Lemaitre Evidence For His Theory example essay topic

It is a scientific theory about the origin of the universe. The universe was created approximately 10 to 20 billion years ago from a cosmic explosion that throw matter in all directions. A scientist call Lemaitre in 1927 proposed that the universe began with an explosion of a primeval atom. This theory was based on observing the red shift in distant nebul as.

Many years later a scientist called Hubble found that distant galaxies in every direction are going away from earth with speeds proportional to their distance. This gave evidence to help justify Lemaitre's theory. This theory explained why distant galaxies are travelling away form earth at great speeds. It also predicts the existence of cosmic background radiation. This is the glow left over from the explosion itself. In 1964 scientist's Penzias and Wilson discovered radiation which confirmed the Big Bang Theory.

The Big Bang Theory is accepted but it can never be proved. In 1927 Lemaitre also stated that the universe must have been expanding due to gravitation. He said the universe was the same in all directions and its composition was the same but not static. He was unable to prove this, so many scientist ignored it. Another scientist Friedmann had independently come to the same conclusion a few years earlier. Because Hubble had found evidence of galaxies moving away at speed.

It gave Lemaitre evidence for his theory. "If you imagined the galaxies rushing away form us as a movie, just run the movie backwards. After a certain time, all those galaxies will rush together". (web March 2003) Lemaitre then suggested the idea that, there was once a primordial atom and this had contained all the matter in the universe. His other support was the idea of entropy, which is everything moving towards greater and greater disorder. This theory interested other scientists and they named this the "big bang".

This theory was later confirmed by scientists Penzias and Wilson as they found evidence of cosmic background radiation, which Lemaitre and other theorists had determine would be the residue of the big bang's explosion many billions of years ago. White Dwarf A white dwarf is the remaining core of a burned out star. The exposed core or white dwarf cools down constantly and will become fainter and fainter until it is finally disappeared because of the decreasing luminosity. It is a small, very dense, hot star that is made mostly of carbon.

These faint stars are what remains after a red giant star loses its outer layers. Their nuclear cores are depleted. They are about the size of the Earth but heavier. They will eventually lose their heat and become a cold, dark black dwarf. Our sun will someday turn into a white dwarf and then a black dwarf. Red Giants A red giant is a large star that is reddish in colour.

It is the late phase in a star's life, when hydrogen has been exhausted and helium is being fused. This causes the star to collapse, raising the temperature in the core. The outer surface of the start expands and cools. This gives it the reddish colour. They are very large and can be over one hundred times bigger than it's original size.