[HN Gopher] Physicists may now have a way to make element 120
       ___________________________________________________________________
        
       Physicists may now have a way to make element 120
        
       Author : _Microft
       Score  : 91 points
       Date   : 2024-07-24 13:06 UTC (9 hours ago)
        
 (HTM) web link (www.newscientist.com)
 (TXT) w3m dump (www.newscientist.com)
        
       | jmclnx wrote:
       | For the curious, it is Unbinilium
       | 
       | https://en.wikipedia.org/wiki/Unbinilium
        
         | pxndxx wrote:
         | That's just a temporary name (un-bi-nil-ium, meaning one-two-
         | zero-ium) and will be assigned a new name once it's actually
         | discovered and verified.
        
           | n4r9 wrote:
           | The highest atomic number of any synthesised element appears
           | to be Oganesson: https://en.wikipedia.org/wiki/Oganesson .
           | Only 5 atoms have ever been synthesised. It's speculated to
           | be a solid at room temperature despite belonging to the
           | "noble gas" family. Chemistry is fascinating.
        
             | hoseja wrote:
             | And it closes the periodic table so nicely. We really
             | shouldn't be trying to go any further until and if they can
             | predict the island of stability with high confidence.
        
               | kamarg wrote:
               | > We really shouldn't be trying to go any further until
               | and if they can predict the island of stability with high
               | confidence.
               | 
               | I don't know much about chemistry since I haven't done
               | anything with it in the last 20ish years. What need is
               | there to be able to accurately predict it before
               | attempting to synthesize it?
        
               | ufmace wrote:
               | The way this stuff seems to work, it doesn't make sense
               | to go theory-first. We can spin up a bazillion theories
               | about it, with no clue which if any are anywhere near
               | true. We've got to just try it, gather experimental data,
               | and see if we can build any more solidly-backed theories
               | around that data.
        
               | jcranmer wrote:
               | The island of stability should occur (indeed, does appear
               | to occur, although we're still neutron-poor) in the
               | elements of the low 110s.
        
               | JackFr wrote:
               | Is island-of-stability stability like 1 second stability
               | or 1 million years stability?
        
               | jcranmer wrote:
               | As I understand it, like 1 year stability. Some of the
               | isotopes we have discovered on the shores have a half-
               | life of around a minute already.
        
               | WorldMaker wrote:
               | They thought they could predict it with high confidence a
               | couple decades ago and then they learned more and
               | confidence lowered again. That's kind of the nature of
               | science, use what you know to find out what you don't
               | know, and keep adjusting your models as you go.
               | 
               | That's also something of the paradox at work at something
               | like this: you sometimes can't have models that strongly
               | predict interesting or "good" outcomes (such as the
               | "island of stability") without a lot more data from
               | experiments and maybe you aren't running the right
               | experiments because you don't have the right model, but
               | you won't have the right model until you run more
               | experiments.
        
               | mensetmanusman wrote:
               | Scientific textbook publishers are salivating at a new
               | element though
        
             | Woshiwuja wrote:
             | Chemistry is weird af. How does sodium (lethal) + clorine
             | (lethal) = salt (yummy)
        
               | sesm wrote:
               | Because it's Cl- ions in salt vs Cl2 in gas.
        
               | o11c wrote:
               | That's literally the same as asking "how come hydrogen
               | (flammable) + oxygen (enhances fire) = water (does not
               | burn)?", but we probably have a better mental grasp of
               | how water works.
        
               | gruturo wrote:
               | Oversimplifying, but you can explain that as "Because
               | water is... the "ash" you get after burning hydrogen and
               | oxygen."
        
               | stergios wrote:
               | I think the intent is that water is a byproduct of
               | combustion.
        
               | withinboredom wrote:
               | I'm pretty sure the intent was that water is a byproduct
               | of combustion.
        
               | nkrisc wrote:
               | Most pure elements are either useless or harmful to us.
               | 
               | You could say that about the constituent elements of
               | pretty much any chemical necessary for life.
        
               | bell-cot wrote:
               | Broadly speaking, it's because elemental sodium and
               | chlorine are very unstable; in other words they have very
               | high potential energy.
               | 
               | A boulder balanced 40m above your head is lethally
               | dangerous; vs. if mostly-embedded in the dirt next to you
               | it's perfectly safe.
        
