IceCube Telescope Takes Shape Below Antarctic Ice 165
PabloSandoval48 writes "The world's largest telescope, currently under construction more than a mile beneath the Antarctic ice, is on schedule to be completed next year, according to a researcher at the University of Wisconsin, the lead institution for a scientific project called IceCube."
N.W.A. (Score:5, Funny)
This IceCube project is part of a secret plan by the New World Alliance to take over current infrastructure.
Re:N.W.A. (Score:4, Insightful)
O'Shea Jackson (born June 15, 1969), better known by his stage name Ice Cube, is an American rapper, actor, screenwriter, film director, and producer.
He began his career as a member of C.I.A and later joined the rap group N.W.A
http://en.wikipedia.org/wiki/Ice_Cube [wikipedia.org]
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Re:N.W.A. (Score:4, Funny)
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IceCube? (Score:4, Interesting)
What, the rapper?
No, seriously. I think I remember reading about this earlier this year in Scientific American or something ... only it was on a big lake in Russia [thelivingmoon.com] and they worked during the winter when everything is frozen. Kind of cool, bleeding edge stuff.
I gather that the one in the Antarctic will be bigger, and give a view in a different direction than the Russian one.
Re:IceCube? (Score:4, Informative)
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But... (Score:4, Funny)
We don't care about the Stars on the Southern hemisphere. Those are boring. The Northern Hemisphere stars are where its at.
Re:But... (Score:5, Informative)
IceCube is a neutrino telescope which looks through the Earth to the Northern Hemisphere. The Earth basically acts as a filter removing potential background signals.
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When you see the Southern Cross for the first time
You understand just why you came this way
They were just playing that song on the radio a few minutes ago. You've obviously never been near the equator, where the Southern Cross appears near the horizon after sunset.
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You can't see it from Florida if I remember correctly (I lived there from 1980-1985); you're nowhere near enough to the equator. I saw it in Thailand, which is damned close to the equator.
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That's ok. This telescope looks north.
Re:But... (Score:5, Informative)
But that's what it sees - the sensors point at the Earth and the filter software discards muon events that track from the sky, keeping events that come from underneath since muons coming from the Northern Hemisphere decay long before they can reach the detector. Neutrinos survive passing through thousands of miles of rock, so if it comes from the middle of the Earth, it's a neutrino. If it comes from the sky, it could be a neutrino, but chances are, it's a muon.
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I'm guessing you've never seen the southern night sky :)
Who cares? (Score:5, Funny)
Re:Who cares? (Score:4, Funny)
Or some sort of ancient chair that shoots missiles into space.
Not a telescope (Score:5, Informative)
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Re:Not a telescope (Score:5, Insightful)
It can infer the direction a neutrino came from, so (given enough time) it can make "images". In fact, they've seen the moon [arxiv.org] already, as a deficit of neutrinos coming from the moon's direction. It is a telescope, just one that doesn't "see" photons and that you don't have to point at a target to see it.
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It is a telescope, just one that doesn't "see" photons
Okay, I thinkI got it.
and that you don't have to point at a target to see it.
Now you're just screwing with me.
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It's omni-directional. The detectors are placed in a way that it can detect the arrival of neutrinos coming from any direction (including, and specially, from below the horizon). This way, we can get a "whole sky" image at once, without moving anything in the experiment.
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So what makes it a telescope more than say a bunch of eyeballs?
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It's ability to trace the sky using a carrier that was never explored in this way (except to "see" what happens in the sun, and during a nearby supernova).
Using optical telescopes, we can get an image of how the universe looks in visible photons. In an x-ray telescope, we get an image of the universe in x-ray photons. In a cosmic ray telescope, we get an image in charged particles. IceCube (plus its northern sister, KM3Net) should be able to get an image of the universe in neutrinos with energies over 1 TeV
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I thought it was using the the earth as a filter, and as such was basically "pointed" at the northern hemisphere?
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Yes, that is why it detects "specially" what comes from below the horizon (or from the northern sky). However, they have some sensitivity to downgoing neutrinos (coming from above the horizon, or from the southern sky), if they arrive with an energy so high that the atmospheric muon background at those energies would be negligible. Or, being more technically correct, they use an array of cosmic ray detectors in the surface [udel.edu] to identify if an event whose energy is above a certain threshold and coming from "ab
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and that you don't have to point at a target to see it.
Now you're just screwing with me.
You don't have to aim it at a target because it's already pointing in every direction all at once... just like a sphere.
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So what makes it a telescope then?
Muons, not neutrinos (Score:5, Informative)
There's a deficit of muons, not neutrinos, from the moon's direction. Neutrinos pass through the moon easily.
