[HN Gopher] What a solid made of electrons looks like
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What a solid made of electrons looks like
Author : gmays
Score : 100 points
Date : 2021-10-01 16:30 UTC (6 hours ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| HenryKissinger wrote:
| Fantastic.
|
| Can Wigner crystals be applied to weaponry? The Department of
| Defense would be _very_ interested.
|
| Cheers,
|
| Henry Kissinger
| eliseumds wrote:
| lol
| fallingfrog wrote:
| I imagine a solid made only of electrons would in fact be a bomb,
| and an absurdly powerful one too. More powerful than a
| thermonuclear warhead pound for pound, by a big margin.
| Koshkin wrote:
| Unless there's too many of them:
|
| https://en.wikipedia.org/wiki/Degenerate_matter
| adrian_b wrote:
| Link to the original article in Arxiv:
|
| https://arxiv.org/abs/2106.10599
| ionwake wrote:
| I saw no photo on mobile or is that just me ?
| qwertox wrote:
| Visible on mobile, a blue photo. Works in full browser as well
| as in a WebView.
| ahmedfromtunis wrote:
| The title is so clickbaity that it became anti-clickbait
| (aclickbaity?): I clicked not to learn how this is even possible,
| but to find out what the eventual catch was.
|
| A better title would be: Here's the first photo ever of a layer
| of pure electrons. Still click-attracting, yet factually correct
| (as far as I understand).
| elil17 wrote:
| I don't see how that's not an accurate title. Graphene is a
| solid and it's very thin.
| ahmedfromtunis wrote:
| Graphene sure is a solid, but it's made out of atoms.
| However, the thin layer of electrons wedged between the the
| other parts of the atoms does *not*, to my knowledge,
| constitute a solid.
| pininja wrote:
| Is their "scanning tunnelling microscope" similar to a atomic
| force microscope [0]? It also drags a probe over the surface so
| I'm wondering if they are in the same family.
|
| [0] https://youtu.be/2Kv6KwADn7Q
| hexane360 wrote:
| They're similar. However, an AFM directly measures the
| deflection of a probe you're rastering, while a STM measures
| the current caused by quantum tunneling between the probe and
| the sample. This is extremely sensitive to height because an
| electron's wavefunction degrades as e^(-sqrt(2*m_e*E)*x/hbar)
| with distance x and energy barrier E.
| ellyagg wrote:
| How hard would it be to make a crystal visible to the naked eye?
| SCUSKU wrote:
| Can anyone explain to me what the implications of this
| achievement are? What properties does an electron crystal have?
| And what are its potential applications?
| elil17 wrote:
| As I understand it there are no known uses.
| latchkey wrote:
| I can only imagine the excitement in the room after running the
| same experiment with the graphene layer on top and seeing this
| result. I bet it was huge hi-fives!
| pdonis wrote:
| The phrase "a solid made of electrons" is rather misleading. It's
| just an ordinary solid (a semiconductor) in which the electrons
| are made to adopt a particular configuration that does not occur
| naturally. It is _not_ a "solid" that is only composed of
| electrons, with no atomic nuclei present.
| crispyambulance wrote:
| The first paragraph of the article clearly describes what the
| title is actually getting at. It's a perfectly fine title that
| catches interest. If the conditions are just
| right, some of the electrons inside a material will arrange
| themselves into a tidy honeycomb pattern -- like a solid within
| a solid. Physicists have now directly imaged these 'Wigner
| crystals', named after the Hungarian-born theorist Eugene
| Wigner, who first imagined them almost 90 years ago.
| Koshkin wrote:
| I think the confusion may be the result of a chain of vague
| associations (or, perhaps, of the "broken telephone effect"):
| "adopt a particular configuration" -> regular spatial
| arrangement -> crystal lattice -> crystal-like -> crystal ->
| solid.
| Pulcinella wrote:
| Solvated electrons are kind of _liquid_ electrons in that they
| are a liquid and the anion is just a free electron instead of
| bound to something.
|
| https://en.wikipedia.org/wiki/Solvated_electron
|
| They can be used to, among other things, reduce pseudoephedrine
| to methamphetamine.
| vbezhenar wrote:
| A solid made of electrons would wreak lots of havoc. Probably
| worse than solid made of antimatter.
| gfody wrote:
| so _not_ the strong-interaction material from 3bp? damn
| hilbert42 wrote:
| Right, that headline had me a bit fazed too. I envisioned a
| sort of 'crystal' of electrons packed together like people in a
| tightly packed elevator or oranges in a box.
|
| My mind boggles, if electrons were packed like this then we'd
| need conditions somewhere between those of a neutron star and a
| black hole singularity I'd imagine.
|
| Does anyone have any concept of what such matter would look
| like - its properties, etc.?
| zardo wrote:
| > Does anyone have any concept of what such matter would look
| like - its properties, etc.?
