Comment by _Microft
13 hours ago
He receives the prize for conceiving the IceCube neutrino detector, a cubic-kilometer-sized detecter in the Antarctics.
https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory
Mechanism is via conversion of neutrinos into charged particles which are then detected via Cherenkov radiation which is produced when a charged particle moves with speeds larger then the speed of light in the medium. (That is only possible because it is less than the speed of light in vacuum which cannot be exceeded.)
This was also discussed recently if you are interested: https://en.wikipedia.org/wiki/Cherenkov_radiation
If anyone was wondering how some of that heavy stuff gets to the south pole to build such a large engineering project, at the farthest possible end of any logistics chain:
https://www.google.com/search?client=firefox-b-d&q=south+pol...
https://en.wikipedia.org/wiki/South_Pole_Traverse
https://octanepress.com/content/south-pole-traverse_antartic...
Significant amounts of things still come in by air cargo at great cost, but a lot also comes the long slow way.
I am adopting “Furthest possible end of any logistics chain” as a more refined version of “middle of fucking nowhere”. Thank you.
It would probably be harder if they wanted to put it, for instance, on the ocean floor at Point Nemo, but for sure the literal south pole is pretty damn expensive on a $ per kg to get stuff sent to. And on an ongoing basis to sustain operations 24x7x365 (it's my understanding it runs almost entirely on diesel fuel and/or Jet-A for a big-ass set of generators).
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This was fascinating, thank you for posting! Here is a video I found of the different types of sleds they use on the traverse - https://www.youtube.com/watch?v=mjrQrKjotpA
Okay but how is this useful to humanity (since thats part of the prizes condition)? Its cool that we can detect them but...now what?
> produced when a charged particle moves with speeds larger then the speed of light in the medium.
Thanks, I had no idea this was possible!
https://xkcd.com/1053/
And remember, the "speed of light in the medium" depends on the wavelength of the light. This is why prisms separate light by color.
Optical sonic boom.
Actually called a "Luminal Boom" or "Photonic Boom".
This is quite nuanced and not as most people assume.
It is the "phase velocity of light in that medium" that is exceeded.
phase velocity of light in a medium = speed of light / refractive index of the medium.
Thus the EM wave is slowed down in a medium and so a charged particle can exceed it producing Cherenkov radiation. This is similar to a sonic boom in atmosphere when speed of sound is exceeded. In both cases the object is traveling faster than the wavefront.
It is only in vacuum that "phase velocity of light" = "group velocity of light" = c (i.e. 300,000 km/sec)
What really is the speed of light in a medium/vacuum, group or phase velocity? - https://physics.stackexchange.com/questions/450377/what-real...
IIRC the group velocity in a medium can also exceed c when you send pulses through certain nonlinear media. Basically, the "lump" of the pulse can appear to "exit before it entered," but what really happens is that the tiny tip of the pulse has already gone through at <= c, and starts growing into the body at the exit before it has completely shrank at the entrance because of the nonlinearity. So it is actually the information/"signal" velocity (the tip of the signal) that cannot exceed c.
Are there interesting relativistic effects related to this other than this Cherenkov radiation?
To be more perfectly precise, it is only in a vacuum with an infinitely repeating regular signal that "phase velocity of light" = "group velocity of light".
The deviation caused by uncertainty in the package arrival time is typically extremely short, but not zero, for finite signals.
The actual "entity" that is restricted to be <=c is "information velocity". An infinitely repeating pattern would have travel at (phase velocity)=c ... but would ironically transmit no actual information (the bit value is restricted to 1, not 0 or 1).
The Telescope in the Ice was a solid book about this.
https://www.amazon.com/dp/1137280085
The book about it can also be used to detect neutrinos too?
Only if you bury it a kilometer below the ice.
I read all of that and other resources online and still couldn't understand why the hell we need to build that and especially in south pole antartica
Neutrinos need a large detector volume for efficiency because they interact so rarely. You can’t detect them directly so you need a transparent medium to detect their collision byproducts. Good detector mediums are water and ice, and are underground to minimise background light. There are relatively few places you can do this. Mine caverns and under the sea are the most common, but marine detectors are notoriously hard to build. Francis Halzen proposed using ice. At the Pole, the glacial plateau is 2 miles high and the breakthrough was confirming that the ice is in fact highly transparent if you go deep enough.
Why the pole specifically? You could probably build a second IceCube 100 miles away, but how are you going to get that materials there? Pole has a skiway for large aircraft and infrastructure to house a large number of people. The traverse (SPoT) only became operational near the end of construction - the initial holes were drilled in 2005 and almost everything had to be flown in.
Telescope In The Ice does a great job of explaining the history and science behind the experiment.
The biggest challenge is finding ice without dust layers from historical volcanic activity, and the South Pole is particularly clean because of it's remoteness as well as the prevailing wind directions. There is, however, one big dust layer that causes signal distortion.
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The best science comes from areas that have no obvious use. The original insights into nuclear physics, quantum physics and relativity were all pure thought experiments. They led to the world we live in.
I'm personally very happy that we're still funding science that isn't obviously monetised.
The reason for Antarctica is that it's the only place you find cubic kilometres of stable ice that doesn't drift around.
My best guess would be just the remoteness.
1: Ice-mass that isn't contaminated by atomic testing fallout (if the ice has been there since the 40s it's without radioactive waste (faschinating to read about how WW2 wrecks is a prime resource of steel since it's a huge amount of steel without trace amounts of radionucletiods from testing fallout).
2: No current interference (nuclear power, radiowaves,etc) creating possible test uncertainties.
3: I'm sure there are other reasons
The negative naturally is cost, but since the expriment succeeded it will probably be useful for any attempts to send robots or even humanity into space beyond the solar system.
Where else would you go look for a cubic km of ice?
Greenland, though that is probably not much better in any measurable way, when it comes to transport.
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If we're serious about AI taking over jobs, we'll probably need to get more comfortable with any kind of undirected work-for-its-own-sake, not less.
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> which are then detected via Cherenkov radiation which is produced when a charged particle moves with speeds larger then the speed of light in the medium. (That is only possible because it is less than the speed of light in vacuum which cannot be exceeded.)
I have been researching applications of FTL as well;
Where is there an actual vacuum on Earth or in microgravity? So, there are Proca waves within dielectric Proca metamaterials and plasmas and waveguides; and photons can have effective mass and/or longitudinal charge Ez in ionized plasma?
So, Maxwellian waves with no longitudinal (Ez,) component can exist in what fraction of the universe if they can only exist in a vacuum?
A Twistor model can model such;
Perhaps this was downvoted in ignorance?
This question could have avoided the offense:
What is the relation between Cherenkov relation and effective mass in longitudinal plasma waves?