Hacker News Reader

Comment by DiThi | Hacker News Reader

> The vastness of the universe make the chance of us being one-of-a-kind thing really low.

But it also means the chance of ever communicating with a different life form is really low.

All it takes is some egotistical civilization that builds von Neumann replicators to build KILROY WAS HERE monuments made of diamond on every moon in the galaxy (it's a big galaxy, but there's millions of years to play with). It's at least mildly surprising that there's no evidence of any extrasolar visitors in our solar system's past.

I don't find it mildly surprising the space-fairing aliens practice leave-no-trace.

This assumes von Neumann replicators are acheivable, and if they are, that any species capable of creating them would want to.

We should be able to detect structures signals from past civilisation, if any such exists. If not, we would probably make it easier to future civilisations to detect us.

Detection is different than recognition. The signs of microscopic life were known and even exploited for thousands of years before anyone realized that what was leavening our bread and making us sick was life.

It was implied that I was talking about advanced civilisations. Without some significant kind of structured radiation we cannot detect them with our current technology.

Probably depends on whether we can expect to find them within something like two thousand light years, or two hundred million plus.

Reply on news.ycombinator.com