A Universe From Nothing

A Universe From Nothing will enlarge your knowledge of our expanding universe by showing you how it began, what we’re learning about it now, and what will happen to it in the future.

Everything we know began in the big bang 14 billion years ago. A lot has happened since then, including a lot of expansion of human knowledge about outer space. We’ve come a long way since thinking that the Earth was the center of our solar system!

Today we know through observation that our universe is expanding. Physicist George Lemaitre predicted that the theory of relativity that came from Einstein meant that our universe was not stationary but growing. Even Einstein rejected this theory, but not long after he was corrected by observation.

To understand how scientists figured this out, you need to know about the Doppler Effect. If you’re sitting somewhere that you can hear the cars going by, you’ll notice that the noise a car makes is different as it moves past you. Take a moment and try it out yourself, it’s pretty interesting!

Research confirms that this same effect happens with light. Objects that are moving away from us have different shades of color than those heading in our direction. In observation of the colors that celestial bodies have, researchers found that almost everything in our universe is moving away from us. Looking more closely, they’ve discovered that the farther away an object is, it is moving away more rapidly. This confirms the theory that our universe is expanding faster.

So we know that the universe is expanding, but what is causing this? Just as blowing a balloon up requires air, so does our universe have a force pushing it outward. The trouble is, there’s nothing we can observe that’s causing this. Physicists thus call this force in empty space “dark” energy. But they still can’t explain where this propelling force comes from or even what it really is. In addition to this mysterious energy, scientists have also discovered that most of the universe is invisible. They call this dark matter, but that’s a little confusing because we can’t see it. A better way to think of this unknown substance is invisible matter due to the fact that it’s not visible to any of our instruments. So how did we discover these strange pieces of our universe? Calculations to determine the rotation rate of our universe show that there must be more mass than we can see. In other words, the observable universe just isn’t heavy enough to cause the speed at which we are rotating. Thus, invisible matter must exist. Next time you look up at the night sky and see the darkness between…