Bob Jenkins' Web Site

July 17 2015 (6pm). New Horizons is beaming pictures back from Pluto. The current one has a fractured plain with some dark things between the plates. I'll speculate that the dark areas are thin lakes of liquid nitrogen, and the plates are frozen methane floating on top of the liquid nitrogen. The nitrogen may all be frozen now, except sort a mushy layer beneath the plates and hotter areas where plates collide. Nitrogen freezes at a higher temperature than the surface of Pluto, so something has to have heated the interior, and the methane ice would be insulating it so it cools slowly.

Most new things show up as rants on my future page.

perpetual motion

Table of Contents (internal links):

Here's a hash table, code for perfect hashing, a good hash function for hash table lookup, a FAQ, some theory, and code to search for new hash functions. I tried designing block ciphers and finding characteristics. I had an article published in Dr. Dobb's in September 1997.
Have the cryptographic pseudorandom number generator ISAAC, a small noncryptographic pseudorandom number generator, a prize for breaking ISAAC, and ISAAC's background and theory. Also take some tests for randomness, and a table of orders of magnitude. Here are also some protocols and a unit vector generator.
See some skits from Boy Scouts, SQL tricks from Oracle, near-future speculations, some paper airplanes, some recipies, some music, and some cartoons that I wrote in college.
Look into pentagonal tiles, formulae for n-body orbit simulations, code for the HOMFLY knot polynomial, voting methods, choosing random passwords, jenny for pairwise testing, some error correction codes, a an april fool's design spec, and a web page for choosing colors.
Consider perpetual motion machines, a dirigiped design, a scale model of the solar system, a page on exploring orbits with Java, Klemperer Rosettes, a simulation of Cruithne (a near-earth object), of figure-eight orbits, of binary star planetary orbits, a set of noncolliding orbits, some Dyson Swarms (pretty pictures!), some methods for the n-body problem, a description of the orbit applet used, and a tentative itzu world.
Home projects
See my half bath, a house design that will never be built, a dollhouse that did get built, some genealogical notes, and a roof rack for Justine's car.
Here is my autobiography, a resume, a cong from the British Museum, a comparison of JPEG and JPEG 2000, a bit on software patents, my mom's art, and some early Bob photos. Here are people I've encountered more than once.

Here are some other sites:

Send mail to Bob at