CERN boffins zap antimatter with ultraviolet lasers in the hope of revealing the secret symmetry of the universe

A team of European researchers have succeeded in slowing down antimatter in a study that could lead to more accurate measures of this strangely elusive substance and help confirm the fundamental symmetry of nature. Antimatter has certain properties – such as electric charge – which are inverted from those of normal matter. In …

[Anonymous Coward]

Another test of General Relativity

Something the paper mentions is that getting cool (slow) enough antimatter is a critical step in another test of GR. Once you can trap enough antimatter and get it cool enough, then you can watch it for long enough to see how it behaves under gravity – which way it falls, really. We 'know' the answer is that it will fall down, but no-one has ever been able to test this experimentally, so we don't actually know it at all: we just believe it. If it doesn't fall down, or if it feels gravity in any way differently than ordinary matter, then GR is a dead theory (not just a bit wrong: dead), which would be very big news indeed.

Incidentally experiments like this are one of the best answers to the idiot 'scientists are all conspiring to keep their comfortable theories alive' people: no-one thinks these gravitational experiments on antimatter will have interesting outcomes – everyone thinks it will just behave the same way matter does under gravity – but here they are doing experiments to check that, because that's what you do.

[Anonymous Coward]

Re: Another test of General Relativity

"Incidentally experiments like this are one of the best answers to the idiot 'scientists are all conspiring to keep their comfortable theories alive' people: no-one thinks these gravitational experiments on antimatter will have interesting outcomes – everyone thinks it will just behave the same way matter does under gravity – but here they are doing experiments to check that, because that's what you do."

Well they certainly won't travel backwards in time now will they! That would be ridiculous, violating all sorts of causal relationships.

1) Gravity is not bending space. Space is just a coordinate system of our choosing for our physics model. At best GR fixes up the coordinate system for some errors. A corrected physics model wouldn't need the fix-up, and space cannot both simultaneously bend to fix-up one model, and not-bend to not-fix-up another model. Recognize that GR is a fixup.

2) You have a universe expansion effect and a compression effect, mislabeled as a fundamental constant force 'gravity'. You hypothesize that these cancel out and that matter is stable at our level, neither contracting nor expanding at *our* level. My! Aren't we special!? Two opposing effects magically cancel at our level! No of course we are not, we just perceive it like that so we built the model like that. It works at local distances and not at universe distances, proof that we misunderstood it.

When I put it like that you can see the ludicrous nature of it. If we were the incredible shrinking man on the incredible shrinking planet, the universe would appear to be expanding, because we would be shrinking faster than the distance between galaxies. One gravity-like clumping effect resulting in an apparent opposing effect, simply because of the way we perceive it. Not *two* opposing effects that magically cancel out at our level, *one* that no longer magically needs to cancel out.

So I put it to you that the effect underpinning gravity and the effect of universe expansion derive from the same effect, and they do *not* handily cancel out to zero at our level.

Stop clinging to falsehoods or get a thicker skin. I'm just an AC here, stating the obvious to you.

If the particle is moving then so must be the electrons in the detector and everything you've ever seen is the net effect of the oscillating field and the oscillating particle.

As I said, 5 words, "electric is an oscillating force".

Gravity is not a fundamental force, it could not be as long as there are well understood electric clumping effects unaccounted for, there must be an electric component of gravity. Hence gravity includes an electric component and is not fundamental.

At least 3 net oscillations result in net zero motion in less than nObservable oscillations with respect to a given observer. Those 3 dimensions, color forces, mass.... they're right here too.

I state the obvious here.

[Anonymous Coward]

Re: Another test of General Relativity

Hello, inevitable anonymous crank.

[Michael Wojcik]

Re: Another test of General Relativity

That's not fair. The "electric universe" dude is a full-fledged kook, not just a crank. That's quality crazy right there.

[uccsoundman]

Re: Another test of General Relativity

I don't think you are a physicist, so where are you reading this? I'd like to read it for myself.

