5 ms·

Of course, because nothing matters more than getting the advantage. Same line of thinking that results in depleted uranium tank shells.

amluto 7y ago
Cesium (in the +1 state) appears to be barely toxic at all. Wikipedia puts its LD50 around that of sodium. Cesium metal is extraordinarily dangerous, but it’s so reactive that none of it will survive long enough to get anywhere near the ground.
- blackflame7000 7y ago
  Yea it's Cesium 137 that everyone worries about and it comes from splitting uranium.
jhayward 7y ago
I have some bad news. We used to put tetraethyl lead in automobile fuel and then burn it in cities next to homes and schools.
- saagarjha 7y ago
  More bad news: we still put it in avgas.
  - tjohns 7y ago
    They're working on a replacement for 100LL avgas, thankfully. There's some flight safety concerns that have delayed it, but it's still a work in progress.
    - jabl 7y ago
      Last I heard the project has stalled. And with the current administration there's unlikely to be political pressure to get it rolling.
      - sokoloff 7y ago
        The concerns I have around the project are more in the FAA certification process than in the EPA. I don’t believe this is a partisan issue; it’s stalled under both Democrat and Republican administrations. I think that the 737-Max issue will put so much more spotlight and brakes on anything that seems remotely risky, that the alternative fuels program (which was already struggling as you note) is unlikely to make serious near-term progress. Almost tangentially, I believe that we have a viable fuel technically (G100UL) that is likely to be (or be the template for) the fuel ultimately selected, albeit possibly a decade or more in the future.
        jabl 7y ago
        Last news I've seen is https://www.avweb.com/air-shows-events/unleaded-avgas-all-on-the-same-page-not/ https://www.avweb.com/air-shows-events/unleaded-avgas-all-on... There's also some news at https://www.faa.gov/about/initiatives/avgas/ https://www.faa.gov/about/initiatives/avgas/ , but nothing substantial..
- dr_dshiv 7y ago
  And when we took the lead away, crime dropped like 50% https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesis https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...
DuskStar 7y ago
> Same line of thinking that results in depleted uranium tank shells. Yeah, since neither was particularly toxic, and both offered significant performance gains over the alternatives. (Uranium is extremely dense, self-sharpens on impact instead of mushrooming, and catches fire after penetration giving you an incendiary payload for free. Supposedly, nothing else comes close for tank rounds)
- regularfry 7y ago
  Uranium is... not nice stuff. I wouldn't classify it as "not particularly toxic". https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819790/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819790/
  - sokoloff 7y ago
    This is in the context of a substance we’re trying to use to destroy enemy tanks and kill/injure combatants, not make s’mores out of.
    - jhonkola 7y ago
      Though it remains in the environment even after the operation and civilians will be exposed to it. This has been the case in e.g. Balkans (https://www.nytimes.com/2001/01/07/world/radiation-from-balkan-bombing-alarms-europe.html https://www.nytimes.com/2001/01/07/world/radiation-from-balk...) and also in Iraq (https://www.theguardian.com/world/2014/jun/19/us-depleted-uranium-weapons-civilian-areas-iraq https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...)
  - DuskStar 7y ago
    Perhaps I should have said "not outrageously toxic" or something of that sort, because that does not sound worse than the stuff we make normal bullets out of - lead.
    - regularfry 7y ago
      Lead doesn't shatter the way uranium does, so it's less inclined to form a breathable dust on impact.
jabl 7y ago
Apparently back in the day they were seriously considering ClF5 as the next generation oxidizer for rocket propellants. Implying that the rocket exhaust would to a large extent consist of HF and HCl. Yikes!
- mnw21cam 7y ago
  ITYM ClF3 (Chlorine Trifluoride) which earned the now famous description "hypergolic with test engineers". https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa... Equally funny is where someone thought that it would be a wonderful idea to burn mercaptans in a rocket, which wasn't quite as toxic, but caused the test site to become a no-go zone just from the unbearable stench.
  - UnFleshedOne 7y ago
    Stench on toxic substances is a feature, not a bug :)
  - jabl 7y ago
    As described in Clark's book, ClF3 was discovered first (before WWII actually). But sometime later someone managed to synthesize ClF5 as well, which had slightly better performance as a rocket fuel oxidizer. Although it retained all the other fun properties of ClF3.

