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).

I disagree: anywhere in the ocean is easier logistics than crawler trains over land: ship it there and chuck it overboard. They do that to install oil rigs all the time (but that's more like float it there and sink it). Eg: https://www.wired.com/2014/07/dockwise-vanguard-shipping

Yeah, but now imagine the cost of putting large active electronics 4,000 meters down on the sea floor and keeping it running, and getting the data back off it... The cost of running the drill rig seen in the photos of the icecube detector would be a fraction of that.

That’s also a thing, e.g. in the Mediterranean.

https://en.wikipedia.org/wiki/KM3NeT

why would "ship it there and chuck overboard" be easier than "crawler train it there and chuck overboard"?

Because shipping is easier than trucking at subzero temperatures on roads constantly being covered in snow.

Also, we've been shipping by water much longer than we've been trucking things on wheels, because the tech is easier: get on floaty wood and paddle.

For sure, there are more difficult places, but I don’t think there is any conceivable place where the supply chain runs through the South Pole on its way. I hope not.

It is expensive and it doesn't need to be there, but the reason its at the south pole is that the US has money for SOMETHING at the south pole. They want to maintain a presence at the south pole for international relations reasons. To be consistent with insternational treaties they need to do science there.

So, the US/NSF is like "we have a bunch of money to do science, but it has to be at the south pole". People like Halzen who had a crazy idea go to NSF and say how can I get a bunch of money to do this. NSF says, we don't have that kind of money in our physics budget, but if you were to do it at the southpole we could fund it.

That's such interesting context. Thank you!

Is the cynical take on this experiment the one where the detectors have a dual purpose?

I was interested to see the photos of the modules. LEDs and an Ethernet port!

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

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

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.

No they weren't.

All of it was driven by a flood of experimental results that were not compatible with classical physics.

See "Ultra Violet Catastrophe" in black body radiation, photo effect.

Planck famously performed curve fitting on the black body spectrum and only afterwards found the theoretical foundation for the function that fit the data.

https://en.wikipedia.org/wiki/Ultraviolet_catastrophe

"No they weren't."

I'm actually not sure exactly what "they" is in this sentence.

I know about the Ultraviolet catastrophe, but that's cherry-picking.

Dirac predicted the Positron before it was discovered.

Quantum entanglement was predicted by Einstein, Podolsky and Rosen before it was shown ("Spooky action at a distance")

Black Holes and Gravitational waves were both predicted before they were detected.

Einstein predicted time dilation before it was detected.

Szilard predicted chain reactions in Nuclear fission before they were demonstrated.

And probably most pertinent to this discussion, Pauli predicted Neutrinos before they were detected.

Half of the list above are critical for GPS, energy, semiconductor research and many other fundamental technologies of the modern age. They were researched and predicted without any thought of a "monetisable" product.

> And probably most pertinent to this discussion, Pauli predicted Neutrinos before they were detected.

Because of the experimental result of missing energy in the beta radiation spectrum.

Bone of these were "pure thought experiments" as you describe. Many were side effects, new predictions of theories to address other experimental results, but none of them happened in isolation.

You simply don't make predictions about the real world in "pure thought experiments".

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.

Another option that's been popular is to get it as deep underground as possible, hard rock mines with empty areas:

https://en.wikipedia.org/wiki/Sudbury_Neutrino_Observatory

https://en.wikipedia.org/wiki/SNO+

https://en.wikipedia.org/wiki/Super-Kamiokande

There's a weird overlap in engineering and physics disciplines between the hard engineering/business practices of the mining industry, and particle physics.

Right, but for those they need to make/move/collect a large amount of transparent material, like heavy water etc for the particles to interact with. But they get that 'for free' with the ice.

and another option is putting it in the sea, see KM3NeT: https://en.wikipedia.org/wiki/KM3NeT

Logistics is much easier for Greenland, but the optical properties of the ice are not as good as at the south pole.

Greenland is much better logistically in some ways (I work on experiments both in Greenland and in Antarctica), but the ice in Greenland is unlikely to be as good for IceCube as in Antarctica, due to a presumed larger number of dust layers from dry periods in Europe.

The US has a research station at Summit Station Greenland but compared to South Pole, it's spartan (like, the first time I went there, I slept in a tent because of lack of hard-sided berthing, but then a Polar bear came a few years later and now hard-sided berthing is required). There are longer-term plans to improve the station in Greenland but we'll see.

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.

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.

dust layers wont effect them neutrinos can pass anything or I am missing a point

You have to see the light from when a neutrino interacts with something, so you want very clear water or ice for that.

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.

> 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.

More clearly, in a dispersive medium like a prism, the wavelength of the light depends on its frequency.

Because the speed of light (in the sense of phase velocity) is the product of wavelength with frequency, both the speed and the wavelength vary with frequency, thus also the refractive index varies with frequency.

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.

AFAIK there are three scenarios;

1) Non-Dispersive medium (eg. vacuum) : v(g) = v(p) = c

2) Normal Dispersion medium (eg. in water) : v(g) < v(p)

3) Anomalous Dispersion medium (eg. absorbing materials) : v(g) > v(p)

where (simplified);

v(g) : group velocity which can be thought of as a function of the overall wave packet (i.e. pulse) and hence contains the actual energy/information/signal.

v(p): phase velocity which can be thought of as a function of a single wave and hence the crest of that wave.

Are there interesting relativistic effects related to this other than this Cherenkov radiation?

Yes, there are. Checkout the "see also" section of Cherenkov radiation on wikipedia which lists some of them - https://en.wikipedia.org/wiki/Cherenkov_radiation

Here is the relevant chapter from the Feynman lectures, Relativistic Effects in Radiation - https://www.feynmanlectures.caltech.edu/I_34.html

If you ask AI, you will get a list with nice short explanatory notes; check it out.

Finally on a related and very interesting vein, Physicists have even brought light to a standstill in tiny gas clouds of sodium atoms cooled to near absolute zero! See the pdf of Scientific American article "Frozen Light" by Lene Vestergaard Hau from her publications webpage - https://groups.seas.harvard.edu/haulab/publications/HauPubli...

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).

Nice. Trying to read/understand "RF Systems and Modulation" is what got me interested in this subject in the first place.

So in my mind i map your comment as; the "carrier signal" single analog frequency is the infinitely repeating regular wave (no information) traveling at v(p) while the "information signal" (analog/digital) imposed on top of it (frequency/amplitude/phase modulation) creates the informational pulse/wave packet traveling at v(g).

Add in different media in the real world and you have a difference between v(g) and v(p) - https://news.ycombinator.com/item?id=49988070

Wow, yes, great perspective!

Optical sonic boom.

Actually called a "Luminal Boom" or "Photonic Boom".

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.

> 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?

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?

If it moves, we can communicate with it. Your mobile phone's neutrino signal will not lose a single bar, wherever you are on Earth, or in the solar system, or in the galaxy.

And now we come to the Macroscope.

How can we make neutrinos useful to us? - https://www.youtube.com/watch?v=F0HQp2nBFhI

What are neutrinos good for? - https://www.youtube.com/watch?v=-6iyyM5XRx4