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.
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.
> 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?
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.
I think that's the way science pretty much always goes. For the most clear example look at the unbelievable mountain of information we have on the distant cosmos. Yet it all assumes the homogeneity of physics in the universe. There's no real reason to believe this is true outside our sample of 1, but without believing this it would be basically impossible to study the cosmos, because we'd have no way to assess differing physics in distant locations, at least not until we are able to reach those locations and carry out experiments.
Drugs are also the same with many, if not the majority of drugs having come from things that were initially intended to treat something else, only to find out what you created has stronger effects elsewhere. The most obvious and amusing one being that Viagra was meant to be a heart medicine. It turned out to have little effect on heart disease, but had a rather pronounced side effect in half the participants!
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.
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.
It’s all about electrochemical potential. Adding or removing electrons from the outer shell of an atom involves a fair amount of energy, either being released or stored. Depending on the atom, they either want their shell filled or emptied. Noble gases have the same number of protons as a filled shell, so they are very stable. Why electron shells exist is a whole other matter.
Water is kind of like ash. Technically full combustion of any hydrocarbon outputs CO2 and Water. Since water isn’t a greenhouse gas it’s not mentioned when discussing combustion usually.
This is one of the reasons why methane leaks are so impactful - not only is methane a terrible green house gas, when it decays in the upper atmosphere, it decays into water vapour and CO2)
As a fun aside, there are plenty of rocket engines that run on hydrogen + oxygen. For instance the Space Shuttle Main Engine [1] was fueled by hydrogen + oxygen, which means its exhaust was literally water vapor.
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"
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.
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.
The general idea is actually quite intuitive. Sodium doesn't like being sodium (metal), and chlorine doesn't like being chlorine (gas), they are very angry and will do anything to change the situation. But they like it when they are together as salt and they are well behaved in this form. This is, of course very simplified.
An example I like is with nitrogen. Nitrogen atoms really want to form nitrogen gas (N2), a form that is really stable and therefore unreactive and generally harmless. However, if the nitrogen atoms are not in this form, and they have the opportunity to turn into it, they will, and they want it so much that it can be violent. That's why a lot of explosives are nitrogen-based, they are made of nitrogen atoms that have been separated from their N2 form by giving them a lot of energy, and when they come back together as the explosive is detonated, all that stored energy is released.
Even greatly simplified, it’s pretty important to understand the difference between a salt and a covalently bonded compound – sodium and chloride don’t really stay together, nice and inert; they disassociate readily in a solution. Salt water has individual sodium and chlorine ions freely floating around. But being ions now, both have gotten what they wanted, and are quite content and nonreactive now.
I assume by "lethal" you mean "highly reactive" as opposed to "poisonous".
Something that really wants to give away electrons and something that really wants to gain electrons are going to really get on well, and will be really stable.
Is there enough water in the mouth to get sodium to explode? Probably just scalds you.
Elemental sodium in the air spontaneously oxidises to sodium hydroxide which is nasty and caustic but the hydroxide layer spontaneously forms bicarb which is comparatively harmless. At a best guess, I'm not convinced a block of sodium not swallowed is lethal... (it will be extremely harmful)
Volume of the mouth is about 150mls (half a can of coke). Maybe you have a big mouth so let's call it 180mls. That's 10 moles of water (assuming saliva is 100% water). At 0.9688gcm^-3 they're basically 1:1 and the stoichiometry is also 1. So max you can fit about 115g of sodium to 90ml of water.
If we ignore the dynamics of the explosion that seems enough to cause a maybe lethal explosion. It would also release 120dm^3 of hydrogen.
They're both lethal because they both want to be in salt. They will turn you to salt and make themselves happy and make you dead. Alternatively if they are already salt they're chillin.
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.
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.
Yes; they had to demonstrate they could form and accelerate titanium beams (made difficult by the high temperature needed to sufficiently vaporize titanium.)
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...
