Antarctic Experiment Finds Puzzling Distribution of Cosmic Rays 119
pitchpipe writes "A puzzling pattern in the cosmic rays bombarding Earth from space has been discovered by an experiment buried deep under the ice of Antarctica. ... It turns out these particles are not arriving uniformly from all directions. The new study detected an overabundance of cosmic rays coming from one part of the sky, and a lack of cosmic rays coming from another." The map of this uneven distribution comes from the IceCube neutrino observatory last mentioned several days ago.
Re:Is it the Earths magnetic field? (Score:5, Informative)
> I mean, it is what protects us from vasts amounts of cosmic rays...
No it isn't. The Earth's magnetic field has negligible effect on cosmic rays: they are far to energetic for it to influence them significantly. What protects us from cosmic rays is the atmosphere.
> ...maybe those differences account for a vast majority of this patterns?
The physicists will have already taken the small (but known) effect of the magnetic field into account.
> And the various celestial bodies that surround us (constantly deflecting
> this rays) account for the rest?
Celestial bodies do not surround us. The sun and the moon together cover less than 1/100,000th of the sky.
Re:Did they discover any mountains too? (Score:5, Informative)
R'lyeh is in the south pacific. Pnakoticos is in the Australian desert. Irem is in Saudia Arabia. Unfortunately, the Pentagonally Symmetrical Elder Things named their last surface city 'Can'ned'spham', which is why the Shoggoths ate them.
Re:Several Days Ago? (Score:3, Informative)
Not neutrinos. (Score:3, Informative)
While it's true that IceCube is designed to be a neutrino telescope, the observations here involve more common and easier to detect cosmic rays (e.g. gamma rays), coming from the southern half of the sky.
See, when IceCube is looking for neutrinos, they look for signals coming from beneath the northern part of the sky. They are essentially using the entire planet earth as a filter for cosmic rays since they can't pass through that much solid material, while neutrinos can with ease. Neutrinos don't interact electromagnetically at all, so to them "solid" matter is mostly empty space. Which includes the detector itself, which is why it's so important to filter out sources of noise.
They can tell what direction something is coming from (see the map), so if it came from the sky, it's probably not a neutrino but some other cosmic ray. And it looks like they were looking at all the data they would be subtracting out from their data sets when looking for neutrinos, and found something interesting about the distribution.
But as the article itself says, our magnetic field could in fact be the cause of this observed feature, since the rays in question are electromagnetic in nature. But I like the supernova theory, because it involves gigantic explosions. :)
Re:Is it the Earths magnetic field? (Score:5, Informative)
No it isn't. The Earth's magnetic field has negligible effect on cosmic rays: they are far to energetic for it to influence them significantly. What protects us from cosmic rays is the atmosphere.
This is incorrect. The International Space Station has a significantly lower cosmic radiation environment due to the Earth's magnetic field. However, the cosmic rays that are energetic enough to be detected under a few hundred meters of ice can easily punch through the Earth's magnetic field.
Celestial bodies do not surround us. The sun and the moon together cover less than 1/100,000th of the sky.
Indeed. The heliosphere might, due to its vast size (and its shock interaction with the galactic medium is apparently a known source of cosmic rays), be an intermediate filter with enough pull to distort the path of incoming cosmic rays.
Re:Is it the Earths magnetic field? (Score:3, Informative)
The Earth's magnetic field shields it from solar "cosmic" rays and probably some secondary galactic ones. The primaries, however, are so energetic that they are merely deflected a bit. What does stop a lot of primaries is the field embedded in the solar wind. Since the heliosphere is asymmetric and poorly mapped this may very well account for the observed asymmetry. I concede that the Earth's field may have more than negligible effect, but I still think that the researchers will have accounted for it.
Re:Scientists: (Score:2, Informative)
Re:Huzzah! (Score:4, Informative)
This would be true only if the universe had an euclidean geometry.
This is hard to visualize in three dimensions, so let's start with a two-dimensional case. Imagine a perfectly flat horizontal surface. Any triangle you draw in that surface will have three internal angles that add up to 180 degrees. If you draw any finite number of points there you could take the average of the xy coordinates and define a "center" for that set of points.
Now imagine a curved surface, let's say the surface of the earth. Define a triangle like this: point A is at zero latitude, zero longitude. Point B is at zero latitude, 90 degrees West longitude. Point C is at the North Pole. This triangle has three angles of ninety degrees, adding up to 270 degrees.
How would you define a "center" for a set of points randomly distributed over the surface of the earth? You could do it only if those points were sufficiently close together so the surface between them could be approximated by a flat surface. You can talk about the center of a continent, but the center of the whole surface of the earth is undefined.
Imagine the same problem in a universe with three dimensions that's curved in a fourth dimension and you will understand a bit of what general relativity is all about.
Re:Huzzah! (Score:3, Informative)
The fourth dimension is not spatial. It's temporal
You mean the fourth coordinate you use in Minkowski's formulae is temporal. Nobody is forced to ordinalize the dimensions used in their conceptual models by any given standard. For example, I learned coordinate systems from programming a TI-99/4a computer that addressed screen characters in "row/column" format. This became a stumbling block for me learning the cartesian (x,y) coordinate system, I kept wanting to notate the Y before the X. Their "first" dimention was my "second".
GP's "fourth" dimension isn't a dimension you use in Minkowski equations at all. It's just a convenient, abstract fourth spatial dimension per Edwin Abbot used to demonstrate the arbitrary concept of folding R^3 into a 3-ball. While that is not identical to any relativistic equations, it is equally helpful at illustrating non-euclidean geometry in general.
Now let's stop this argument where it is before the string theorists get in. 8I