a reply to: BrianFlanders
I tend to agree with you, FTL may likely be impossible and LS as well. I have read that even if the Alcubierre drive works, one techanical issue with
warp bubbles is that the temperature inside the warp bubble is so hot from Hawking radiation, 5M(?) 5k(?) degrees F that nothing could survive.
The story of the dimming star, KIC 8462852, fascinates me. While everyone is trying to dismiss the alien theory, a year or so ago, they searched
galaxies to look for this type of artificial light reduction and said they could not find it. This seems to be exactly the signature that would
indicate advanced (very advanced) life. But, I also wonder if this is a sign that very advanced life is also home bound to their star and can't leave
it. Therefore, they are expanding their world with a Dyson swarm because there is no feasible means to leave. If that is the case, there technology
is likely good enough that they know earth is habitable. They may have even sent probes here and know life is here. But, if communication is limited
to light speed, they would not yet know our level of advancement.
Perhaps when they understand we have reached the nuclear age, they will send a message to us, which would be about 3,000 years from now to tell us who
they are, the limits on travel and how to survive by making greater use of our star. If we can reach the starts, I think it will take 1,000 years to
100-200 hundred years to have a working full time colony on Mars. By that I mean self sustaining. 300-500 hundred years to send probes and receive
data from nearby stars to identify 5 or 6 planets that should be targeted for a visit. either because they have sustainable life, but not intelligent
life on the planet or the planet can clearly support life. 200 - 300 years to put together a mission that is successful. In my view, we haven't
started working on 1, full time colony on Mars until we have the first human land there. Then the 1,000 year time line starts. Also, we need to
develop the technology to send probes that have a turn around time of 300 - 500 years. That technology does not exist. We also need telescopes that
are capable of identifying the targets much more precisely. Perhaps that is only 30 - 40 years away....But, 100 years as the OP suggested is wildly
optimistic. 50 years has almost passed since the moon landing and we have not progressed since.
Mars is geometrically harder than the moon and the stars are unfathomably harder. I really don't think we have been physically visited by aliens. I
allowed for the possibility of probes above. My bet is that interstellar is impossible for carbon based life due to radiation, temperature issues
etc. Rather, interstellar travel will be limited to artificial life, albeit, the future of the human race is likely a hybrid with machines and
perhaps if we accept that as human, then it will occur.