               | dekhn wrote:
               | because salt, when it's in water, breaks down into sodium
               | ions (not lethal) not elemental sodium and chlorine ions
               | not chlorine gas. Your body has all the tools required to
               | handle sodium and chlorine ions (literally "pumps" that
               | move them in and out of cells, and organs that process
               | the ions so they can be excreted in urine.
               | 
               | But yes, in general it's interesting how little
               | difference there is from "essential nutrient" and "human
               | poison"
        
               | vikingerik wrote:
               | Because one really really wants to give away an electron,
               | and one really really wants to accept an electron, and so
               | when they meet and consummate that they're both
               | delighted.
        
               | Ekaros wrote:
               | They are small first of all so reactive. And having so
               | close full orbitals they really really want to get rid or
               | take that electron. Thus aggressively make things
               | happen...
               | 
               | And why it is yummy, well they are pretty useful atoms in
               | lot of chemistry and in general balancing things that
               | happens in body. Thus it is nice to have sufficient
               | amount around... Best way to encourage this is to make it
               | taste good like sugar does too.
        
             | smcin wrote:
             | "Formerly known as Ununoctium (Uuo)"
        
         | Pet_Ant wrote:
         | I prefer "eka-radium" because it tells you that it's under
         | "radium" in the table.
        
           | jl6 wrote:
           | Or shat-beryllium?
        
       | pfdietz wrote:
       | https://archive.ph/MqCpl
        
       | pfdietz wrote:
       | TL;DR: accelerating titanium ions to 0.1 c into a plutonium
       | target made 2 atoms of Livermorium.
       | 
       | The difficulty here is that such a collision leaves the result
       | very "hot", so it tends to decompose. This tendency is minimized
       | by reducing the energy of the incoming ion, but that reduces the
       | rate of fusion.
       | 
       | Needless to say, this doesn't present much in the way of
       | practical benefit from producing some new science fictional
       | material. It's purely of scientific interest.
        
         | eichin wrote:
         | Key point I missed: Livermorium here is just a benchmark for
         | the new titanium-beam process (having been discovered in 2000.)
         | Actually using it to attempt to produce element 120 is a future
         | step.
        
           | pfdietz wrote:
           | Yes; they had to demonstrate they could form and accelerate
           | titanium beams (made difficult by the high temperature needed
           | to sufficiently vaporize titanium.)
        
             | eichin wrote:
             | Heh, the materials science side of particle physics is all
             | sorts of fun: accelerate the particles to 10% of the speed
             | of light - no big deal, but actually vaporizing them in the
             | first place...
        
         | beerandt wrote:
         | The tangent on manipulating Titanium in order to prepare it for
         | the beam was more interesting to me, and IMHO sounds like a
         | much more practical and potentially useful bit of knowledge
         | coming from this.
         | 
         | Titanium is a pita to work with.
         | 
         | But also... the 'island of stability' is fascinating, and I
         | think we have to assume that we don't know enough about the
         | Strong Force until we either prove it exists and is reachable,
         | or doesn't/isn't.
        
           | pfdietz wrote:
           | The problem with the strong force is that it doesn't have
           | some nice tidy description, like the inverse square law for
           | the electrostatic force.
           | 
           | It's spin dependent, and not just involving interactions of
           | pairs of nucleons. There are at least three-nucleon terms in
           | the potential. It looks like something accidental, not
           | elegant or designed. It just "happens" to give stable nuclei
           | that end up allowing something like us to have come into
           | existence. I get the feeling of anthropic effects on display.
        
             | jcghgxt wrote:
             | I don't get this. Do nucleons bind and hold together
             | because of the strong force or gravity? I thought strong
             | force only keeps quarks together via gluon exchange
        
               | pfdietz wrote:
               | Nucleons in nuclei are bound by the strong force. It's
               | (vaguely) analogous to the way the electromagnetic force
               | still binds neutral molecules together (van der Waals
               | force).
               | 
               | At the scale of the nucleus, gravity is many, MANY orders
               | of magnitude weaker.
        
       | gjsman-1000 wrote:
       | I'm a little disappointed the article didn't talk about why they
       | are skipping 119.
        
         | lightedman wrote:
         | It still hasn't been synthesized, as far as we know of. Not
         | even a single atom.
        
