i'm a little skeptical of the idea that light is the absolute limit, but i'm not at all skeptical about the idea of a boundary point occurring in mass-energy transfer. the reason light is claimed to be the speed limit is because it's assumed to be pure energy. no mass. there's no experimental support for this claim; rather, we have a particle-wave duality that ought to cast some questions on it. on top of that, the math makes more sense when you acknowledge the existence of the always present implied epsilon, rather than pretend it's not really there.

but, if light is not the fastest thing then the fastest thing cannot be much faster because light cannot have much mass. there is some space for the possibility of moving two or three times the speed of light, but not faster than that.

so, therefore aliens are impossible, right? no. because, you're making another assumption without realizing it: that aliens must have comparable life spans to humans. if an alien could live for tens of thousands of years, space travel would be an entirely feasible proposition.

some biologist will reject this offhand. but, the truth is that we seem to have taken a wrong turn on the evolutionary tree in terms of longevity, some time many millions of years ago. had we evolved from turtles, we would likely live for several centuries rather than several decades. there's no intrinsic requirement for cell death; arguments about the laws of physics on earth only apply to the earth. a different kind of environment may actually select for extreme longevity.

it seems to be clear that space travel is not something that humans will be possible of for many eons, if ever at all. we're running up against a biological limit rather than a technological one. now, there's abstract ways around this. we could consider cloning our consciousness to data storage and then reuploading it into a new clone created from scratch - that way we could exist in the computers for the thousand of years of travel time. but, that is not just solving the problem of space travel, it is solving the problem of mortality.

i think the key point in grappling with this is in realizing what the actual problem is in contemplating the likelihood of travel, and it's that our lives are too short.