In Brief
- Neutrinos will give astronomers a type of x-ray vision far better than actual x-rays. Being the most unreactive type of subatomic particle, they pass through intervening matter as though it were hardly there—revealing the cores of stars and other dramatic but otherwise hidden places in the cosmos.
- Alas, the very property that makes neutrinos so useful means they tend to fly through detectors without registering. Only this year have instruments become sensitive enough to detect cosmic sources unequivocally.
- Neutrinos come in multiple varieties and can metamorphose in midflight. This peculiar property provides additional information about their celestial origins.
When the Nobel Foundation awarded Ray Davis and Masatoshi Koshiba the 2002 Nobel Prize in Physics, it could have chosen to emphasize any of their many accomplishments. Davis made his name detecting neutrinos from the sun—the first of these notoriously elusive particles ever seen from beyond our planet—and Koshiba discovered them coming from the great supernova explosion of 1987. Their work was an experimental tour de force and helped to establish that neutrinos, which theorists had assumed were massless, in fact have a small mass. Yet the Nobel Foundation recognized Davis and Koshiba, above all, for establishing a new branch of science: neutrino astronomy.
With their work, neutrinos graduated from a theoretical novelty to a practical way to probe the universe. In addition to studying neutrinos to glean the particles’ properties, scientists can now use them to lift the veil on some of the hidden mysteries of the universe. In an undertaking akin to the construction of giant optical telescopes a century ago, astronomers have been designing and building vast neutrino telescopes in anticipation of seeing new wonders. These observatories have already caught tens of thousands of neutrinos and made pictures of the sun in neutrinos. Neutrinos from other cosmic sources are hard to tell apart from those produced in Earth’s upper atmosphere, but instruments should be able to do so by this time next year.
This article was originally published with the title Through Neutrino Eyes.
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8 Comments
Add CommentPhotons are considerd to have both particle & wave nature .I dont know whether its mass has been calculated or not. But from its wave property , two light wave superimpose to form a resulting wave ie. two photons during superimposition occupy the same space. But we know that two object of same mass cant occupy the same space. Thus is this consideration of photon as particle(havimg mass) irrelevent?
Reply | Report Abuse | Link to thisI'd like to follow this discussion
Reply | Report Abuse | Link to thisCosmic Gall
Reply | Report Abuse | Link to thisEvery second, hundreds of billions of
these neutrinos pass through each square
inch of our bodies, coming from above dur-
ing the day and from below at night, when
the sun is shining on the other side of the
earth! --- From An Explanatory Statement
on Elementary Particle Physics by M. A.
Ruderman and A. H. Rosenfeld, in American
Scientist.
Neutrinos, they are very small.
They have no charge and have no mass
And do not interact at all.
The earth is just a silly ball
To them, through which they simply pass,
Like dustmaids down a drafty hall
Or photons through a sheet of glass.
They snub the most exquisite gas,
Ignore the most substantial wall,
Cold-shoulder steel and sounding brass,
Insult the stallion in his stall,
And, scorning barriers of class,
Infiltrate you and me! Like tall
And painless guillotines, they fall
Down through our heads into the grass.
At night they enter through Nepal
And pierce the lover and his lass
From underneath the bedyou call
It wonderful; I call it crass.
John Updike, in
The New Yorker
December 17, 1960,
Reprinted
February 9 & 16, 2009
bastavsaikia - As an naive pedestrian, I can't help with your questions, but I do have a couple of thoughts on the matter. Photons, like all other particles, are only detected when their energy is absorbed, halting their motion, perhaps transforming them from energy waves into material particles. Particles may simply represent the characteristic static manifestations of energy waves.
Reply | Report Abuse | Link to thisI think the zero rest mass photon is considered to acquire some effective mass by virtue of its momentum when not 'at rest'. Just a thought...
be my guest ....
Reply | Report Abuse | Link to thisIf you put enough photons in one place,say about 300,000 of them depending on the wavelength,you will have the mass of an electron.E=mc2 still applies and it works both ways.When you apply enough energy to a gamma photon and you end up with a neutrino.What happens is that the photon punchs a hole in Space-Time creating an event horizon and thus a photonic black hole and or a neutrino and in the process gaining mass.You need only do the math and you will see this is true.The total amount of energy adds up.The reason for multiple variations is because the plank length is reached andTime nearly equals 0 and causes theses fluctuations.
Reply | Report Abuse | Link to thisI dont think anyone can correctly say that a photon is a particle in the same sense that an electron or a proton is. The notion that a photon is a particle comes from Plancks universal quantum of action that requires photons to be quantized in discrete amounts of energy. Within this context light has a frequency and a wavelength but it comes to us in a series of discontinuous pulses. There is no coherent way to fully understand this in a continuous universe. However the Planck constant clearly indicates that the physical universe is discontinuous. It can be compared to a cosmic movie where atoms everywhere appear and disappear synchronously. The alternate mode of physical atoms is their timeless quantum energy equivalents so each recurrence of particulate matter defines one still frame in the movie and one primary interval of time. Atoms are particles and waves at the same time. Since light is the only action within each synchronous frame it travels in discontinuous pulses that define linear external space with respect to the inner spherical space of the atom.
Reply | Report Abuse | Link to thisRelative particulate motions occur as relative quantum jumps in position between successive space frames. For example an electron jumps from orbit to orbit in an atom without traversing the space between orbits. High relative particle motions betray their wave motion between a particulate mode and quantum mode consistent with de Broglies wave equation and relativity effects.
Neutrinos are distinct from ordinary photons. For example they result with the decay processes of neutrons which are associated with the strong and weak forces in atoms heavier than primary hydrogen. One might think of them as a particle-like energy remnant of neutron decay that represents the binding energy released from the neutron when it decays. Neutrons are stable inside stable atoms but decay with a half life of about eleven minutes outside the atom. The situation inside stars is much more fluid.
For more see articles freely available at www.cosmic-mindreach.com. The article on Cosmology and System 3 may be of special interest.
Electrons jumping between orbits was an illusion of 2D drawing. Electrons actually occupy 3 dimensional orbitals that overlap one another, and an orbital is actually a probability space where the electron will be found. At any given instant we don't know where the electron is in that space, but if you wait for 1 second the electron was in all points of the space several times at various instants. When the energy level changes the electron merely moves in a different probability space at the overlap between the two, or it may move up through several overlaps because it can only take on or lose energy at an overlap theoretically.
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