In the Valley of the Legless, the knobby-kneed man in king.

Yes. This is realistic. Depressing too.

I don't believe any of the scenarios involving aliens. Humanity will never take that idea seriously until we have real evidence of an alien culture. Even if you believe aliens probably exist (or existed, or will exist), the idea of preparing for them to show up and have some sort of meaningful interaction with humans is ridiculous. The odds against it are infinitesimal. Might as well prepare to win the mega-millions lottery after buying a single ticket. Discovering FTL might make us look harder, but I don't think it would change our currently dismissive attitude toward the potential of aliens.

If we discovered FTL travel tomorrow, and it was so expensive as to require a major investment from a government to use it, I doubt much of anything would change. If it were cheap and easy and accessible (backyard rockets), then it might change things dramatically. There would be a period of flitting back and forth to potentially habitable worlds. Then, when one was discovered, there would probably be a bloody brawl to squat on/claim pieces of it. It's hard to imagine how things would develop once a "new home" were found. Likely we would just transplant all of our old problems to a new place. (Sigh.) This is why I still think of The Martian Chronicles as a semi-realistic treatise on what would happen if we could colonize another planet.

Let me be clear guys, I just stumbled on an article then the wiki. I would say:
1. it sure sounds like a space thing. I could be wrong but you are, essentially, creating a warp bubble and riding the "shockwave" from that. Does not sound like you would want to do that to your planet of origin.
2. Since I proposed 20 years I would suspect some cool advances in info tech and robotics. We seem close to an orbiter.So, lets say there would be a big push to make an orbiter that worked. Aerospace type.
3. Don't see the panic to man to perimeter. I suspect it would be a piss poor reaction of Meh. I suspect some folks (nasa and the like) would be fired up but I really think the local economy and resource shortages would overshadow this. I wish it was not so but I fear it would be.

As to inhabitable worlds, yeah, that would be important. We have found a few in the goldilocks zone but they don't sound very earth like.

But I would be right next to you Clash, legless and all. Although, I would love to be part of an Expeditionary force to find new habitable planets. That would be a hell of a death though...killed by alien virus/allergen.

I've said before, they don't seem to think about the possibility of inhabitable moons of goldilocks zone gas giants, heating effects of Hot Jupiters and Brown Dwarves outside the GZ, or extending the goldilocks zone around close binaries to allow for mutual heating. All that needs to be explored. I'm booking a trip for two legless old men!

-clash

The thing is right now we have scientists saying that FTL is impossible and so we don't have to worry about BEMs coming to eat us and occupy our world just because they're BEMs and we might possibly be a threat to them someday and so by simple survival logic the only reaction is to exterminate us now before we pose a threat.

If ANY form of FTL is proven to work, that comforting thought goes bye bye and politicians wouldn't hesitate to fan the flames of the ultimate form of xenophobia for gain.

Some might create or try to create fear of aliens out of good motives, to unify humanity, a'la Ozymandias in the watchman novel, others might fan the flames for their own personal gain.

So it's still a possibility, and if ANY ftl is proven to work, it becomes a bigger possibility.

Look, I am not saying that should not be a concern but take 9/11 as an example of humans ability to be prepared. All the evidence says we could well have set up the defenses before hand, possibly thwarted what our intelligence angencies said was a threat, but it took an attack, a viable observable quantifiable attack to make us stand up and do something. Now, take that and say, make it a vague unobserved threat from a possible species that may not exist. We didn't do anything against a known foe who we knew wanted us dead.

All I am saying is that I think most world governments would be indifferent to exploration and unexcited about an "imagined" foe. I really wish it would be different but I suspect it would not be.

Wild ass possibilities never amount to a panic by themselves. We know that, for instance, human life on earth could be wiped out be one big meteor strike. Having no real idea what to do about that, and knowing that the odds are "sooner or later, but long against right now" we just kind of shrug it off. Even if we knew FTL was possible, I think we would react the exact same way to the possibility of alien invasion.

1. We don't know if FTL travel is possible, we suspect not. If we did...
2. We don't know if alien life exists, we suspect it could in the future, might in the present, and/or might have in the past. If we knew aliens existed right now ...
3. We don't know if they are "warlike/expansionistic." If they are...
4. We don't know if they would have any reason to want to take our planet or kill us (Are they overcrowded? Are they able to breathe on Earth? Could the terraform it if not?)

I think we wouldn't panic until somewhere between stage 2 and 3.