From:	Robert Watkins <robert.watkins@******.COM>
Subject:	Re: Real-Life Computing ...(OT, obviously)
Date:	Thu, 28 May 1998 09:54:11 +1000

Erik Jameson writes:
> Okay. Can someone, in relatively brief terms, explain what this
> is? Don't
> get too technical, don't go too long. But this is something that has
> piqued my interest, so I'd love it if someone could offer an explanation
> suited for the layman who has a bit of knowledge about quantum mechanics.

Quantum computing, and quantum programming, is an experimental technique
that offers a lot of potential for increasing computer power, at the cost of
making it hideously more complex (I know that I would want much better tools
for quantum programming than are available now... even trying to understand
what's going on makes my brain hurt).

Basically, it uses probabilistic outcomes, and this causes all sorts of
funky effects. Instead of a simple XOR gate which follows one of two
outcomes, it follows _both_ outcomes simultaneously. As a result, a quantum
program is in all possible states of its execution at any given time (in
theory. In practice, it's a little harder).

The fundamental principle uses something which I _think_ is called a qubit.
A qubit is a quantum bit. A normal bit has two states: on or off, usually
represented by 1 or 0. A qubit can be represented as a sphere (well, an
ellipsoid in practice), with the two poles representing 1 or 0, and the
surface of the sphere representing the probabilistic range of the qubit.
This is then used as the basis of your computations, the way the bit is used
in normal computations.

Theoretical studies have showed quantum programming to be incredibly
powerful. As an example, it converts a decryption algorithm for cracking
_all standard encryption algorithms_ from an exponential problem to an Order
N problem (instead of taking n^n seconds, it takes n seconds). (Fortunately,
the same boffins who came up with this thing also designed quantum
encryption algorithms).

Now, imagine that the Crash of '29 was caused by an experimental quantum
program, and that was what enabled it to blow through all existing computer
security as if it wasn't there...

That's about the limit of my knowledge. Like I said, it makes my brain hurt.

--
.sig deleted to conserve electrons. robert.watkins@******.com