Pita is relative. Getting Ti to oxidize? Easy - getting it got enough to strip the oxigen off? Very hard, and about 1000x harder than just oxidize, getting it into a pure plasma? Now this is where it just gets insane. Then beyond insane is accelerating individual atoms. ( Pretty much they just issue you a PhD. ) Then get it to .1c speed? Pretty much everyone you will talk to on a daily basis either has a Noble, or is goimg to get one, in a place where the building is named after one laureat, the parking lot is named for another, the room another, and the drinking fountain another. I have stood there, and it's pretty intimidating. A handful of the very top top people in the world. I guess it could be fun for some...I would use the verb... Plasmatize.
The discovery of Fluorine...elemental, killed 8 and rendered 3 disabled.
I have been following this for 40 years. Congratulations on the attempt.
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.
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.
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
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.
Genuinely want to know, what is the scientific interest here? The synthesis of super heavy elements always seems to be the same story, they detect its presence for a tiny fraction of a second, and then it decays away. What is learnt from doing this?
Well, I'm sure there's all sorts of interesting nuclear physics to be learned like island of stability stuff, but given the context of who's doing this work and competing for credit - I guess even out of the cold war context it's a great way to show that 1) my country is better than your country at nuclear physics get rekt or 2) my country and your country get along now, look at us do nuclear physics together or 3) what's up, new player here, btw I'm also good at nuclear physics check out this element I found.
Or in this case 4) oh no your country and my country don't get along anymore! time to asset scientific dominance by "re entering the super heavy race" (https://www.science.org/content/article/u-s-back-race-forge-...) and getting the department of energy to start funding this again so we're back on top.
Seriously: this is one of the very most important topics in physics today. It is not written of discussed nearly enough. My father was part of an international team, ignored in the U.S. and worshipped internationally.
I would assign the noun- royal pita.
I read every article I come across about this, and I would strongly encourage you to write more. What upsets me is politics getting in the way of science.
I'm not sure I get what you're saying here. Competing with Russians over heavy element synthesis is one of the very most important topics in physics today? What is the actual scientific value of the research, what do we learn from it? Is it just that one day we might find a stable element?
I think there's a bit of institutional momentum here, along with the historical realization that "finding new elements" was really valuable in the past (not that these new elements would be valuable). There's also a bit of international competition.
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.
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:
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.
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?
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.
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.
"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.
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...
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.
Their concentration is the result of the equilibrium between neutrons that decay into proton and electron pairs and proton-electron pairs that recombine into neutrons.
The complete neutron star still behaves like a giant nucleus with null electric charge, i.e. with Z=0.
Surely it's not an atom because it doesn't have electron orbitals? (Although I suppose electrons could orbit it, in the classical sense rather than the quantum sense!)
It is the limit case of a neutral atom, like the neutral atoms of the noble gases, which has 0 electrons instead of having 2 electrons, 10 electrons etc.
From a big enough distance, there is no essential difference between neutrons and the neutral atoms of any noble gas. They all are neutral particles which do not react chemically.
The weak van der Waals forces between the atoms of the noble gases decrease from radon to helium and neutron fits in this progression. At extremely small distances between neutrons, weak attraction forces appear between them, which are analogous to the van der Waals forces generated by residual electromagnetic interactions, but they are generated by residual strong nuclear interactions.
A positive hydrogen ion has 0 electrons too, the same as a doubly-ionized helium atom, triple-ionized lithium atom, etc.
The relationship between neutrons and these ions is the same as for instance between helium and lithium ions, beryllium ions, boron ions, etc.
Calling a neutron as the limit case of an atom is a choice, but this choice simplifies many descriptions of things related to atoms and ions, in the same way as including zero in the cardinal numbers simplifies the descriptions of many things related to numbers, because there is no longer any need to describe separately some special cases.
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.
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.
> Lavoisier renamed 'vital air' to oxygène in 1777 from the Greek roots ὀξύς (oxys) (acid, literally 'sharp', from the taste of acids) and -γενής (-genēs) (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.
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.)
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).
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.
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.
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])).
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.
It's quite possible for anything to happen. Neutron stars are based on a theory. Now it happens that that particular theory was fromulated by some of the most brilliant minds I can imagine. Gravity and the strong neuclear force can do things we cannot fathom. Things may be going on in the interior of neutron stars...