         | madcaptenor wrote:
         | There are Reasons why even-numbered elements are slightly more
         | stable (although frankly I don't understand them). If you look
         | at the recent timeline
         | (https://en.wikipedia.org/wiki/Discovery_of_chemical_elements)
         | 112, 114, 116, 118 were all discovered before 113, 115, 117.
        
         | munificent wrote:
         | I'm not enough of a physicist to understand the article, but
         | this Wikipedia page talks about why even numbers of protons and
         | neutrons are more stable:
         | 
         | https://en.wikipedia.org/wiki/Even_and_odd_atomic_nuclei
        
       | ssijak wrote:
       | Hypothetically, is it possible that periodic table is infinite,
       | its just too hard to create other elements?
        
         | mglz wrote:
         | Hard to create and the results seem to get more and more
         | unstable, making it very hard to do any science on them.
         | However there is a theorized "island of stability", where
         | superheavy elements might stick around for a bit longer:
         | 
         | https://en.wikipedia.org/wiki/Island_of_stability
        
           | delecti wrote:
           | That theorized island is centered around elements we've
           | already discovered though, being in the range of ~110
           | protons. So element 120, being discussed, is already well
           | past that point.
        
             | seanw444 wrote:
             | Why couldn't there be multiple islands of stability, and
             | why couldn't they be way higher in proton count? All you
             | should really need is a fairly "balanced" nucleus, right?
             | Is there some property of larger nuclei that makes them
             | increasingly more difficult to balance?
        
               | mannykannot wrote:
               | I just posted some notes on this in another reply:
               | https://news.ycombinator.com/item?id=41057818
        
               | adrian_b wrote:
               | There are with certainty multiple islands of stability,
               | when each layer of nucleons becomes complete.
               | 
               | However, in each island of stability the most stable
               | element is much less stable than the most stable element
               | of the previous island of stability. Therefore in most
               | higher islands of stability the decay times will become
               | too short.
               | 
               | It is possible and rather likely that only the first
               | undiscovered island of stability may contain relatively
               | long-lived elements, e.g. with half-lives over one
               | second.
               | 
               | An island of stability finishes at bismuth, which is
               | radioactive, but which has a huge half-life. The next
               | island of stability contains the long-lived thorium and
               | uranium and the still relatively long-lived neptunium and
               | plutonium, after which the half-lives decrease very
               | quickly.
               | 
               | Whichever will be the longest-lived elements of the next
               | island of stability, their half-lives will be many orders
               | of magnitude smaller than those of thorium and uranium.
        
               | daedrdev wrote:
               | Notably Lead-208 has magic numbers of protons and
               | neutrons so is extra stable, with lead itself
               | representing the last stable element
        
             | adrian_b wrote:
             | The next magic numbers after 82 are not known with
             | certainty.
             | 
             | Nevertheless, it was usually supposed that 126 is the next
             | magic number for protons, in which case it has not been
             | reached yet. Other possible values, from more recent
             | computations, are 122 and 124, also not reached yet.
             | 
             | Moreover, the isotopes that are the most stable for the
             | already synthesized elements are expected to have more
             | neutrons than in the isotopes that have been successfully
             | produced. So it is not impossible that an "island of
             | stability" might have already been reached, but only with
             | isotopes that have so few neutrons that they remain outside
             | the zone of stability.
        
         | HPsquared wrote:
         | "IUPAC defines an element to exist if its lifetime is longer
         | than 10^-14 second, which is the time it takes for the atom to
         | form an electron cloud.[7]"
         | 
         | If the nucleus disintegrates before electrons can cluster
         | around it, you're not really in the realm of chemistry any
         | more. Chemistry is all about those electrons.
        
           | staunton wrote:
           | One could argue that neutron stars are nuclea... If so, at
           | least nuclea production doesn't stop any time soon. Probably
           | you wouldn't call it an atom though...
        
             | adrian_b wrote:
             | The neutron is really an additional chemical element, the
             | element with Z=0.
             | 
             | It belongs in the group of noble gases, together with
             | helium, neon, argon, krypton, xenon and radon. Like radon,
             | it is unstable, but also like radon it is widespread in
             | nature as a product of radioactive decays.
             | 
             | The element with Z=0 has multiple isotopes, like any other
             | chemical element. Unlike for any other element, the
             | possibility of gravitational stabilization makes the number
             | of its stable isotopes potentially infinite.
             | 
             | The neutron stars can be seen as belonging to the isotopes
             | of the chemical element with Z=0.
        