[Anonymous Coward]

Re: Another test of General Relativity

If you're asking me: I used to be a physicist and I guess I just read:ifthere's a good single source for ohysics/maths news I don't know of it. don't know where I read about the CERN antimatter gravity experiments (but I was a GR person so I'd notice them if they were mentioned. Sorry not to be more help.

[Intractable Potsherd]

Re: Another test of General Relativity

@tfb: I think reply was aimed at the (inevitable) anonymous bullshitter whose knowledge seems to come from the "electric universe" websites.

[Paul Kinsler]

Re: Space is just a coordinate system of our choosing

Not really - you might like to know there are physicists and mathematicians who very much prefer to write things in entirely coordinate-free notation (perhaps at this point you might look up the definition of a tensor).

We can certainly put coordinate systems of our choosing onto a chosen space (or a spacetime), but how useful this is depends very much on the spacetime and the coordindates (e.g. a black hole spacetime, and the non-trivial process of getting coordinates that work at the event horizon).

[Throatwarbler Mangrove]

Re: Another test of General Relativity

Don't worry, anonymous crank, I still love you! Your Dadaist interpretation of physics gives every comment thread you're in a delightful touch of whimsy!

[Filippo]

Re: Another test of General Relativity

There's nothing particularly "ludicrous" about two opposing forces canceling each other out at some stable point, and the opposite is far from "obvious". Also, using emotional language doesn't lend weight to scientific arguments.

[Anonymous Coward]

Re: Another test of General Relativity

These EU types are one of the weirdest conspiracy theory groups going, along with the Freemen on the Land whackjobs. They believe in just so much science (law) and then disregard all subsequent science (law) and the opinions of nearly all scientists (lawyers).

All the time they hold the simultaneous contradictory opinions that they are far smarter than the rest of us because they can see the real truth obscured not just to all of us plebs but to nearly all the actual experts; and that this real truth is obvious (AC's use of "I state the obvious here" being absolutely stereotypical) often combined with the near ubiquitous humblebrag ("I'm just an AC here, stating the obvious to you").

I suspect the cause is the same, and related to the popularity of nearly all other current CTs: actual book learning is hard and the Internet has been, since September 1993, far too easy to use.

[Michael Wojcik]

Re: Another test of General Relativity

I hadn't noticed the similarities between the electric-universe and sovereign-citizen types before, but now that you mention it...

They seem to share a belief in the magical power of words, too, whether it's e.g. "vibration" for the electric-universers or "proper" names for the sovereign citizens.

[Rich 11]

Re: Another test of General Relativity

Electric Universe nutter to arrive in -1, -2, -3, -4... and there he is.

[Conundrum1885]

Re: Another test of General Relativity

I have a standing bet with several folks that antimatter will turn out to have different gravitational acceleration to matter.

Whether this extends to the point that it could be the key to interstellar travel is as yet untested, however even a tiny change under certain conditions may permit an Alcubierre drive to function with accessible power requirements.

I've also often wondered if an isotope like 22Na might be key to such a drive, and in fact looking for its decay products in the form of characteristic gamma and X-rays be a sign that one is in use.

[Anonymous Coward]

Re: Another test of General Relativity

If antimatter behaves differently to matter under gravity then all of the maths that led to the Alcubierre drive no longer applies to the universe (se the 'GR is a dead theory' thread for why). So ... no, it won't make it work.

[swm]

Re: Another test of General Relativity

There is the CPT theorem. This says that if you negate the electric charge of everything, look in a mirror, and go backwards in time, that nothing changes (at least in the mathematics. The "proof" of this theorem assumes causality and some other very plausible things. If the CPT theorem is false then we live in a very strange universe. (Could be true.)

There is no way to combine general relativity with the standard model (the canonical quantization process results in a unrenormalizable theory) and the standard model falls apart at very high energies. So we know our (highly accurate) theories are wrong but we don't know how to fix them.

[jmch]

Re: Another test of General Relativity

"If the CPT theorem is false then we live in a very strange universe."