The macro stars and the micro. I for sure thought that 118 was the limit, and again, this has been a life long interest of mine.
I have the isotope chxart on the wall at home.
P.s. kudos for paying attention in school.
P.p.s extra thanks the people who kept the Laurence hall of science going, and it's periodic table working.
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.
Chemistry happens in the electron cloud surrounding the atoms. Specifically the orbitals. While there may be some electrons in and around a neutron star, they are not organized into orbitals. By definition, a neutron star cannot undergo chemical reactions.
What happens in neutron stars is somewhere between nuclear reactions and quantum effects. Both of which are decidedly not "chemistry" in the way most people use that word.
More generally, only normal atoms can undergo chemistry. All of chemistry depends on the arrangement of electron orbitals. Once you leave that domain, you're in an entirely different field of physics.
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.
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.
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
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
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.
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?
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.
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.
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]"
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.
The "desktop particle accelerator" is excellent. I wondered what?? Clicked on the link and then yes indeed didn't think of it :-) Love xkcd and his what-ifs.
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.
> 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...
Your idea doesn't generalize. With A-B-C-D-E, only C experiences no net forces along the horizontal axis, while all the others (A, B, D, E) are repelled outward. Therefore the electromagnetic force is not cancelled as you seem to imply.
Of course, in practice, we don't know what the inside of a black hole is like, as quantum gravity is very much unsolved.
We like to say gravity is "weak", however it seems to operate on many orders of magnitude larger distances.
Even if you make the argument that the energy complicit in the strong/weak forces is cumutavily much greater than the energy due to gravity, I'm still not sure "weak" is the right word for the job...
Gravity onstensibly runs at infinite speed over infinite area (the effect of gravity waves non-withstanding).
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.
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:
protons can generate neutrons and neutrons can generate protons . why are there no nuclea with only neutrons ? — these could be as big as you want because there is no electric repulsion . the answer is that only neutron nucleus would have — by pauli exclusion principle — very large kinetic energy . so nucleus turns couple of its neutrons into protons to lower the kinetic energy of neutrons . same reason for small fraction of protons in neutron stars
A good question, and mostly beyond my pay grade. Almost certainly based on models rather than direct observation, though informed by the latter.
I'm struggling to find a strong source, but this page, by M. Coleman Miller at the University of Maryland, describes properties suggesting modelling over observation. Specifically it describes "the guts of a neutron star":
Even further down, you mainly have free neutrons, with a 5%-10% sprinkling of protons and electrons.
With an subsequent 'graph:
Yes, you may say, that's all very well for keeping nuclear theorists employed, but how can we possibly tell if it works out in reality? Well, believe it or not, these things may actually have an effect on the cooling history of the star and their spin behavior!
What follows is more description of theory with a few points based in what is directly observable, largely spin (via radio astronomy) and some temperature observations largely in X-ray observations, and the occasional gamma-ray burst.
I've seen similar suggestions, but it's ... probably not an especially useful conceptualisation.
The conceptualisation of elements is useful to us because physical characteristics of atoms are (mostly) stable over time, with atoms having distinctive masses, atomic numbers, and most importantly, electron shells. The latter account for most of what we consider to be "chemistry", along with some other effects, most notably the van der Waals force.
Neutron stars ... lack most of this. They're in constant flux, they (probably) don't have stable masses (if only due to constant accretion) or atomic numbers, they probably don't have anything resembling an electron shell, and in interactions with other objects any electromagnetic forces would probably be overwhelmed by gravity or, say, spin-induced magnetism. If a measure of a concept or model's usefulness is how much it explains behaviours, "neutron-star-as-element" doesn't buy you much.
Though there's possibly some truth or conceptual validity to it.
Questions are almost always worth asking, and there's at least some philosophical interest in this case. But from a practical perspective as a chemical phenomenon, not much use.
