[HN Gopher] A milestone in the hunt for metallic hydrogen
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A milestone in the hunt for metallic hydrogen
Author : pseudolus
Score : 66 points
Date : 2020-02-01 11:52 UTC (11 hours ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| abrie wrote:
| Diamond anvil cells are amazing tools. If you find this stuff
| interesting, check out Emma McBride's public SLAC lecture[1],
| "New Materials at the Pressures of Earth's Core"
|
| [1]https://www.youtube.com/watch?v=PL6pI6WAd3Q
| syllable_studio wrote:
| ^ That's pretty darn cool, thanks. Among the things you'll
| learn: - Around 4000 miles into Neptune's crust, there is a sea
| of hydrogen where carbon crystallizes into diamond which falls
| like rain to the center of the planet forming a diamond layer.
| And that layer is actually solid crystals of diamond inside a
| sea of metallic liquid carbon. Lol wat? Damn, nature.
| londons_explore wrote:
| Can anyone here explain to me how a diamond anvil cell works?
| The metal gasket is under the same pressure as the diamond, so
| presumably it would deform and let the pressure out?
|
| And if it were strong enough to contain the pressure, why not
| make the whole thing out of the same metal?
| caconym_ wrote:
| Not an expert, but I believe one big benefit of using diamond
| is that it's easier to observe the sample through it
| (visually as well as X-ray imaging techniques, etc.).
| caconym_ wrote:
| I love the downvote with no explanation.
|
| Nobody has answered the question "why diamond?"
| authoritatively yet. If you know the answer, let's have it;
| otherwise, fuck off.
|
| edit: according to the "Observational Techniques" section
| of [0], "one of the tremendous advantages of the DAC over
| many other high pressure techniques is that the diamond
| anvils are transparent to so many forms of radiation. The
| sample may be viewed at pressure and temperature using an
| optical microscope. Lasers, of various wavelengths, may be
| used to measure optical Raman, Brillouin, or IR spectra.
| X-rays may be used to measure nuclear resonance scattering
| and diffraction from both single and polycrystals."
|
| So if you haven't already fucked off, I cordially invite
| you to do so now, and let the grown-ups talk in peace.
| Thanks.
|
| [0] https://serc.carleton.edu/NAGTWorkshops/mineralogy/mine
| ral_p...
| infinity0 wrote:
| I gave you some extra upvotes on your past comments because
| I think these unexplained downvotes are despicable too.
| caconym_ wrote:
| Heh, thanks. Whatever, though. I don't care about
| downvotes and I'd have jumped in even if it were somebody
| else's comment--I just really don't like to see
| collective moderation tools (is that the right term?)
| used by people who have no clue what they're talking
| about to shut down discussion.
|
| I'm a little sorry to have used such "uncivil" language
| ... but also, I'm not.
| ddebernardy wrote:
| My Physics classes are rusty, but if you've 400GPa across a
| 1mm^2 surface, and the back of the two opposing diamonds is
| e.g. 1cm^2, then you've a straight pressure reduction then
| and there -- not unlike what might happen with a lever or a
| pulley. So you can then apply a smaller force on the outside,
| allowing you to use a less sturdy/expensive cristal or metal
| (or liquid, apparently [0]).
|
| [0]: https://en.wikipedia.org/wiki/Diamond_anvil_cell
| caconym_ wrote:
| This doesn't answer the question of why diamond if the
| gasket material can also stand up to the pressure, though.
| You can certainly make a truncated cone-ish shape out of
| metal.
| Randor wrote:
| Hmmmm,
|
| I'm not a physicist but I've long suspected that Jupiter has a
| metallic hydrogen core.
| flyGuyOnTheSly wrote:
| Hydrogen (being the least massive of all known elements) would
| not accumulate in the core.
|
| Lower mass elements would be displaced by higher mass elements
| like uranium, thorium, gold, platinum, etc...
| londons_explore wrote:
| That depends how dense metallic hydrogen is...
| fnord77 wrote:
| r = 0.076 g/cm3 vs. water = 1.0 g/cm3
| Randor wrote:
| Hmmm,
|
| Well you might want to go over to wikipedia and correct the
| articles: https://en.wikipedia.org/wiki/Jupiter
| https://en.wikipedia.org/wiki/Planetary_core
|
| Like I said, I am not a I'm not a physicist or
| astrophysicist, I am just a software engineer. But in 2017
| when I attempted to model the interior of gas giants... my
| model predicted a core surrounded by high density regions.
| The model resembled a close-packed lattice.
|
| https://en.wikipedia.org/wiki/Close-packing_of_equal_spheres
|
| I was just playing around with math so I am probably wrong.
|
| Best Wishes, -David Delaune
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