The first 7 words in that phrase are superfluous

[Pirate Dave]

Re: Another test of General Relativity

So why is it "dead" as opposed to "just a bit wrong"? If you can explain it in terms a CompSci grad (as opposed to a Physics grad) can understand, all the better.

[Anonymous Coward]

Re: Another test of General Relativity

GR's model is that gravity is the shape of spacetime. Objects moving under gravity simply move along the straightest lines they can (geodesics) in a spacetime which is deformed by the mass & energy around them. In other words the paths things take under gravity depend only on the geometry of spacetime, because gravity, in GR, is the geometry of spacetime. But since there is only one geometry this means that all objects must move the same way under gravity: if some objects, say, fell up and some fell down then a geometrical explanation of gravity falls hopelessly to bits. So if antimatter does not behave the same way matter does under gravity, GR fails completely: you can't patch it.

[Pirate Dave]

Re: Another test of General Relativity

Ah, thanks. That's understandable. But a buttload to think about and try to make sense of.

[Zolko]

defeating the Big Bang theory

the problem with anti-matter is that, if indeed anti-matter is exactly the opposite of normal matter, as all current experiments have measured, then the Big Bang theory is false: it stipulates that our universe was born from a big bang of energy, but then equal amounts of matter an anti-matter should have been created, which is observably false.

And if the Big Bang theory is false, it both invalidates a whole bunch of research (and its funding), but it also opens a whole new window into new research ideas (which will need funding)

[Cuddles]

Re: defeating the Big Bang theory

Nonsense. We've known this isn't true since the 1950s, and even that turned out to be replicating something that was first seen in the 1920s, although no-one had realised what it meant back then. If CP violation hadn't been observed then the Big Bang would indeed have a problem, but we've known the imbalance of matter and antimatter wasn't a terminal issue for it since before it even became the favourite theory for the origin of the universe. I never will understand why people make claims like this as if they've realised something that a century's worth of scientists have somehow missed.

[Zolko]

Re: defeating the Big Bang theory

"CP violation"

yes yes yes, ... let's see: The Standard Model contains at least three sources of CP violation

https://en.wikipedia.org/wiki/CP_violation#Matter%E2%80%93antimatter_imbalance:

1) The first of these, involving the Cabibbo–Kobayashi–Maskawa matrix in the quark sector, states that:

Observations and predictions : Note, however, that the specific values that the angles take on are not a prediction of the standard model: They are free parameters. At present, there is no generally-accepted theory that explains why the angles should have the values that are measured in experiments. => pure conjecture and fantasy

2) The strong interaction should also violate CP, in principle, but the failure to observe the electric dipole moment of the neutron in experiments... => it's so gross it's not even funny

3) The third source of CP violation is the Pontecorvo–Maki–Nakagawa–Sakata matrix in the lepton sector. The current long-baseline neutrino oscillation experiments, T2K and NOνA, may be able to find evidence of CP violation over a small fraction of possible values of the CP ... => pure conjecture again

Now up to you: give links to true experimental measurements of the matter/anti-matter dissymmetry ! And I didn't even begin to talk about the cosmologic inflation to invalidate the Big Bang theory.

[Anonymous Coward]

Re: defeating the Big Bang theory

You are confusing yourself. There is no doubt that CP violation happens: Cronin and Fitch won the 1980 Nobel prize for their observation of it in 1964. Our mathematical models – theories in other words – may or may not successfully predict it. If they don't predict it then they are, simply, wrong, since it is observed to happen.

But whether they predict it or not is entirely irrelevant here: we know with extremely high confidence that it happens, and so we can use this experimental fact to make other predictions, even if we don't have a model which predicts CP violation. And one of the things that follows from the fact of CP violation is matter-antimatter asymmetry.

It does (or did a few years ago) appear that there may not be enough CP violation we've yet detected (not predicted: detected) to account for the matter-antimatter imbalance we observe. However I don't think this is clear, and if it is the case, given the very compelling evidence for the big bang, the assumption will be that we're not seeing all the CP violation there is, not that the big bang didn't happen..

