Comment by dschuetz | Hacker News Reader

Comment by dschuetz | Hacker News Reader

Parent Full thread

Because there is no way to build a machine to generate continuously very strong magnetic fields (the limit is just below 40T iirc, by room temperature, Bitter Electromagnets). This is magnitudes lower than a 1200T pulse in that article. 40T is barely enough to lift up a small animal and keep it suspended in the air, because of the blood iron and water. How would you continuously crush hydrogen with that? The magnetic flux is way to weak on the atomic scale.

One could argue, why not use superconducting electromagnets (used in fusion machines), but surprisingly the limit is lower there, something above 20T!

So, pulses are much stronger, but also very short. Continuously strong fields need insane machinery which might have thermodynamic limits of what is possible to achieve.

Thanks for your answer. I'm really curious how practical metallic hydrogen it.

>How would you continuously crush hydrogen with that?

Why do you the crush to be continuous? I thought the idea of metallic hydrogen was that it is stable once you get it in a metallic state.

Applying continuous pressure on solid hydrogen is equivalent to keeping the ice cool to prevent melting. On earth, I suppose, solid hydrogen would melt, boil and slowly evaporate without external pressure, if not furiously explode when mixing with oxygen. The better questions are, does it take less pressure to keep hydrogen solid than continuously and literally crushing it? Besides that, how do you keep solid hydrogen under pressure from all directions at once?

metallic hydrogen is believed to be metastable, predicted to remain a solid down to 20-40GPa (60-120T).

there are two main hypothetical uses for it: a solid rocket fuel (with a x4 increase in specific impulse) and a superconducting wire with zero transmission loss across long distances (making solar farms in remote places attractive). there may also be military applications eg. hypersonic thermobaric weapon delivery systems.

the other replies in this thread are more realistic. the experiment is likely to study what happens to atoms in high magnetic fields, electrons for example start to pool together in strange ways. as with most scientific research, useful applications are often beyond the horizon and emerge from serendipitous discovery.

Reply on news.ycombinator.com