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.)
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:
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.
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.
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)
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 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.
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.
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.
I appreciate the boldness of this project, it has an element of sci-fi to it. Building a base at the south pole to bury sensors in ice to measure elusive particles. The stuff of dreams!
To be fair, the base was already there and logistically essential. The IceCube topside building is just a part of the Amundsen-Scott South Pole Station, about a km or so from the Elevated Station.
This image* from Wikipedia surprised me. The topside building is...you could say...the tip of the iceberg. The detectors span a huge area going over 2km deep. The predecessor AMANDA array was also down there.
We think of receiving a Nobel Prize as something super rare and exceptional and it is. What still always astounds me though, is this:
There are nearly 300 living laureates. Enough to hold a yearly meetup for them in Lindau, where usually about 40 gather. This year, for the event's 75th anniversary, there were even about 70. Imagine that.
IIRC Oppenheimer facilitated / sponsored a meeting there after the Manhattan Project, as a gathering where physicists could talk freely about physics for a change.
All of science is collaborative and this is especially true in these big experiments: the IceCube collaboration is over 400 people [1] from several dozen institutes. There are a lot of experiments where giving a Nobel prize would be impossible because there's no "principal investigator" for the experiment.
I wonder - was there really no other people they could have given it to? The detection of gravitational waves was split between a theorist, experimentalist and a person who had a big hand in shepherding the project along. Could not the same have been done here?
I would imagine the problem is that there are too many of them.
For better or worse the prize can only go to 3 people. Over the years there are generally many dozens of people who make absolutely critical contributions to these kinds of experiments. In this case, though, the same guy was listed as the PI of the UW Madison group, and Madison is very clearly "the" operator of the project.
Halzen is by any measure an awesome physicist, but he's also a good "fit" for the Nobel because of this unique situation.
Pretty cool. One of the big challenges in trying neutrino detection in ice is dealing with funding agencies. The optical properties of ice only get good when you are actually a few kilometers deep in very old ice. That is you can't just build a demonstrator in the nearest glacier with a few leftover photomultipliers, you need to go directly to Antarctica and bore a three kilometer hole into the ice. And projects where the MVP is quite expensive are always very hard to get funded.
I remember one of my professor, a pioneer of neutrino detectors in Europe, mentioning Ice Cube in a lecture more than 20 years ago. Long time scale (due to funding).
We hire two people to stay over the winter and operate the detector each year. No icecube affiliation or physics background required, although a technical background helps.
I had a professor who talked about working there. In his words, “Thank God for whiskey!”
While there is some romantic imagery (penguins!) down there, and the disconnect from the rest of the world might be appealing, for large parts of the year you’re just stuck inside.
Neutrino physics is the frontier. It’s one area where we know there are “physics beyond the standard model” though IceCube hasn’t quite been able to answer the neutrino mass question.
That's an uncharitable take. The proposed observatory was through pristine dense forest, and one of the most important elephant corridors in Asia. It was opposed by the democratically elected government, and litigated in courts in an open and transparent way. The physics gains do not outweigh the environmental cost, and the fact that scientists were able to get valuable data from an observatory in the lifeless Antarctic is further justification not to build this.
IceCube observatory is for studying the high energy cosmic neutrinos from a distant galaxy or black holes. But the one proposed INO is to study the low and medium energy atmospheric neutrinos. INO was designed to study the mass ordering of neutrinos. Both observatories are for studying different aspects and properties of neutrinos and are not the same.
Sometimes I think it would be nice if there were biographies that laid out when and how Nobel laureates made their discoveries. Then wouldn't it be possible to pattern how people discover certain phenomena?
Not Nobel laureates, but people have tried this. I once was looking for the early education of famous scientists and found the book Cradles of Eminence [1], which compares the childhoods of several hundred famous people.
One thing I noticed was that more than a few were seriously sick in childhood and had to be homeschooled. This includes Edward Morley, Peter Higgs, René Descartes (though I'm not sure how rare it was at his time), and the mathematician Julia Robinson, who was bedridden with scarlet fever at 9 years old, then had to get tutoring to catch back up, and had this to say about it [2]:
> I have since read that a solitary childhood or, what amounts to the same thing, a period of isolation resulting from an illness is frequently noted in the early lives of scientists. I am not sure what the significance of this finding is. Obviously I had to amuse myself for long periods of time, but I didn’t do so with mathematics. I am inclined to think that what I learned during that year in bed was patience.
> By the time I was well enough to go back to school, I had missed more than two years. My parents arranged to have me tutored by a retired elementary school teacher. In one year, working three mornings a week, she and I went through the state syllabuses for the fifth, sixth, seventh, and eighth grades. It makes me wonder how much time must be wasted in classrooms.
Sidenote: I found the book [1] through asking a free LLM what source this quote might be referring to. They are reasonably good at this kind of literature search, especially because it's easy to judge whether they gave you something useful.
Uh not sure Halzen personally made discoveries, in the original sense of the word!
Indeed, "in-spiraling" seems more like a one-man discovery (or has more of a chance to become one) than many (not all, obv) nobel prize winning work
The mechanism for which Higgs was awarded was also independently discovered by at least ten other people (I can't count)
>The Higgs mechanism is therefore also called the Brout–Englert–Higgs mechanism, or Englert–Brout–Higgs–Guralnik–Hagen–Kibble mechanism,[9] Anderson–Higgs mechanism,[10] Anderson–Higgs–Kibble mechanism,[11] Higgs–Kibble mechanism by Abdus Salam[12] and ABEGHHK'tH mechanism (for Anderson, Brout, Englert, Guralnik, Hagen, Higgs, Kibble, and 't Hooft)
Can't wait for OpenAI to get the nobel prize; Swedes are more sympathetic than mathematicians!! (so that human beings might completely separate discovery from reward/awards/recognition. Discovery is a human right!!!)
