What exactly is the “Great Filter” theory, and how does it work?

Question

What exactly is the “Great Filter” theory, and how does it work?

In: Other

Answer 1

I think of the great filter as the huge barrier that must be overcome to go to other planets in other stellar systems . With current tech and the fastest rocket ship it would take thousands of years (close to 100,000 years) to reach just our nearest star system Alpha Centauri.

There’s also the radiation, extreme temps, and who knows what else.