Friday, Cassini will dive into Saturn’s atmosphere and put an end to its nearly 20 year mission. Over those years we learned an incredible amount of information about Saturn, its rings, and its many moons. During the grand finale, Cassini will continue to send back information about Saturns atmosphere before burning up like a shooting star.
Hey! Just wondering, how did a solar eclipse prove the theory of relativity?
According to the theory of relativity space is not static. The movements of objects can change the structure of space.
In Einstein’s view, space is combined with another dimension - time - which creates universewide “fabric” called space-time. Object travel through this fabric, which can be warped, bent and twisted by the masses and motions of objects within space-time.
One prediction of general relativity was that light should not travel in a perfectly straight line. When traveling through space-time and approaching the gravitational field of a mass object, the light must bend-but not too much.
Then the English astronomer Sir Frank Watson Dyson proposed that the total solar eclipse of 1919 could prove, because the Sun would cross the
bright Hyades star cluster. Star light would have to cross the gravitational field of the sun on the way to Earth, but would be visible due to the darkness of the eclipse. This would allow precise measurements of the positions displaced by the gravity of the stars in the sky.
Because of this, teams of researchers strategically positioned themselves in two locations that would initially provide the best conditions for observing the eclipse. One group stayed in Ilha do Príncipe, in São Tomé and Príncipe, and other researchers settled in Sobral, Ceará (Brazil).
Eddington, who led the experiment, first measured the “true” positions of the stars during January and February of 1919. In May, he went to remote Prince Island (in the Gulf of Guinea, on the west coast of Africa) to measure Positions of the stars during the eclipse, seen through the gravitational lens of the sun.
The total eclipse lasted about 6 minutes and 51 seconds, during those few minutes the astronomers captured several photos of the total eclipse.
When Eddington returned to England, his data from Príncipe confirmed Einstein’s predictions.
Eddington announced his discoveries on November 6, 1919.
Consider this: You can see less than 1% of the electromagnetic spectrum and hear less than 1% of the acoustic spectrum. As you read this, you are traveling at 220 km/sec across the galaxy. 90% of the cells in your body carry their own microbial DNA and are not “you.” The atoms in your body are 99.9999999999999999% empty space and none of them are the ones you were born with, but they all originated in the belly of a star. Human beings have 46 chromosomes, 2 less than the common potato. The existence of the rainbow depends on the conical photo-receptors in your eyes; to animals without cones, the rainbow does not exist. So you don’t just look at a rainbow, you create it.
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NASA Lunar Science Institute, 2012
(via dig-my-earth)
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