Right now, in some distant corner of the galaxy, an alien astronomer could be looking at live footage of dinosaurs.
It’s not science fiction. It’s simple physics.
Light has a speed limit, and it’s a slowpoke on a cosmic scale. It takes time for light to travel across the mind-boggling vacuum of space.
So, if an alien civilization lived 65 million light-years away and had a telescope powerful enough to zoom in on our little blue planet, they wouldn't see our cities, our satellites, or us. The light from our world that's just reaching them now left Earth 65 million years ago.
Their "live" view would be the Late Cretaceous period. They'd be watching T. rex stalk through fern forests and Triceratops herds grazing on ancient plains.
Let that sink in. The most epic nature documentary ever is broadcasting from Earth right now, traveling at the speed of light. We just can't see it ourselves.
The past isn't gone. It's just being streamed to a distant part of the universe.