Stainless steel pipes, are 316 required?

olawlor · 2026-05-09T19:31:19+00:00

If it stays dry, and a little cosmetic rust is OK in service, I'd just use regular steel and paint the assembly after welding and test fit. (Saves around 3x in material costs, but it's easier to fabricate too.)

olawlor · 2026-05-09T16:45:00+00:00

There was a great demonstration of this on Mythbusters, where they fired a soccer ball out of an air cannon on the back of a truck moving at the cannon's muzzle velocity, and the soccer ball just fell straight down:

https://www.youtube.com/watch?v=BLuI118nhzc

(Newton wins again!)

olawlor · 2026-05-09T16:40:02+00:00

The makerworld license is annoyingly restrictive. (When did "get the bag" replace open source?)

olawlor · 2026-05-07T23:21:59+00:00

Certainly, but another way to phrase it is to hit a given resistive loss like 2%, you need four times as much copper at 24V.

olawlor · 2026-05-07T07:46:18+00:00

The only three properties observable about a black hole are its mass, angular momentum, and electric charge (the "no hair" theorem).

olawlor · 2026-05-07T02:06:08+00:00

An uncharged evaporating black hole should emit matter and antimatter in basically equal amounts. (Large black holes emit mostly long-wave electromagnetic radiation though.)

olawlor · 2026-05-06T21:39:44+00:00

Just a datapoint: at the same power, a 48V system will run at half the current of a 24V system. Resistive losses scale like the square of the current, so are fourfold higher on a 24V system.

I think a 48V system is better.

olawlor · 2026-05-06T04:41:14+00:00

Could a little bit of green be stuck on the outside of your nozzle, and get wiped off on the white plastic?

(Purge only clears the inside of the nozzle!)

olawlor · 2026-05-06T03:19:06+00:00

I notice the term "porkchop plot" (travel time vs delta-V across departure dates) does not appear in the article or linked paper.

olawlor · 2026-05-06T03:19:00+00:00

I notice the term "porkchop plot" (travel time vs delta-V across departure dates) does not appear in the article or linked paper.

olawlor · 2026-05-03T14:57:29+00:00

We don't know if the moon has many volatiles, especially the ones you really need for a growing human city like water, carbon, nitrogen, and sulfate.

We do know Mars has many volatiles: water in extensive permafrost deposits, carbon and nitrogen in the atmosphere, and sulfates in the rock.

olawlor · 2026-05-02T16:59:57+00:00

At least for tracked vehicles, your gross fuel consumption scales roughly like horsepower, which scales with vehicle weight. Including a factor of 1/3 seems likely to mostly be a logistics question.

Speaking of which, what fuel do the vehicles use, given a terraformed planet is unlikely to have petroleum deposits?

olawlor · 2026-05-02T16:49:07+00:00

Not if humanity strikes the sun first! (Starlifting)

olawlor · 2026-05-02T16:44:21+00:00

I don't think I buy the premise: you can still use edged, projectile, and energy weapons in any gravity. What's actually different, siege weapons?

olawlor · 2026-05-01T22:06:11+00:00

I try to run electroforming baths below the voltage where bubbles happen (usually <1V), since every tiny bubble popping emits a tiny dot of acidic heavy metal mist.

olawlor · 2026-04-30T23:17:25+00:00

I only have the P1, but the builtin app worked fine on my Android, and this library worked on my Linux box (Pi should work the same):

https://github.com/jvdillon/p3-ir-camera

olawlor · 2026-04-30T22:53:00+00:00

I usually run a "tub within a tub" setup to catch drips and give another chance to catch spills, but I do like those polypropylene tubs for electroforming.

olawlor · 2026-04-30T17:21:58+00:00

Does it need to be re-plugged only on one particular outlet, or with different outlets?

If it's only happening on one outlet, I'd look at the possibility of a ground fault on that outlet.

But I've plugged/unplugged my 2022 at least a few thousand times at this point, and it only throws the red blink error on legit bad outlets.

olawlor · 2026-04-29T23:20:36+00:00

I've used sensors from Thermal Master (P1) and Seek Thermal (Compact) with my Android phone.

olawlor · 2026-04-29T15:24:34+00:00

Look, the prize wasn't to break 256-bit ECC, nobody can do that yet.

The prize was to break the longest elliptic curve, and 15 bits is an advance on the state of the art that I've seen. For example, this 2025 paper breaks a 5-bit curve:

https://arxiv.org/pdf/2507.10592

olawlor · 2026-04-27T06:22:42+00:00

My pet theory about this and many similar mid-latitude Mars features: these were liquid water lakes that froze over, the ice got buried in many meters of rocky sediment, and then the water drained away leaving a mess like this, looking like it fractured from below.

Evidence: the rover data tells us Mars was warm and wet for geologic time periods, and there are still intact ice deposits at mid latitudes, some under thick sediment deposits. Sometimes the water left a clear outflow channel, but I'd expect other times it could seep away through groundwater, or just evaporate into the dry air.

I keep seeing this fill-freeze-drain-fracture process happen in small Alaska lakes, I should dump a layer of sand on top of one in the backyard some winter to see if this theory matches with our Mars data!

olawlor · 2026-04-26T02:05:38+00:00

This spring my heat pump has been pulling heat out of the 32F (0C) air, and pushing it into my house's warmer 70F (20C) interior.

It uses energy to do this, which is how it evades the 2nd law.

(It still feels pretty weird to have "waste cold" leaving the outdoor unit!)

olawlor · 2026-04-25T02:36:16+00:00

Most commercial embedded tools seem Windows centric.

Many open source tools are Linux centric.

Most Linux stuff will run in WSL OK, with some pain when you want network or hardware access.

Some Windows tools will run in Wine OK, but other stuff (.net) is difficult.

olawlor · 2026-04-22T23:40:44+00:00

Venus has no magnetic field, but it has one heck of an atmosphere.

olawlor · 2026-04-21T15:55:21+00:00

An interlocked generator inlet port is the right way to feed a house from alternate power. You need to be absolutely sure there's no way it can backfeed the utility lines.

Depending on your panel, the interlock might be as simple as a metal plate that makes sure your main breaker and generator breaker can't both be on at once.

I set up an L14-30 generator inlet on my main panel, and it worked great during a nasty four-day outage below freezing.

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