I was thinking about a bird inside a cage.

If I were a bird, I would see only a small part of the world. If I were a human inside the same cage, I would see much more. Neither of us would be wrong.

It would simply be perspective. Then I started thinking about Earth.

From the ground, we can see only a limited distance. But move 1 km upward, and suddenly the horizon becomes much wider. Go into space, and the perspective changes completely.

        So I started wondering about the universe.

We can see roughly 46.5 billion light-years in every direction, but that doesn't necessarily mean the universe ends there. That's simply the limit of what we can currently observe.

Maybe humans are also inside a kind of cage.

Not necessarily a cage built by someone, but a cage made from our senses, our technology, our brains, and our current understanding of physics.

A bird doesn't know what's outside its cage because it doesn't have the ability to understand it. Maybe we're doing something similar.

We have discovered things that existed long before we knew they existed. So why assume that everything beyond our current ability to observe is nothing?

I'm not saying something must exist beyond our imagination. I'm saying we don't know. 

And that's what fascinates me.

Maybe the universe isn't limited by our understanding. Maybe our understanding is simply limited by our perspective.