Physicists Propose Listening For Dark Matter With Plasma-Based 'Axion Radio' (arstechnica.com) 29
Physicists at Stockholm University and the Max Planck Institute of Physics have proposed a novel design for an "axion radio" that employs cold plasmas (gases or liquids of charged particles) to "listen" for dark matter. Their paper has been published in the journal Physical Review Letters. Ars Technica reports: "Finding the axion is a bit like tuning a radio: you have to tune your antenna until you pick up the right frequency," said co-author Alexander Millar, a postdoc at Stockholm University. "Rather than music, experimentalists would be rewarded with 'hearing' the dark matter that the Earth is traveling through." [...] According to quantum mechanics, particles can exhibit wavelike behavior as well as particle characteristics. So an axion would behave more like a wave (or wave packet) than a particle, and the size of the wave packets is inversely proportional to their mass. That means these very light particles don't necessarily need to be tiny. The downside is that they interact even more weakly with regular matter than [weakly interacting massive particles], or WIMPS, so they cannot be produced in large colliders -- one current method for detecting WIMPs.
Physicists don't know what the axion's mass might be, so there's a broad parameter space in which to search, and no single instrument can cover all of it, according to co-author Matthew Lawson, also a postdoc at Stockholm University. That's why physicists have been developing all kinds of smaller experiments for detecting axions, from atomic clocks and resonating bars, to shining lasers at walls on the off-chance a bit of dark matter seeps through the other side. Yet most instruments to date are capable of detecting axions only within a very limited mass range. [...] Lawson et al. have come up with an innovative design for a tunable plasma-based haloscope. Their proposed instrument exploits the fact that axions inside a strong magnetic field will generate their own small electric field. This in turn drives oscillations in the plasma, amplifying the signal. [...] At the moment, Lawson et al.'s design is theoretical, but several experimental groups are actively working on building prototypes. "The fact that the experimental community has latched onto this idea so quickly is very exciting and promising for building a full-scale experiment," said Millar.
Physicists don't know what the axion's mass might be, so there's a broad parameter space in which to search, and no single instrument can cover all of it, according to co-author Matthew Lawson, also a postdoc at Stockholm University. That's why physicists have been developing all kinds of smaller experiments for detecting axions, from atomic clocks and resonating bars, to shining lasers at walls on the off-chance a bit of dark matter seeps through the other side. Yet most instruments to date are capable of detecting axions only within a very limited mass range. [...] Lawson et al. have come up with an innovative design for a tunable plasma-based haloscope. Their proposed instrument exploits the fact that axions inside a strong magnetic field will generate their own small electric field. This in turn drives oscillations in the plasma, amplifying the signal. [...] At the moment, Lawson et al.'s design is theoretical, but several experimental groups are actively working on building prototypes. "The fact that the experimental community has latched onto this idea so quickly is very exciting and promising for building a full-scale experiment," said Millar.
Welcome to the scientific process. (Score:3)
While the math says there could be dark matter. We can use that as a hypothesis to explain the universe. However we need a way to find and measure it, to see if this current "Fudge Factor" in the math is a real value. If it can be measured, and quantified. then this is no longer an unknown variable, but a natural phenomenon to be studied.
This doesn't mean in 20 years we will have Dark Matter powered CPU's or some exotic energy source. But with a better understanding on how the universe works, that is a possible new variable that we can use to perhaps improve exploration of space, measure distance, the age of the universe, and perhaps in a couple hundred years find a way to hack the system for our own use.
The discovery of electricity and infrared and ultraviolet didn't have any practical use for decades,
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I'm not a physicist but as I understand it, dark matter can be measured for example by gravitational lensing https://en.wikipedia.org/wiki/... [wikipedia.org]
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Discovered by galatic rotational curves (Score:2)
Dark matter was proposed by Fritz Zwicky [wikipedia.org] in 1933 when he studied galactic clusters, and named it dark matter in German.
However, it was Vera Rubin [wikipedia.org] who measured galaxy rotation curves [wikipedia.org] in the 60s and 70s, starting the current theory.
Dark matter is matter that is turns out to be more abundant than 'regular' baryonic matter. The difference is that it only interacts with gravity. That is, it does not reflect or deflect photons, and therefore it is 'dark'.
Axions and WIMPS are proposed particles that fit the model,
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It can be inferred that way, but we're not so sure that the observation is actually the result of dark matter. It could be something else. Further experimental observations will help us decide.
