**Space: Finite or Infinite?**

People have always wondered if the universe is finite or infinite in length. One of the first philosophers to theorize about space was the Greek Archytas of Tarentum. In the 4th century, he wondered what would happen if one traveled to the end of the world and stretched out a hand. The hand would meet either space or matter, which would extend the boundary of space even further. He concluded that space was infinite. Aristotle disagreed. He believed that space was finite. Isaac Newton believed space was infinite, flat, and forever the same. Is space infinite? We may never know for sure.

**What it is**: the fabric, structure, and framework of the cosmos

**Where it is**: all around us

**How we move through space:** in three dimensions (forward and backward, up and down, and left and right)**Early measurements of space:** Greek mathematician Euclid used geometry to measure regions of space

Einstein revolutionized the concept of space, by adding a fourth dimension, which was:

space

time

motion

### Correct!

Einstein believed time was the fourth dimension of space. The fourth dimension is necessary to explain how things move through space.

Space can be warped by the presence of an object.

### Fact

As Einstein stated in his General Theory of Relativity, any object with mass warps the space around it.

Things that are the same size bend the space around them in exactly the same amount.

### Fiction

The amount of space that bends around an object all depends on its mass! A chocolate M&M® will bend more space than a marshmallow—because it has more mass.