Re:Muons, not neutrinos (Score:4, Informative)
Not all the neutrinos, just nearly all. The moon is large enough to catch a statistically discernible (to IceCube) amount of neutrinos, casting a "neutrino shadow" on the Earth.
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The ability to make an image isn't the defining characteristic of a telescope. I can see the moon through my window, but it's no telescope.
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Your eyes are a "telescope". We usually reserve the word for instruments that let us examine astrophysical objects in a way that we can't do with our naked eyes, but an optical telescope works in exactly the same way as your eyes. Just change the retina for a CCD.
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ACK!! who the h*ll are they hiring over at EETimes these days?
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Also, the part where it's not telescopic is a bit of a problem.
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From Wikipedia
A telescope is an instrument designed for the observation of remote objects by the collection of electromag
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This array is more like a scintillation counter. It measures local phenomena. Perhaps, opportunistically, it could be used to infer something about distant objects, but in that sense it's still no more a telescope than a light bulb is a power meter.
Telescope? (Score:4, Interesting)
I'm not sure that a neutrino detector is any more of a telescope than the sensor that decides when it's time for the lights to come on at night.
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Why? It captures information from a flux of particles (not photons, but neutrinos in this case) emitted by astrophysical objects. It allows us to study properties of those objects (and of the detected particles as well). It doesn't have a resolution high enough to give us an "image" of most of those objects, but Hubble can't image most single stars too. IceCube won't give you a pretty picture for APOD, but it will do everything else we can do with an optical telescope, or a charged particle telescope such a
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Why? It captures information from a flux of particles (not photons, but neutrinos in this case) emitted by astrophysical objects.
Because when speaking to a broad audience it behooves scientists to avoid terminology that they know will be confusing and misleading to laypeople. Anything else is an abrogation of their responsibility to communicate science clearly and unambiguously to the public.
Besides, no one in these fields ever calls anything like this an (unqualified) telescope. So the purpose of doing so for a general audience seems to me to be solely to mislead and confuse, and I'm not at all clear why anyone would want to do th
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Besides, no one in these fields ever calls anything like this an (unqualified) telescope.
Yeah, but they do say things like radio telescope or x-ray telescope, and those are very different from what most laypeople think of as a telescope. I certainly think that omitting the word "neutrino" was a big mistake, but does it go beyond that? The question is, can it be called a type of telescope?
Curiously, the link you provide to Auger describes it as a "cosmic ray observatory", almost as if the people who create
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Anything else is an abrogation of their responsibility to communicate science clearly and unambiguously to the public.
The only time theres a 'responsibility' to communicate science 'clearly and unambiguously to the public' is when a government administration is trying to justify public spending on science to the electorate.
And thats not a responsibility of the scientists.
The scientist has a responsibility to communicate science clearly and unambiguously to OTHER SCIENTISTS.
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> actually it is looking at events created locally by neutrinos from my
> understanding, it isn't actually recording ANY remote events.
And a CCD array just looks at events created locally by photons.
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Why? It captures information from a flux of particles emitted by astrophysical objects.
So does the sensor on my roof that detects sunlight, but I don't refer to that thing as a telescope. It's a sensor, or a detector, not a telescope.
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Re:Telescope? (Score:5, Insightful)
The key feature of a telescope as I interpret the word is amplification of visual phenomena. It makes tiny things seem big. Perhaps the nitpickers would say that the main feature of a telescope is that it can resolve finer and finer details - I'd say that's the same thing. An ancillary of this is that it tends to gather a large amount of otherwise feeble light from some small field-of-view so that, when that field of view is zoomed in to occupy the whole of a sensor (a camera, the eye, etc.) there is still something there to see.
This neutrino detector doesn't have any sort of magnification in that sense. It doesn't even work in the electromagnetic spectrum! It's purpose isn't to zoom in on a phenomenon, but to detect it and tell us where it came from. It doesn't zoom in. By that token I would say that it is an observatory, not a telescope. It does, however, have light amplification through the use of photomultipliers. And, by virtue of its size, can be thought of as having better resolving power and sensitivity than its predecessors. By measuring neutron flux intensity as a function of angular position, it should be able to produce a sky map much that those from more conventional (optical, radio, IR) telescopes. Does this make it a telescope? I don't know.
For comparison, the Compton Gamma Ray Observatory [wikipedia.org] faced a similar challenge: it didn't have an aperture or light gathering and focusing mirrors common to "telescopes" of other wavelengths. It is not possible to do that with any materials we're familiar with - gamma rays are absorbed or pass right through; there can be no reflectance or refraction. GRO was, much like this neutrino experiment, a target that waited for gamma rays to pass through. Once they did the instruments would figure out their energy and where in the sky their originated from. Notice that they called it an "observatory", not a "telescope."
