Showing posts with label William Derham. Show all posts
Showing posts with label William Derham. Show all posts

Sunday, October 18, 2009

The Universe: 1715



--From Astro-theology--

Forget about the Earth revolving around the sun. The big realization was that stars were like the sun and perhaps even had planets of their own, which is why this diagram shows the distant stars as having planets orbiting around them.

In our solar system the planets were all thought to likely be habitable and the consensus was that the Moon was covered in oceans. But even though there was a consensus, people who claimed the Moon had observable liquid water were still willing to listen to dissenters. Before telling his personal account of seeing lunar oceans, the author of this book quotes Huygens:
In the Moon I find no likeness of Seas although Kepler and most others are of a different opinion. For those vast plane regions, which are much darker than the Mountainous parts, and are commonly taken for Seas, and bear the names of Oceans; in those very places viewed with a long Telescope, I find little round Cavities, with shadows falling within them; which cannot agree with the Surface of the Sea...
If your theories are strong, they can withstand the criticism of others.

Saturday, October 17, 2009

Perspective: 1715

The prodigious and inconceivable Rapidity assigned by the Ptolemaicks to the Heavens, is by the Copernican Scheme taken off, and a far more easy and tolerable Motion substituted in its room. For is it not a far more easy Motion for the Earth to revolve round its own Axis in 24 hours, than for so great a number of far more massy, and far distant Globes, to revolve round the Earth in the same space of time? If the Maintainers of the Ptolemaick Systeme do object against the Motion of the Earth, that it would make us dizzy and shatter our Globe to pieces, what a precipitant, how terrible a Rapidity must that of the Heavens be? What a Velocity must the Sun have to run its course, at the distance 21 or 22 Semidiameters of the Earth? What a Velocity must that of the Fixt Stars...
--From Astro-theology--

Does the Earth spin in the universe or is the Earth fixed and the universe spin around us?

If we were fixed then the star Betelgeuse, which is about 640 light years away, would travel 3.80 X 10^16 km every day at a speed of 1468757.4 times that of light. Since nothing can travel faster than the speed of light (other than a rumor) the planet Earth must rotate.

So, if you think the universe revolves around you, hopefully this demonstration of math and physics will convince you of the error of you ways.