         | AnimalMuppet wrote:
         | Define "periodic table".
         | 
         | The operating definition has been "a list of all elements that
         | humans have discovered and/or made". By that definition, it is
         | not currently infinite, nor will it ever be.
         | 
         | If instead you define it to mean "all elements that might
         | theoretically exist under all theories of physics that are not
         | currently definitively ruled out", then it may be it infinite.
         | But that's not the normal definition.
        
           | breck wrote:
           | This.
           | 
           | We give too much importance to the "Periodic Table". It's
           | just a man-made microlang. Nature is unconcerned with it.
           | There is much more beyond it.
           | 
           | P.S. While I'm criticizing the PT, might as well mention that
           | I think we've probably done people a diservice by giving
           | misnomer names like "Hydrogen" and "Oxygen" to these
           | elements, which is completely disconnected from the
           | mathematical beauty and patterns that those names represent.
        
             | snapcaster wrote:
             | What would you name Hydrogen and Oxygen?
        
               | NeoTar wrote:
               | Inverting the names makes sense.
               | 
               | Wikipedia: Oxygen
               | 
               | > Lavoisier renamed 'vital air' to oxygene in 1777 from
               | the Greek roots oxus (oxys) (acid, literally 'sharp',
               | from the taste of acids) and -genes (-genes) (producer,
               | literally begetter), because he mistakenly believed that
               | oxygen was a constituent of all acids.
               | 
               | Hydrogen comes from 'water', which contains hydrogen and
               | oxygen.
               | 
               | So, since all acids must have Hydrogen, Oxygen is
               | actually a better name for Hydrogen. This then leaves the
               | name Hydrogen free for Oxygen.
        
               | breck wrote:
               | Great question.
               | 
               | Singtium and Octium, perhaps.
        
           | mannykannot wrote:
           | One of the initial consequences of the periodic table was
           | that the gaps were correctly seen as suggesting the existence
           | of elements that had _not_ then been discovered (or made, of
           | course) and as a guide to their chemical properties, which
           | was useful in finding them.
           | 
           | I think it is clear what question is being asked here. There
           | will be a limit on the maximum size of a nucleus stable
           | enough to count as an element, as there are a couple of
           | effects which, at some point, will be insurmountable (and
           | which are also responsible for an isotope of lead being the
           | largest stable element.)
           | 
           | One is that the electrical repulsion of the protons is long-
           | range, while the strong nuclear force binding the nucleons
           | together is short-range. To simplify quite a bit, in a large
           | nucleus, each proton is being repelled by every other one,
           | while it is being bound only by its neighboring nucleons.
           | 
           | The second effect prevents this being worked around by adding
           | more neutrons, as one reaches a point where it is
           | energetically favorable for a neutron to convert to a proton
           | via beta decay.
           | 
           | As mentioned by others, there is likely an 'island of
           | stability' around the largest elements created so far, but
           | this is, at best, only a brief respite from the inexorable
           | effects described above.
           | 
           | The estimates of the half-live of any given element on the
           | island of stability ranges over several orders of magnitude.
           | That being so, it seems unlikely that there is any clear idea
           | which isotope is the largest possible in this universe.
           | 
           | Neutron stars are, of course, very large agglomerations of
           | nucleons, but it seems pointless to call them elements (and
           | there is an upper limit on their size, anyway.)
        
         | jmyeet wrote:
         | It depends on your definition of an element. Is it just a
         | nucleus or does it have to have electrons too? Because if there
         | are electrons, there is a hard limit [1]. The relativistic
         | speed of the electron in the 1s orbital is Z/137 of the speed
         | of light (Z = atomic number).
         | 
         | [1]:
         | https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry
        
           | AnimalMuppet wrote:
           | That won't be a hard limit. Your link says that it is a
           | perturbative theory; it won't hold for a velocity that is a
           | significant fraction of the speed of light. The Z/137 formula
           | won't hold for large Z.
        