[Anonymous Coward]

Re: defeating the Big Bang theory

Er, no Mr. Dunning-Kruger. Symmetry breaking in the early universe is a basic part of big bang. ( CP ... )

[Flocke Kroes]

Re: defeating the Big Bang theory

Antimatter is not exactly the same as normal matter. Experiments with kaons detected a difference 1964. The standard model includes this asymmetry (which is not sufficient to explain the quantity of matter in the universe) and two other sources. One of the other sources has also been shown to be too small but the third has recently been measured. This might or might not be enough asymmetry. We will have to wait for the results of more precise experiments.

[Pascal Monett]

Re: then the Big Bang theory is false

Where do you draw that conclusion ?

I believe that there are quite a few highly-qualified physics experts that might not agree with you.

Of course, as always, please point me to your Nobel prize-winning PhD that demonstrates that everyone is wrong.

Oh, you're not done writing it ?

No Problem, we'll wait.

[User McUser]

Re: defeating the Big Bang theory

the problem with anti-matter is that, if indeed anti-matter is exactly the opposite of normal matter, as all current experiments have measured, then the Big Bang theory is false: it stipulates that our universe was born from a big bang of energy, but then equal amounts of matter an anti-matter should have been created, which is observably false.

I am not a physicist but it seems to me that if there "should" have been equal amounts of matter and antimatter at the Big Bang AND if the CPT thing is true, then the "simple" answer is that there WAS (is?) equal amounts of both matter and antimatter, each moving through Time in opposite directions with the Big Bang as a central point between them.

Basically out there somewhere/somewhen in what we would call the distant "past" (eg: "before" the Big Bang) there exists an antimatter universe equal to ours but with the arrow of time reversed. From that universe's perspective our anti-matter universe collapsed in on itself and spawned their matter universe. And from our perspective we would see the same exact thing.

[eldakka]

Re: defeating the Big Bang theory

> if indeed anti-matter is exactly the opposite of normal matter

Anti-matter is not "exactly the opposite" of normal matter.

Its charge is the opposite. Most other factors (few exceptions as noted in @Flocke Kroes post) are the same as ordinary matter. E.g., an anti-matter electron has the same mass (not the 'opposite' mass) as a normal-matter electron, the difference is it's charge is the exact opposite, the same 'value' but with a positive sign in front of it instead of the negative charge a normal-matter electron has.

[Pascal Monett]

Wait a minute

Excited antimatter particles emit normal photons ?

Shouldn't they emit anti-photons ?

I'm bewildered.

[Anonymous Coward]

Re: Wait a minute

They do. Photons are their own antiparticles

[KittenHuffer]

Re: Wait a minute

They, and several other particles, swing both ways!

[TrumpSlurp the Troll]

Re: Wait a minute

I didn't know it was that kind of parti(clue).

[ThatOne]

Re: Wait a minute

> anti-photons ?

Upvote because I wondered too.

So it seems budget ran out, Nature had to take some shortcuts, and reused some existing particles to fill in the blanks... Happens to the best, apparently.

[Anonymous Coward]

Re: Wait a minute

Incidentally, this is one of the reasons that it would be bizarre if antimatter behaved differently under gravity: some particles are their own antiparticles and they can behave only one way under gravity, which is the way GR predicts, of course..

[Charlie Clark]

Re: Wait a minute

How quantum do you want to go? Photons are the discrete expression of electromagnetic waves observable in precisely such experiments. But, unlike the fundamental particles, photons have no mass at rest, gaining it as a side-effect of their energy.

[Paul Kinsler]

Re: no mass at rest, gaining it as a side-effect of their energy.

The source term in GR is the stress-energy tensor, and so it is in fact not even necessary to consider a "rest mass", unless for some other reason it happens to be useful.

[Charlie Clark]

Re: no mass at rest, gaining it as a side-effect of their energy.

You're right, of course. It's just that it can be one way of explaining photons to people with little knowledge of theoretical physicists: they can be thought of as particles, except that they aren't…

[Eclectic Man]

Re: no mass at rest, gaining it as a side-effect of their energy.

