DonPMitchell

A bit of nostalgia. As a teen, I had a large dangerous chemistry set, and I tried several times to make black powder. With a mortar and pestle, it was never possible to grind it finely enough to burn fast. A friend in college told me he made black powder with a home-made ball mill, and the stuff he made burned in an instant flash. I bought a small ball mill from United Nuclear to try this, but it was only somewhat successful. The lead shot is probably not big enough, but it was still better than the stuff I made in highschool.

SIGGRAPH's recording of my talk on ""Spectrally Optimal Sampling for Distribution Ray Tracing" See: http://mentallandscape.com/Publications.htm

A solution of glycerin and potassium permanganate undergoes a reaction that causes it to go from liquid to solid almost instantly.

Coyotes in the ravine behind my house. They make a variety of different types of calls, including dog-like barks and the classic coyote howls.

The Atlas rocket, designed by Charlie Bossart, had a hull of stainless steel about 1 mm thick and no framework. It was a strong structure, but it required internal pressurization or it would buckle and collapse.

A Night To Remember is an excellent film about the sinking of the Titanic. Made in 1958, there were living witnesses to help with the accuracy of the story. This short snippet illustrates the subtle acting of that era. Without saying it, he's telling her the ship is sinking, and she's getting the message but not freaking out or acting like she's in a TikTok video.

The two VeGa probes deployed a balloon-born probe and a surface lander in 1985. The spacecraft bus continued on to a rendezvous with Halley's Comet.

I chatted with Jordan Peterson on video in 2017. We talked about on-line education.

The Swedish space historian Sven Grahn visited my home in 2013. He shot a 30 minutes interview about my work on the history of Soviet planetary probes.

The flow of shallow water is analogous to 3D flow of compressible gas. Here is a demonstration of a DeLaval nozzle which produces supersonic flow.

Color and height maps of Mars. I'm not happy with the color, but it is difficult to find an accurately colored map of the planet. The real color of Mars is probably more brownish and subdued.

Height and color maps of the Moon.

Color, height and ocean depth maps rendered in ray tracer.

Color and height map rendering of the planet Mercury,

Magnesium burns with an intense ultraviolet-rich light.

Yet another genetic video

Another genetically generated video

A genetic algorithm written in C++ generates random video functions and allows mutation, selection and cross-breeding to allow the user to guide it toward interesting forms.

A model sterling engine run surprisingly fast.

The Texan SS is an air rifle (which is not officially considered to be a firearm). The tank pressure is 3000 psi, and it shots a .45 caliber slug at 1000 feet/sec. Subsonic, but comparable to a .45 hand gun.

A dying tree on my property had to be cut down before it fell (possibly on my house). These guys have a _real_ job, unlike me. :-)

A thick copper pipe slows the fall of a strong magnet by generating an electric current and counter-acting magnetic field.

I rendered a small segment of the "megacycles" model with my new ray tracer. This is rendered in 4K, and I'm seeing if Rumble will support that.

I made color maps and height maps of Venus from Magellan and Venera-15 radar maps. The tint was derived from Venera-14 spectrometer data, the spectrum of the ground divided by the spectrum of the sky, to approximate the color if illuminated by white light. I rendered the sphere as shiny plastic to (literally) highlight the bump mapping.

This was a ray traced animation made by John Amanatides and myself in 1989, using the AT&T Pixel Machine. This was a device that did floating point computation using an array of 32-bit digital signal processing chips made by AT&T. The ray tracer was called FX.