Antimatter Atoms Can Be Precisely Manipulated and Cooled With Lasers (newscientist.com) 68
One of our most precise mechanisms for controlling matter has now been applied to antimatter atoms for the first time. From a report: Laser cooling, which slows the motion of particles so they can be measured more precisely, can make antihydrogen atoms slow down by an order of magnitude. Antimatter particles have the same mass as particles of ordinary matter, but the opposite charge. An antihydrogen atom is made out of an antiproton and a positron, the antimatter equivalent of an electron. Makoto Fujiwara at TRIUMF, Canada's national particle accelerator centre, and his colleagues used an antihydrogen trapping experiment called ALPHA-2 at the CERN particle physics lab near Geneva, Switzerland, to create clouds of about 1000 antihydrogen atoms in a magnetic trap. The team developed a laser that shoots particles of light called photons at the right wavelength to slow down any anti-atoms that happen to be moving directly towards the laser, slowing them down bit by bit. "It's kind of like we're shooting a tiny ball at the atom, and the ball is very small, so the slowing down in this collision is very small, but we do it many times and then eventually the big atom will be slowed down," says Fujiwara. The group managed to slow the anti-atoms down by more than a factor of 10.
Well, then... (Score:1)
can't wait for YouTuber experiments (Score:2)
The "lets see what happens when we collect a kilogram of antihydrogen" sort of experiments.
I'd absolutely like and subscribe. But I'd like to be very far away during recording.
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The future is bright, though it comes in flashes :-/
How much energy (Score:1)
Will one hydrogen atom and one anti hydrogen make? Anyone physics qualified know?
And what is a meaningful amount for energy production?
Re: How much energy (Score:3)
Nevermind, it ainâ(TM)t much, but a grams worth.. now youâ(TM)re talking!
https://www.google.co.uk/amp/s... [google.co.uk]
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At the current rate of production, we should reach 602000000000000000000000 hydrogen atoms (1 gram) sometime in the next 8 billion years.
Re: How much energy (Score:5, Interesting)
Re:How much energy (Score:4, Informative)
Jokes aside, if anything anti-matter might be used to store energy, and that is also only with magic Star Trek technology.
Because in reality you will have to consider a couple of basic things here:
Energy requirement of safely generating anti-matter.
Energy requirement to safely store anti-matter.
Energy requirement to control the annihilation process to safely get the energy stored in anti-matter out again.
All in all the process would be extremely inefficient for any kind of energy generation. Probably even Trek's hack writers (from a science perspective, their philosophical stuff is sometimes quite good) were aware of this, so they mostly only used stuff like this for warp cores and photon torpedoes, where the extremely high energy density of anti-matter might be useful.
Re: How much energy (Score:2)
The reason to use antimatter is for starship fuel. It would require collecting huge amounts of energy, probably 100 or more times as much, to condense some of it to antimatter. (Done with very bright lasers or other techniques).
Being able to manipulate antimatter with lasers make it possible in theory to build an engine to use it.
I know this is probably centuries away (depending on if the Singularity hypothesis is correct or not). So useless for today's world.
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Energy requirement of safely generating anti-matter.
For reference, back of the envelope calculations indicate that to create useful amounts of anti-matter for use in an interstellar vessel, a civilization should be comfortable with engineering projects that can encircle a star. Not necessarily a Dyson sphere, or even a habitable ringworld, but a structure within the orbit of Mercury used to power the lasers required to concentrate enough energy in a small enough spot. It's a silly amount of energy.
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That should work as a good Big Dumb Object in scifi. For one we don't fully understand what happens inside a singularity in the first place. So plenty of artistic license to invent whatever physics suits the lazy writer. And then the energy levels that could be generated by this... Big Bang machines perhaps.
Somewhere in the vast works of science fict
Re:How much energy (Score:4, Informative)
>Do you know some rich veins of anti-matter that we can mine and annihilate with regular matter?
Ironically enough, yes!
At least rich by Earthside anitmatter standards. Apparently cosmic ray collisions with the Earth's atmosphere can create anitmatter, which gets captured by the Earth's magnetic field. https://arstechnica.com/scienc... [arstechnica.com]
As for the energy efficiency of storing energy as antimatter:
- for now, generating antimatter is extremely energy intensive, probably getting really close to 0% efficiency. But there's no long-term theoretical limit on that, we just need to dream up a vastly more practical way of doing it. Assuming we can't "mine" enough for our purposes.
- It should take approximately zero energy to store antimatter. Probably you'd use a superconducting magnetic bottle, which consumes no energy to maintain directly. You do need to keep your superconductors very cold - but in space you can do that with nothing but a few mylar sheets. The James Webb telescope's sun shield is designed to keep it at 55K, well below the 77K boundary that defines "high-temperature" superconductors
- Controlling the annihilation comes down to controlling the release from the magnetic bottle, which should consume negligible energy.
Basically, if we had a way to generate antimatter efficiently, the losses from the rest of the system could be made relatively negligible, at least in space. Which is handy, since space travel is the application where antimatter energy densities would really be incredibly valuable.