           | pfdietz wrote:
           | What would happen in sufficiently heavy nuclei is spontaneous
           | creation of an electron positron pair, with the electron
           | remaining bound and the positron emitted. This would require
           | the binding energy of the electron be great enough for this
           | to be energetically possible.
        
           | perihelions wrote:
           | I don't believe chemical elements would cease to exist above
           | Z=137--they just get progressively stranger, electronic
           | effects get more relativistic. It is not a hard limit.
           | 
           | (It's not as if the speed of electrons would *exceed* _c_
           | above Z=137; it just approaches it asymptotically. The 1 /137
           | factor comes from the _non-relativistic_ approximation
           | (simply, the plain Bohr model [0])).
           | 
           | [0] https://en.wikipedia.org/wiki/Bohr_model#Derivation
        
         | blindriver wrote:
         | There's a hypothesis that I heard back when I was in high
         | school 40 years ago that maybe the atoms start stabilizing
         | again once you go high enough in the atomic number. It was just
         | a hypothesis but kind of cool to think about.
        
           | px43 wrote:
           | It's called the "Island of Stability" :
           | https://en.wikipedia.org/wiki/Island_of_stability
        
         | russdill wrote:
         | No, at some point gravity becomes important and you can make
         | enormous atomic nuclei. Neutron stars are about 5% protons. I
         | don't think people would think these would count though as it's
         | not like you can have chemistry between neutron stars and the
         | electrons do not behave like they do in atoms. And past another
         | point you just get a black hole.
         | 
         | So clearly there is a limit. Either bounded by the point where
         | gravity becomes dominant or when you get a black hole.
        
           | jessriedel wrote:
           | For sufficiently heavy nuclei, you would cease to have any
           | bound states way, way before gravitational effects were
           | important.
        
           | zelphirkalt wrote:
           | Neutron stars certainly do have attraction ... don't see why
           | they can't have some chemistry as well. They seem cool after
           | all.
        
         | philipov wrote:
         | No. Regardless of anything about definitions or stability that
         | other commenters have mentioned, the mass of possible elements
         | is bounded by General Relativity.
         | 
         | There is a theoretical upper bound on the mass of an elementary
         | particle at which it will collapse into a black hole.
         | Fundamental particles can not be heavier than the Planck Mass,
         | and Atoms should have a corresponding value at which they will
         | likewise collapse into a black hole.
         | 
         | Black holes do not satisfy even the loosest definition of an
         | element.
        
           | exe34 wrote:
           | that's probably a lot higher than the sort of atomic number
           | we can realistically reach in the lab?
        
             | philipov wrote:
             | Oh, it's immensely massive compared to anything that's
             | likely to possibly exist as an element. But in proving
             | something is finite, it doesn't matter if we overshoot by a
             | million million percent, all we have to do is establish any
             | bound at all. We don't have to engage with the question of
             | what we can do in a lab, because the question only requires
             | any theoretical limit to exist.
             | 
             | It may be difficult to predict just how far we can go in a
             | lab, but the existence of black holes means there _must_ be
             | some limit.
        
           | arcadi7 wrote:
           | nonsense . heavy nuclea are bound states of many constituents
           | . no different from grain of salt . grain of salt can be much
           | heavier than planck mass (which is about few micrograms
        
           | arcadi7 wrote:
           | nucleus is extremely fluffy by general relativity standards .
           | for black holes the mass and size are linearly proportional .
           | the solar mass black hole has few mile size and has density
           | few times smaller than that of the nucleus . solar mass is
           | about 10^57 protons or about 10^55 heavy nuclea like uranium
           | . so in order for general relativity to be important for
           | uranium nucleus, it has to have a size of 5 miles/10^55 or
           | about 10^-49 cm . instead heavy nuclea have a size of about
           | 10^-15 cm . so nuclea are 34 orders of magnitude fluffier
           | than they should be for any general relativity to be of any
           | relevance . they are as good as grain of salt
        
         | mppm wrote:
         | No, the stability of elements peaks at iron and nickel and
         | declines again after that. If you look at the curve of binding
         | energy per nucleon [1], the trend is quite obvious. Note in
         | particular that at some point past uranium, the average binding
         | energy declines to below that of helium, making the isotopes
         | extremely susceptible to alpha particle emission. There are
         | some "islands of relative stability", where heavy elements are
         | stabilized by "magic numbers" of protons and neutrons -- which
         | is why thorium and uranium are so long lived. But we can be
         | quite certain that there is no such thing as Element 200.
         | 
         | [1] https://en.wikipedia.org/wiki/File:Binding_energy_curve_-
         | _co...
        
