Would we really know they are there?

[Yminale]

It's a certainty that mass extinction has occurred on the Earth in the past. It seems pretty likely that it will happen again in the future, unless technology somehow can prevent or mitigate it. I imagine this state of affairs is probably pretty common on other inhabited planets, if any, and on many of them the frequency and severity could be much worse than here.

At this point of time, it's all about fusion. If we can survive long enough to develop fusion power than humanity has a good chance to survive anything short of a gamma ray burst.

 

[Winterwind]

And fusion power protects us from nuclear war, planet-killer asteroids, etc, how, exactly?

 

[Wanderlust]

And fusion power protects us from nuclear war, planet-killer asteroids, etc, how, exactly?

Spaaace

Will allow for quick long distance travel in the solar system. Also a reason to go out there, ie to collect resources for the fusion.

 

[Asbo Zaprudder]

There is a project starting that looks for signs of cosmic level engineering (Dyson spheres, Ringworlds, Time-space gates etc.) that could only be done by an advance civilization.

Do you have a link or something for further info on this project?

I heard it on the Mysterious Universe podcast but I can't find the original article.

This is the best I can do.
http://io9.com/5797597/are-we-surrounded-by-dyson-spheres

I see the author of that article makes the common mistake that Dyson spheres are solid, which they are not -- well, at least, not as Dyson originally imagined them.

"RESPONSE: In reply to Maddox, Anderson and Sloane, I would only like to add the following points, which were omitted from my earlier communication.

1. A solid shell or ring surrounding a star is mechanically impossible. The form of "biosphere" which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star. The size and shape of the individual objects would be chosen to suit the inhabitants. I did not indulge in speculations concerning the constructional details of the biosphere, since the expected emission of infrared radiation is independent of such details."

quoted from http://www.islandone.org/LEOBiblio/SETI1.HTM