Low-Background Steel • Hacker News Board

Re: Low-Background Steel

#111

Post by doukdouk » Mon, Jul 20, 2020, 7:35 AM UTC

fennecfoxen wrote: post #74

nix23 wrote: post #72

Earlier quoted context omitted.

> because what else would one use? Energy witch can be food, oil, gas, the energy transformator is a human (or his brain) a maschine or a animal, and the exchange between energie to the endresult is often money. So money/exchangemedium has just the worth both partys agreed on.

Now you are measuring electricity instead of the light you read by, and fuel instead of the vacation trip you take with it. You have worsened the problem I refer to.

Surely energy input is the right metric. If I use a gallon of gas to power a life-saving ambulance or if I burn it just for fun, those two actions should have the same importance.

Re: Low-Background Steel

#112

Post by Razengan » Mon, Jul 20, 2020, 8:45 PM UTC

shantara wrote: post #57

Razengan wrote: post #7

Earlier quoted context omitted.

We already know what can last for literally millions of years: Life. Maybe we could encode some information in birdsong, tree rings, or the matting patterns drawn by fish in the seafloor. :) https://www.youtube.com/watch?v=hpdlQae5wP8

This reminds me of Whisper, one of my favorite exotic alien concepts. The alien civilization in question has selected a planet with as stable environment as possible, and planted it full of genetically engineered grass. The sound of wind blowing through the grass creates an acoustic computer which hosts a virtual space its creators have uploaded themselves into. https://www.orionsarm.com/eg-article/470007b39d192

I have never heard anything like that (using sound) before. Amazing!

Re: Low-Background Steel

#113

Post by burfog » Tue, Jul 21, 2020, 9:32 AM UTC

awalton wrote: post #101

nwallin wrote: post #48

Earlier quoted context omitted.

The Battle of Midway was fought in spectacularly deep water, on the order of 17,000-18,000 feet deep. This would make salvaging difficult, if not impossible. Scapa Flow is shallow enough for divers. Once we run out of cheaply salvageable steel, we'll likely turn to steel smelting processes that do not introduce air into the steel. These processes require dramatically more energy and are thus more expensive, but will…

> Once we run out of cheaply salvageable steel, we'll likely turn to steel smelting processes that do not introduce air into the steel. This would be exceptionally difficult, as oxygen is a basic requirement for steel making as we have ever known it. Steel is made from iron mixed with carbon and then heated to melt. Then oxygen is added which burns the excess carbon into carbon dioxide and reacts with all of the othe…

Start with iron pentacarbonyl, which is conveniently a liquid that can be distilled. That gets rid of nearly all impurities.

Re: Low-Background Steel

#114

Post by missedthecue » Tue, Jul 21, 2020, 8:38 PM UTC

mcculley wrote: post #94

missedthecue wrote: post #91

Earlier quoted context omitted.

Dykes are cheap.

I'm assuming you mean "dike" and not "dyke". Dikes will not protect property in Florida. Our buildings are sitting on top of porous limestone.

oof yes. Dyke is not what i meant.

But florida already has a dike system. Hundreds of miles of them and they work quite well.