Friday, December 7, 2007

260)Neutrinos: Such small particles with so little mass that when they rain down on planet Earth they pass right through it!; Practical applications.

Education has been important to my family for a long time. My forefathers founded al-Azhar University in Cairo some 1000 years ago, at the time of the Fatimid Caliphate in Egypt. Discovery of knowledge was seen by those founders as an embodiment of religious faith, and faith as reinforced by knowledge of workings of the Creator's physical world(Aga Khan IV, 27th May 1994, Cambridge, Massachusets, U.S.A.)

A thousand years ago, my forefathers, the Fatimid imam-caliphs of Egypt, founded al-Azhar University and the Academy of Knowledge in Cairo. In the Islamic tradition, they viewed the discovery of knowledge as a way to understand, so as to serve better God's creation, to apply knowledge and reason to build society and shape human aspirations(Aga Khan IV, 25th June 2004, Matola, Mozambique)

Neutrinos are such small particles and have so little mass that when they rain down on planet Earth they pass right through it. However, a new application can use this phenomenon to get very accurate information on our earth's interior, to map its interior fabric and structures:


Going to extremes

Nov 15th 2007
From The Economist print edition

Mapping the Earth with neutrinos

TELESCOPES that point down instead of up sound like a weird idea but, if they are designed to detect subatomic particles called neutrinos, they can tell astronomers what is happening in the sky on the other side of the planet. That is because most of the neutrinos that reach the Earth pass right through it. The planet thus forms a useful screen against other sorts of particles that might confuse the telescope. Such devices could, however, also see what is happening deep inside the Earth. At least, that is the suggestion made this week by a team led by Maria Gonzalez-Garcia of Stony Brook University, in New York state.

At the moment, the only data on the Earth's interior are the paths of earthquake waves that are reflected and refracted by the various layers of the planet's interior. These, together with reasonable guesses about the Earth's overall composition, have been used to put together the familiar model of an iron core, a rocky mantle and a thin crust. But the evidence is indirect. If Dr Gonzalez-Garcia is correct, then physicists will have opened a direct window on the subterranean world—at a minimal extra cost.

Most of the neutrinos that travel through the Earth come either from the sun or from sources far beyond the solar system. Some, however, are the result of collisions between cosmic rays and the gases of the upper atmosphere. As luck would have it, these tend to have about the right level of energy to be absorbed by rock more often than their extraterrestrial counterparts. That means they can, according to Dr Gonzalez-Garcia, be used like X-rays passing through a human body, to pick out denser rocks from lighter ones.

Of course, you would need an appropriate neutrino telescope to do this. Luckily, one is being built at the South Pole at the moment. Called IceCube, it will work by detecting the flashes of light generated on those rare occasions when a neutrino hits one of the atoms in a molecule of water in the ice.

When IceCube is completed in 2011, it will be a boon to astronomy. But it will also be the first telescope capable of spotting enough neutrinos to make it worthwhile to take measurements of the interior of the Earth. If Dr Gonzalez-Garcia is right, it will thus be the world's first geoscope as well.

Easy Nash

Islam, eminently logical, placing the greatest emphasis on knowledge, purports to understand God's creation:Aga Khan 4(2006)
The God of the Quran is the One whose Ayats(Signs) are the Universe in which we live, move and have our being:Aga Khan 3(1952)
Our interpretation of Islam places enormous value on knowledge. Knowledge is the reflection of faith if it is used properly. Seek out that knowledge and use it properly:Aga Khan 4(2005)
All human beings, by their nature, desire to know(Aristotle, The Metaphysics, a few hundred years BC)