News "Metallic Hydrogen Is Going to Change Everything"

[JonnyBGoode]

Scientists Have Found the 'Holy Grail' of Physics, Metallic Hydrogen

The substance has the potential to revolutionize everything from space travel to the energy grid.

getpocket.com

Excerpt:

The best rocket fuel we currently have is liquid hydrogen and liquid oxygen, burned for propellant. The efficacy of such substances is characterized by “specific impulse,” the measure of impulse fuel can give a rocket to propel it forward.

“People at NASA or the Air Force have told me that if they could get an increase from 450 seconds [of specific impulse] to 500 seconds, that would have a huge impact on rocketry,” Isaac Silvera, the Thomas D. Cabot Professor of the Natural Sciences at Harvard University, told Inverse by phone. “If you can trigger metallic hydrogen to recover to the molecular phase, [the energy release] calculated for that is 1700 seconds.”

Metallic hydrogen could potentially enable rockets to get into orbit in a single stage, even allowing humans to explore the outer planets.

 

[kuddel]

[...]
Eugene Wigner and Hillard Bell Huntington predicted that under an immense pressure of around 25 GPa (250,000 atm; 3,600,000 psi) hydrogen would display metallic properties
[...]
The initial prediction about the amount of pressure needed was eventually shown to be too low. Since the first work by Wigner and Huntington, the more modern theoretical calculations point towards higher but nonetheless potentially accessible metallization pressures of around 400 GPa (3,900,000 atm; 58,000,000 psi).
[...]

Good luck with building a pressure vessel for this :/

source: https://en.wikipedia.org/wiki/Metallic_hydrogen

 

[Linguofreak]

Most likely, metallic hydrogen is not stable at STP: you pressurize it to get it into the metallic phase, and it reverts as soon as you let up the pressure. To use it for spaceflight, you would need, as kuddel said, a tremendously strong pressure vessel, which, unless you made incredible advances in materials science, would likely add so much weight to your spacecraft as to eliminate any benefit you'd get from the extra ISP.

But it might be metastable at STP, meaning that it prefers to be normal hydrogen under normal conditions, but when you let up the pressure after forming the stuff, there's an activation energy that must be met before it will revert to normal hydrogen. The problem is that in this case it's likely to be very touchy: if your rocket vibrates to much, maybe the contents of your fuel tank decide to revert to normal hydrogen without waiting to get into the combustion chamber. In this case, there will be a earth shattering kaboom, and you will not go to space today. This also applies if it's not stable, and you're keeping it under pressure, and your pressure vessel isn't quite strong enough and cracks open.

 

[RisingFury]

maybe the contents of your fuel tank decide to revert to normal hydrogen without waiting to get into the combustion chamber. In this case, there will be a earth shattering kaboom, and you will not go to space today.

If there is an earth shattering kaboom, you might just go to space.

 

[jedidia]

Most likely, metallic hydrogen is not stable at STP: you pressurize it to get it into the metallic phase, and it reverts as soon as you let up the pressure.

Isn't the little bit they made stable for at least a while? The way I understood it they are not sure yet whether it is truly metastable in the long run, but it doesn't seem to evaporate instantly when the pressure is taken off. I might be getting some things wrong here, of course, but that's the gist I took away from reading about its first creation a year or so ago.

 

[Linguofreak]

If there is an earth shattering kaboom, you might just go to space.

Your body, or bits of it, may go to space today.

You will not go to space today.

 

[Ajaja]

Yep, no pressure then

 

[jarmonik]

Yes, that could be interesting if the metallic form remains in the standard pressure. Now we would need some kind of Hydrogen-Oxygen Alloy.

 

[jedidia]

Rusty hydrogen?

 

[Xyon]

Yep, no pressure then

Well, that seems to be the question, doesn't it?