Further essays: SS-M1: Eppur si muove (and yet it moves)

Today we know that Earth is spherical and that it spins on its axis, and that the Sun is stationary and we orbit the Sun. The Heliocentric model echoes this belief that Earth and other planets revolve the Sun which is near the centre of the solar system. We are the third planet on this astronomical model.

Many people like Galileo Galilee and Giordano Bruno were persecuted by the Church because they fought for what we all believe today regarding the heliocentric model. However, a few centuries ago many people believed that God’s Earth was at the centre of the universe, and that all other objects orbit around it. This was called the Geocentric model.

Heliocentrism is naturally opposed to geocentrism, The Roman Catholic Church chose to adopt the geocentric model because it did not conflict with Biblical stories that God revolved everything around us.

Biblical references Psalm 93:1, 96:10, and 1 Chronicles 16:30 include text stating that "the world is firmly established, it cannot be moved" [1]. In the same manner, Psalm 104:5 says, "the Lord set the earth on its foundations; it can never be moved" [2]. Further, Ecclesiastes 1:5 states that "And the sun rises and sets and returns to its place" [3] etc.

Thus, the Church then chose to condemn anyone who spoke or wrote about heliocentrism “unless they spoke of it as a mathematical theory only” [4].

But the transition between these two theories met much resistance, not only from the Catholic Church and its reluctance to accept a theory not placing God's creation at the centre of the universe, but also from the sceptics’ who still needed more evidence.

Many such sceptics’ have argued that the Earth is flat because if the Earth were spherical people would fall off, surely? [5]

But we know the Earth isn’t flat. Countless ships and planes have circumnavigated the globe and haven’t ever fallen off the map or seen the edge of the planet!

Another such question is why don’t we feel the earth rotating? [6]

Put simply because we never feel motion. We only feel changes in motion. For example, when we read or sleep in a fast travelling vehicle, as long as the vehicle doesn't speed up, slow down, turn, or hit a rough spot we wont notice the change. It makes no difference whether you're moving fast or slow, horizontally or vertically.
You feel nothing until either the speed or the direction changes.
Our Earth, is moving approximately 1,040 miles an hour at the equator, You don't feel the speed in the direction east along the ground, because it never changes.

If you go outside on a clear night, you can observe the stars rise in the East and set in the West. Why is this?

This is because the Earth moves on its axis which means the Earth is spinning; one side of the Earth would be facing the sun (day time) and the other the moon (night time)

What would happen if the Earth didn’t rotate on its axis?

You could get a situation where there's no rotation. In this case, a day would take an entire year, and it would only happen because of the Earth's orbit around the Sun - Earth wouldn't actually be turning in space but still going around the sun. In this case, Earth would always show the same face to the Sun - half the planet would be frozen, and the other half would be hot.

Fortunately, the Earth does rotate, giving us a day and night every 24 hours. If the Earth didn't rotate, there would be no day or night. As the Earth turns on its axis, each part of the planet gets a chance to face the Sun and be warmed in a relatively short period of time.

But it can still be argued that it isn’t Earth that is moving it may well be the Sun - so what if the Sun went around the Earth?

If Earth were not revolving around the Sun, that would mean the same stars would rise and set at the same times, every night. But astronomers have agreed the “stars will be found positioned 1 degree further clockwise” [7] each night compared to the same time the previous night, and this cycle appears to make a full cycle every 365 days, this implies that we are revolving around the Sun once per 365 days.

If the Sun rotated around us, then it would be the same height in the sky year-round since it would have a more fixed path. But it's not. It gets higher in the sky in summer and lower in fall.

I posed a “Philosophical question” on my Facebook account asking if there is proof that Earth doesn’t spin on axis or doesn’t orbit the Sun.

One sceptic on my Facebook friend list had offered me “proof” that we don’t indeed move at all. Comment by Mr. K. :

“if your hovering in a helicopter.
your airspeed indicator is at 0.
your altitude indicator should be level.
your horizontal situation indicator should be steady.
your vertical speed indicator is at 0.

now hover for a couple of hours, the same land is still under you.
should it not be different land, since the ground beneath the helicopter
is rotating on its axis?”

My retaliation to the above statement would be that we all are affected by gravity, Earth is trapped by the sun's gravity. That's why we orbit the Sun. Since the Sun is moving and we are trapped by the Sun's gravity, we are anchored to it. So were also rotating with the Earth. However, if you take that helicopter in to space and hover for a while you will see the land beneath is different and moving.

Bibliography

ARTICLES

Campos, thais, “Philosophers Condemned by the Inquisition” ,(2010), paragraphs 1 / 2/ http://www.suite101.com/content/philosophers-condemned-by-the-inquisition-a209126 [accessed 26/02/2011]

BOOKS

The Southern Sky Guide, David Ellyard and Will Tirion , Cambridge University Press, 3rd edition, http://books.google.co.uk/books?id=5Gn0ivM4EK0C&pg=PA13&lpg=PA13&dq=stars+appear+to+change+positions+by+about+1+degree+each+night&source=bl&ots=u9siMO0GM-&sig=6ZKFUNrMJiLPZXkbj824poP-2k0&hl=en&ei=olpsTa-nEYSHhQeB_6WDBA&sa=X&oi=book_result&ct=result&resnum=10&ved=0CEwQ6AEwCQ#v=onepage&q&f=false

[accessed 27/02/2011]

WEBSITES

J. Richman and C. Pellis ,(2010),Geocentric and Heliocentric Theories. Available from: http://

http://www.youtube.com/watch?v=iiBIFlvu-X0

Gingerich, O.,(2007), “Galileo sun -centred system”. Available from: http://

http://www.youtube.com/watch?v=GmwAr54L_pM&feature=related

Psalm 93:1