           | AdamH12113 wrote:
           | Why does that graph look like it's upside-down? Shouldn't
           | having more binding energy per nucleon make an isotope less
           | stable, not more? Are the energies implied to be negative
           | potential energy?
        
             | HPsquared wrote:
             | Binding energy = energy released when the nucleons bind
             | together.
             | 
             | In other words, energy required to break them apart.
        
         | pfdietz wrote:
         | Ignoring neutron stars or exotic states of quark matter, I
         | think conventional nuclei will become effectively unbound to
         | proton or neutron emission if sufficiently massive.
        
         | empath75 wrote:
         | https://en.wikipedia.org/wiki/Continent_of_stability
         | 
         | At some point it becomes "quark matter" and might exist in
         | collapsed stars.
        
         | ars wrote:
         | At some point the element will decay faster than it can exist.
         | There are already subatomic particles that get created on one
         | side of the particle and decay on the other, i.e. their
         | lifetime is shorter than that time it takes for light to travel
         | from one side of the particle to the other.
         | 
         | Atoms are much bigger than subatomic particles, so they have to
         | live even longer in order to exist.
        
       | HPsquared wrote:
       | It's all about stability. If you try and jam too many protons and
       | neutrons together, they won't stay together for long. If the
       | nucleus disintegrates before there's time for electrons to form
       | and act like a chemical element, it's not really in the realm of
       | chemistry any more.
       | 
       | "IUPAC defines an element to exist if its lifetime is longer than
       | 10^-14 second, which is the time it takes for the atom to form an
       | electron cloud.[7]"
       | 
       | https://en.m.wikipedia.org/wiki/Island_of_stability
       | 
       | https://en.m.wikipedia.org/wiki/Superheavy_element
       | 
       | (Edit: this was intended in response to ssijak's question about
       | the theoretical limits)
        
         | tomcam wrote:
         | It's answers like this that may hacker News one of the best
         | places ever
        
         | adrianN wrote:
         | If you jam _a lot_ of protons and neutrons together they become
         | stable thanks to gravity. I wonder where the crossover point
         | is.
        
           | stouset wrote:
           | Ah yes, good ol' element unnil^{54}ium, a proton star. That
           | would make a great "Things I Won't Work With" entry for Derek
           | Lowe.
        
             | LeifCarrotson wrote:
             | Correct me if I'm wrong, but aren't nuclear-density
             | collapsed matter stars exclusively zero-net-charge neutron
             | stars? I suppose you could instantiate an "oops all
             | protons" neutron star with a charge of 10^54 coulombs in
             | Universe Sandbox, but I struggle to imagine how that would
             | come to or continue to exist physically.
             | 
             | More importantly, I think that the Coulomb's Law repulsion
             | effect would more than cancel out the gravitational
             | attraction effect - both laws work as Force = (constant x
             | particle1 x particle2) / distance^2, and the
             | electromagnetic force is much, much stronger than gravity
             | at all distances.
        
               | stouset wrote:
               | Look I never said it was a good idea.
        
             | dmd wrote:
             | xkcd what if covered it: https://what-if.xkcd.com/140/
        
           | acchow wrote:
           | My understanding is that the repulsion between the positive
           | charges (protons) far exceeds the gravitational force.
        
             | vikingerik wrote:
             | For normal nuclei it does, but when you get up into a solar
             | mass sized blob of them, gravity exceeds it. That's because
             | the repulsion is going in all directions and nets out
             | against itself but all the gravity points inwards
             | cumulatively.
             | 
             | (Edit because we got a little confused in the replies: If
             | it were all protons, they would repel and overcome gravity.
             | But real matter isn't that, it's always protons and
             | neutrons and electrons with close to no net repulsion so
             | gravity wins.)
             | 
             | Similarly, radioactive nuclei (alpha emitters and
             | spontaneous fission) happen because the electromagnetic
             | repulsion exceeds the strong force, which has a very short
             | range and doesn't reach across those large nuclei.
        
