<nerd shit>
I am highly skeptical that the speed of light is any sort of constraint on a more advanced civilization. The actual speed is three hundred thousand kilometers per
second. If you remove the time component, you're just left with a distance. We've already known for decades that the passage of time is relative to gravitational force. Einstein made a pretty big deal about it in his groundbreaking book on relativity. The most plausible theory for faster-than-light (FTL) travel arose from that under the name
Alcubierre drive, which suggests that, given what we
already know about the nature of space-time1, some sort of vehicle could move FTL if "a configurable energy-density field lower than that of vacuum (i.e. negative mass) could be created."
2 So basically, if you were to abuse space-time a bit and create a field (sort of like a pressure gradient, but dealing with gravity rather than fluids) in which time moves at a faster rate than time outside the field, you could theoretically travel at one tenth the speed of light inside the field but, relative to time outside the field, the time spent travelling inside the field would correlate with an object moving
FTL at light speed.
The most significant issue with this is that everything is still relative to the speed of light. I get something of a nonsense answer if I even try to calculate time dilation relative to an object moving FTL (unless you accept the premise that time can be wound backwards). The conclusion that seems most logical is that, once you pass the speed of light, regardless of how little time passes for you, to everyone outside of your warp bubble/gradient, you're always stuck moving at the constant speed of light. In other words, if you were traveling 10x FTL (three million km/s), you could do a round-trip to a planet fifty lightyears (ly) away in just ten years your time, but you would still arrive home to an Earth on which a hundred years has passed since you left, just the same as if you had only been travelling at lightspeed (300,000 km/s). There's a lot of great speculative fiction dealing with the effects of
time dilation3, most famously Joe Haldeman's novel
The Forever War, although that mostly deals with accelerating and decelerating from
near light-speed (but, obviously, given how difficult it is to calculate time dilation at FTL speeds, this makes the most sense).
Contemplate for a moment the possibility that some advanced civilization a thousand ly away has already sent probes to Earth and they have arrived. Regardless of whether or not they traveled at or beyond light speed, at the very least a thousand years has passed on the planet from which they were dispatched. Assuming they phone home, it would take another thousand years for the probes to return the message that something was found. Assuming the origin planet is one of the "goldilocks" planets, it's likely that they're caught up in similar planetary, solar and stellar gravity wells that make the rate of the alien civilization's time pass at roughly the same rate as it passes for us on Earth. Therefore, it could take thousands of years on both sides for any advanced civilization to even figure out how to communicate with us before actually deciding to do so.
So if you think about it, for us to even be able to participate in any sort of interstellar politics, the human lifespan would likely need to be extended quite a fair bit to sustain the motivation to try and communicate with potential pen pals we would not even hear from for ages at a time, and if you were to see a UFO today, the race that sent it may not even know of your existence for another millenium.
</nerd shit>
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