On 5/26/2018 12:58 PM, wrote:
Unfortunately or fortunately, depending on your perspective, the
distances between stars are far too great, to reasonably permit
contact or interaction between intelligent species.

There are likely many ( perhaps infinite ) cases where intelligent
life has evolved and reached a technology for spave travel, but the
constraint of the light speed limit, and likely something far slower,
is perhibitive of contact or interaction.

This is confirmed by the fact that we've seen no contact so far.


Perhaps.

How long do you believe an intelligent and inventive
species can exist?

You might want to read Arthur Clarke's sci-fi book
"The Fountains of Paradise",
https://en.wikipedia.org/wiki/The_Fountains_of_Paradise

It describes "starglider" on pages 74, 82, 92 to 96.
Interesting ideas.