I subscribe strongly to a pragmatic approach to knowledge and understanding. That is, knowledge isn't so much true as it is useful, in that it provides a useful mental model of the world. There are cases where multiple truths are possible, as with wave-particle duality, or mass-energy. Either classification may be useful, that is, provide predictive, understanding, or manipulative power, depending on contexts and circumstances. Some of the classic philosophical paradoxes (Sorites, Ship of Thesus, falling tree in a forest) resolve at least somewhat under this view. What is often called "truth" I think of as "useful mental models". The distinction is that whilst both are grounded in observation and empiricism, "truth" is an absolute, whilst "usefulness" is a bit like evolutionary fitness: changing over time, dependent on circumstance, not entirely arbitrary, but also not perpetually fixed.
So, is a neutron star a gigantic nucleus? Yes, in a sense, in that it's primarily made of what we'd otherwise consider nuclear material. Does this give us useful insights on neutron star behavior above and beyond those given by gravitational, thermodynamic, and electromagnetic descriptions? No, not really, because the attendant characteristics and properties of much smaller nuclei (from atomic number 1 to the low 100s or so) simply don't apply. There's not much behaviour that is explained, predicted, or controlled by applying that knowledge.
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.
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.
> string theory has currently failed to combine them in a testable way
String theory may well be wrong/currently untestable, however failure to invalidate the null hypothesis is not proof that somehow we don't have a meaningful understanding of other, proven theories/laws.
Put a different way, if an apple falls from a tree on earth, I don't panic because I don't understand quarks or electron orbitals. I calculate the point/speed/force of impact to acceptable margins of error.
I think the point is that string theory is a huge model with so many parameters that it can fit everything. This is overfitting. Because of that it does not have predicting power.
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.
I was thinking of neutron stars all along - which, correct me if I’m wrong, look like they have similar density to an atomic nucleus and for which the upper limit is apparently 3 Sols. [0]
"Neutron star = nucleus" is very elided. The crust of neutron stars contains ordinary elemental matter with a density around that of a white dwarf (specific density of ~10⁶), but descending down to the core it explodes to ~10¹⁴, which is nucleus density and a little beyond.
There's also the whole menagerie of nuclear pasta [1] where gnocchi and spaghetti you could maybe consider "nuclei" unto themselves. There's also waffles & lasagna, but when you get into the anti-spaghetti and anti-gnocchi realms, then you're into the "one nucleus" region.
Just let a single proton loose in the vicinity of a pure neutron star, wait to be attracted to it and tada, we made a super heavy and stable hydrogen isotope!
I do not believe that it would be stable. The proton would convert to a neutron and release an electron. If it were stable for the neutron star to have protons in or on it, then it would already have some.
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.
The point about stability is that as the curve of stability is not a straight line. That is as the number of nucleons increases, you need proportionally more and more neutron to be stable. So you cannot just smash small nuclei together to form bigger ones. Somehow you need to add some extra neutrons.
The below linked video is about a fraudulent attempt by Victor Ninov to claim success at making 116 and 118, but explains the experiments, I think, quite well.
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.
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.
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
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.
Soon as you said Ninov, I knew whose video that was immediately. BobbyBroccoli seems to make rather good documentaries on weird subjects, and they seem to be pretty well researched.
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.
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.
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…
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.
Generally these newer elements themselves aren't directly applicable to day to day objects or tools given the difficulty in creating even individual atoms and the short life of said atoms. It's almost completely about advancing the general atomic and subatomic understanding by pressing at the edges.
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.
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?
Are there even transitionally stable conditions in other places in the universe where these elements exist for more than fleeting time?
I would imagine in conditions of high heat, plasma, RF energy and pressure many things "exist" but I don't see that as quite the same. I guess if their spectral line emissions from stars says they are a continuum of existence then thats something, but I wondered if there were wierd islands of stability e.g. inside crystal lattices under pressure, or in solution in some wierd, non-plasma state. Absent an observer round that star we can't know but can we hypotheise physical states which would let it be?
