This right here is why interstellar travel is impossibly dangerous. In other words…there is almost zero chance you could travel between star systems at the speed of light without hitting a piece of dust or debris the size of a grain of sand. If the kinetic energy from a grain of sand at 99.9% the speed of light is enough to wipe out north America, then your little space ship stand NO CHANCE against even the tiniest dust particle at or near the speed of light. This means speed of light travel is pointlessly, impossibly dangerous. You would not survive. There is so much debris floating around out there. Not as much BETWEEN systems, but you’d have to fly through the asteroid belt first, then the Oort cloud and if you survived that you’d be in outer space between two star systems. Assuming you’re heading to Alpha or Proxima Centauri, there is 4.2 to 4.3 light years between our star systems. This means, even AT 100% light speed, it would take 4.3 years for you to reach the other system…that’s 4.3 years of time…flying in a STRAIGHT LINE..50% of that time spent accelerating to the speed of light. At the halfway mark you MUST SLOW DOWN or you’ll shoot right through the other system…so you spend the next 2+ years decelerating. Now…clearly you’ve not going the speed of light the whole time. So your trip will be longer. Lets say for sake of argument we had FTL (faster than light) travel. And that technology could instantly accelerate to SOL (speed of light) without killing you (which is impossible)…but stay with it for a bit. There is a high likelihood your ship would impact another celestial body. It doesn’t even have to be big. a grain of sand will destroy your spaceship. It would vaporize your ship. Some will say it would fly right through the ship and do nothing but make a pinhole. Perhaps. Perhaps not. Are you willing to take that chance? Even if it didn’t vaporize your ship, the particle would fly straight through your body if your flight path cross it’s path. The kinetic energy from this impact would rip the ship apart and your internal organs would be mush, if it didn’t vaporize the ship anyway. Oh…and the whole 99.9% speed of light thing. Ain’t gonna happen. The ship would be so big and require so much energy it would be prohibitive to build something like it. I don’t think we’ll do FTL travel. Is it possible? Maybe…if it is possible…it’s likely too dangerous…so dangerous it’s a suicide mission to try. Space isn’t EMPTY. People like to think “space is BIG” so that means it’s EMPTY. That’s a false conclusion. There is lots of dust and debris out there. There are JUPITER SIZED rogue planets floating between star systems. Look it up if you don’t believe me. And those are the only rogues. There are asteroid and comets and meteoroids and all sorts of dust between star systems. Our technology can BARELY see Jupiter sized rogue planets between systems. Here’s something to give you a better perspective. Asteroids. In the asteroid belt. We’ve mapped the orbits of tens of thousands of them. Yet that’s still only the bigger ones that are visible to us. We can’t see anything smaller than a certain size, and we can’t see s*** when we look toward the sun…also, asteroids are dark against a black background. The only way we are able to see them is when when look away from the sun and we can see the sunlight reflecting off their surface. And that’s INSIDE our solar system. We can’t see much outside it other than stars (because they’re BURNING BRIGHT LIGHTS). We can barely see rogue planets. Oh and that Oort cloud (a giant cloud of comets surrounding our solar system) we can’t see that, but we can detect it. It’s a hypothesis. But here’s the thing…even if it’s not real…it doesn’t matter. Because there’s lots of other matter out there. Namely left over debris from other star system, planets and asteroids and comets that have been ejected out of their home start system and they’re out there floating around in space. There’s too much debris out there to be flying around blind at or near the speed of light. One impact and the whole ship and crew are toast. So this idea of flying around the galaxy at faster that light speed or even light speed is b*******. It’s stupid. We are stuck here in our little system. At least until we build generations ships…and by the time that happens our technology will have developed so exponentially on orders of magnitude much greater than they are now that humans will likely no longer exist…we will merge with technology. And faster than light travel will become needless because we will have achieved technological immortality. FTL travel is pointless…I think…and even if it’s not, it’s certainly too dangerous.