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I think amplification is the wrong criteria to define a telescope, a better criteria would be "convergence" or "focusing" of whatever spectrum we are looking at. That is the only common theme I can see in a Telescope, they all converge large amount of spectrum to a focal point. This may not be in a physical sense and may be done inside of a computer via munging of captured data from various physical detectors.
In that respect, I still come to the same conclusion, that this is not a telescope.
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This may not be in a physical sense and may be done inside of a computer via munging of captured data from various physical detectors.
In that respect, I still come to the same conclusion, that this is not a telescope.
Um, if you accept that a telescope need not focus by using physical reflection but by combining data from multiple detectors distributed over an area, then this would most definitely be a telescope in that respect.
If we must for some reason draw a distinction between traditional telescopes and
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> That is the only common theme I can see in a Telescope, they all converge
> large amount of spectrum to a focal point. This may not be in a physical
> sense and may be done inside of a computer via munging of captured data from
> various physical detectors.
That's what this device does.
Compton has multiple gamma ray telescopes in it :P (Score:2)
The key feature of a telescope as I interpret the word is amplification of visual phenomena. It makes tiny things seem big.
This neutrino detector doesn't have any sort of magnification in that sense. It doesn't even work in the electromagnetic spectrum! It's purpose isn't to zoom in on a phenomenon, but to detect it and tell us where it came from. It doesn't zoom in.
Sure it does. It allows you to take a source of infrequent interactions and amplifies them by increasing the size of the detector. This is wh
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I think it's correct to call IceCube an observatory, but not a telescope. All telescopes are observatories, but the inverse isn't true. Observatory is a broad term (my house can be an observatory), but telescope refers to a specific kind of instrument (I definitely do not live in a telescope).
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That was the point of my last paragraph... Observatories are facilities that contain astronomical instruments. But you don't call the instrument itself an observatory whether that instrument is a telescope or not.
There should be no dispute whatsoever that IceCube is an observatory. But I think it is fair to call it a neutrino telescope as well.
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In any case, the U. Wisc. team that is running the project calls it a telescope [wisc.edu]. So I'm going with that.
Mythbusters-style (Score:3, Funny)
Did anybody else imagine a huge lense made of ice like they made in Mythbusters to light a fire?
In the distant future (Score:3, Insightful)
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> Anyone/anything will wonder what on earth [sic] this is.
Especially after the ice melts and it's all lying in a tangled mess on the ground.
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Well, it will be quite apparent that it is our ill-advised polar ice-cap melting apparatus, which was ultimately the cause of our downfall.
so The chair is really still there? (Score:4, Funny)
so The chair is really still there?
IceCube telescope (Score:3, Funny)
Largest "telescope"? (Score:2, Interesting)
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I think it qualifies readily as most voluminous.
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Telescope Unreachable for Repairs (Score:2)
A mile down?
Beneath arctic ice?
And a cable's come loose?
Hummer 4 announced at low, low cost! Buy three today!
Ice Cube? (Score:3, Funny)
Nice but... (Score:2)
Interesting... (Score:5, Interesting)
Re:Interesting... (Score:5, Informative)
Re:Interesting... (Score:5, Funny)
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Re:Interesting... (Score:4, Informative)
Re:Interesting... (Score:4, Interesting)
Ice Cube operates by observing visible Cerenkov radiation from electrons and muons created when high-energy neutrinos hit an atom in the ice, as they traverse the ice. Of course, ice being transparent to visible light is important here, and lunar regolith is opaque to visible light.
However it has been proposed to look for radio waves being emitted in a similar manner. Cerenkov radiation [wikipedia.org] is caused by moving faster than the speed of light in the medium -- it's the "blue glow" if you look at the picture on that wikipedia link, and emits a broad spectrum of radiation, down into radio frequencies. Depending on the composition of the regolith, it may be transparent to radio waves. This can be done from the Earth by pointing your antenna at the moon, or from satellite(s) in orbit around the moon. You might be interested in the Goldstone [ucla.edu] project. So, at least with proposals I've heard about, getting people on the moon to make big holes is not an important component, but the surface of the moon may still be useful for similar experiments. You never know though, maybe tomorrow someone will post a new idea!
Re:Interesting... (Score:5, Informative)
Would there, however, be any benefit to having such a project set up under lunar regolith/base rock if we could ever get back to the moon?
Yes.
The reason why: there are virtually no high-energy muons in lunar cosmic rays, and high-energy muons, one way or another, are the major cosmic-ray background in these experiments.
The reason why there are virtually no high-energy muons in lunar cosmic rays is due to their primary mechanism of production: on Earth, cosmic-ray protons smack into atoms at the top of the atmosphere, producing high energy pions, which decay into muons etc... and because of the low density of the atmosphere, the decay time is much less than the stopping time, so the muons have most of the orignal energy of the primary cosmic ray available to them.