|
| It would have a lot of charge.
| grok22 wrote:
| phased => fazed? https://www.merriam-webster.com/words-at-
| play/phase-vs-faze; sorry off-topic
| hilbert42 wrote:
| _Duh, ucks, how did miss that? Thanks for that, I 've now
| corrected it. It's what happens when posting from a phone
| whilst on the move. Most timely correction too, if I'd
| reread it tomorrow when too late to correct it then I would
| really have been fazed! Here's an upvote. :-)_
| lisper wrote:
| https://news.ycombinator.com/item?id=28469275
| ddingus wrote:
| Thanks for that!
|
| I read the piece, saw the headline and was immediately
| confused: Like we can have matter that is ELECTRONS only?
| jerf wrote:
| Even science reporters are having a hard time keeping up with
| what materials science has been up to lately. With no
| disrespect to them really intended, they can just about keep up
| with the semiconductor world's concept of tracking "holes"
| rather than electrons, but it seems like going any farther into
| the quasiparticle world is just too much for them. It's rare to
| see an article that doesn't have some sort of verbiage that
| indicates the reporter doesn't really understanding what's
| going on, if indeed I've ever seen one at all.
| OJFord wrote:
| In undeserved fairness, I think it's 'just' a clickbait
| headline, and the author does have a better understanding
| than you suggest.
|
| The article quickly explains (even the caption on the lead
| image) that it's an arrangement within a normal solid sheet.
|
| I don't really understand in what sense the internal electron
| arrangement is 'a solid', but hey, as clickbait, it worked.
| pininja wrote:
| I think this is the same argument made by Veritasium -
| poorly summarized: do whatever it takes to hook people in
| that have never heard the topic before, then teach them
| something new. https://youtu.be/S2xHZPH5Sng
| OJFord wrote:
| But you make it sound like a good thing! I don't like it
| at all.
| jacobolus wrote:
| Are there any recent summaries by materials scientists
| written for laypeople?
| karaterobot wrote:
| I get that it's hard.
|
| Often, I'll read a science article in a blog, or local
| newspaper, or general-interest magazine. I'll see something
| obviously incorrect, and say "well, it's not a science
| outlet, they can't be expected to know the science that well,
| and they're just explaining it to lay people anyway, so it's
| good enough. I'll double check this with a reliable science
| news source."
|
| But you'd think if anyone could get it right, and trust their
| readers to care about them getting it right, it would be
| Nature! If Nature is going to start going to lower their
| standards to go after clicks, I dunno what reliable source
| I'm supposed to double check things with.
| TeMPOraL wrote:
| > _If Nature is going to start going to lower their
| standards to go after clicks, I dunno what reliable source
| I 'm supposed to double check things with._
|
| Reddit.
|
| I'm serious. If you search for the discussion about the
| news article on a right subreddit, or HN, or spelunk
| Twitter enough, there's a good chance you'll find a domain
| expert - sometimes even the paper's author themselves, or
| someone who works with them - explaining the science
| correctly and/or pointing out the bullshit in the press
| report.
|
| (I wonder if it wouldn't be more efficient if scientists
| were writing press releases themselves, and the
| journalists/PR people would be chasing grants for them
| instead. It seems like a better match for their individual
| skills anyway.)
| xnyan wrote:
| >Reddit
|
| >I wonder if it wouldn't be more efficient if scientists
| were writing press releases themselves
|
| Agree, and I think everyone here has experienced the
| phenomenon where someone on reddit/HN/twitter has
| explained something far better than a media outlet. The
| thing to keep in mind when trying to understand this is
| that absolutely __everyone__ responds to incentives. With
| a news organization, no matter what that organization is
| or their goals, the chief incentive is readership, not
| accuracy or anything else. Not saying that the writers
| are anything other than well intentioned and honest or
| that they don't care deeply about the truth, but the
| reality of mortal existence is to maximize behaviors that
| you believe benefit you.
|
| A news org is benefited by people reading what they say,
| not by being right. Reddit/twitter/HN often is a better
| source of truth because people often post because they
| have a desire to be heard, be understood, share
| information, tell the truth or some other reason that
| does not involve selling ads against you reading what
| they say.
| ceejayoz wrote:
| > Agree, and I think everyone here has experienced the
| phenomenon where someone on reddit/HN/twitter has
| explained something far better than a media outlet.
|
| I've experienced the opposite, though, too.
|
| Posts with thousands upon thousands of upvotes and a
| little comment with a dozen saying "this is entirely
| wrong, and here's a bunch of proof, and here's an expert
| explaining it properly".
| prox wrote:
| r/Askscience is pretty good though more often than not.
| It depends a lot on which sub you are in.
| LargoLasskhyfv wrote:
| Sounds like messy _decentralised authority_ to most, I
| guess.
|
| How could _that_ even work?
| smoldesu wrote:
| I think I've been lied to infinitely more times on Reddit
| than I have been on PBS.
