APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

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Expand view Topic review: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by hstarbuck » Mon Feb 14, 2011 8:06 pm

Some other folks are detecting neutrinos (Cherenkov radiation from interaction with the ice) in the sky above the Antarctic shelf using balloons. http://www.phys.hawaii.edu/~anita/web/index.htm

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by DavidLeodis » Mon Feb 14, 2011 1:43 pm

It's a great photo. 8-) It gave me though a vertiginous feeling just looking at it!

:| << That may be a suitable smiley for a neutrino. :wink:

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by NoelC » Mon Feb 14, 2011 7:23 am

<In the voice of Mae West>: "My, he's an energetic - if peculiar - Vela."

-Noel

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by neufer » Sun Feb 13, 2011 5:44 pm

alphachap wrote:
How come the hole pictured is so wide?
  • 1) Perspective

    2) Worried about water freezing around probes before everything is set in place

    3) Hoping to catch VERY LARGE Neutrinos. :arrow:

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by neufer » Sun Feb 13, 2011 5:37 pm

Image
owlice wrote:
Oh, please; that's a horseshoe crab!

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by alphachap » Sun Feb 13, 2011 5:27 pm

How come the hole pictured is so wide?

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by owlice » Sun Feb 13, 2011 4:58 pm

Image
Oh, please; that's a horseshoe crab!

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by neufer » Sun Feb 13, 2011 4:41 pm

Beyond wrote:
One peculiar thing i notice about the Vela Nebula is that the yellow area kind of resembles the face on Mars.
The Vela Nebula is clearly an Opabinia!
http://en.wikipedia.org/wiki/Opabinia wrote:
Image
Image
Image
<<Opabinia is an animal genus found in Cambrian fossil deposits. Its sole species, Opabinia regalis, is known from the Middle Cambrian Burgess Shale of British Columbia. Fewer than twenty good specimens have been described. The head shows unusual features: five eyes, a mouth under the head and facing backwards, and a proboscis that probably passed food to the mouth. Opabinia probably lived on the seafloor, using the proboscis to seek out small, soft food.

When the first thorough examination of Opabinia in 1975 revealed its unusual features, it was thought to be unrelated to any known phylum, although possibly related to a hypothetical ancestor of arthropods and of annelid worms. However other finds, most notably Anomalocaris, suggested that it belonged to a group of animals that were closely related to the ancestors of arthropods and of which the living animals onychophorans and TARDIGRADES may also be members.

In the 1970s there was an ongoing debate about whether multi-celled animals appeared suddenly during the Early Cambrian, in an event called the Cambrian explosion, or had arisen earlier but without leaving fossils. At first Opabinia was regarded as strong evidence for the "explosive" hypothesis. Later the discovery of a whole series of similar lobopod animals, some with closer resemblances to arthropods, and the development of the idea of stem groups suggested that the Early Cambrian was a time of relatively fast evolution but one that could be understood without assuming any unique evolutionary processes.

Opabinia looks so strange that the audience at the first presentation of Whittington's analysis laughed. The length of Opabinia regalis from head to tail ranged between 4 centimetres and 7 centimetres. The animal also had a hollow proboscis, whose total length was about one third of the body's and which projected down from under the head and then curved forwards and upwards. The proboscis was striated like a vacuum cleaner's hose and probably flexible, and it ended with a claw-like structure whose inner edges bore spines that projected inwards and forwards. The head bore five eyes: two on stalks near the front and fairly close to the middle of the head, pointing upwards and forwards; two larger eyes, also stalked, near the rear and outer edges of the head, pointing upwards and sideways; and a single eye with a shorter stalk between the larger pair of stalked eyes, pointing upwards. It has been assumed that the eyes were all compound, like arthropods' lateral eyes, but this reconstruction, which is not backed up by any evidence, is "somewhat fanciful". The mouth was under the head, behind the proboscis, and pointed backwards, so that the digestive tract formed a U-bend on its way towards the rear of the animal. The proboscis appeared sufficiently long and flexible to reach the mouth.

The main part of the body was typically about 5 millimetres wide and had 15 segments, on each of which there was a pair of lobes (flaps) pointing downwards and outwards. The lobes overlapped so that the front of each was covered by the rear edge of the one ahead of it. The body ended with what looked like a single conical segment bearing three pairs of overlapping lobes that pointed up and out, forming a tail like a V-shaped double fan.

Interpretations of other features of Opabinia fossils differ. Since the animals did not have mineralized armor nor even tough organic exoskeletons like those of insects, their bodies were flattened as they were buried and fossilized, and smaller or internal features appear as markings within the outlines of the fossils.>>

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by Chris Peterson » Sun Feb 13, 2011 4:32 pm

Beyond wrote:One peculiar thing i notice about the Vela Nebula is that the yellow area kind of resembles the face on Mars. However, the face on Mars diappears when seen close up. I wonder if the same thing would occur with the Vela nebula?
It isn't a matter of "close up", but of resolution. With faces in particular, we focus on very basic features: eyes, nose, mouth. And our brains appear hard-wired to see faces. So we see them very easily in low resolution images. But as the resolution increases, all sorts of other structure becomes apparent, which masks the eyes-nose-mouth effect.

So yes, if we had a higher resolution x-ray image of the region around the pulsar, I'm sure that the "face" would disappear.

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by Beyond » Sun Feb 13, 2011 4:16 pm

One peculiar thing i notice about the Vela Nebula is that the yellow area kind of resembles the face on Mars. However, the face on Mars diappears when seen close up. I wonder if the same thing would occur with the Vela nebula?