Neutron stars are made of a solar mass of neutrons and protons packed so tightly together that they're almost like a single giant nucleus. They can collide and shatter into countless particles of every imaginable heavy element. Of course most of these quickly decay but they decay into other heavier things that are more stable. This is possibly where heavy elements in our solar system such as uranium, platinum and gold came from. If we could visit Earth shortly after its formation 4.5 billion years ago maybe we'd see trace amounts of even more exotic elements! https://en.wikipedia.org/wiki/Neutron_star_merger#Distributi...
I have to ask: given the vanishingly small half-life of these elements (order of milliseconds) and tiny, tiny number of atoms produced ... what is the point of these experiments ? What can they possibly teach us ?
You never know where the next breakthrough will come from, but clearly some places are more likely and some less. In this case I guess something that could happen is that theories predict the element will last for say 1 femtosecond but experiments show it only lasts for 0.95 femtoseconds, and then the disparity helps shed light on quantum chromodynamics or something.
I know that it's speculated that there's another point in the periodic table much further down the line where another bunch of stable elements could exist
Every time I read references to one of the transuranic elements, I can't help but want to share this absolutely delightful narrative about actually building a wall of bricks from each element in the periodic table. Hilarious stuff.
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[ 2.6 ms ] story [ 247 ms ] threadhttps://en.wikipedia.org/wiki/Unbinilium
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?
Drugs are also the same with many, if not the majority of drugs having come from things that were initially intended to treat something else, only to find out what you created has stronger effects elsewhere. The most obvious and amusing one being that Viagra was meant to be a heart medicine. It turned out to have little effect on heart disease, but had a rather pronounced side effect in half the participants!
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.
Water is kind of like ash. Technically full combustion of any hydrocarbon outputs CO2 and Water. Since water isn’t a greenhouse gas it’s not mentioned when discussing combustion usually.
This is one of the reasons why methane leaks are so impactful - not only is methane a terrible green house gas, when it decays in the upper atmosphere, it decays into water vapour and CO2)
https://science.nasa.gov/earth/climate-change/steamy-relatio...
[1] - https://en.wikipedia.org/wiki/RS-25
You could say that about the constituent elements of pretty much any chemical necessary for life.
A boulder balanced 40m above your head is lethally dangerous; vs. if mostly-embedded in the dirt next to you it's perfectly safe.
But yes, in general it's interesting how little difference there is from "essential nutrient" and "human poison"
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.
An example I like is with nitrogen. Nitrogen atoms really want to form nitrogen gas (N2), a form that is really stable and therefore unreactive and generally harmless. However, if the nitrogen atoms are not in this form, and they have the opportunity to turn into it, they will, and they want it so much that it can be violent. That's why a lot of explosives are nitrogen-based, they are made of nitrogen atoms that have been separated from their N2 form by giving them a lot of energy, and when they come back together as the explosive is detonated, all that stored energy is released.
Elemental sodium in the air spontaneously oxidises to sodium hydroxide which is nasty and caustic but the hydroxide layer spontaneously forms bicarb which is comparatively harmless. At a best guess, I'm not convinced a block of sodium not swallowed is lethal... (it will be extremely harmful)
If we ignore the dynamics of the explosion that seems enough to cause a maybe lethal explosion. It would also release 120dm^3 of hydrogen.
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.
The discovery of Fluorine...elemental, killed 8 and rendered 3 disabled.
I have been following this for 40 years. Congratulations on the attempt.
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.
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.
At the scale of the nucleus, gravity is many, MANY orders of magnitude weaker.
Or in this case 4) oh no your country and my country don't get along anymore! time to asset scientific dominance by "re entering the super heavy race" (https://www.science.org/content/article/u-s-back-race-forge-...) and getting the department of energy to start funding this again so we're back on top.
I would assign the noun- royal pita.
I read every article I come across about this, and I would strongly encourage you to write more. What upsets me is politics getting in the way of science.
https://en.wikipedia.org/wiki/Even_and_odd_atomic_nuclei
https://en.wikipedia.org/wiki/Island_of_stability
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.
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.
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.
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.
Their concentration is the result of the equilibrium between neutrons that decay into proton and electron pairs and proton-electron pairs that recombine into neutrons.
