First Hot-Ice Computer Created 120
KentuckyFC writes "Sodium acetate is the stuff inside chemical handwarmers that emits heat when it crystalizes after you press that little metal widget. That's why it is known as hot ice. Now a computer scientist in the UK has created a computer made entirely out of hot ice. The device processes information by exploiting the movement and interaction of wavefronts of crystallisation as they move through the material. The data input is in the form of metal wires that trigger crystal nucleation. The output works by reading off the direction of the moving wavefronts and the edges of the resulting crystals. The researcher has created AND and OR gates and solved a few problems such as finding the shortest path through mazes. There are even a few videos of the computer in action. The resulting computer is far from perfect, however. The data readout sometimes gives no solution and at other times gives circular results, the hot ice equivalent of a BSOD."
already being slashdotted, USE THE CACHE, LUKE (Score:5, Informative)
(Patience, it may take a bit for Coral to get the videos cached.)
Re:Err, not a BSOD (Score:5, Informative)
Actually, the analogy of a crash rather than an infinite loop is more appropriate.
In an infinite loop, the same instructions are executed over and over.
In the hot-ice computer, "execution" occurs when the stuff crystallizes. Once the hot-ice crystallizes at a given spot in the matrix, it cannot crystallize again until you reset the system. (by boiling it and melting all of the crystals)
So, when the crystals form into a circular path in the system execution stops because there's no place for the reaction to spread before it stops.
Re:already being slashdotted, USE THE CACHE, LUKE (Score:2, Informative)
http://www.youtube.com/user/Fixarum [youtube.com]
Re:You need a NAND or a NOR gate to make a compute (Score:1, Informative)
All you need is ether an NAND gate or an NOR to make all the other gates and do any sort of computing
Re:You need a NAND or a NOR gate to make a compute (Score:3, Informative)
I'm fully aware of that. This poster [slashdot.org] was slightly confused on that point. What NekoYasha and I were pointing out was that the building blocks they had in Wireland could be used to build NAND or NOR. If you have AND and NOT, you can build NAND, and therefore you can build all the rest. Both the XOR and AND-NOT gates could trivially provide "NOT", and so now you have a path to NAND.
The basic idea is that the question "Is this set of gates strong enough to compute all boolean functions?" can be answered definitively "yes" if you can show some combination of gates in that set can provide either NAND or NOR. If no combination of gates in the set can provide either NAND or NOR, then it's not complete.
The hot-ice computer can't make NAND or NOR yet, only AND or OR. They need to figure out how to make NAND or NOR (probably by figuring out how to make NOT, and combining it with AND or OR).