6 ms·
New element is lighter than Hydrogen
- mindcrime 4y agoNot sure "new" is the best way to describe this, given the following, but whatever. Muonium is an exotic atom made up of an antimuon and an electron, which was discovered in 1960 by Vernon W. Hughes and is given the chemical symbol Mu.[1] [1]: https://en.wikipedia.org/wiki/Muonium https://en.wikipedia.org/wiki/Muonium
- gus_massa 4y agoThe video is slightly too enthusiastic, but accurate. Except the idea to add it to the periodic table, that is weird. Some of the new elements have a lifetime of a few ms that is very short, but still like 1000 times the half life of a muon... Anyway, it's interesting the idea that a few μs are enough to have "chemistry". (Not glassware chemistry. In a few μs it would disintegrate while you are pouring it from the beaker to the test tube :) .) I think it's enough to have a HMu or Mu_2 or other thing that is similar to molecular hydrogen, and measure some of their properties like the spectrum. I think they still didn't make HMu or Mu_2, but those particle physicist in their tunnels are doing weird things. The mass of a muon is 1/10 of a proton and x100 the mass of a electron. A common approximation in computer simulation of molecules is to assume that atoms are so "heavy" that they are essentially still while the electrons "move around". I guess it's still a good approximation for muons. If you like this, you may enjoy reading about positronium https://en.wikipedia.org/wiki/Positronium https://en.wikipedia.org/wiki/Positronium The half live is x1000 shorter, but they are easer to produce. I'm wondering if that's enough to get "chemistry", but I guess no. Anyway, the chemical properties would be too strange because the positron is too light.
- Y_Y 4y agoIn fact the proton-electron mass ratio is often a parameter (!) in plasma simulations. It turns out going from ~1/1837 to something like 1/100 makes things numerically easier without breaking the physics.
- knicholes 4y agoI'm not a chemist, but what do you mean it would disintegrate? Like it's literally disintegrating into smaller atoms?
- pknomad 4y agoNot a chemist either (took organic and baby pchem a while ago tho), but I believe he means it would just fall apart since there's no strong force or weak force to keep it together the way it would for a typical atoms. Muon's a fermion so it can't disintegrate into smaller atoms.
- fsh 4y agoThe muon decays into a positron and a pair of neutrinos: https://en.wikipedia.org/wiki/Muon#Muon_decay https://en.wikipedia.org/wiki/Muon#Muon_decay
- gus_massa 4y agoThe reaction would be Muon + Electron -> (Positron + Neutrino + Antinutrino) + Electron -> (Positron + Electron) + Neutrino + Antinutrino -> (Photon + Photon) + Neutrino + Antinutrino -> Photon + Photon + Neutrino + Antinutrino The Neutrino and Antineutrino would pass through you, the lab and the whole Earth, almost without interactions, so it's safe to ignore them. The photons will be very energetic and be actually Gamma Rays. Option 1) If it's a tiny amount like the one that can actually be produced, you will get a a few gamma ray. Option 2) If you can see the drop of liquid Mu_2 in the beaker, you will probably see a flash of gamma rays that will kill you and everyone in the lab. I'm too lazy to calculations but I guess an explosion of a few megatones (that is like a modern nuclear bomb). Also, perhaps many of the Electrons and Positrons will not colide immediately, and you would be showered also with some beta radiation. But the Positrons will colide after a short time and release the energy as gamma rays anyway. The exact amount of destruction of a drop of Mu_2 is a good question for https://what-if.xkcd.com/ https://what-if.xkcd.com/
- anonymouskimmer 4y ago> "Except the idea to add it to the periodic table, that is weird." It's weird because as indicated in your and other comments, having a different basis for the nucleus of its atoms, muonic elements would be on a completely separate periodic table from protonic elements.
- fsh 4y agoPs_2 molecules have been observed in 2007: https://www.nature.com/articles/nature06094 https://www.nature.com/articles/nature06094
- gus_massa 4y agoMore "chemistry" than what imagined: https://en.wikipedia.org/wiki/Di-positronium https://en.wikipedia.org/wiki/Di-positronium https://en.wikipedia.org/wiki/Positronium_hydride https://en.wikipedia.org/wiki/Positronium_hydride
- throwawaymaths 4y agoThe video had a more banal title about 24 hours ago when it first hit my feed. I guess they went sensational and now it's on hn
- branon 4y ago[flagged]
- dotancohen 4y agoThey've just redefined the meaning of the word "element". It used to be, roughly, a description of the properties of an atom with a specific number of protons and the remaining components (neutrons and electrons) to make it stable - even for short periods (radioactive elements that decay). Now they are using the term to refer to an assembly with muons. That said, people knowledgeable in the field are apparently accepting this definition. So who am I to say it's wrong? Especially if these assemblies are capable of chemistry.
- mindcrime 4y agoFWIW, that was kind of my first thought. I mean, if it doesn't have a nucleus with at least 1 proton, is it really an atom, and does it really count as an "element"? But I guess that's just semantic quibbling. shrug
- Xorakios 4y agosemantic quibbling is critical in science! I don't care about "who" vs "whom" but I care a lot about "=" vs "--"
- gnulinux 4y ago> Especially if these assemblies are capable of chemistry. As per Wikipedia these exotic atoms have been known for a while but they're extremely long lived (<~in the order of microseconds) so how can we talk about chemistry in such a tiny time scale? Would that be enough time to observe this exotic atom bonding with other mainstream or exotic atoms?