The complete neutron star still behaves like a giant nucleus with null electric charge, i.e. with Z=0.
From a big enough distance, there is no essential difference between neutrons and the neutral atoms of any noble gas. They all are neutral particles which do not react chemically.
The weak van der Waals forces between the atoms of the noble gases decrease from radon to helium and neutron fits in this progression. At extremely small distances between neutrons, weak attraction forces appear between them, which are analogous to the van der Waals forces generated by residual electromagnetic interactions, but they are generated by residual strong nuclear interactions.
A positive hydrogen ion has 0 electrons too, the same as a doubly-ionized helium atom, triple-ionized lithium atom, etc.
The relationship between neutrons and these ions is the same as for instance between helium and lithium ions, beryllium ions, boron ions, etc.
Calling a neutron as the limit case of an atom is a choice, but this choice simplifies many descriptions of things related to atoms and ions, in the same way as including zero in the cardinal numbers simplifies the descriptions of many things related to numbers, because there is no longer any need to describe separately some special cases.
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.
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.
Wikipedia: Oxygen
> Lavoisier renamed 'vital air' to oxygène in 1777 from the Greek roots ὀξύς (oxys) (acid, literally 'sharp', from the taste of acids) and -γενής (-genēs) (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.
Singtium and Octium, perhaps.
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.)
[1]: https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry
(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
Imagine 500 years in the future when we have laptop particle accelerators... We may have whole diffent reality around 'strange'.
The line from the remake of 'the man who fell to earth.' "He has miscalculated the chirality."
The macro stars and the micro. I for sure thought that 118 was the limit, and again, this has been a life long interest of mine.
I have the isotope chxart on the wall at home.
P.s. kudos for paying attention in school.
P.p.s extra thanks the people who kept the Laurence hall of science going, and it's periodic table working.
So clearly there is a limit. Either bounded by the point where gravity becomes dominant or when you get a black hole.
What happens in neutron stars is somewhere between nuclear reactions and quantum effects. Both of which are decidedly not "chemistry" in the way most people use that word.
More generally, only normal atoms can undergo chemistry. All of chemistry depends on the arrangement of electron orbitals. Once you leave that domain, you're in an entirely different field of physics.
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.
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.
[1] https://en.wikipedia.org/wiki/File:Binding_energy_curve_-_co...
In other words, energy required to break them apart.
At some point it becomes "quark matter" and might exist in collapsed stars.
Atoms are much bigger than subatomic particles, so they have to live even longer in order to exist.
"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)
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.
https://en.m.wikipedia.org/wiki/Betatron
(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.
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.
Now think of 10^50 protons in a line. They're all experiencing net gravity towards the middle.
With gravity, A is attracted inward, B is not attracted, C is attracted inward.
Of course, in practice, we don't know what the inside of a black hole is like, as quantum gravity is very much unsolved.
So the conclusion is any proton star would just explode? That's what I already thought.
Even if you make the argument that the energy complicit in the strong/weak forces is cumutavily much greater than the energy due to gravity, I'm still not sure "weak" is the right word for the job...
Gravity onstensibly runs at infinite speed over infinite area (the effect of gravity waves non-withstanding).
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.)
They're ... both big (by atomic scales) and massive (atomic and astronomical).
I'm struggling to find a strong source, but this page, by M. Coleman Miller at the University of Maryland, describes properties suggesting modelling over observation. Specifically it describes "the guts of a neutron star":
Even further down, you mainly have free neutrons, with a 5%-10% sprinkling of protons and electrons.
With an subsequent 'graph:
Yes, you may say, that's all very well for keeping nuclear theorists employed, but how can we possibly tell if it works out in reality? Well, believe it or not, these things may actually have an effect on the cooling history of the star and their spin behavior!
What follows is more description of theory with a few points based in what is directly observable, largely spin (via radio astronomy) and some temperature observations largely in X-ray observations, and the occasional gamma-ray burst.
