I know the basics of solar system like how earth moves around sun, and that we have so many planets, elliptical orbit of earth, and how far is sun from earth etc etc. I want to take a step back and understand how mankind has been able to construct this knowledge of solar system piece by piece.Questions:

-- Sun is something we see on daily basis, so it would not be strange if humankind got curious to know about it, and made theories,observations,maths to prove it. How did Copernicus and others came up with the theory that earth moves around sun in elliptical orbit. How did they prove it? Has there been any actual way by which we have actually observed sun being in center and earth moving around in elliptical orbit. or we made such theory and result of this theory have been proved by other observations like day,night,change in weather at a point and at different points on earth.

-- How did human have an inkling that there are other stuff on space apart from sun and moon and some stars, like mars,jupiter and other planets, because these planets are not visible from earth. Did human accidently bump into these planets while moving around in spacecraft like they bumped into America.

-- When was the first man made satellite made? When did the first spacecraft go into space. Weren't people afraid to step their foot outside their spacecraft in an utter uncertainty now knowing what waits them on an alien planet, living condition on it etc.

-- How has the distance between sun and earth been calculated? and speed of light? and size of sun?

-- What are the most used tools used to acquiring such knowledge apart from telescope? What is the range of most powerful telescopes that man has made?

-- And why are humans so curious to know more and more about Mars in particular? Is it because it is relatively easier to study Mars for some scientific reason? how we do scientist intend to put their Mars knowledge to practical use?

-- What is the difference between spacecraft and rocket? What is the application of each?


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    $\begingroup$ Please ask one question per thread. meta.physics.stackexchange.com/questions/13/… $\endgroup$ Feb 15, 2011 at 6:54
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    $\begingroup$ With so many questions you would better start with reading some popular book on space and astronomy. If the library is too far then Wikipedia might help: en.wikipedia.org/wiki/Outer_space $\endgroup$
    – gigacyan
    Feb 15, 2011 at 7:51
  • $\begingroup$ A few of these questions aren't quite related to physics, so I figured "off topic" is as good a close reason as any other of the limited number of choice... but the real (at least, the main) reason I'm closing it is that it's too broad - you should have one question per post, as Mark pointed out. $\endgroup$
    – David Z
    Mar 13, 2011 at 22:15

1 Answer 1

  1. The first experiments ever to be conducted in regard to orbits and the earth spinning was done by i believe Galileo he hung a pendulum from the ceiling of his granary it was on a 360 degree hinge of some sort he then swung it,he coverd the floor in a layer of fine dust he left it for a full day and when he returned the markings in the dust suggested that the earth spins now that was simply to prove that the earth spins on its axis.Issac Newton was the one that suggested that an object in motion must remain in motion until another force acts on it. This force was of course gravity which from the sun on our planet and all other planets in our solar system is a tremendous force which keeps us in orbit.

  2. The notion that humans had bumped into the other planets is a cute one. The truth is that scientists throughout the ages have all had suspicions that there were other planets in our solar system of course with no way to prove this they were just theories but the truth is astronomers were able with their ancient telescopes to see perhaps as far as mars but up until the last century that was as far as they got.

  3. The first ever satellite was the sputnik created by russian engineers it was sent into orbit in 1957. Now the first man to ever land on the moon was Neil Armstrong followed by Buzz Aldrin the were not afraid to step out of thier ships because NASA did an extremely good job of preparing them for that mission and trust me if you landed on themoon you wouldnt just not go on it was in the words on Armstrong One small step for man,A giant leap for mankind.

  4. Im going to skip part one of this question. Part 2. the speed of light was calculated by interferometer technique this i believe was to shine a beam of light at a multisided mirror and the resulting reflection would show where the light ended up they knew the exact speed that the mirrors were spinning so they could calculate the speed.Not sure about the last part.

  5. Nowadays rockets and satellites provide the bulk of the research.

  6. Humans were very curious to know about mars for several reasons the primary being that it is the only planet besides earth that would be able to support any kinds of life form.

  7. The spacecraft as used in the mercury and apallo missions were rockets with payloads i.e. the satellites, the lunar lander, and space capsules. These rockets would fall back to earth as soon as their purpose was served. The space shuttle was to be a ship that would return in full


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