Jan 27 2017

Scientists Create Metallic Hydrogen

jupiter-magnetic-fieldIt was just announced that for the first time scientists were able to create a small amount of metallic hydrogen in the lab. This is a significant breakthrough, and is sure to lead to further discovery, although it remains to be seen what specific practical applications may emerge.

Hydrogen, as most people know, is a gas at familiar temperatures and pressures. The universe is comprised of about 90% hydrogen. There is very little free hydrogen on the Earth, since it is a very light gas, but there is lots of hydrogen bound up in molecules, such as water.

In 1935, physicists Eugene Wigner and Hillard Bell Huntington hypothesized that under extreme pressure hydrogen atoms may form into a metal – metallic hydrogen. The point at which this happens was named the Wigner-Huntington transition, which explains the title of the recent paper. Metallic hydrogen can further be a liquid, in which the electrons and protons are free flowing, or they can form a crystalline structure and be a solid.

Astronomers infer that the core of Jupiter may be hot liquid hydrogen. We know that Jupiter is made mostly of hydrogen, and we can calculate that the pressure deep in Jupiter’s core must have millions of times the pressure on the surface of the Earth. That is sufficient pressure, according to theory, to compress hydrogen into its metallic form.

We also know from direct measurement that Jupiter has a very strong magnetic field, with 20,000 times the intrinsic strength and a million times the volume of Earth’s puny magnetic field. A strong planetary magnetic field is caused by the rotation of a conducting material. Earth has a core of liquid iron. So, what is at the core of Jupiter that is generating its much more powerful magnetic field? Currently astronomers believe it is a core of liquid metallic hydrogen.

The difficulty in making metallic hydrogen on Earth is creating the extreme pressures. That is what scientists have finally accomplished. They used diamonds, pressure greater than at the center of the Earth (495 GPa), and extremely cold temperature to achieve solid metallic hydrogen.

As stunning as this achievement is, perhaps more important is what comes next. They will slowly release the pressure to see what happens. There are different theories, but as the authors (Isaac Silvera and Ranga Dias) say, we can theorize endlessly, or we could just see what happens. The big question is – will the metallic hydrogen just revert to regular hydrogen, or will it stay in its metallic state?

The best case scenario will be that the solid metallic hydrogen will be like diamonds, which form under high pressure but are a stable solid once formed. Stable solid metallic hydrogen would likely be a superconductor, and (if it could be produced in quantities – big if) could be used for many electrical applications.

The other possibility is that the metallic hydrogen is metastable at room temperature. This means it is in equilibrium but still will evaporate into gaseous hydrogen from the surface. There are two exciting applications being put forward for metastable metallic hydrogen.

The first is as rocket fuel. When metallic hydrogen turns into gaseous hydrogen it will expand greatly, and can be burned with oxygen. The result would be a rocket fuel with four times the energy density as our current best fuel. That does not sound like much, but it could revolutionize space travel. We could get heavier payloads into orbit with fewer stages.

The second possible application is in fusion reactors. Right now there are efforts to make controlled fusion of hydrogen for the sustained production of clean energy. If we could design and build an operational fusion reactor, that would be a massive game-changer for our energy infrastructure. There is some speculation that metallic hydrogen deuterium may aid in achieving fusion at lower pressures than for regular hydrogen.

There are two huge questions at this time that will determine if metallic hydrogen remains a laboratory curiosity or can be harnessed for practical applications: What happens when the pressure is released, and will it be possible to mass produce?

 

19 responses so far

19 Responses to “Scientists Create Metallic Hydrogen”

  1. SteveAon 27 Jan 2017 at 8:48 am

    Exciting news, but sadly there are some dissenting voices:

    “But physicist Eugene Gregoryanz of the University of Edinburgh, who works on similar experiments, decries the study’s publication as a failure of the journal’s review process. Given the evidence presented in the paper, Gregoryanz is skeptical that the claimed pressures were actually reached and notes that the researchers presented results from only one experiment. “How is it possible to do only one experiment and claim such a big thing?” he says.”

    https://www.sciencenews.org/article/new-claim-staked-metallic-hydrogen

  2. SteveAon 27 Jan 2017 at 8:54 am

    And thinking about it, why haven’t they slowly released the pressure already? Is there something else they have to do first?

  3. pdeboeron 27 Jan 2017 at 9:17 am

    Don’t forget about hydrogen fuel cells. The main problem there is the instability and weight of compressed hydrogen.

  4. Kawarthajonon 27 Jan 2017 at 9:19 am

    You should read the press release from Science Daily. It is full of predictions about how metallic hydrogen will “transform life on Earth”. Yeah, no big deal, just transforming all life on Earth. They may be getting the cart before the horse, not sure.

    The press release is very short on details about the actual experiment, but very heavy on predictions about how this experiment will improve everything!!!!! Maybe they’re looking for more funding…

    https://www.sciencedaily.com/releases/2017/01/170126142854.htm

  5. Ivan Groznyon 27 Jan 2017 at 10:42 am

    “Exciting news, but sadly there are some dissenting voices:”

    those are 3% of contrarians, anomaly hunters and conspiracy theorists…

  6. Steven Novellaon 27 Jan 2017 at 12:29 pm

    Of course this has to be replicated. It is new, so by definition tentative.

    Physicists have been working on this recently, and there was big competition for who could do it first. I wonder if some of the negativity is from competing groups who just got beat out. This does not invalidate their concerns, just gives some context.

    We’ll see how it plays out.