<https://www.astro.umd.edu/~miller/nstar.html>
Miller's bio at UMD emphasizes his theoretical work:
Cole Miller's research in the last few years has focused on theory and modeling of high-energy radiation from neutron stars and black holes.
<https://www.astro.umd.edu/people/miller.html>
The conceptualisation of elements is useful to us because physical characteristics of atoms are (mostly) stable over time, with atoms having distinctive masses, atomic numbers, and most importantly, electron shells. The latter account for most of what we consider to be "chemistry", along with some other effects, most notably the van der Waals force.
Neutron stars ... lack most of this. They're in constant flux, they (probably) don't have stable masses (if only due to constant accretion) or atomic numbers, they probably don't have anything resembling an electron shell, and in interactions with other objects any electromagnetic forces would probably be overwhelmed by gravity or, say, spin-induced magnetism. If a measure of a concept or model's usefulness is how much it explains behaviours, "neutron-star-as-element" doesn't buy you much.
Though there's possibly some truth or conceptual validity to it.
I subscribe strongly to a pragmatic approach to knowledge and understanding. That is, knowledge isn't so much true as it is useful, in that it provides a useful mental model of the world. There are cases where multiple truths are possible, as with wave-particle duality, or mass-energy. Either classification may be useful, that is, provide predictive, understanding, or manipulative power, depending on contexts and circumstances. Some of the classic philosophical paradoxes (Sorites, Ship of Thesus, falling tree in a forest) resolve at least somewhat under this view. What is often called "truth" I think of as "useful mental models". The distinction is that whilst both are grounded in observation and empiricism, "truth" is an absolute, whilst "usefulness" is a bit like evolutionary fitness: changing over time, dependent on circumstance, not entirely arbitrary, but also not perpetually fixed.
So, is a neutron star a gigantic nucleus? Yes, in a sense, in that it's primarily made of what we'd otherwise consider nuclear material. Does this give us useful insights on neutron star behavior above and beyond those given by gravitational, thermodynamic, and electromagnetic descriptions? No, not really, because the attendant characteristics and properties of much smaller nuclei (from atomic number 1 to the low 100s or so) simply don't apply. There's not much behaviour that is explained, predicted, or controlled by applying that knowledge.
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.
String theory may well be wrong/currently untestable, however failure to invalidate the null hypothesis is not proof that somehow we don't have a meaningful understanding of other, proven theories/laws.
Put a different way, if an apple falls from a tree on earth, I don't panic because I don't understand quarks or electron orbitals. I calculate the point/speed/force of impact to acceptable margins of error.
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
[0] https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheimer%E2%...
I was thinking of neutron stars all along - which, correct me if I’m wrong, look like they have similar density to an atomic nucleus and for which the upper limit is apparently 3 Sols. [0]
[0] https://en.m.wikipedia.org/wiki/Neutron_star#:~:text=Neutron....
P.S. Quote from the link:
> Would this black hole cause the universe to collapse? Hard to say.
There's also the whole menagerie of nuclear pasta [1] where gnocchi and spaghetti you could maybe consider "nuclei" unto themselves. There's also waffles & lasagna, but when you get into the anti-spaghetti and anti-gnocchi realms, then you're into the "one nucleus" region.
[1]: https://doi.org/10.1103/PhysRevC.96.025803
[On The Way To Super Elements](https://archive.org/details/FlerovIlyinovOnTheWayToSuperElem...)
https://www.youtube.com/watch?v=Qe5WT22-AO8
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
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.
https://www.youtube.com/watch?v=l6lGe5jgZgI
besides learning about them briefly in chem classes as the "man made elements", haven't heard much from them otherwise
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.
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?
I would imagine in conditions of high heat, plasma, RF energy and pressure many things "exist" but I don't see that as quite the same. I guess if their spectral line emissions from stars says they are a continuum of existence then thats something, but I wondered if there were wierd islands of stability e.g. inside crystal lattices under pressure, or in solution in some wierd, non-plasma state. Absent an observer round that star we can't know but can we hypotheise physical states which would let it be?
https://englishatlc.com/wp-content/uploads/2016/03/randall-m...