re: Barring some incredible propulsion breakthrough...
Once again, sending us fragile biological humans is not the most practical way to explore the stars. By the time serious interstellar voyages are possible, humans will be outmoded as crew. As will most organic life forms for those other civilizations that decide to sail the galaxy as well.
It is possible that there are other universes out there with different laws of physics. Even if we could find them, we may not be able to live in them. So unless we find a way to retune things here, we will have to deal with the hand that nature gave us. But humans are really good at getting around these things eventually.
If we can think it, we can do it.