# Mathematics

In 1837, Charles Babbage invented *The Analytical Engine*, a
mechanical card-programmed digital computer which anticipated almost
every aspect of the electronic computers which would not appear for
more than a century afterward. These pages are a virtual museum where you can
explore the Engine both through historical documents and a Java-based
*emulator* which allows you to experience for yourself what it
would have been like to program a steam-powered computer.
Cellular Automata Laboratory
invites you to explore the world of cellular automata with
the aid of high-speed programmable simulators for both
MS-DOS and Windows. Cellular automata rules are defined
by short programs written in Java, C, Pascal, or BASIC; rule
definitions in Java can be compiled even if you don't have
a Java compiler by using a Web-based compilation server.
The accompanying on-line
laboratory manual,
equivalent to more than 250 printed pages, explains
the theory of cellular automata, how to use the simulator
programs, documents the many
ready-to-run rules included,
describes how to create your own original experiments,
and contains a comprehensive
bibliography.
Five.
A neural network simulator
memory demonstration for the Commodore 64--really!
Includes complete source code in BASIC.
An informal introduction to analysis of experiments to determine
whether results are significant or consistent with chance.
Independent binary processes such as coin flipping and the output of
hardware random bit sequence generators are the focus of the
discussion.
The
Probability Pipe
Organ lets you run interactive experiments which demonstrate how
the results from random data approach the normal
distribution expectation as the number of experiments grows large.
**Update:** HTML5 animation eliminates the need for Java applet
support. (The Java version
remains available.)

A program for the analysis (*not generation*) of random and
pseudorandom sequences. A variety of tests, including many from
Knuth, are applied to the contents of a file and the results reported
on standard output. In portable C; public domain. October 1998
update adds frequency histogram display, optional analysis of input as
a bitstream, CSV output for postprocessing by other programs, and
improved HTML documentation.
Before computers and calculators, there were slide rules. It is difficult for people today to appreciate just how magic it was to be
able to carry a small tool, made of bamboo and plastic, that could perform many of the computations of engineering and science which
used to be so tedious in mere seconds, as long as you were happy with its limited precision.
This document explores this vintage computing tool, using it to solve a variety of
problems ranging from loading a turnip truck to interstellar flight.
A simple mathematical game reminiscent of blackjack invites
you to flex both your intuitive and formal analytical
skills, while demonstrating how superficially unrelated topics
in mathematics may be deeply connected when examined in
more detail.
What can you learn, in three years of computer time, about
an obscure problem in recreational mathematics? Not very
much, at least in this case. But hey, negative results
are still results, right? And still the Quest beckons to
your idle loop. In 1995, Tim
Irvin continued the Quest to two million digits.
His story
illustrates both how fast computers have gotten in the the last five years,
and how much of that power is often devoted to the idle loop.