On the Moon, which notably lacks an atmosphere, the primay cosmic rays smack into the lunar regolith and therefore the pions are created in a very dense medium, and lose most or all of their energy before decaying. The muons thus created are relatively low energy and stop within a few meters--as opposed to terrestrial cosmic ray muons which are still seen in experiments like the Sudbury Neutrino Observatory, 2 kilometres underground.
As such, a relatively small, relatively shallow detector on the Moon could produce comparable performance to the best terrestrial detectors, at only a few orders of magnitude higher cost.
It may be worth mentioning that no one working in the field ever calls a neutrino detector a "telescope", as in English that word when used without qualification virtually always means "optical telescope", so the usage in this article is misleading and confusing, to the point where if were done deliberately I would consider the person doing it to be either stupid or dishonest. I guess maybe the person who wrote the article or provided the information for it has English as a second language.
Re:Interesting... (Score:5, Insightful)
It may be worth mentioning that no one working in the field ever calls a neutrino detector a "telescope", as in English that word when used without qualification virtually always means "optical telescope", so the usage in this article is misleading and confusing, to the point where if were done deliberately I would consider the person doing it to be either stupid or dishonest. I guess maybe the person who wrote the article or provided the information for it has English as a second language.
Sure, unqualified it implies optical, but on the other hand we have radio telescopes, infrared telescopes, x-ray telescopes, and gamma-ray telescopes. Why not the IceCube neutrino telescope? Surely, though, the lack of the word "neutrino" in the title and the summary was a gross omission.
Wait, why are we speculating? (Score:4, Informative)
The IceCube website and U Wisc. [wisc.edu] says it's a telescope. So, case closed as far as I'm concerned.
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I agree that the background reduction due to lack of atmosphere is very convenient, but as zero.kalvin points out, you still need a 'refracting medium', that is, a really large volume of transparent material such as water or ice (in which you can catch the Cherenkov light whenever a neutrino is kind enough to interact and produce fast charged particles). The large volume is not needed to suppress background, but to beat the very small cross section; in order to detect neutrinos you need them to interact wit
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The large volume is not needed to suppress background, but to beat the very small cross section; in order to detect neutrinos you need them to interact with your detector, and the only way to achieve that is to make it as big as possible.
Yes, and then again no. I have designed and built (reactor) neutrino detectors that have a volume of less than a cubic metre (and some very impressive background-suppression tricks) and have detected reactor neutrinos (~10 m from the core).
Background is not simply separable from rate. In particular, background tends to ramp up as energy goes down, so even though there are many more low-energy neutrinos in most interesting cases we typically are cut off at a few MeV because of backgrounds. The Moon offers
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--TrisexualPuppy
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Close, they're just digging for the other Stargate and the chair.
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Uh...the Hubble is 13.2 m long with a maximum diameter of 4.2 m, or a volume of about 183 cubic m. This thing has a volume of about 1,000 cubic m.
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One cubic kilometer is not 1000 cubic meters.
Re:World's largest, eh? (Score:4, Informative)
> This thing has a volume of about 1,000 cubic m.
1 cubic km. That's 10E9 cubic m.
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Thanks. I knew I shouldn't have changed units. :-)
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Honestly, I work in the building next door in D.C.! :-)
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Yep... and since the density of water is ~1g/cm^3 (1000kg/m^3), it's a *billion tons* of water perfused with sensors.
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Hubble's aperture size is only about 2.5m though, which means it doesn't even crack the top 50 of large optical telescopes.
Since this is a very odd kind of optical telescope, when it goes in it will dwarf everything for a very, very long time (well, except other ones just like it ;).
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The Hubble doesn't count because it's nowhere near the largest. It doesn't even make the top 50 list, more like around 55'ish. The Hubble gets great images because it is in space, and doesn't have to deal with atmosphere and light pollution. It can also catch wavelengths that are largely absorbed by the atmosphere, like infra-red and UV. That makes it extremely useful, however almost all of the ultra-long range research (~13 billion light years) is done with earth based telescopes and fancy corrective s
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I see what you did there ... it goes the other way round!
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> If something gets broken, it's a step backwards for them.
They can drill another hole and drop in a replacement. Presumably they've designed in some redundancy.
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I'm sure they could add a new detector a few meters from a failed one and compensate for the deviation from perfect geometry in software: they have to have the ability to do that anyway. However, with 5000 detectors they've surely got enough redundancy to tolerate a few dead ones without significant degradation in performance.
Re:It is a big problem (Score:4, Informative)
Re:PCI (Score:4, Insightful)
> ...shouldn't they reconsider the PCI bus being phased out...
It is just barely possible that they might consider vendors other than Intel. Hint: ISA industrial stuff is still available.
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This should have been moderated "+3 Snarky", not "+3 Insightful".