Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: ali on 26/07/2008 15:10:56
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ali asked the Naked Scientists:
Does the Sun revolve around earth?
What do you think?
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ali asked the Naked Scientists:
Does the Sun revolve around earth?
What do you think?
No.
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To be strictly accurate, you can say that they both orbit around their common centre of mass. Because the relative masses are more similar, this wobble is more noticeable in the Moon / Earth orbit - it causes the tides to be twice a day, aamof.
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If we knew nothing of Newtons laws of gravitation the the evidence of planetary motion could well lead to the conclusion that the Earth is the centre of the universe and the Sun and other bodies orbit it in a series of epicyclic orbits.
This view was forced on astronomers by the religious authorities and they were well adviced to find evidence for it.
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Interestingly, it was not the application of a 'law' like Newton's which clinched the choice of the Heliocentric Universe (that all came later). It was the fact that the model was, in the end, simpler, with fewer 'friggs' to get it to fit observation.
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Yes, but, if I remember correctly, there is another "evidence" of the fact is Earth to move around the Sun and not the opposite: the Doppler shift of cosmic background radiation.
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While I acknowledge there must be some Doppler shift in the CMBR due to the Earths rotation about the sun is it really possible to measure this given the noise like nature of this radiation and the much larger shifts due to our rotation about the galaxy etc
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While I acknowledge there must be some Doppler shift in the CMBR due to the Earths rotation about the sun is it really possible to measure this given the noise like nature of this radiation and the much larger shifts due to our rotation about the galaxy etc
I presume the noise shouldn't be a real problem, since the direction of Earth's movement changes during its revolution around the Sun, so the Doppler shift due to this movement changes direction with respect to the other Doppler shift (there are two periods in the year in which the two Doppler shifts are in perpendicular directions, for example); about if the Doppler shift due to Earth's movement around the Sun is high enough to be detected at all...this is where I really don't know for sure.
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Yes, but, if I remember correctly, there is another "evidence" of the fact is Earth to move around the Sun and not the opposite: the Doppler shift of cosmic background radiation.
That's interesting - it sort of suggests some sort of absolute motion through the ether.(?)
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Yes, but, if I remember correctly, there is another "evidence" of the fact is Earth to move around the Sun and not the opposite: the Doppler shift of cosmic background radiation.
That's interesting - it sort of suggests some sort of absolute motion through the ether.(?)
It is really interesting, but unfortunately I don't know more than that; if you find other informations, post them.