Hacker News: plasmatorch

New comment by plasmatorch in "Ask HN: Who is hiring? (May 2026)"

plasmatorch — Fri, 01 May 2026 18:06:42 +0000

Atomic Machines is building a manufacturing platform for a new class of micromachines, here in the Bay Area. We have open roles in SW/EE/ME.

My team is hiring for this role, ONSITE in Emeryville, CA: https://job-boards.greenhouse.io/atomicmachines/jobs/4113507...

New comment by plasmatorch in "Fluorite lenses: Corrective capabilities beyond ordinary optical glass"

plasmatorch — Wed, 17 Jan 2024 08:53:34 +0000

Aside from cranking the math, here's how I think about it: in the far field of a small aperture, the electric field has spherical phase (think expanding circles), and the field distribution is the Fourier transform of the aperture. A lens is an element that adds spherical phase - a plane wave passing through a convex lens now has a spherical phase distribution. So the lens focal point is now the tiny aperture in that system, and since the math works out the same no matter which way the light is going (reciprocity), the focal point is the FT of the field at the input of the lens.

Goodman is great, Hecht and Zajac covers more fun with optics at an intro level.

New comment by plasmatorch in "Beaming solar energy from space"

plasmatorch — Thu, 03 Nov 2022 02:22:23 +0000

IIRC, it took about 50~100 W from a power supply to beam ~2.5W to a target antenna array, but that was fairly early on, so it's likely better now.

New comment by plasmatorch in "Beaming solar energy from space"

plasmatorch — Thu, 03 Nov 2022 01:01:20 +0000

I worked on this project a few years back, on the power transmission bits. It's pretty cool from the engineering side; the mechanics need to be very light, and unfold into a large area. The beaming part is just a large phased array. The hardest bit is likely high efficiency, cost effective PV cells that can survive in space, but this is a field that Atwater has been in a long time, and is very, very good at.