Galileo Galilei

The Milky Way Demystified

/ Emma / 7 Comments

Alright, people…time to finish off our exploration of the Milky Way Galaxy, our home in the cosmos!

For the past nine weeks, we’ve covered everything from how our galaxy was “discovered” to how it may have formed. But there’s so much more to explore–and, starting next week, we’ll begin covering the vast universe of galaxies beyond our own!

But before we do that…I want to wrap up our discussion of our own galaxy with an overview to tie the last nine posts together.

(By the way, has anyone noticed I actually managed to chug out a post a week for the entire Milky Way “module”? I’m a bit impressed with myself for that!)

Anyway…on to the Milky Way!

Continue reading →

Discovery of the Milky Way

/ Emma / 2 Comments

Ever seen this before?

It’s not a sight that most of the developed world gets to see–at least not all the time. Light pollution from major cities completely obscures this view. Even in the suburbs where I live, I can kind of make it out–because I know where to look and what to expect.

The best way to really see it is to head out into the desert. Or the open ocean. Really, any place that’s a bit geographically removed from civilization. Growing up, Joshua Tree National Park was always my go-to for dark skies.

Even on an exceptionally dark night, though, you won’t necessarily see this. You’ll definitely be wowed by the vast, bright sprinkling of stars overhead, more than you ever see under less than ideal conditions. But the image above was taken with a long exposure.

That is, the camera shutter remained open for a while to collect more light for one image than your eyes ever will. You and I pretty much only see one image per moment.

So what is this gorgeous, hazy band, anyway?

Continue reading →

The Sun’s Magnetic Show

/ Emma / 9 Comments
galileo sunspot rotation

Do you recognize the name Galileo Galilei?

Galileo was the classical astronomer who made the drawing above. I have little idea what his writing actually says—it’s in Latin—but it’s clear enough what this early diagram is all about.

It’s a drawing of his observations of the sun.

And it’s proof, discovered way back in Galileo’s time but not accepted until much later, that the sun actually rotates.

How do we know that?

Continue reading →

Galileo and Motion

/ Emma / 4 Comments
galileo measurable.jpg

Before Galileo’s time, Aristotle was the god of gravity.

Seriously. Before Galileo came along, the question of how gravity worked was answered with another question: “What would Aristotle say?” Obviously, this method was faulty, since Aristotle was actually wrong about most scientific things he wrote about.

But Galileo began a tradition that would persist into the modern day. He’s credited for having performed the first true science experiments when he observed falling objects.

You could, of course, call Tycho Brahe’s night sky observations and Kepler’s correct application of mathematics to the heavens true science, but neither of them really performed experimental science. That distinction lies with Galileo.

Wait a second…so I thought Isaac Newton was the guy who discovered gravity?

Continue reading →

Galileo and the Telescope

/ Emma / Leave a comment
Galileo-Galilei-Quotes-3.jpg

When you hear the name “Galileo Galilei,” what immediately comes to mind?

If you thought, “inventor of the telescope,” you’re not alone. I also wouldn’t be surprised if you thought “condemned by the Inquisition for believing the Earth orbited the sun.”

But neither of these are true. If you’ve been following my more recent astronomy posts, you probably realize why—in Galileo’s time, people already knew that the Earth moved around the sun.

The idea that he invented the telescope is more understandable…but, again, it’s not true.

So what is true about Galileo, and how did he contribute to our understanding of astronomy?

Continue reading →