Re: Welcome to the scientific process. (Score:2)
I'm under the impression that dark matter is pretty much defined as whatever the various measurements that indicates a whole lot of mass that otherwise can't be observed is.
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Dark matter is just the name of a broad category of theories based on the existence of particles that other than gravity don't really interact with anything. It is a front-runner because the other possible explanations of observations would be more complex just less likely seeming.
But until we can capture dark matter in a bag (so to speak), it's just a theory, and it's not the only one. Other proposed theories involve undiscovered behavior of gravity under conditions we have not been able to examine so far.
Actually, it's the other way around: (Score:1)
We measure effects, that imply vastly higher gravity than the masses we see, when using our current theories.
Which means that either our measurements are wrong, or our theories are wrong and we need to add a source for that gravity or alter an existing source's effects.
I think assuming a new kind of particle is the stupidest answer out there.
(Undoubtedly emerging from the Religion of String that happily carries on for decades, despite never being testable or offering any useful predictions. Aka what makes s
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Do you really think no one is looking at those things? There have been lots of competing non-particle explanations of dark matter. Most of the good ones have been falsified by experimental evidence, unfortunately.
Are you really thinking nobody looked at OpenSSL? (Score:2)
Yet it still had a security hole that broke OpenBSD's streak.
Your argument really boils down to ad populum.
Yes, I really think that a huge load of very smart and seemingly smart people can look at this very hard for very long, and still be wrong and stupid. Because it is a much harder problem that you can imagine.
Anyone of *them*, if they really are that smart, knows that.
They would also not use ad populum, let alone in a strawman argument to serve as an implied ad hominem.
Maybe this is not a level of discu
P.S.: This comment contained a free typo. (Score:2)
Of you find it, you can keep it!
The gift horse that keeps on giving!
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I think assuming a new kind of particle is the stupidest answer out there.
About same level of stupidity as assuming that we've seen all of them.
Alright, there are theoretically stupider ones (Score:2)
But you must admit that it is hard to imagine one stupider that isn't also ridiculous time cube territory. Because it's right at the border to that territory. And only because it streched and expanded the border quite a bit.
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Keep in mind that similar thinking was in play when researchers observed anomalous effects while looking into the effect of Crookes tubes on phosphors. Through further efforts to characterize the odd observations, we discovered x-rays. Not quite so famous, we also soon after determined that n-rays aren't a thing.
The experiment in TFA is an attempt to determine which is true for dark matter.
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This doesn't mean in 20 years we will have Dark Matter powered CPU's or some exotic energy source.
Hollywood will have Dark Matter powered something much sooner than that.
Holy Cow (Score:1)
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Not really. A simple hypothesis for dark matter is that it is a sector that simply has no connection to the normal matter section except through gravity. Al these negative experiments just invalidate the current experimenter's pet theory but do not weaken the case for dark matter in any way since there was never any reason to assume that pet theory was true.
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I think modern particle physics works on the quantum principle that if it can happen, it will happen. So particle physicists reason that if some weirdo particles can happen in any of their theories, then they will happen. Think of it as a full-employment program for particle physicists. Now about those 10^500 string theories...them are all true, somewhere, somehow...quantum physics guarantees it.
Super Boring Collider (Score:1)
Now Playing on Axion Radio... (Score:2)
Coldplay.
Physics (Score:2)
About 1880-1900 physicists thought they had the whole universe figured out. They had Newton's theory of gravity and basic mechanics and Maxwell's equations to figure out magnetism and electricity at once, a unified theory. There were some weird things people were looking into like radioactivity and the photo-electric effect but we had like 95% of the universe explained. The weird 5% turned into quantum physics and relativity and two whole new forces the weak and strong nuclear forces. The 5% had fusion an
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I think you mean a whole can of wormholes. It gives the space nutters a reason to hope.
Connected to the Universe (Score:2)
My smartphone shows the temperature at the northpole at every time of day.
It has a specific buzz when there is a realtime LIGO gravity wave detection.
It has a different buzz when there is a tsunami and another one for nuclear explosions.
I can put on axion radio and solar flare music.
I am connected to the universe.
This could go sideways... (Score:2)
I think that dark matter is a myth created to rationalize our incomplete understanding of the laws of gravity at larger scales. What you might pick up by listening to plasma is the covert radio traffic of the military as they use longitudinal waves, which as we all know, can't exist. These imaginary waves have the property of passing right through faraday cages because they don't induce current in conductors, and can only be received by inducing currents in plasmas..
Light up Dark Matter. (Score:2)
To observe dark matter, they propose to light it up with a "tunable plasma-based haloscope".