5 ms·

Low-background steel

159 points by valgaze 10y ago

dclowd9901 10y ago
Would pipes in my 1927 house be made of this brand of metal?
- pmiller2 10y ago
  Unlikely. Even if you have galvanized steel pipes, it's a good bet they've been replaced at some point since the house was built.
donatj 10y ago
So am I reading this correctly that there's no solution other than reusing old steel?
- turbohedgehog 10y ago
  No, it's possible, it just requires a pure environment, which costs the manufacturer more than just salvaging ship steel. https://www.reddit.com/r/explainlikeimfive/comments/4opq1p/eli5_why_does_steel_need_to_be_recovered_from/d4f099t?context=3 https://www.reddit.com/r/explainlikeimfive/comments/4opq1p/e... https://en.wikipedia.org/wiki/Scuttling_of_the_German_fleet_in_Scapa_Flow https://en.wikipedia.org/wiki/Scuttling_of_the_German_fleet_...
- sandworm101 10y ago
  It isn't difficult. You just have to filter the oxygen you use when making new steel. But there is such a limited market that I doubt anyone bothers as enough old steel can be found. (I assume there are still plenty of old railway lines out there). It would probably be possible to purify new steel through extensive re-smelting with filtered oxygen.
  - dogma1138 10y ago
    Wouldn't you also need a source of carbon that is not contaminated by nuclear fallout? Afaik it's not the oxygen at all but rather radio isotopes in the air, it's the same reason we can't use carbon dating on anything since the first nuclear test because the isotope ratios are screwed up now and we can't estimate by how much.
    - mikeash 10y ago
      Doesn't the carbon usually come from coal?
      - dogma1138 10y ago
        I don't know for sure hence the question mark :) What I know that Carbon 14 which is used for carbon dating is a cosmogenic isotope which is created when high energy cosmic rays hit carbon atoms in the atmosphere and in other places. Nuclear tests release radiation which created much more carbon 14 than what was created with the natural process of absorbing cosmic rays. I'm not sure what's the current source of carbon for steel, I don't think it's coal it was always too impure and contain allot of contaminants especially sulfur, and I that high end crucible and powdered metal steels are made with considerably more pure and precise sources of carbon, from wikipedia it seems that the source of carbon for modern steel is charcoal (which is affected by C14 imbalance) and coke (which i have no clue if it's affected by post nuclear blast radioisotopes or not) which is refined coal but this only references to modern steel (late 17th century onwards, and I'm not sure what is used today).
        y4mi 10y ago
        sadly, there are not private messages on HN, nor is your eMail public so i'm posting this as a comment. you might be interested in reading this http://hyperboleandahalf.blogspot.de/2010/04/alot-is-better-than-you-at-everything.html http://hyperboleandahalf.blogspot.de/2010/04/alot-is-better-... its a minor typo which you consistently repeat :)
        10y ago
- Herodotus38 10y ago
  One ridiculous idea would be asteroid mining, although I'm not sure what the background radiation would in an asteroid. Plus, the whole cost issue.
  - patall 10y ago
    why would you do that? They need uncontaminated steel not uncontaminated ore. There is plenty of the latter on earth.
