Solid Hydrogen

Discussion in 'Physics & Math' started by danshawen, May 11, 2017.

  1. danshawen Valued Senior Member

    Messages:
    3,942
    https://www.inverse.com/article/269...ebook&utm_medium=inverse&utm_campaign=organic

    A former colleague of mine in a position to know about such things once told me that solid hydrogen is not a superconductor.

    Perhaps, perhaps not, but now two Harvard physicists claim to have discovered that by adding more pressure to diatomic hydrogen than it would experience at the center of the Earth, the atoms have dissociated into monoatomic hydrogen, which has the potential to boost rocket engine thrusts to unprecedented force.

    The future is here.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. exchemist Valued Senior Member

    Messages:
    6,464
    Rather questionable: https://en.wikipedia.org/wiki/Metallic_hydrogen

    ....especially the claim of metastability, which I cannot substantiate anywhere (nor can I think from a chemical viewpoint why it would be true) and without which metallic hydrogen is just one more exotic curiosity with no immediately obvious applications.
     
    danshawen likes this.
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. danshawen Valued Senior Member

    Messages:
    3,942
    Check the difference in thrust, tabling for a moment the idea that a container strong enough to contain it would likely be very, very heavy.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. exchemist Valued Senior Member

    Messages:
    6,464
    Difference between what and what?

    And what mass does one have to assume for a pressure vessel withstanding 5 million atm.?

    And what does one assume for the cost of generating rocket propellant scale quantities of hydrogen under such pressures?

    The future.....is, er, in the future.
     
    danshawen likes this.
  8. danshawen Valued Senior Member

    Messages:
    3,942
    Hydrogen fuel is as ubiquitous as water. Pressure vessels like those may not be practical to launch from Earth, but other launch sites may be practical.
     
  9. Q-reeus Valued Senior Member

    Messages:
    2,533
    Not the future - the past. As in past thread regurgitated owing to poor memory syndrome: http://www.sciforums.com/threads/metallic-hydrogen-once-theory-becomes-reality.158742/
    My own bucket of cold water input began #12 there.
     
    danshawen likes this.
  10. danshawen Valued Senior Member

    Messages:
    3,942
    This article has just a little more detail. If hydrogen makes a truly metastable solid as this article suggests, then a super strong vessel to contain the pressurized solid form of hydrogen would not be necessary.

    I don't think anyone in the last forum discussion made mention of the possibility of a more advanced form of hydrogen fuel cell technology, with crazy energy densities surpassing the most advanced battery technologies currently available. This would still be possible even if the whole superconductor thing didn't work out.

    Fuel pellet type fusion reactors might also become a practical reality. Fuel pellet type thermonuclear armaments too, of course. Kim Jong Un is probably excited about getting his hands on something like that.

    And so you were all about as excited about this as you were rumors of cold fusion or polywater? What a jaded lot this is.
     
  11. Q-reeus Valued Senior Member

    Messages:
    2,533
    The lack of excitement is owing in part to the mundane nature of the purported 'breakthrough physics'; squeeze hard enough and a phase transition is the natural expectation. In the case of H, it gets down to a triumph of applied technology - diamond anvil refinements to the nth degree.
    A bigger reason for ho hum especially for me is the inherent expensive. Humongous expense. Assuming metastabllity at STP is at all an achievable outcome. Very doubtful.
    Hence my assessment only clandestine intelligence/military applications involving tiny amounts will eventuate if at all.
    Assassination via untraceable micro-explosives. Or pure fusion nuclear weapons - or at least pure fusion triggering of nukes.
    But don't let that stop you and others dreaming of a shiny metallic H future actually benefiting humanity.
     
    Last edited: May 12, 2017
    exchemist and danshawen like this.
  12. danshawen Valued Senior Member

    Messages:
    3,942
    http://www.popularmechanics.com/science/a24945/scientists-may-have-made-metallic-hydrogen/

    This Popular Mechanics article suggests, the Harvard researchers might actually have been viewing metallic aluminum from the aluminum oxide coating on the diamond pressure vessel.

    Somehow, like Neville Longbottom, it's always Harvard (that is embarrassed), and usually when it tries to do anything but business.

    If Popular Mechanics says it is so, what really are the chances...?
     
  13. exchemist Valued Senior Member

    Messages:
    6,464
    What I do not see in any of this is confirmation of the most striking part of the claim, which is metastability.

    I do not see why there should be such metastability: it would depend on the presence of some activation barrier to reversion to diatomic hydrogen - presumably implying great strength in the metallic bonding. But in view of the high ionisation energy of hydrogen - considerably higher than for any element that is metallic at atmospheric pressure - I somehow don't see the delocalisation of electrons needed for a metallic structure being very favoured.

    What is the evidence for metastability? Especially given that the sample allegedly was eventually lost as a result of the anvils breaking - so, er, evidently not that metastable, apparently........
     
    danshawen likes this.
  14. danshawen Valued Senior Member

    Messages:
    3,942
    http://www.sciencemag.org/news/2017...drogen-metal-potentially-ending-80-year-quest

    Please Register or Log in to view the hidden image!



    The former colleague I mentioned in the OP (no superconducting metallic hydrogen) was the director of weapons research programs involving the creation of metallic hydrogen at a national laboratory engaged in that research.

    If it had also been a superconductor transition to the metallic state, this might have made it easier to probe what the Harvard researchers were after, and pure aluminum becomes a superconductor at 1.75 degrees Kelvin.

    The "liquid metal" hydrogen state is not superconducting either, but dissociating one of the hydrogen bonds might open a crack in the door for the requisite Cooper pair transitions to happen.
     
    Last edited: May 12, 2017

Share This Page