Heck, as long as we're imagining we can make antimatter efficiently enough to be worth the effort, perhaps we could synthesize blocks of anti-lithium or larger atoms. They should have similar properties to the normal-matter version, and just be an inert lump so long as nothing touches it. Then we wouldn't need to contain it so much as just push it around so it doesn't touch the sides of the vessel. Heck, we might even combine energy generation and lump-propulsion: just target it with thin jets of normal from many different directions, with the net annihilation backlash from any stream imbalance propelling it away from the densest streams. Or even use magnetic or electrostatic propulsion - without requiring a magnetic bottle to contain an antimatter gas either would be far more efficient.
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The problem is harvesting the energy, which I understand consists of gamma rays.
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The problem is harvesting the energy, which I understand consists of gamma rays.
Also pairs of neutrinos/antineutrinos carry off about half the energy.
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Not much of a problem. Coat the reactor vessel with a few centimeters of lead, several centimeters of cement, or whatever other gamma-ray shielding you like, then use the hot shielding to boil water to power a steam engine, just like pretty much any nuclear reactor.
There's also been some research into gamma ray "solar cells" that will likely come to fruition long before we've got antimatter reactors, that would potentially be simpler and more efficient than heating a steam engine.
It's a REALLY rotten battery. (Score:2)
[harvesting the energy is] Not much of a problem. Coat the reactor vessel with a few centimeters of lead, several centimeters of cement, or whatever other gamma-ray shielding you like, then use the hot shielding to boil water to power a steam engine, just like pretty much any nuclear reactor.
And then you're paying the carnot cycle penalty BIG time, throwing away the temperature difference between the temperature of the hot end of the heat engine and a black-body temperature where the average photon emission
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[discussion of energy lost as neutrinos]
Now if what you're after is thrust, if you could get the neutrinos to be emitted in one direction (an the gammas in the other) they would be rocket exhaust, not pure waste. If (unlike a Star Trek universe ship) you don't mind having gamma rays for a rocket exhaust plume, you can collect your thrust by bouncing them off a "mirror" and sending them in the same direction as the neutrons. The losses in the "mirror" might still be an embarrassment of riches, energy-wise.
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>And then you're paying the carnot cycle penalty BIG time
True, but that's true of virtually any high-density energy source, which is why I pointed out that that's how we do it with our most advanced nuclear reactors.
Sadly Carnot-cycle efficiencies look to be a limiting factor for a very long time indeed. The only big exception that springs to mind is p-B fusion, which emits almost all the energy as He4 nuclei with a very narrow range of kinetic energies, which could potentially be captured electrostatic
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>From the radiation belts? It would most likely cost orders more energy to collect/separate those positrons than you'd get out of the annihilation.
Well, the antimatter belts, but yes, quite likely. But potentially orders of magnitude less energy than producing it with known techniques.
At our current level of technology about the only large-scale application of antimatter that remotely makes sense is powering fast interstellar spaceships, where the gains from short-circuiting the rocket equation greatly
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In theory, yes, if you have a superconductor you can have very strong magnetic fields using little energy. However, superconductors won't simply violate thermodynamics by defying conservation of energy.
Here it's important to understand that antimatter still has mass. And if you want to move anything that has mass from place to place, which will have to be done if i was to be used on something like a space ship, you'll need kinetic energy. T
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Yes, you will have to impart energy to accelerate the mass, but no more than needed to accelerate the corresponding mass of normal matter, which is negligible compared to the energy needed to accelerate the rest of the ship, and not significantly amplified if you're transferring the energy by magnetic fields rather than direct contact.
We're talking 180 TJ per gram of antimatter, once you include the normal matter it annihilates with. 1000x as much energy as from a similar mass of 100% fissioned uranium, or
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8.35608e-14 watt hours by mass energy equivalence
Okay people who name things ... (Score:3)
An antihydrogen atom is made out of an antiproton and a positron, the antimatter equivalent of an electron.
Why aren't they either "antiproton" and "antielectron" or "negatron" and "positron", etc ...? Seriously, how about some symmetry, otherwise just name them Bob and Alice.
(Though, to be fair, "Negatron" sounds like the name of a Transformer -- who picks up girls by giving them negative compliments.)
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What's in a name? A while hell of a lot.
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...That's an unfortunate name for something that's so profoundly important...
Worst example I've encountered: the process of removing oxygen from silicon to make integrated circuits. The process isn't called "oxygen removal" or "oxygen stripping" or "deoxygenation", but "chlorine gettering". Chlorine is blown across the silicon wafer and gets the oxygen. Chlorine was found to be the best getter of oxygen, so the process is called "chlorine gettering".
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I'm not wasting my time, I'm Netflix watching.
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Why aren't they either "antiproton" and "antielectron" or "negatron" and "positron", etc ...? Seriously, how about some symmetry, otherwise just name them Bob and Alice.
Didn’t you hear? Antimatter breaks symmetry.
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Because positrons are relatively easy to make and they were discovered before we realized that every particle has an anti- particle and stopped naming the new ones.