    - Herodotus38 10y ago
      One could grab an asteroid primarily composed of water ice, obtain oxygen via hydrolysis and then use either earth mined iron or iron from a different asteroid type. Like I said though the idea is ridiculous. I'm also not sure how much nitrogen is needed in steel making or where the best extra planetary source would be.
  - paulsutter 10y ago
    Along with asteroid mining will be space manufacturing, even 3D printing. It takes a lot less energy to move the finished product than the move the raw materials. 24x7 solar power, and less industrial pollution are other advantages of space manufacturing.
- frozenport 10y ago
  No, the modern technique is to calibrate the device, and hence remove any background effects. Low background steel was used to calibrate some parent device, probably analog.
  - analog31 10y ago
    You can subtract the background, but you can't subtract the noise in the background, which goes as the square root of the number of background counts (typical rule of thumb). So you need low background if you want to detect weak signals above background in a finite amount of time.
    - Houshalter 10y ago
      Why wouldn't it take a finite amount of time? With a large enough sample size, shouldn't any weak effect be distinguishable?
      - analog31 10y ago
        Yes, but the sample size might be limited, for instance for the whole body counter shown in the article. Anecdote: One of my friends in grad school was involved in an accident at a national lab, where some radioactive material was released into the air. He had to sit in a thing that counted gamma rays coming from him, to see if he had consumed any of the bad stuff, and it completely enclosed him in a large scintillation detector. So, he was the sample.
    - frozenport 10y ago
      This is also true, that's why pre-ww2 steel is used by national labs on specialized physics projects. On the other hand I am not aware of commercial medical products that use the stuff.
dave2000 10y ago
It's a bit like Jazz (and to a lessor extent most other forms of music) from before the 1980's, where they started that horrific over-production which made it sound plasticy and homogenous.
- Bromskloss 10y ago
  I'd love to hear an example of this recent jazz, if you have one.
  - dave2000 10y ago
    Pretty much any post 1980's Jazz. You can start off comparing Miles Davis's Amandla with anything he was doing in the '60s or '70s (Live Evil, On the Corner, Cellar Door Sessions etc). Herbie Hancock is another one who did stuff both pre and post 1980. Amandla still has some great tracks, and there's some great post 1980s Jazz out there. But it always sounds like too much attention has been paid to how much reverb there is, how much echo on the drums, and to limit how much the guitar -if present- deviates from permitted parameters. Jazz from the '50s to '70s doesn't have these problems, and a lot of it was extremely well recorded, compared with all the dreadful sounding recordings of most rock from the '60s and '70s.
- aphextron 10y ago
  "Smooth Jazz" can die in a fire
sevenless 10y ago
The same kind of thing pays for archeology with ancient Roman lead: http://physicsworld.com/cws/article/news/2010/apr/23/ancient-romans-join-neutrino-hunt http://physicsworld.com/cws/article/news/2010/apr/23/ancient...

