[E. Pluribus Unum]

The universe is so incomprehensibly large that I have no doubt that there have been and are innumerable planets supporting life over billions of years, but each of those planets would millions of light years apart, and they would all exist at different points in time.

If the closest planet with life is a million light years away, it's just the same as if we were alone in the universe.

[jsanders2001]

They’re sitting right next to you in the 5th Dimension

[NativeSon]

it's just the same as if we were alone in the universe.

most people cannot grasp the enormity of our galaxy let alone the universe. Mathematics is important here, if "tricky numbers" make sense, you're Polly not sitting out side on a cold night waiting for visitors to sneak down to make crop circles.

[Drew68]

The universe is so incomprehensibly large...

Carl Sagan wrote something in Cosmos that really blew my mind. He said there are roughly 10,000 stars visible on a clear night to the naked eye. A handful of sand holds roughly 10,000 grains. There are more stars in the universe than individual grains of sand on every beach and desert on the planet.

Yes, the universe is that big!

I have no doubt that uncountable other planets have life, even intelligent life. Many of them have probably mastered intergalactic space travel at sub-light speeds. They just don't know we're here. If they had telescopes that could detect made-made objects, geometric shapes and such, they wouldn't see them if they were more than 4,000 light years away. If they were looking for radio signals, that lowers it to about a mere 80 or so light years away.

[Bloody Sam Roberts]

If the closest planet with life is a million light years away, it's just the same as if we were alone in the universe.

Spot on. Folks who ask where all the aliens are have no comprehension of the size of this universe.

To paraphrase Douglas Adams, they have about as as much understanding of space and time as a concussed bee.