Video narration
Does the night sky show you the whole universe? Looking up, stars and galaxies can feel like the whole story. But they're only what you can see from here. Everything that exists, including the space between things, belongs to the universe. Here's the surprising part: space isn't a room outside the universe. Space itself is part of it, and it expands. That doesn't mean the universe is exploding into some larger, empty space. The space that exists is stretching. We see distant galaxies because their light has had time to reach us. That's only as far as its light has reached us, not a wall at the universe's edge. The stars visible from Earth are only a small part of what the universe contains. So, does the night sky show you all of it? No. You see a glimpse; the universe is all of space and everything in it.