               | kaashif wrote:
               | > That's because the repulsion is going in all directions
               | and nets out against itself but all the gravity points
               | inwards cumulatively.
               | 
               | Is that true? All of the protons repel all other protons
               | with the electric force and attract with the
               | gravitational force, and it seems like gravity is just
               | much weaker at all distances...
               | 
               | I haven't thought about this very hard though.
        
               | vikingerik wrote:
               | Think of three protons in a line, A-B-C. Proton B is
               | repelled in both directions so experiences no net force.
               | 
               | Now think of 10^50 protons in a line. They're all
               | experiencing net gravity towards the middle.
        
               | wakamoleguy wrote:
               | A is repelled outward, B is not repelled, C is repelled
               | outward.
               | 
               | With gravity, A is attracted inward, B is not attracted,
               | C is attracted inward.
        
             | __MatrixMan__ wrote:
             | I think that gravity starts winning once it becomes strong
             | enough to encourage the positive charges to evacuate,
             | leaving neutrons where there once were protons, like the
             | juice leaving a squeezed orange.
        
             | dredmorbius wrote:
             | Gravity is strictly accumulative. All other forces are
             | paired with positive and negative carriers
             | (electromagnetic, weak nuclear, strong nuclear).
             | 
             | Protons can generate neutrons through beta decay. I suspect
             | something like this happens in neutron stars, which don't
             | spontaneously fly apart into a proton cloud, so far as
             | we've observed.
             | 
             | This SE comment explains why neutron stars don't contain
             | (many) protons:
             | 
             | <https://physics.stackexchange.com/a/149656>
             | 
             | (The ratio seems to be ~100:1 neutron:proton.)
        
           | mensetmanusman wrote:
           | Don't we all. This is the reason general relativity and the
           | standard model don't fit under one framework (string theory
           | has currently failed to combine them in a testable way), we
           | don't understand why or when gravity starts to become
           | important.
        
             | cvoss wrote:
             | I don't think that's accurate. We can pretty carefully
             | calculate the forces involved and answer the question as
             | posed. Related: We can calculate how strong a magnet has to
             | be to hold your artwork on the fridge in opposition to the
             | force of Earth's gravity.
             | 
             | The GR vs Standard Model breakdown occurs at the extreme
             | limits of GR, for example Planck scale regions of space and
             | black hole singularities. A heavy nucleus is way too big to
             | probe these limits and is well within the domain of physics
             | where we don't see a conflict between the two theories.
        
           | FredPret wrote:
           | Apparently the smallest a neutron star could theoretically be
           | is 0.1 - 0.2 Solar masses. [0]
           | 
           | And then 1.4 Solar masses is the upper limit. [1]
           | 
           | [0] https://physics.stackexchange.com/a/143174/43351 [1]
           | https://en.wikipedia.org/wiki/Chandrasekhar_limit
        
             | kevinastone wrote:
             | The Chandrasekhar limit is the maximum size of a white-
             | dwarf, not a neutron star. It's usually defined as the
             | minimum size of a neutron star (since it has to overcome
             | electron-degeneracy pressure). The TOV limit[0] is the
             | maximum size of a neutron star.
             | 
             | [0] https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheime
             | r%E2%...
        
           | out_of_protocol wrote:
           | Don't forget electrons. Without them, you'll see something
           | violent, up to instant black hole (relevant xkcd:
           | https://what-if.xkcd.com/140/ )
           | 
           | P.S. Quote from the link:
           | 
           | > Would this black hole cause the universe to collapse? Hard
           | to say.
        
         | mensetmanusman wrote:
         | I hope the universe lets us upgrade the periodic table once we
         | reach 120. Maybe we earn a new alpha constant that enables a
         | whole new level of new elements for long distance space travel.
        
       | charlie0 wrote:
       | Specifically, is there anything that can be done with this
       | element in the real world that would otherwise be impossible?
        
