Is outer space empty?

This turns out to be a very profound question. And the answer has two parts. You might have to ask your mom or dad to help you with some of the videos.

Let's start with trying to figure out what "empty" means. Imagine you have a box of some kind. For example like this

It’s just a theory

"It's just a theory," dismissively, even derisively uttered often accompanied with the phrase "not a law". How often have you heard that remark and why does it frequently evoke such strong emotional responses? In fact, just what is a theory and what is a law?

What is gravity?

Good question! Both interesting and intriguing! Some of history's greatest scientists have struggled to answer this question. The history alone is facinating. Well, enough preliminaries, let's get right to the answer. If you don't understand any of the words I am using ask your mom or dad to explain them. In science words are important and we have to use the right words so we can convey our meaning properly to others.