  7. BBBlueon 27 Jan 2017 at 1:01 pm

    But Silvera says that he just wanted to get the news out there before making confirmation tests, which, he says, could break their precious specimen. “We wanted to publish this breakthrough event on this sample,” he says. To preserve the material, he and Dias have kept it in the cryostat; the lab has only two cryostats, and the other is in use for other experiments, he says. “Now that the paper has been accepted, we’re going to do further experiments.” http://www.nature.com/news/physicists-doubt-bold-report-of-metallic-hydrogen-1.21379

    Waiting for their paper to be accepted seems like an odd reason not to do confirmation tests before now. Darwin they are not.

  8. Steven Novellaon 27 Jan 2017 at 1:33 pm

    My guess is they wanted to beat out their competitors, so published as soon as they thought they could justify it. They would hate to be scooped while running confirmatory tests. So we have to treat the findings as preliminary until confirmed.

  9. Kabboron 27 Jan 2017 at 1:45 pm

    Do scientists doing cutting edge research fear that their thunder will get stolen by competing groups if they don’t get their papers in as soon as possible? I’m not in any science research field, so I don’t have a good sense if this is a plausible reason to stop work while the paper is in the review process. It seems to me that if this has such a high bar for potential as stated this is Nobel prize material, and I could see researchers scrambling to get the credit.

  10. BBBlueon 27 Jan 2017 at 2:10 pm

    Imagine a tiny bead of metallic hydrogen stored in the fridge while all this is going on. Do they take a peek every now and then to make sure it is still there? Scientist opens the door: “Alright, who ate my metallic hydrogen!”

  11. pandadeathon 28 Jan 2017 at 9:58 am

    Hi
    I recently left this field and to say there was a competition is to put it very very mildly. Groups have been claiming and refuting production of metallic hydrogen since at the mid nineties (at least that is when the conflict started to get nasty). Since there are relatively few high pressure people (mostly geoscientists and chemists, and a few condensed matter physicists ) everyone knows everyone and to get three peer reviewers who you do not have conflicts of interest is rough. Also you know who your reviewers are due to familiarity with their style and such. Sometimes the reviewers are competitors who ask for ridiculous measures that they know are impossible to stall you paper publication. Other times, you see a negative review and assume that is what is happening. I can’t begin to describe the level of paranoia that goes on there.

    There are two big meetings if this group airapt and the Gordon conference (one each year). This was realeased on arxiv before the meeting. This is typical behavior (I did it myself) and then you gain support for your work and send it to publication after the meeting (I once had two papers stalled in review until the meeting) Its kinda like what I imagine a political convention being

    The Edinburgh group (Gregoryanz McMahon etc) announced the same thing a few years ago (though being more safe called phase IV) and it was opposed heavily by Silvera and his group.

    Personally I hope it is true but that field is toxic and there is a lot of baggage.

    (Btw I was once told by Silvera to never publish the “real experimental tricks” just publish enough to get past the reviewer not enough to give away what you do. And Gregoryanz student announced at a conference that expetimental methods were “trade secrets ” ).

    So take that for what it is worth. It is exciting but honestly it should have happened at least ten years ago and would have if people had worked together.

  12. daedalus2uon 28 Jan 2017 at 11:03 am

    I am pretty sure that even if metallic hydrogen is “stable” enough to be stored, it will never be used as rocket fuel. It will be too dangerous.

    Ozone has a lot of stored energy and would be a much better rocket fuel than oxygen. The problem is that liquid ozone will detonate as a high explosive at the touch of a feather.

    Acetylene has a lot of stored energy and would also be a great rocket fuel. The problem is that it will detonate.

    It would be like trying to launch a rocket filled with nitroglycerine (except nitroglycerine is only “weakly” explosive and is pretty stable by comparison). If anything goes wrong, you have a multi-hundred ton explosion. This would be much worse than launch pad explosions that have already happened because they were not detonations, they were deflagrations. There would be a crater in the launch pad where the rocket was.

  13. Steven Novellaon 28 Jan 2017 at 12:03 pm

    pandadeath – thanks for the info. If you are willing, I would like to cite you as a reference if I talk about that on the SGU, but I need to have a real name. You can e-mail that to me at info@theskepticsguide.org (again, if you are willing).

    Thanks.

  14. pandadeathon 28 Jan 2017 at 1:02 pm

    I will email it.

  15. BBBlueon 28 Jan 2017 at 3:09 pm

    pandadeath- Seems like they could have easily continued work while their paper was being reviewed, or is the strategy in such a competitive environment not to risk the effect of negative results on a pending publication even if one has doubts about the first result?

  16. BillyJoe7on 29 Jan 2017 at 2:39 am

    PD,

    Thanks for taking the time to provide the background.
    It explains a lot.
    Seems open enquiry and free exchange are ideals that are not always satisfied. 🙁

  17. Newcoasteron 29 Jan 2017 at 9:02 pm

    Interesting stuff. I actually first heard about this on The Rachel Maddow Show, and she talked about how intense pressure can change things, and then used that as a segue to the rising pressure from various of the groups opposed to tRump.

    Science…meet politics.

  18. SteveAon 30 Jan 2017 at 4:21 am

    pandadeath:

    Thanks for the insights. Very illuminating. I’d never really considered the implications of the peer review process in such a small community.

  19. pandadeathon 31 Jan 2017 at 10:49 am

    They are definitely still working on it. My understanding is that they have not yet released the pressure to keep the sample until they find a metastable pathway.

    A big issue is that under several GPa, the sample can only be studied remotely. And most people would not accept that it is metallic with transport measurements at least. To fully conclude it is a metal the Fermi surface needs to be mapped.

    I would expect the they are doing structural studies or applying for time to do structure studies. Magnetic studies would be great but not possible since the diamond anvil cell is made of metal.

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