| all2 wrote:
| There's a quote about this that I rather like
|
| > "Briefly stated, the Gell-Mann Amnesia effect is as
| follows. You open the newspaper to an article on some
| subject you know well. In Murray's case, physics. In mine,
| show business. You read the article and see the journalist
| has absolutely no understanding of either the facts or the
| issues. Often, the article is so wrong it actually presents
| the story backward--reversing cause and effect. I call
| these the "wet streets cause rain" stories. Paper's full of
| them.
|
| > In any case, you read with exasperation or amusement the
| multiple errors in a story, and then turn the page to
| national or international affairs, and read as if the rest
| of the newspaper was somehow more accurate about Palestine
| than the baloney you just read. You turn the page, and
| forget what you know." - Michael Crichton (1942-2008)
|
| Pulled from https://www.epsilontheory.com/gell-mann-
| amnesia/
| xondono wrote:
| I really wonder how much is willful ignorance for the benefit
| of clickbait
| mabub24 wrote:
| A lot of reporters don't get final say on the headlines for
| their articles. That could be the case here.
| xxpor wrote:
| My first reaction to the headline was "I wonder how many teslas
| the magnets they're using to keep it together are?"
| colechristensen wrote:
| It's essentially impossible to make an electron-only
| substance. The highest density normal-matter stars (white
| dwarfs) are kept from collapsing with the force of electric
| repulsion in atoms and they do collapse by proton-electron
| collision and conversion into neutrons.
|
| From Feynman:
|
| If you were standing at arm's length from someone and each of
| you had one percent more electrons than protons, the
| repelling force would be incredible. How great? Enough to
| lift the Empire State Building? No! To lift Mount Everest?
| No! The repulsion would be enough to lift a "weight" equal to
| that of the entire earth!
| eloff wrote:
| Wow! That is a great visualization of how strong the forces
| are. It's incredibly strong, I had no idea
| a1369209993 wrote:
| > If you were standing at arm's length from someone and
| each of you had one percent more electrons than
| protons[[0]]
|
| The latent energy of electromagnetic repulsion between the
| two of you (never mind between the parts of each of your
| bodies) would be a bit more than
| ((1%*80kg/2amu*electroncharge)^2 coulombconst / meter), or
| on the order of a megaton. Not megaton _tnt_ , a megaton of
| just _energy_ (comparable to a million tons of antimatter).
|
| 0: https://gravityandlevity.wordpress.com/2013/05/22/what-
| if-i-...
| MaxikCZ wrote:
| So we only need to push a lot of electrons into some matter
| and get maglev trains without superconductors?
| colechristensen wrote:
| Not really. "only", no. Trying to levitate trains with
| static charge would introduce all kinds of hard problems,
| some easy to imagine, some probably would take a lot of
| engineering to discover.
|
| The electric field would be hard to contain just under
| the train, the charge would really really try hard to
| find somewhere else to be, there would be some crazy
| ionization of the air going on... flying a kite in a
| thunderstorm would probably be quite safe by comparison
| to being close to such an apparatus.
| theophrastus wrote:
| So this results in a single wavefunction constrained to a
| particular space group[1]?
|
| [1] https://en.wikipedia.org/wiki/Space_group
| rvieira wrote:
| I find materials science fascinating. Is there any recommendation
| of a blog on this topic for laypeople?
| jordanpg wrote:
| Just take care not to touch it...
| 9wzYQbTYsAIc wrote:
| Mandatory reminder that hexagons are the bestagons.
|
| https://m.youtube.com/watch?v=thOifuHs6eY
| amelius wrote:
| How does that generalize to three dimensions?
| LeifCarrotson wrote:
| As a Hexagonal Close Packing lattice, which is the correct
| way to represent the maximum density arrangement of equal
| spheres.
|
| If you've seen a stack of spheres, with the bottom layer in
| rows offset by one radius such that each sphere touches six
| others at the same height, and the next layer nestled in the
| intersections of this bottom layer, that's a hexagonal close
| packing.
|
| Also, the "hexagons are the bestagons" attitude generalizes
| to three dimensions by dismissing face-centered cubic packing
| as an inferior way to look at the arrangement.
|
| To generalize the Youtube video aspect, see also this Matt
| Parker/Steve Mould video on spherical packing:
| https://www.youtube.com/watch?v=3inLMXcetUA
| amelius wrote:
| Given that the stacking of spheres is built from a stack of
| planar layers, wouldn't that mean that the stack is prone
| to shearing forces, sliding the layers over each other?
|
| Wouldn't a packing that is irregular in all directions be
| more robust?
|
| In the "bestagons" video, it is explained that the hexagons
| win because there are no straight lines in the packing, but
| I'd expect these to correspond to planes in the 3d case.
| Yajirobe wrote:
| How does that generalize to four dimensions?
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