> I never thought of c being a real problem to space travel. > We just need to figure out how to use propellant efficiently enough among a few other slightly d

> I never thought of c being a real problem to space travel. > We just need to figure out how to use propellant efficiently enough among a few other slightly difficult challenges Both of these sentiments are pretty common misconceptions I've seen on HN. First, if c was infinite, the energy required to accelerate a constant amount would grow quadratically. This alone is a tough problem. Maybe we could "just" solve it. On the other hand, if c was finite, the energy required to accelerate would grow exponentially. This is more than a "slightly difficult" problem.