@ Charlie Clark: I am trying to get my head around the concept of a photon 'at rest'.

I think I need a -------->

[eldakka]

Re: no mass at rest, gaining it as a side-effect of their energy.

Maybe if you offer the photon a beer, it might bring it to an 'at rest' state. It certainly works for me.

[Pirate Dave]

Re: no mass at rest, gaining it as a side-effect of their energy.

"Maybe if you offer the photon a beer"

I heard they only like "light" beer.

[Charlie Clark]

Re: no mass at rest, gaining it as a side-effect of their energy.

There's this problem with mass/energy equivalence and the observable fact that things get heavier the more energy they have. Hence, the general use of the term "at rest" when describing the mass of particles.

I probably need a beer as well, although after my Calvados excess over Easter maybe not.

[Paul Kinsler]

Re: photons - particles, except that they aren't…

Indeed; photons are countable, but, unlike massive particles, are not also naturally localizable (although you can always build yourself a shiny-on-the-inside box and use it as a trap :-).

[Kubla Cant]

from 300kmh down to below 50kmh

Does "kmh" mean kilometres per hour? That's what Google tells me.

My knowledge of particle physics is very limited, so I was disappointed to find that something as exotic as an anti-atom has a speed measured in such mundane units. And such mundane values, too. Once zapped with the laser, it wouldn't even qualify for a speeding ticket.

And why not km/h?

[Anonymous Coward]

I think so. I'd write km/h but then I'd write mph, so, well.

In order to do the kinds of experiments they want to do they need the speeds of the stuff to be low enough that they can observe their changes under gravity in a reasonably small experiment, so they need to be very low indeed.

[Eclectic Man]

PEDANT ALERT

In "mph", the 'p' stands for "per", so it is read as miles per hour. "kmh" would be Kilometre-Hours, so km/h would be kilometres per hour.

[Anonymous Coward]

Re: PEDANT ALERT

yes, and I think that speedometers say 'kph', don't they? I still think it's km/h but I can't excuse the notation.

[Howard Sway]

RE : Once zapped with the laser, it wouldn't even qualify for a speeding ticket.

You can't tell this with sufficient accuracy, as the uncertainty principle states that speed and position can never be measured correctly together, so when a quantum speeding ticket gets issued, the offending particle instantly emits an anti-speeding ticket, thus keeping everything nicely balanced out.

I state the obvious here.

[Yet Another Anonymous coward]

Re: RE : Once zapped with the laser, it wouldn't even qualify for a speeding ticket.

Worse, the police impose a speed and position on you by measuring it - so it's entrapment !

[Eclectic Man]

Definitions

I like that the article carefully explains that hydrogen is the simplest atom, but expects us to know what "quantum degenerate gases" means.

Any physicists on el Reg able to give a poor, ignorant mathematician an explanation?

[Anonymous Coward]

Re: Definitions

Degenerate matter is matter where the Pauli exclusion principle is a significant contribution to the pressure. The general term for these states is a 'Fermi gas' I think.

If you've got a bunch of fermions, then each quantum state can only be occupied by one fermion. Normally the stuff is so hot and / or sparse that there are enormously more available states than particles, so the pressure from the exclusion principle is negligible: thermal pressure hugely dominates. But it can become significant in at least two extreme cases.

If you put it under extreme pressure, then everything gets crushed together until exclusion pressure starts to matter. This happens in nature in white dwarf stars and neutron stars, where thermal pressure is not enough to hold the star up alone. As far as I know there's no hope of replicating these conditions experimentally.

Alternatively if you get the gas very cold then thermal pressure goes down until exclusion pressure starts to matter, and I think this is what they're talking about here. I have no idea if these states are accessible experimentally. But laser cooling would be how you'd get there if they are.

They might (perhaps are) be talking about Bose-Einstein condensates, which are gases of bosons very close to their ground state. These definitely are studied experimentally, and laser cooling is how you get there.

