The Hubble Space Telescope is one of the most famous telescopes in the world.
Oops, excuse me—one of the most famous telescopes built.
Hubble, after all, is certainly not in this world. Unless you call the universe the “world,” it’s about as far from being in this world as you can get. It’s in space.
Hubble isn’t that different from an ordinary, ground telescope. It’s only as big as a bus. There are bigger optical telescopes. Its mirror is 2.4 m across—hardly an achievement by modern-day standards.
Palomar Observatory, which was the biggest telescope in the world when it was built, has better optics than Hubble, meaning its images are a bit crisper.
But that doesn’t keep astronomers from continuing to use Hubble. In fact, if you want to use Hubble, you have to get in line—it hardly has time to complete all the projects astronomers ask of it, even observing the night sky 24/7.
So why is Hubble so useful? Continue reading
In the 4th century B. C. E. (Before Common Era), scientists believed the Earth was the center of the universe. Before that, they were convinced the Earth was flat.
Now, if anyone so much as mentions that the Earth is the center of the universe, they are quickly corrected. The very idea is absurd. (Although there are in fact online “societies” for people who believe the Earth is flat.)
We now know that not only is the Earth not the center of the universe, but neither is the sun, which is undeniably the center of the solar system. Were we to zoom out much further and take a look at our galaxy, the Milky Way, we would find that the sun is not even near the center of its own galaxy.
In fact, it’s located in a small “spur” of stars just off one of the spiraling arms of the galaxy. Since the current theory states our universe is infinite, there can’t even be a center, and thus our galaxy is not the center of everything. How wrong those early astronomers were!
But what does all this mean? Where exactly are we in the universe?