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Their was and still continues to be plenty of quarrels among the scientific
community over the two types of sciences known as geology and astronomy. The science of astronomy is the study of the make
up of the solar system as well as the entire universe. The science of geology is the study of the history of the earth, which
may be seen in some of the features of the earth as depicted in rocks or in fossils. It is also the study of the geological
features of the earth. Many people may not agree with the fact that the universe is billions of years old, although there
is plenty of evidence to support this. The reason why people may not support the theory that universe is so ancient is because
the fact that the theory of the universe being so old contradicts the religious beliefs of many people. The massive amount
of evidence such as how the sun heats up and how long it lasts clearly leads many scientists to believing that the age of
the sun, much less the universe is millions and millions of years old. Their was and will continue to be a lot of controversy
on the interesting subjects of both astronomy and geology.
Here is the diagramatic
representation of our insignificance in our Milky Way Galaxy, much less the entire universe:
The above picture had been downloaded from google.
Albert Einstein discovered an equasion which equates the energy to the mass of and
object, multiplyed by the speed of lif squared That, in addition to the unearthing of radioactivity at approximately
the same time, made many scientists to have new ideas regarding the sun's heat. A pretty famous astronomer Henry Norris Russell speculated. about the properties that the sun's mysterious heat source must have originated from and
made several surprisingly, accurate conclusions. But it appears to have been Sir Arthur Eddington, Einstein's american fellow physicist, who first noticed the mass deficit of helium as
compared to hydrogen, and suggested the fusion of hydrogen into helium might be the ultimate source of the sun's power
One day, however, Albert Einstein derived the surprising equivalence between mass and energy (E=mc2)
as a curious side effect of special relativity theory. That, plus the discovery of radioactivity at about the same time, led
to new ideas about the sun's heat. A pretty famous astronomer Henry Norris Russell speculated about the properties that the sun's mysterious heat source must have originated from and
made several surprisingly, accurate conclusions. But it appears to have been Sir Arthur Eddington, Einstein's american fellow physicist, who first noticed the mass deficit of helium as
compared to hydrogen, and suggested the fusion of hydrogen into helium might be the ultimate source of the sun's power.
The above picture has been downloaded from google.
It is Hans Bethe who usually gets credit for first proving the amazing process of
nuclear fusion as the sun's energy source, beyond Eddington's level of speculation, in a one page letter to the editor of
Physical Review. This paper became the beginnings of Chandrasekhar's book, which really established the full scale of mathematical physics
in stellar structure and evolution. But Bethe's work came too late, after the relevant chapters of Chandrsekhar's book were
already written.
the
above has been downloaded from google:
But while the basic theories of how molecules and atoms seemed
to work, somethings amazing known as reaction rates and reaction channels remained unknown. The post WWII boom
in nuclear physics, sparked by war research and the Manhatten Project, changed all of that. With the new knowledge firmly
in hand, it could finally be determined, once and for all, if nuclear fusion would really generate the needed energy fast
enough to serve as the energy source for stars. The answer was yes. Here is a really cool representation of nuclear fusion
in the sun:
The above picture has been downloaded from google:
All of this work established the theories of the amazing
reality of fusion powered stars, but only stellar surface could be observed, not stellar interiors. That has since changed,
with the creation of sciences known as helioseismology and neutrino astronomy,
both of which allow us to peer into the solar interior.
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Pre Main Sequence
Collapse |
The standard model of stellar birth has long maintained
that stars are the end result of the gravitational collapse of large clouds of dust and gas. These clouds are well known to
exist, and are indeed prevalent throughout this galaxy, and all other galaxies we can see in sufficient detail.
The above had been downloaded from google.
The exact mechanism of collapse and star formation remains the topic
of considerable discussion amongst astrophysicists. However, that the overall model is correct was confirmed by a series of
dramatic images returned by the Hubble Space Telescope. Her is an example and representation of this:
 this had also been downloaded from google. The collapse of a great cloud into a star or a cluster
of stars is not a mystery. The force that does it is gravity. The outer parts of the clouds fall inward as a result
of their own weight. That weight is very small, but not zero. It happens, but it takes time.
This
has also been downloaded from google.
As the protostar collapses, the interior of the collapsing
cloud naturally heats up. As the temperature rises, the speed with which the particles that make up the cloud collide with
each other also rises. As the collisions become more energetic, the atoms deep inside the cloud collide so strongly that the
electrons are stripped away from all of the nuclei. The gas becomes a completely ionized plasma, a mix of free electrons and
free atomic nuclei, the vast majority of which are hydrogen nuclei, which are protons. Eventually, the temperature gets high
enough for the protons to stick together. That's when proton fusion begins, and that's when the collapsing cloud becomes a
true star.
The above had been downloaded from google.
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