In a paper published today in the journal Nature, the ALPHA collaboration reports the first ever measurement on the optical spectrum of an antimatter atom. This achievement features technological developments that open up a completely new era in high-precision antimatter research. It is the result of over 20 years of work by the CERN1 antimatter community.
"Using a laser to observe a transition in antihydrogen and comparing it to hydrogen to see if they obey the same laws of physics has always been a key goal of antimatter research," said Jeffrey Hangst, Spokesperson of the ALPHA collaboration.
[...] With its single proton and single electron, hydrogen is the most abundant, simple and well-understood atom in the Universe. Its spectrum has been measured to very high precision. Antihydrogen atoms, on the other hand are poorly understood. Because the Universe appears to consist entirely of matter, the constituents of antihydrogen atoms – antiprotons and positrons – have to be produced and assembled into atoms before the antihydrogen spectrum can be measured. It's a painstaking process, but well worth the effort since any measurable difference between the spectra of hydrogen and antihydrogen would break basic principles of physics and possibly help understand the puzzle of the matter-antimatter imbalance in the Universe.
Additional coverage from The New York Times and National Public Radio.
Observation of the 1S–2S transition in trapped antihydrogen (DOI: 10.1038/nature21040) (DX)
(Score: 0) by Anonymous Coward on Thursday December 22 2016, @11:27PM
Good good now all we need is some antideuterium to fuel a warp reactor and the vulcans will come to observe our primitive planet and not laugh at us smugly.
(Score: 3, Insightful) by turgid on Thursday December 22 2016, @11:44PM
HIggs boson, gravity waves and now this! This is pretty cool.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].
(Score: 3, Interesting) by MichaelDavidCrawford on Thursday December 22 2016, @11:53PM
one can create a short-lived hydroven-like bound state between an electron and a proton. But it doesn't have a nucleus, rather the two particles have symmetric orbitals.
There is also charmonium, whose spectrum was measured in the early 80s.
Yes I Have No Bananas. [gofundme.com]
(Score: 4, Interesting) by Immerman on Friday December 23 2016, @12:27AM
I assume that should read "electron and positron" rather than proton. I don't think I've ever heard it given a name before. Now I'm curious as to whether it has multiple excitation states and corresponding emission lines, or would just come apart. Not to mention whether such a thing can be created with more than two particles.
Hadn't heard of charmonium, but having looked it up that sounds like an entirely different class of thing, charm flavor of quarkonium, a rare kind of meson created by bonding a quark with it's own anti-quark. But since mesons are unstable outside a nucleus, it would seem like measuring their spectrum would mean something completely different than it does for atoms or electron-positron couplings, but that's about the point where I could no longer make sense out of the wikipedia article.
(Score: 0) by Anonymous Coward on Friday December 23 2016, @03:34AM
https://en.wikipedia.org/wiki/Positronium [wikipedia.org]
It is in general unstable and will decay into two gamma rays in about 10-10 second.
(Score: 5, Informative) by Anonymous Coward on Friday December 23 2016, @02:57AM
It would have been helpful, I think, to have included the following additional quote FTFA in TFS instead of leaving us in suspense.
(Score: 0) by Anonymous Coward on Friday December 23 2016, @03:24AM
This is a great example of when the nil null hypothesis makes sense. Now if two groups of people/rodents/cells are supposed to be "exactly the same on average", different story.
(Score: 4, Funny) by mhajicek on Friday December 23 2016, @03:45AM
My son just informed me that antimatter is just like normal matter only emo.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 0) by Anonymous Coward on Friday December 23 2016, @04:59AM
why physical interaction with your past self can have catastrophic consequences. Without realizing it your past self and your anti-self coming into contact will result in an antimatter reaction blasting them both out of existence.
Be very afraid of contacting your past self!
This has been a PSA of the time police: Don't left your future self become a temporal terrorist!
(Score: 3, Interesting) by terryk30 on Friday December 23 2016, @08:35AM
FYI, from the linked NYT article:
the team at CERN is working on new experiments, including one that looks at how antihydrogen is affected by gravity.
In other words, will it "fall up from" or down to the normal-matter Earth. IIUC most physicists expect the boring result, but it does need to be checked. But who knows; maybe we'll be surprised.