Tom Elwood -best of the internet.

Sunday, September 6, 2026

Breakthrough 36 passenger electric passenger plane for short-haul 2hr flights

https://youtu.be/nM86DBOqgPM?is=3_Gr-GjwTn2XH1z-

2:53 Jet engines are far more complex - take the turbine blades, for example which must be grown as a single crystal of a nickel super-alloy to withstand the heat and physical forces.

https://youtu.be/QtxVdC7pBQM?is=SCbLua2xNvguGoTK

5:30 they built a 400kW electric motor. (Standard Tesla motors are 137 - 200 kW.)

7:45 actuators: Boeing aircraft have 2 or more backup systems to drive hydraulic systems (electric pump, ram-air turbine in case of total engine failure) — what backup systems will this aircraft have for flight control systems? Maybe a hydraulic pump run by the hybrid engine.

9:45 hardest design challenge was dealing with a diverted flight destination: 1 in every 1000 flights is diverted. That's why they needed a hybrid engine design.

12:55 first flight

So intriguing. Detecting back-scatter reflections that occur at temperature or pressure points in fiberoptic cable can be used to efficiently monitor oil boreholes, seismic activity, elephants walking onto Indian railroads, whales singing in the ocean, and tankers or submarines. Telecom companies often lay down excess cable capacity, and these as-yet unused fibers can be used for such monitoring.

Saturday, September 5, 2026

Tesla ramps up production

https://youtu.be/MvLQ0ygZoqM?is=CNria5Z1NT3uFMfT

Lofty goals to increase production rates to unheard-of rates. Unboxed production explained at 12:32.

Best explanation of JPEG

https://youtu.be/0me3guauqOU?is=K4Bpw4XNWvZMtrfl

Very clear detailed description of how compression happens mathematically.

Best explanation of MP3 music compression

https://youtu.be/jFjDoELxonU?is=iC_N0zX5G_9o8f38

There are a lot of videos out there, but this poorly-edited one is actually one of the better ones.

Also, useful to view this description of how human hearing functions, at 1:31 in this video.

https://youtu.be/jFjDoELxonU?is=iC_N0zX5G_9o8f38

Lidar satellites see more

https://youtu.be/UKLuei1CnZY?is=ZKH-uyd20wjBr7pU

Unimpeded by clouds or smoke, LIDAR satellites pan across Earth's entire surface every 12 days. 2:16 Successive images can be compared to observe sub-mm movement. (That implies the satellite plane above the earth is more stable than a sensor on the ground itself.)

4:09 They mapped the interior of a pyramid by listening to it vibrate [from background seismic vibrations] from space.

Friday, September 4, 2026

Man who made counterfeit $100 bills describes his journey through crime and punishment

https://youtu.be/FGAVpJfG1yQ?is=NlNNU3ase1EYAOy1

This man started counterfeiting at age 19 and spent months protecting his craft and avoiding "bill checker" methods for years and millions of dollars. He used an eye-shadow product to mimic the shiny ink, a fine-tipped glue nozzle to make raised lines, and sprayed a chemical to make the bill-checker pen show the correct color. Ironically, he has to go to bookstores and steal blank pages from Bibles to get the right paper quality.