srini
Wednesday, March 21, 2007
Friday, March 16, 2007
Friday, March 09, 2007
Tuesday, March 06, 2007
Discovery of planets - hoping to find life!
Data collected by NASA's orbiting Spitzer Space telescope on two Jupiter-like gas planets hundreds of trillions of kilometres away - one in the constellation of Pegasus and the other in the constellation of Vulpecula - point towards some vital evidences.
One of the planets had evidence of small sand-like particles, called silicates, in the atmosphere, sugesting it is wrapped in high, dusty clouds unlike any planet in our solar system. Spitzer observed for the first time enough light to figure out signatures of molecules in the atmospheres of planets outside our little one. It was deemed as a step in a long chain of events hopefuly leading to discovering life on some other planet.
These two planets - terrifically hot gas giants whizzing around their stars in alarmingly close orbits were considered to be unlikely to harbour life, presently. But scientists hoped to use similar techniques to scour smaller, rocky planets more like the Earth for indications of life, perhaps in the form of oxygen or possibly chlorophyll. The probability of water being there hidden by a thick layer of clouds, was not ruled out.
Finally, the 'present' must consider the time delay in getting the data - howmany lightyears of distance they are away etc.!
srini
Data collected by NASA's orbiting Spitzer Space telescope on two Jupiter-like gas planets hundreds of trillions of kilometres away - one in the constellation of Pegasus and the other in the constellation of Vulpecula - point towards some vital evidences.
One of the planets had evidence of small sand-like particles, called silicates, in the atmosphere, sugesting it is wrapped in high, dusty clouds unlike any planet in our solar system. Spitzer observed for the first time enough light to figure out signatures of molecules in the atmospheres of planets outside our little one. It was deemed as a step in a long chain of events hopefuly leading to discovering life on some other planet.
These two planets - terrifically hot gas giants whizzing around their stars in alarmingly close orbits were considered to be unlikely to harbour life, presently. But scientists hoped to use similar techniques to scour smaller, rocky planets more like the Earth for indications of life, perhaps in the form of oxygen or possibly chlorophyll. The probability of water being there hidden by a thick layer of clouds, was not ruled out.
Finally, the 'present' must consider the time delay in getting the data - howmany lightyears of distance they are away etc.!
srini
Monday, March 05, 2007
Coming to nuclear density calculations!
Based upon the atomic radius of hydrogen (32 picometres) and the proportion of the volume of nucleus with respect to the total atomic volume (10**-13 approx), the nuclear density of hydrogen is 1/15 that of the core matter achieved after gravitational collapse, which means that the radius of the single proton is about 40% of the radius of the nucleus. But hold! we have to see what similar calculations on atoms of other elements have to say. It could be true that neutrons are smaller than thought to be.
Taking the case of Radon with atomic mass at 222a.m.u. and atomic radius at 140 picometres,
it can be seen that the nuclear density of Radon is about 2.5 times that of hydrogen. That means the protons and neutrons are more closely packed in the nuleus of Radon than in Hydrogen.
One has to do the exercise on sufficient number of samples to arrive at a reliable conclusion!
srini
Based upon the atomic radius of hydrogen (32 picometres) and the proportion of the volume of nucleus with respect to the total atomic volume (10**-13 approx), the nuclear density of hydrogen is 1/15 that of the core matter achieved after gravitational collapse, which means that the radius of the single proton is about 40% of the radius of the nucleus. But hold! we have to see what similar calculations on atoms of other elements have to say. It could be true that neutrons are smaller than thought to be.
Taking the case of Radon with atomic mass at 222a.m.u. and atomic radius at 140 picometres,
it can be seen that the nuclear density of Radon is about 2.5 times that of hydrogen. That means the protons and neutrons are more closely packed in the nuleus of Radon than in Hydrogen.
One has to do the exercise on sufficient number of samples to arrive at a reliable conclusion!
srini
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