Re:Okay people who name things ... (Score:4, Interesting)
Positrons aren't just "easy to make", they occur naturally in inverse beta decay so they would have been found even if antimatter hadn't already been predicted to exist.
But the short answer to GP's question is "historical accident", just like conventional current.
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That's why they're easy to make.
All antimatter occurs naturally in decay events, only one of which occurs with any regularity on the surface of the Earth.
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Re: Okay people who name things ... (Score:1)
I like âoecontraterrineâ instead of antimatter. Used on Buck Rogers when terrorists threatening magnetic containment in a power plant
Re: Okay people who name things ... (Score:1)
https://buckrogers.fandom.com/... [fandom.com]
What about regular matter? (Score:2)
Photons are their own anti-particle so shouldn't you be able to do this with matter as well? Is there something that makes this feat specific to antimatter?
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It doesn't really matter.
Is there an editor in the house? (Score:4, Funny)
... particles of light called photons ...
Just what audience are they writing this for anyway?
Re:Is there an editor in the house? (Score:4, Funny)
... particles of light called photons ...
Just what audience are they writing this for anyway?
Yea, their wave crowd just collapsed entirely.
Step 1 (Score:2)
Step 1: Make 20 pounds of anti-lead
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there is no step 2
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2) reboot species over on mars
"Warp core breach" (Score:2)
If Star Trek is an accurate lesson on science history, get ready for "anti-matter containment failure" events. Which is a fancy term for "very big explosions".
https://www.youtube.com/watch?... [youtube.com]
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That's just shoddy safety design. Why are they using a form of antimatter that needs containing? Just chuck a lump of anti-lead into the reactor and push it around with jets of normal matter to simultaneously generate power and keep it suspended with the backlash.
That's great and all... (Score:2)
It's still an open question in physics if antimatter falls "up" with respect to normal matter because the quantities of antimatter that we can produce at one time and the speeds that the particles typically move at are not generally practical for gravitational experimentation.
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Sir Isaac Newton told us why
An Apple falls down from the sky
A brick, a bolt, a bar, a cup
All of them fall down, not up.
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Yeah.. I think the Standard Model predicts it should behave the same gravitationally - but it's widely accepted that the Standard Model is incomplete, and scientists are eagerly seeking any evidence of a false prediction.
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The standard model makes no such prediction because it does not encompass gravity. Luckily for us, the AEgIS collaboration at CERN is nearing the point where they can measure the freefall behavior or antihydrogen directly.
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Hmm, now that I think on that, you're right.
I suppose it's actually General Relativity that predicts antimatter will have positive gravitational mass: E=mc^2, perhaps more informative in the original form: m=E/c^2. Often misunderstood as saying you can convert mass and energy, but actually saying that mass is a property of energy. Matter is just one form of energy, convert matter to radiation, or vice-versa, and the total mass remains the same.
Since antimatter has positive energy, it should have positive
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That's directly the subject of this story. They slowed and confined about a thousand anti-hydrogen molecules in a magnetic trap. Seems pretty arbitrary to me.
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A thousand anti-hydrogen atoms is at not less than about 20 orders of magnitude smaller than what I was referring to.
Perhaps I should have been more specific and said arbitrary *macroscopic* amounts of antimatter.
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Rutherford first split a single atom, later there was the hydrogen bomb, which split many orders of magnitude more atoms. Likewise, if a thousand anti-hydrogen atoms can be bottled and there is a practical reason for bottling more then now it is more a matter of engineering than basic science.
Apologies for the bad analogy :) The chain reaction certainly helped, and I sincerely hope there is no such thing as an antimatter chain reaction.
For what it's worth, there are already practical uses [wikipedia.org] for antimatter. It
Cool! (Score:2)
I can't believe nobody said it yet.
Geneva, Switzerland (Score:2)
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There are 23 places named Geneva in America.
There are 2 places named Geneva in Jamaica.
There is one place named Geneva in South Africa.
There is one place named Geneva in Dominica.
There is one place named Geneva in Switzerland.
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2 in Europe, 1 in Africa, 1 in Indonesia...
So, do you specify "In the USA" when talking about NY?
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If you are in Africa, Europe or Indonesia, it might be worth mentioning. We have a London, Ontario and it is often called London, Ontario to avoid confusion.
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Usually it's New York City, New York. Not many places have a New York City in a State/Province called New York. New York City, New York is unambiguous like Geneva, Swittzerland.
It's also why people who insist you cannot call the USA "America" are wrong - because there is not another Country that uses the name "America" in its name. It is an unambiguous reference.
Do they fall up or down? (Score:2)
Has the gravitational effect on antimatter ever been determined for sure?
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I don't believe so. We have captured antimatter in orbit around Earth, but with it being captured by the magnetic field lines it's probably not certain that "orbit" is technically the correct term.
Can we rename the anti-proton? (Score:2)
Can we just use "Notron"... or maybe "Negatron"?
As in:
* Matter is composed of Protons and Electrons
* Anti-matter is composed of Notrons and Positrons.