amluto 7y ago

Cesium (in the +1 state) appears to be barely toxic at all. Wikipedia puts its LD50 around that of sodium. Cesium metal is extraordinarily dangerous, but it’s so reactive that none of it will survive long enough to get anywhere near the ground.

blackflame7000 7y ago
Yea it's Cesium 137 that everyone worries about and it comes from splitting uranium.

jhayward 7y ago

I have some bad news. We used to put tetraethyl lead in automobile fuel and then burn it in cities next to homes and schools.

saagarjha 7y ago
More bad news: we still put it in avgas.
- tjohns 7y ago
  They're working on a replacement for 100LL avgas, thankfully. There's some flight safety concerns that have delayed it, but it's still a work in progress.
  - jabl 7y ago
    Last I heard the project has stalled. And with the current administration there's unlikely to be political pressure to get it rolling.
    - sokoloff 7y ago
      The concerns I have around the project are more in the FAA certification process than in the EPA. I don’t believe this is a partisan issue; it’s stalled under both Democrat and Republican administrations. I think that the 737-Max issue will put so much more spotlight and brakes on anything that seems remotely risky, that the alternative fuels program (which was already struggling as you note) is unlikely to make serious near-term progress. Almost tangentially, I believe that we have a viable fuel technically (G100UL) that is likely to be (or be the template for) the fuel ultimately selected, albeit possibly a decade or more in the future.
      - jabl 7y ago
        Last news I've seen is https://www.avweb.com/air-shows-events/unleaded-avgas-all-on-the-same-page-not/ https://www.avweb.com/air-shows-events/unleaded-avgas-all-on... There's also some news at https://www.faa.gov/about/initiatives/avgas/ https://www.faa.gov/about/initiatives/avgas/ , but nothing substantial..
dr_dshiv 7y ago
And when we took the lead away, crime dropped like 50% https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesis https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...

DuskStar 7y ago

> Same line of thinking that results in depleted uranium tank shells. Yeah, since neither was particularly toxic, and both offered significant performance gains over the alternatives. (Uranium is extremely dense, self-sharpens on impact instead of mushrooming, and catches fire after penetration giving you an incendiary payload for free. Supposedly, nothing else comes close for tank rounds)

regularfry 7y ago
Uranium is... not nice stuff. I wouldn't classify it as "not particularly toxic". https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819790/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819790/
- sokoloff 7y ago
  This is in the context of a substance we’re trying to use to destroy enemy tanks and kill/injure combatants, not make s’mores out of.
  - jhonkola 7y ago
    Though it remains in the environment even after the operation and civilians will be exposed to it. This has been the case in e.g. Balkans (https://www.nytimes.com/2001/01/07/world/radiation-from-balkan-bombing-alarms-europe.html https://www.nytimes.com/2001/01/07/world/radiation-from-balk...) and also in Iraq (https://www.theguardian.com/world/2014/jun/19/us-depleted-uranium-weapons-civilian-areas-iraq https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...)
- DuskStar 7y ago
  Perhaps I should have said "not outrageously toxic" or something of that sort, because that does not sound worse than the stuff we make normal bullets out of - lead.
  - regularfry 7y ago
    Lead doesn't shatter the way uranium does, so it's less inclined to form a breathable dust on impact.

jabl 7y ago

Apparently back in the day they were seriously considering ClF5 as the next generation oxidizer for rocket propellants. Implying that the rocket exhaust would to a large extent consist of HF and HCl. Yikes!

mnw21cam 7y ago
ITYM ClF3 (Chlorine Trifluoride) which earned the now famous description "hypergolic with test engineers". https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa... Equally funny is where someone thought that it would be a wonderful idea to burn mercaptans in a rocket, which wasn't quite as toxic, but caused the test site to become a no-go zone just from the unbearable stench.
- UnFleshedOne 7y ago
  Stench on toxic substances is a feature, not a bug :)
- jabl 7y ago
  As described in Clark's book, ClF3 was discovered first (before WWII actually). But sometime later someone managed to synthesize ClF5 as well, which had slightly better performance as a rocket fuel oxidizer. Although it retained all the other fun properties of ClF3.