When it comes to science, we have it made. We have computers and spaceships and calculators! Just think if all of these things went away. How would you know what stars looked like? Better yet, how would you even know what they were? How would you know those stars are like our sun and that some of those little lights were planets like Earth? How would you know anything? Why, you would have to use your eyes and your brain. I wonder what people came up with back before all of these things were invented . . . Let's go back in time and find out.
Science had one good thing going for it before all of our great inventions. Many, many years ago there was a lot less light from cities. These lights today make it hard to see the stars. Long ago, people could stare up into the night and see many more stars than you see now with just your eyes. Look at all of those stars! Pretty, right? Oh look, there's a woman staring up into the night sky.
ME: "Excuse me! May I ask what you are looking at?"
WOMAN: "I am looking at those pretty lights. I really like astronomy
, which is the study of stars and other things in the night sky."
ME: "What are all of those little lights?"
WOMAN: "Those are little holes in the great black ball all around us."
ME: "Are you sure they are not balls of gas and energy just like our sun?"
WOMAN: "Ha! Of course not! They are too small!"
It's not easy being a scientist ahead of your time.
With no tools, that woman had no idea what the stars really were. Let's jump ahead a few hundred years and see if we can get a better answer.
ME: "Excuse me, sir! What can you tell me about all of those lights in the night sky?"
MAN: "Why, those are constellations
, groups of stars placed there by the gods to make different shapes."
ME: "What kind of shapes?"
MAN: "There's a man. There's a crab. There's a big bear and a little bear. That shape over there is a dragon."
ME: "I do not see a dragon"
MAN: "Well, good. Maybe it will eat you instead of me."
If you look really hard you can make the hunter Orion out of these stars, or maybe not.
To try and find answers, people played connect-the-dots with stars. This did not always go well, though
Let's jump another hundred years ahead.
WOMAN: "I have seen something very weird our night sky."
ME: "What's that?"
WOMAN: "There are some lights in the sky that do not hold still. I call them the wanderers
because they do not stay in one place. They move in a line across the sky. They are too slow to be comets but move much faster than the other stars. What do you think those are?"
ME: "Maybe they are planets, just like Earth."
WOMAN: "Ha! That makes no sense."
This may look like a star but it's really the planet Venus.
Photo by Thomas Breton
There were some parts of the night sky that did not fit with the holes in a big black ball idea. Some lights moved. People did not know it at the time, but these were planets.
Let's talk to someone who lived after the 1600s.
MAN: "You will never guess what I have found! The lights in the sky are not holes at all! They are balls of light!"
ME: "No! Really? How did you figure that out?"
He pats a long metal tube.
MAN: "Why, with this telescope
, which is an instrument that helps make things that are far away look much, much closer."
ME: "You are a genius!"
MAN: "I know. You see, by putting two lenses a little ways apart, it will make a clear picture even though the thing you are looking at is far away."
ME: "So what are the stars?"
MAN: "I think they might be balls of light just like our sun!"
ME: "I wish I had thought of that."
Now this is going to really help.
It's no wonder it took us so long to figure out what the stars are. With just our eyes, astronomy was nothing but a lot of guesses about what the stars might be. People came up with a lot of ideas that made no sense, like constellations were pictures drawn by the gods, and moving lights in the sky. The telescope really shed some light on space. Or, really, it brought the light closer to our eyes.
Physics for Kids. "Telescopes" Physics for Kids, 2010. <http://www.ducksters.com/science/physics/telescopes.php
Kids Astronomy. "Introduction
to Telescopes" Kids Astronomy, 2013.