159 points by valgaze 10y ago

dclowd9901 10y ago

Would pipes in my 1927 house be made of this brand of metal?

pmiller2 10y ago
Unlikely. Even if you have galvanized steel pipes, it's a good bet they've been replaced at some point since the house was built.

donatj 10y ago

So am I reading this correctly that there's no solution other than reusing old steel?

turbohedgehog 10y ago
No, it's possible, it just requires a pure environment, which costs the manufacturer more than just salvaging ship steel. https://www.reddit.com/r/explainlikeimfive/comments/4opq1p/eli5_why_does_steel_need_to_be_recovered_from/d4f099t?context=3 https://www.reddit.com/r/explainlikeimfive/comments/4opq1p/e... https://en.wikipedia.org/wiki/Scuttling_of_the_German_fleet_in_Scapa_Flow https://en.wikipedia.org/wiki/Scuttling_of_the_German_fleet_...
sandworm101 10y ago
It isn't difficult. You just have to filter the oxygen you use when making new steel. But there is such a limited market that I doubt anyone bothers as enough old steel can be found. (I assume there are still plenty of old railway lines out there). It would probably be possible to purify new steel through extensive re-smelting with filtered oxygen.
- dogma1138 10y ago
  Wouldn't you also need a source of carbon that is not contaminated by nuclear fallout? Afaik it's not the oxygen at all but rather radio isotopes in the air, it's the same reason we can't use carbon dating on anything since the first nuclear test because the isotope ratios are screwed up now and we can't estimate by how much.
  - mikeash 10y ago
    Doesn't the carbon usually come from coal?
    - dogma1138 10y ago
      I don't know for sure hence the question mark :) What I know that Carbon 14 which is used for carbon dating is a cosmogenic isotope which is created when high energy cosmic rays hit carbon atoms in the atmosphere and in other places. Nuclear tests release radiation which created much more carbon 14 than what was created with the natural process of absorbing cosmic rays. I'm not sure what's the current source of carbon for steel, I don't think it's coal it was always too impure and contain allot of contaminants especially sulfur, and I that high end crucible and powdered metal steels are made with considerably more pure and precise sources of carbon, from wikipedia it seems that the source of carbon for modern steel is charcoal (which is affected by C14 imbalance) and coke (which i have no clue if it's affected by post nuclear blast radioisotopes or not) which is refined coal but this only references to modern steel (late 17th century onwards, and I'm not sure what is used today).
      - y4mi 10y ago
        sadly, there are not private messages on HN, nor is your eMail public so i'm posting this as a comment. you might be interested in reading this http://hyperboleandahalf.blogspot.de/2010/04/alot-is-better-than-you-at-everything.html http://hyperboleandahalf.blogspot.de/2010/04/alot-is-better-... its a minor typo which you consistently repeat :)
        10y ago
Herodotus38 10y ago
One ridiculous idea would be asteroid mining, although I'm not sure what the background radiation would in an asteroid. Plus, the whole cost issue.
- patall 10y ago
  why would you do that? They need uncontaminated steel not uncontaminated ore. There is plenty of the latter on earth.
  - Herodotus38 10y ago
    One could grab an asteroid primarily composed of water ice, obtain oxygen via hydrolysis and then use either earth mined iron or iron from a different asteroid type. Like I said though the idea is ridiculous. I'm also not sure how much nitrogen is needed in steel making or where the best extra planetary source would be.
- paulsutter 10y ago
  Along with asteroid mining will be space manufacturing, even 3D printing. It takes a lot less energy to move the finished product than the move the raw materials. 24x7 solar power, and less industrial pollution are other advantages of space manufacturing.
frozenport 10y ago
No, the modern technique is to calibrate the device, and hence remove any background effects. Low background steel was used to calibrate some parent device, probably analog.
- analog31 10y ago
  You can subtract the background, but you can't subtract the noise in the background, which goes as the square root of the number of background counts (typical rule of thumb). So you need low background if you want to detect weak signals above background in a finite amount of time.
  - Houshalter 10y ago
    Why wouldn't it take a finite amount of time? With a large enough sample size, shouldn't any weak effect be distinguishable?
    - analog31 10y ago
      Yes, but the sample size might be limited, for instance for the whole body counter shown in the article. Anecdote: One of my friends in grad school was involved in an accident at a national lab, where some radioactive material was released into the air. He had to sit in a thing that counted gamma rays coming from him, to see if he had consumed any of the bad stuff, and it completely enclosed him in a large scintillation detector. So, he was the sample.
  - frozenport 10y ago
    This is also true, that's why pre-ww2 steel is used by national labs on specialized physics projects. On the other hand I am not aware of commercial medical products that use the stuff.

dave2000 10y ago

It's a bit like Jazz (and to a lessor extent most other forms of music) from before the 1980's, where they started that horrific over-production which made it sound plasticy and homogenous.

Bromskloss 10y ago
I'd love to hear an example of this recent jazz, if you have one.
- dave2000 10y ago
  Pretty much any post 1980's Jazz. You can start off comparing Miles Davis's Amandla with anything he was doing in the '60s or '70s (Live Evil, On the Corner, Cellar Door Sessions etc). Herbie Hancock is another one who did stuff both pre and post 1980. Amandla still has some great tracks, and there's some great post 1980s Jazz out there. But it always sounds like too much attention has been paid to how much reverb there is, how much echo on the drums, and to limit how much the guitar -if present- deviates from permitted parameters. Jazz from the '50s to '70s doesn't have these problems, and a lot of it was extremely well recorded, compared with all the dreadful sounding recordings of most rock from the '60s and '70s.
aphextron 10y ago
"Smooth Jazz" can die in a fire

sevenless 10y ago

The same kind of thing pays for archeology with ancient Roman lead: http://physicsworld.com/cws/article/news/2010/apr/23/ancient-romans-join-neutrino-hunt http://physicsworld.com/cws/article/news/2010/apr/23/ancient...