The common denominator is money and time. The only way to get more results is to put more funding out there (and accepting that not everything is about a direct ROI).
It could be the beginning of Neutrino astronomy [1]. So far, we only used the electromagnetic spectrum, from radio waves to gamma rays, to observe the universe. If we could equally leverage neutrinos or gravitational waves, we could observe much more of the universe. For example, the cosmic microwave background radiation enables us to deduce the conditions at 300ky after the Big Bang. The cosmic neutrino background [2] could give us insight in the conditions 1s after the Big Bang.
Similar to the Millennium prize by the Clay institute, the amount of luck and effort you need to receive the prize don't make it worthwhile. Plus, it's generally expected to use that money for further research. It would be advisable to focus on other endeavors, if money is your motivator.
Photons work better for driving a car too but being able to hear is still quite useful.
In other words: we already have lots of things that measure photons. You see things on two totally different media it's a lot more compelling than just one.
That may be the case, but it doesn't explain why neutrinos would be essential for intergalactic communication. Maybe the person I was responding to didn't realize neutrinos travel very close to the speed of light, not infinitely fast?
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://news.ycombinator.com/item?id=49655286
https://en.wikipedia.org/wiki/Cherenkov_radiation
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.
https://www.amazon.com/dp/1137280085
Thanks, I had no idea this was possible!
https://xkcd.com/1053/
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...
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.
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.
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.
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.
I appreciate the boldness of this project, it has an element of sci-fi to it. Building a base at the south pole to bury sensors in ice to measure elusive particles. The stuff of dreams!
https://www.infographics.se/
https://www.behance.net/JohanJarnestad
*https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory#/...
There are nearly 300 living laureates. Enough to hold a yearly meetup for them in Lindau, where usually about 40 gather. This year, for the event's 75th anniversary, there were even about 70. Imagine that.
IIRC Oppenheimer facilitated / sponsored a meeting there after the Manhattan Project, as a gathering where physicists could talk freely about physics for a change.
[1]: https://icecube.wisc.edu/collaboration/meet-the-collaboratio...
For better or worse the prize can only go to 3 people. Over the years there are generally many dozens of people who make absolutely critical contributions to these kinds of experiments. In this case, though, the same guy was listed as the PI of the UW Madison group, and Madison is very clearly "the" operator of the project.
Halzen is by any measure an awesome physicist, but he's also a good "fit" for the Nobel because of this unique situation.
https://science.nasa.gov/image-article/apod-2011-february-13...
While there is some romantic imagery (penguins!) down there, and the disconnect from the rest of the world might be appealing, for large parts of the year you’re just stuck inside.
https://archive.org/details/quarksleptonsint0000halz
https://timesofindia.indiatimes.com/city/chennai/why-the-neu...
One thing I noticed was that more than a few were seriously sick in childhood and had to be homeschooled. This includes Edward Morley, Peter Higgs, René Descartes (though I'm not sure how rare it was at his time), and the mathematician Julia Robinson, who was bedridden with scarlet fever at 9 years old, then had to get tutoring to catch back up, and had this to say about it [2]:
> I have since read that a solitary childhood or, what amounts to the same thing, a period of isolation resulting from an illness is frequently noted in the early lives of scientists. I am not sure what the significance of this finding is. Obviously I had to amuse myself for long periods of time, but I didn’t do so with mathematics. I am inclined to think that what I learned during that year in bed was patience.
> By the time I was well enough to go back to school, I had missed more than two years. My parents arranged to have me tutored by a retired elementary school teacher. In one year, working three mornings a week, she and I went through the state syllabuses for the fifth, sixth, seventh, and eighth grades. It makes me wonder how much time must be wasted in classrooms.
Sidenote: I found the book [1] through asking a free LLM what source this quote might be referring to. They are reasonably good at this kind of literature search, especially because it's easy to judge whether they gave you something useful.
[1] https://archive.org/details/cradlesofeminenc0000goer_l9f8/pa...
[2] https://web.archive.org/web/20181207045746/https://www.maa.o...
Indeed, "in-spiraling" seems more like a one-man discovery (or has more of a chance to become one) than many (not all, obv) nobel prize winning work
The mechanism for which Higgs was awarded was also independently discovered by at least ten other people (I can't count)
>The Higgs mechanism is therefore also called the Brout–Englert–Higgs mechanism, or Englert–Brout–Higgs–Guralnik–Hagen–Kibble mechanism,[9] Anderson–Higgs mechanism,[10] Anderson–Higgs–Kibble mechanism,[11] Higgs–Kibble mechanism by Abdus Salam[12] and ABEGHHK'tH mechanism (for Anderson, Brout, Englert, Guralnik, Hagen, Higgs, Kibble, and 't Hooft)
https://en.wikipedia.org/wiki/Higgs_mechanism
Can't wait for OpenAI to get the nobel prize; Swedes are more sympathetic than mathematicians!! (so that human beings might completely separate discovery from reward/awards/recognition. Discovery is a human right!!!)
[1] https://en.wikipedia.org/wiki/Neutrino_astronomy
[2] https://en.wikipedia.org/wiki/Cosmic_neutrino_background
In other words: we already have lots of things that measure photons. You see things on two totally different media it's a lot more compelling than just one.