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by neufer » Sun Feb 13, 2011 1:34 pm

Just to be clear: Neutrinos are NOT coming from the Vela nebula :!:
Very high energy galactic cosmic rays MAY be coming from
the Vela nebula or something else peculiar is happening.
http://www.news.wisc.edu/18256 wrote:
<<"IceCube was not built to look at cosmic rays. Cosmic rays are considered background," Abbasi says. "However, we have billions of events of background downward cosmic rays that ended up being very exciting."

Abbasi saw an unusual pattern when she looked at a "skymap" of the relative intensity of cosmic rays directed toward the Earth's Southern Hemisphere, with an excess of cosmic rays detected in one part of the sky and a deficit in another. A similar lopsidedness, called "anisotropy," has been seen from the Northern Hemisphere by previous experiments, she says, but its source is still a mystery.

"At the beginning, we didn't know what to expect. To see this anisotropy extending to the Southern Hemisphere sky is an additional piece of the puzzle around this enigmatic effect — whether it's due to the magnetic field surrounding us or to the effect of a nearby supernova remnant, we don't know," Abbasi says.

The new result publishes Aug. 1 in The Astrophysical Journal Letters, published by the American Astronomical Society.

One possible explanation for the irregular pattern is the remains of an exploded supernova, such as the relatively young nearby supernova remnant Vela, whose location corresponds to one of the cosmic ray hotspots in the anisotropy skymap. The pattern of cosmic rays also reveals more detail about the interstellar magnetic fields produced by moving gases of charged particles near Earth, which are difficult to study and poorly understood.

Right now "we can predict some models, but we don't have concrete knowledge of the magnetic field on small scales," Abbasi says. "It would be really nice if we did — we would have made a lot more progress in the field.">>
http://en.wikipedia.org/wiki/Galactic_cosmic_ray wrote:
<<Galactic cosmic rays (GCRs) consist of those cosmic rays that enter the solar system from the outside. They are high-energy charged particles composed of protons, electrons, and fully ionized nuclei of light elements and are a strong source for cosmic ray spallation in the atmosphere of the earth.

The magnetic fields of the Earth, the sun, and the galaxy itself tend to scramble the paths of the galactic cosmic rays.

Most galactic cosmic rays have energies too low to penetrate the Earth's atmosphere, and the radii of their helical trajectories in the Earth's magnetic field tends to channel them to the poles. When they strike the atmosphere, they can create large showers of secondary particles, including exotic ones such as muons, and these secondary particles are what can be detected at the Earth's surface.

Very high-energy cosmic rays can penetrate the Earth's atmosphere, and the radii of their helical trajectories are thousands of kilometers, so they are not as effectively channeled by the Earth's magnetic field.
>>

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by royalpalms6@msn.com » Sun Feb 13, 2011 1:13 pm

Could this concept of melting ice be used on the moons of Jupiteror Saturn?

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by León » Sun Feb 13, 2011 12:59 pm

Fishing for Neutrinos, excellent metaphor of Beyond to use in my blog Amanda is the detector that is placed, sixty in each well Down Vela pulsar, the Vela nebula in the constellation Vela from which the greatest number of neutrinos detected by the observatory in Antarctica.

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by DLH » Sun Feb 13, 2011 12:14 pm

"lowered into the frezzing abyss"

Correction needed.

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by alter-ego » Sun Feb 13, 2011 8:28 am

Beyond wrote:Fishing for Neutrinos. At first i thought that someone had neglected to say what was used for bait, but after reading about them, they don't seem to be attracted to anything, so It's just a matter of dangling the hook until they happen to hit it while passing by. I wonder what the daily limit is :?:
It appears the yearly quota of pertinent events is several hundred. I don't think there is a regulated limit since this is a catch and release program ;-)

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by bystander » Sun Feb 13, 2011 8:14 am

Re: APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by Beyond » Sun Feb 13, 2011 5:39 am

Fishing for Neutrinos. At first i thought that someone had neglected to say what was used for bait, but after reading about them, they don't seem to be attracted to anything, so It's just a matter of dangling the hook until they happen to hit it while passing by. I wonder what the daily limit is :?:

APOD: Ice Fishing for Cosmic Neutrinos (2011 Feb 13)

by APOD Robot » Sun Feb 13, 2011 5:10 am

Image Ice Fishing for Cosmic Neutrinos

Explanation: Scientists are melting holes in the bottom of the world. In fact, almost 100 holes melted near the South Pole are now being used as astronomical observatories. Astronomers with the IceCube Neutrino Observatory lowered into each vertical lake a long string knotted with basketball-sized light detectors. The water in each hole soon refreezes. The detectors attached to the strings are sensitive to blue light emitted in the surrounding clear ice. Such light is expected from ice collisions with high-energy neutrinos emitted by objects or explosions out in the universe. Late last year, the last of IceCube's 86 strings was lowered into the freezing abyss, pictured above, making IceCube the largest neutrino detector yet created. Data from a preliminary experiment, AMANDA, has already been used to create the first detailed map of the high-energy neutrino sky. Experimental goals of the newer IceCube include a search for cosmic sources of neutrinos, a search for neutrinos coincident with nearby supernova and distant gamma-ray bursts, and, if lucky, a probe of exotic physical concepts such as unseen spatial dimensions and faster-than-light travel.

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