With our proper place in the Universe worked out, and some powerful telescopes to probe the cosmos, astronomers started making some real progress. The next few hundred years was a time of constant refinement, with astronomers discovering new planets, new moons, and developing new theories in astronomy and physics.
Now we reach time with names that many of you will be familiar: Galileo, Kepler, Copernicus. This is an age when the biggest names in astronomy used the best tools of their time to completely rearrange their understanding of the Universe, putting the Earth where it belonged – merely orbiting the Sun, and not the center of everything.
We know you love a good series. This time we’re going to walk you through the history of astronomy, starting with the ancient astronomers and leading right up to the most recent discoveries. Today we’re going to start at the beginning, and in Part 1 we’ll talk about the astronomers who first tried to understand the true nature of the Earth, the planets and our place in the cosmos. In part 2 we’ll talk about the Greeks, who worked out the size and shape of the Earth, the distance to the Moon and Sun, and even had some accurate ideas about our place in the Universe.
Astronomers have been cataloging star positions for thousands of years, from the first calculations made by Hipparchus, to the more recent star catalogs made by the spacecraft named after him. This is astrometry; another way to find our place in the Universe.
Everything in the Universe is spinning. In fact, without this rotation, life on Earth wouldn’t exist. We need the conservation of angular momentum to flatten out galaxies and solar systems, to make planets possible. Let’s find out about the physics involved with everything that spins, and finally figure out the difference between centripetal and centrifugal force.
Why are some objects in the Solar System bright while others are dim? Much of an object’s brightness is caused by its albedo, or how well it reflects radiation from the Sun. If you want to know how big a distant moon, comet, or asteroid is, you’ve got to know its albedo.
Today we tackle more thrilling mysteries of the Universe. And by tackle, we mean, acknowledge their puzzling existence. Some mysteries will be solved shortly, others will likely trouble astronomers for centuries to come. Join us for part 2.
The Astronomy Cast team has finished their podcasts on the mysteries of the Solar System and the Milky Way, it’s now time to move on to the biggest mysteries of all: The mysteries of the Universe. Let’s wonder about dark matter and dark energy, and the very nature of reality itself.