I haven’t seen this spelled out this way before
The Laws of Physics: Travel from another star in any reasonable time requires near-light speed travel. A ship propelled by onboard conventional rocket fuel would require more fuel than there is mass in the visible universe to accelerate to near light speed and slow down at the end of the voyage, so clearly some more advanced fuel would be required. But even using nuclear fusion one would use more than 2,000 times the mass of the ship in fuel for each acceleration and deceleration to and from near-light speed.
It makes sense to me, intuitively, and I know it’s all tied into time slowing down and mass increasing as we approach C, but I’d like to see the equation, just so I could stare at it in awe.
It leaves me thinking that we only get there by string theory, and not by conventional or nuclear power. That is, there have to be a few extra spacial dimensions which let us leap across 3D space as if we were navigating the pages of a newspaper by crumbling it up into a ball and drilling between sheets.
But discovering how those extra dimensions work is the basic challenge of Flatland. The two-dimensional being can only see a mere slice of the three-dimensional being. That makes for a very scary proposition, If we are as the squares and pentagons of Flatland, and we are being attacked by spheres, then they see and understand us in a way that we can never comprehend them. So, unless that extra-dimensional thing is a beneficent god, it’s a bad situation.
On the other hand, if there are extra-dimensional beings in our vicinity, then, if they didn’t like us, they would have gobbled us up long ago. Therefore, if they are out there, they are at least tolerating us. But are they going to instruct us in extra-dimensional travel?