[TRT]

Re: Definitions

I often wondered how the "freeze" setting on a Moonbase Alpha hand laser worked.

[Rich 11]

Re: Definitions

As far as I know there's no hope of replicating these conditions experimentally.

That might be a good thing.

[Anonymous Coward]

Re: Definitions

You are hereby stripped of your 'mad scientist' and 'evil genius' badges. Please return them as you leave.

[Eclectic Man]

Re: Definitions

Steady on there, tfb. he only said it "might" be a good thing. Clearly he is trying to dissuade the rest of us from trying so that he gets there first.

I suggest you reinstate his 'mad scientist' and 'evil genius' badges until further evidence is provided. 'Innocent until proven guilty' you know.

[Anonymous Coward]

Re: Definitions

The badge committee has deliberated on this. We agree to conditionally restore the mad scientist badge. However we can not consider restoring the evil genius badge at this time: no evil genius would have used diversionary tactics such as this, but would instead have used the opportunity to monologue, at great length, on the exact and detailed nature of their plan to construct a small container of neutronium in their volcano-based laboratory and thus extract vast wealth from the nations of the Earth.

[Rich 11]

Re: Definitions

I'll admit I am not a traditional evil genius. On this article about antimatter I have so far managed to bite my tongue and not say anything about my secret plan to blow up the Vatican.

[Anonymous Coward]

Re: Definitions

Oh, I'm sorry. I blew it up last week (it's all being kept secret by the Illuminoids, of course). I would have waited if I knew you were planning to save me the trouble. I have always found that traditional nuclear devices are more practical for this sort of thing, however: they're easy to come by and you don't have to deal with all those annoying mad scientist types with their wild hair and endless tedious boffining.

[Rich 11]

Re: Definitions

OK, thanks for letting me know. It makes me doubly glad that my sub-plot to smuggle out Raphael's Adoration of the Magi and replace it with a perfect copy took place right on schedule, a fortnight earlier. You've saved me the trouble of boosting its market value stratospherically.

[Yet Another Anonymous coward]

Re: Definitions

>Bose-Einstein condensates, which are gases of bosons very close to their ground state. These definitely are studied experimentally, and laser cooling is how you get there.

superfluid liquid Helium is a Bose-Einstein (IIRC) and you can make this in a bucket

[89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921]

Re: Definitions

...but will it stay inside?

[fajensen]

Re: Definitions

Nope. Superfluid helium posess no friction, so mere (lack of) surface tension will pull it all the way over the bucket edge and then it rapidly siphons off.

[89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921]

Re: Definitions

https://www.youtube.com/watch?v=2Z6UJbwxBZI

[89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921]

So in the hypothetical time reversed antimatter universe, things go into Uranus more often?

[Phil O'Sophical]

Sounds like a right bugger to me.

[89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921]

Buggery is right, in the hypothetical time reversed antimatter universe

[Charlie Clark]

However, anti-particles do have the same mass as their matter counterparts.

I thought that this was no longer to be considered to be the case: the masses are very close but not the same.

[Anonymous Coward]

Re: However, anti-particles do have the same mass as their matter counterparts.

This paper gives the results of an experiment measuring the charge-to-mass ratios of protons and antiprotons: they're the same to within 69 parts per trillion. I think but am not sure that they are assumed to be actually the same.

[Charlie Clark]

Re: However, anti-particles do have the same mass as their matter counterparts.

Thanks for the information. I last looked at this a long time ago when I think variance in mass was still considered possible, or likely even. But this could have been tied in to one of the many theories around the lack of symmetry distribution.

[Anonymous Coward]

Re: However, anti-particles do have the same mass as their matter counterparts.

Well, I think it's certainly a thing you want to measure! Your theory can say 'masses are identical' till the cows come home, but if they're not, they're not. So it's nice people are measuring this!

[TRT]

But what happens if you mix pasta and antipasta?

[eldakka]

> But what happens if you mix pasta and antipasta?

FSM gets flatulence.

[Anonymous Coward]

CERNtown destruction?