Unfortunately I can't think of anything dog-related, but here's neat little nugget of knowledge I bet you never thought of...
When you look up at the night sky, you are actually
looking into the past. Due to the physics of light travel, the farther an object is away from Earth, the longer it takes for its light to travel to Earth. When the light finally reaches Earth, we are essentially seeing it the way it looked when it originally left the object millions or billions of years ago.
How
is that?