on most types of paper. If you use the sort of paper typically used in printers and photocopiers, the pen leaves a mark that looks as if it was made by a pencil. However the line will not smudge, and cannot easily be rubbed out. This has a number of advantages, especially if you are left handed!
Since there is no ink, there is nothing to dry out, so the pen will work just as well in 25 years time as it does today.
3. Heat of your Hand Stirling Engine $339.70
The site sells three Stirling engines all uniquely interesting the one I am particularly fond of (pictured above) is the "Heat of your Hand Engine" This ultra low temperature-differential Stirling Engine will actually run on the heat of your hand! Place this beautiful precision engine on any warm surface and within a few minutes it's chugging away. The engine runs whenever the temperatures of the top and bottom plates differ by more than about 10 degrees Celsius.
2.Reversing Goggles $86.90
Since the time of Leonardo da Vinci (1452 - 1519) people have wondered about the fact that the images of the world that fall on our retina are upside down, yet we see the world the right way up. Back in the 1890s the American scientist George Stratton conducted an experiment to see what would happen if he viewed the world through an inverting prism. He found that after 4 days, his brain started to compensate, and he could see the world the right way up again.
1.Pseudoscope Kit $86.90