- thehappypm 4y agoMilliseconds is very long for particle physics.
- est 4y agoDoes the "new element" really exist, made & verified in labs, or just predicted by theory?
- coldpie 4y agoGood question! I found this link via the Muonium Wikipedia page: https://phys.org/news/2022-11-muonium-reveal-physics-standard.html https://phys.org/news/2022-11-muonium-reveal-physics-standar... A quote: "A major challenge to making these measurements very precisely is having an intense beam of muonium particles so that statistical errors can be reduced. Making lots of muonium, which incidentally lasts for only two microseconds, is not simple. There is one place in the world where enough positive muons at low energy are available to create this: PSI's Swiss Muon Source." So I think yes, it is real matter that can be and has been created... for two microseconds :)
- elil17 4y agoTwo microseconds is a really, really long time for particle physics stuff
- Brian_K_White 4y agoAssuming it's travelling at the speed of light, it's a beam 600 meters long, or 3/8 mile.
- User23 4y agoThe Swiss Muon Source website[1] is interesting to glance at. It has schematics among other things. [1] https://www.psi.ch/en/smus https://www.psi.ch/en/smus
- waynecochran 4y agoWatch the video
- jacooper 4y agoOh I thought that's was about a new version of Element, the matrix chat client, that's lighter than hydrogen, the light matrix chat client
- Arathorn 4y agome too...
- brilee 4y agoA lot of transuranic elements exist for microseconds and just barely long enough for spectroscopic measurements to be taken. Yet, they're granted a spot at the end of the periodic table. Humans like categorizing things, perhaps to a fault...
- libraryatnight 4y agoAre we experiencing element creep? :)
- singularity2001 4y agoAre single µ⁺ e⁻ pairs less or more stable than a whole plasma of this mixture? Since µ⁺ decays into e⁺ and some, the e⁺ e⁻ antimatter annihilation likely creates a whole lot of chaos in that plasma (?)! e⁺ e⁻ doesn't always immediately annihilate: https://en.wikipedia.org/wiki/Positronium https://en.wikipedia.org/wiki/Positronium "we expect to increase the Ps density to the point where many thousands of atoms interact and can undergo a phase transition to form a Bose–Einstein condensate" Interesting side read: The current experimental limit on the muon electric dipole moment, |dμ| < 1.9 × 10−19 e·cm set by the E821 experiment at the Brookhaven Laboratory, is orders of magnitude above the Standard Model prediction. Also appearing in the https://en.wikipedia.org/wiki/Proton_radius_puzzle https://en.wikipedia.org/wiki/Proton_radius_puzzle
- peter_d_sherman 4y agoA related question (that I still haven't been able to find a good answer to!) -- is: How did all of the Hydrogen in the Universe -- get there in the first place? ? Simply saying that "the Big Bang created it" might be true -- but is tremendously lacking in terms of a nuanced scientific understanding as to how the Hydrogen was, in effect, apparently created from "empty space" -- in the first place! If Muonium is real (I retain a half-skeptical, yet half open mind about this point, which I feel is a healthy position to take at this point of time without knowing more) -- then perhaps Muonium could be a stepping-stone in this future understanding... Of course, if Muonium is real and is a precursor to Hydrogen, that is, if we can make Hydrogen out of some kind of Muonium reaction, then we must replace our initial question of "How did all of the Hydrogen in the Universe get there in the first place?" with "How did all of the Muonium and/or other Hydrogen precursors that created the initial Hydrogen in the Universe get there in the first place?" Ultimately, the question comes down to "how do you create something from empty space", which comes down to "how do you create something from quantum foam/perturbations" (if the empty space consists of quantum foam/perturbations) -- which probably brings up the question of solitons, specifically how solitons can be created and sustained in quantum foam (in essence, the creation of a particle...) Perhaps the concepts surrounding Muonium could provide some ideas and/or clues in that direction... Anyway, an interesting and thought-provoking video!
- Maursault 4y ago> How did all of the Hydrogen in the Universe -- get there in the first place? Backwards! How did all the Universe get there around the Hydrogen? > Ultimately, the question comes down to "how do you create something from empty space", which comes down to "how do you create something from quantum foam/perturbations" (if the empty space consists of quantum foam/perturbations) -- which probably brings up the question of solitons, specifically how solitons can be created and sustained in quantum foam (in essence, the creation of a particle...) Why would you assume space comes before matter? Because you have it backwards, and ultimately the correct question to ask is: how do you create space from empty matter?
- peter_d_sherman 4y ago
- deleted 4y ago[deleted]
- scotty79 4y agoEven weirder thing: https://www.britannica.com/science/positronium https://www.britannica.com/science/positronium https://en.m.wikipedia.org/wiki/Positronium https://en.m.wikipedia.org/wiki/Positronium
- snapplebobapple 4y agoSo the real question needs to be where do i get enough of this stuff to fill my airship? With the extra lift i should be able to carry a second grand piano, resurrecting my plans to entertain my guests with duelling pianos.