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Scientists Finally Turn Hydrogen Into a Metal, Ending a 80-Year Quest (arstechnica.com)
An anonymous reader quotes a report from Ars Technica: In 1935, scientists predicted that the simplest element, hydrogen, could also become metallic under pressure, and they calculated that it would take 25 GigaPascals to force this transition (each Gigapascal is about 10,000 atmospheres of pressure). That estimate, in the words of the people who have finally made metallic hydrogen, "was way off." It took until last year for us to reach pressures where the normal form of hydrogen started breaking down into individual atoms -- at 380 GigaPascals. Now, a pair of Harvard researchers has upped the pressure quite a bit more, and they have finally made hydrogen into a metal. All of these high-pressure studies rely on what are called diamond anvils. This hardware places small samples between two diamonds, which are hard enough to stand up to extreme pressure. As the diamonds are forced together, the pressure keeps going up. Current calculations suggested that metallic hydrogen might require just a slight boost in pressure from the earlier work, at pressures as low as 400 GigaPascals. But the researchers behind the new work, Ranga Dias and Isaac Silvera, discovered it needed quite a bit more than that. In making that discovery, they also came to a separate realization: normal diamonds weren't up to the task. "Diamond failure," they note, "is the principal limitation for achieving the required pressures to observe SMH," where SMH means "solid metallic hydrogen" rather than "shaking my head." The team came up with some ideas about what might be causing the diamonds to fail and corrected them. One possibility was surface defects, so they etched all diamonds down by five microns to eliminate these. Another problem may be that hydrogen under pressure could be forced into the diamond itself, weakening it. So they cooled the hydrogen to slow diffusion and added material to the anvil that absorbed free hydrogen. Shining lasers through the diamond seemed to trigger failures, so they switched to other sources of light to probe the sample. After loading the sample and cranking up the pressure (literally -- they turned a handcrank), they witnessed hydrogen's breakdown at high pressure, which converted it from a clear sample to a black substance, as had been described previously. But then, somewhere between 465 and 495 GigaPascals, the sample turned reflective, a key feature of metals The study has been published in the journal Science.
Done 20 years ago in a gas gun:
http://www.nytimes.com/1996/03/26/science/big-gun-makes-hydrogen-into-a-metal.html
From the article,
Metallic hydrogen may be a room temperature superconductor and metastable when the pressure is released and could have an important impact on energy and rocketry.
Here's Wikipedia's take on the issue:
Basic research generates new ideas, principles, and theories, which may not be immediately utilized but nonetheless form the basis of progress and development in different fields. Today's computers, for example, could not exist without research in pure mathematics conducted over a century ago, for which there was no known practical application at the time. Basic research rarely helps practitioners directly with their everyday concerns; nevertheless, it stimulates new ways of thinking that have the potential to revolutionize and dramatically improve how practitioners deal with a problem in the future.[5]
I don't care if it's 90,000 hectares. That lake was not my doing.
So, we could pump 3.8 billion mega-watts through a wire no thicker than a human hair.
All known and predicted superconductors have a magnetic field limit where superconductivity breaks down. The higher the current density in a wire, the higher the magnetic field strength, so hence there is a limit to how much current you can put through a superconductor of a given size, and it is low enough to mean you need decent sized wires still. The exact limit depends on the material and the temperature, and so you see high temperature superconductors that work at liquid nitrogen temperatures used with the more expensive liquid helium so more current can be crammed through them.
, but the way superconductors work is by essentially pushing the electron next to them to the side.
All conductors work this way. The actual drift speed of electrons in even a copper wire is quite small.
you could effectively have faster-than-light communication
Nope, the electrons push on each other using the electromagnetic force, which moves at the speed of light or slower. The electrons at the end of the wire don't push on the other end instantly, and the force gets communicated down the wire at a speed slower than c.
We already have transparent aluminum, and have for a long time.
It's just in the past couple of years that they've developed a method to make large sheets of it.
A belief based on science. In other words, they haven't tested it yet, but the formula using current data indicates it may happen.
No faith required.
Hey, they've believed hydrogen would become metallic when exposed to enough pressure. It took a long time to test it, but guess what, it does! At around 495 gigapascals, a pressure we hadn't been able to do until just recently.
Aluminium oxynitride
Pics cuz it happened.
It was just the wrong Wikipedia link. In reality, Ice IX it was.
Water is a horrible reflector, only reflecting ~5% at normal incidence, as does anything else with an index of refraction around 1-2. Also, just about any smooth material is reflective at shallow angles. This both comes from Fresnel equations. To get anything close to a metal-like reflectivity of >50% at normal incidence requires a very large real component to the index of refraction.
Number of protons determines the element. "The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen isotope, protium, has no neutron in the nucleus."
Freezing hydrogen may make it solid, but certainly not a metalFreezing hydrogen may make it solid, but certainly not a metal.
Why not? Metal is not a binary state of being where either you are or you are not. It sounds awfully exotic, but it is actually more common than most people realise. Take for example tin.
Tin as you know it is a metal. Shiny, conductive of heat and electricity, alloys with other metals freely, etc. That is in fact beta tin. Tin has another form, alpha tin, which is dull and insulating and decidedly nonmetallic. This form is the most stable below about 13 degrees C in pure tin. What's more, it's autocatalytic and will cause beta tin to transform to alpha tin. It also takes up more space, so the transformation is destructive and known as "tin pest". It has destroyed numerous things over the course of history.
If you like (I recommend it), you can watch time lapse videos on youtube where a solid block of metal tin turns to grey powder over the course of hours when cooled to a quite low temperature.
If you go look at the periodic table, there's a diagonal line which separates non metals from metals. Everything near the line does not behave entirely in ways that one might consider a metal to behave. Aluminium for example, is not quite such a metallic metal as you might think. It's pretty metallic, but in some ways behaves in distinctly nonmetallic ways. Tin is near the line. Hydrogen is on it.
SJW n. One who posts facts.
I, for one, wanted to see pictures (why does no one ever think of the pictures??!). There are some here: https://www.thenews.com.pk/lat...
Sapphire is aluminum oxide, Al2O3. Oxides are not salts. It's a transparent ceramic.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
The densities and measurements they give show that the hydrogen in the metallic state they created is only about 10 times denser than other forms of solid hydrogen that have been around a long time and two orders of magnitude lower density than what NIF achieves at much higher temperatures. Your reaction rate drops to effectively zero (less than 0.1 reactions per second for a cubic meter of the stuff) at 1 million Kelvin for such a density for a mixture of deuterium and tritium, and is even slower for just deuterium. The reaction rates at the low end drops about four orders of magnitude for every order of magnitude drop in temperature...
Maybe you should look into estimates about deuterium fusion in brown dwarfs and how deuterium fusion doesn't happen even in Jupiter because you need nearly ten times its mass to get enough pressure.
Metal is a state of matter, not a category of elements.
Carbon is a metal.
No it ain't. It is sometimes considered a metalloid, but I've never heard it considered to be a metal.
it is opaque
Er, well, diamond isn't, nor is lonsdaleite.
and shiny
Graphite is only a bit. Fullerenes certainly aren't. Diamond is, as is glassy carbon and londsdaleite.
Are you going to claim that diamond is not a metal
Yes. Elements can be both metals and nonmetals. Tin for example is usually a metal, with all the expected properties (shiny, condctive of heat and electricity, ductile), but if the tin pest strikes you end up with nonmetallic tin which is dull, brittle and insulating.
Very few things in science fit into nearly deeined boxes. Metallicness is one of those.
SJW n. One who posts facts.