         | Pet_Ant wrote:
         | These elements will never exist in any number for any
         | meaningful amount of time for the human scale.
         | 
         | That said, these extreme elements are great tests of the
         | understanding of mechanics of atomic nuclei. Personally, I
         | expect this improved understanding to become important in
         | nanofabrication/nanotechnology as we are getting individual
         | atoms to stick to each other.
         | 
         | There are other implications I'm sure for those studying the
         | early superhot universe.
         | 
         | There is also the chance this is a stepping stone to the Island
         | of Stability: https://en.wikipedia.org/wiki/Island_of_stability
        
         | retrac wrote:
         | We have no idea because we don't know the properties of super-
         | heavy elements. There is some conjecture from theory about an
         | "island of stability" where super-dense elements above 118
         | become more stable, with half-lives in human terms like many
         | seconds (rather than microseconds or nanoseconds). If so it
         | would open all sorts of doors for physics and chemistry
         | experiments on super heavy elements we can't do today because
         | they disappear too quickly. It has even been suggested that
         | these elements are effectively stable and account for some of
         | what we call dark matter. (That one is unlikely.). Though
         | really the chances are that such elements destroy themselves so
         | quickly they can't be usefully examined.
        
         | daedrdev wrote:
         | Some of the longer lived of the manufactured elements have
         | medical uses. There's a chance the elements in the island of
         | stability might have interesting properties
        
       | news_to_me wrote:
       | For some background on the quest to discover new elements, I
       | highly recommend this video:
       | https://www.youtube.com/watch?v=Qe5WT22-AO8. The main story about
       | Ninov's fraud is pretty interesting, but the beginning does a
       | good overview of the recent history.
        
         | pests wrote:
         | Yes this was a great video.
        
       | excalibur wrote:
       | Here's hoping the person who winds up with the naming rights is a
       | proper nerd. I want it to be called something fun, like
       | vibranium, adamantium, or midichlorium.
        
         | gosub100 wrote:
         | I hope they patent it, just to draw attention to the absurdity
         | of IP law.
        
           | nayuki wrote:
           | I hope they use said patent to sue supernovas for creating
           | element 120 without license
        
         | mrguyorama wrote:
         | New elements are named by
         | https://en.wikipedia.org/wiki/IUPAC/IUPAP_Joint_Working_Part...
         | 
         | They typically try to honor someone or something relevant to
         | particle physics or nuclear physics. So, no fun allowed, unless
         | you are a physicist in which case you probably find naming
         | things after historical physics figures fun.
        
           | NeoTar wrote:
           | I'm a physicist (completely unrelated field though), but I
           | want to name it after Ytterby in Sweden so rather than having
           | four elements named after one town, we now have five...
           | 
           | https://www.youtube.com/watch?v=l6lGe5jgZgI
        
       | xyst wrote:
       | what are the applications for these new elements? more
       | destructive atomic bomb? any medical applications?
       | 
       | besides learning about them briefly in chem classes as the "man
       | made elements", haven't heard much from them otherwise
        
         | curiouscavalier wrote:
         | Been a while since I was in this area, so I may be off base.
         | But my knee jerk thought on Ubn is getting another valuable
         | data point on nuclear structure. We've got a magic number at
         | Z=82 and one at N=126. Do we get it one at higher Z? This
         | doesn't answer it directly, but it's a step along the path. And
         | at the very least is a great data point for
         | confirming/constraining various structure models.
        
         | empath75 wrote:
         | There are some predicted islands of stability at various points
         | further out in the periodic table:
         | https://www.scientificamerican.com/article/the-quest-for-sup...
        
       | odo1242 wrote:
       | Dang, just one away from discovering the g block!
        
         | odo1242 wrote:
         | Context: The periodic table currently can be arranged into four
         | "blocks": the S block (first two columns), the P block (last
         | six columns, excluding Helium), the D block (transition metals,
         | in the center), and the F block (under the periodic table).
         | 
         | The 121st element would end up in the G block, which isn't in
         | any of these locations but rather gets its own special
         | location.
        
       | puzzledobserver wrote:
       | While we hear a lot about isotopes (nuclei with same proton count
       | but different neutron count), we don't hear as much about nuclear
       | isomers (nuclei with the same proton count and same neutron
       | count, but somehow having different configurations).
       | 
       | 1. Are nuclear isomers a thing?
       | 
       | 2. Corollary: Could it be the case that some nuclei are stable
       | and others are unstable, even though they have the same numbers
       | of protons and neutrons?
        
         | Denvercoder9 wrote:
         | The answer to both your questions is yes. Wikipedia has a
         | pretty extensive article about it:
         | https://en.wikipedia.org/wiki/Nuclear_isomer
        
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