Yes, by peacefully and politically resolving the issues between India and Pakistan a lot of the "defense" expenditure and human and material resources can be redirected towards space exploration.
About radiation shielding I once read that at least on the Moon a below ground shelter built from lunar soil / regolith it has to have a correct amount of the soil as cover. Too less and the cosmic radiation penetrates. Too much and the soil itself generates secondary radiation by reacting with cosmic radiation.
Secondly, I wonder how SpaceX is intending to take care of radiation shielding on its Starship that can supposedly carry 100 people to Mars orbit. Do they intend to use water as the shield or some novel in-development material ?
What does that mean in simple words ?
Another thing. In Faster Than Light travel, or even somewhat less than it ( through Warp Drive ? ), how does the spacecraft detect and avoid collision with asteroids, other spacecraft or diving into planets, suns and gas fields ?
living underground is one option but you have already highlighted the issue "what of radiation in the soil"?, living underground is a temporary solution. How effective it proves against cosmic radiation in the long term.
Other option is terraforming the moon and mars but that again is a monumental task both in terms of scientific, logistic and financial terms.
I haven't read much on SpaceX Starship but within the current scientific capabilities I would assume multiple layers of outer hull mixed with lot of lead and may be water but here comes the next challenge every ounce increase as mass of the ship reciprocates in a larger spend of reaction mass. Unless of course we as humans could come up with more efficient propulsion system I don't know fission, fusion, antimatter, dark matter or quantum.
Now about alcubierre, according to special theory of relativity "mass" cannot exceed/approach the speed of light (remember e=mc squared) instead of travelling in space ina straight line according to alcubierre space will be bend.
Imagine a flexible stick, an ant (human space ship) travelling from one end to the other will take a lot of time but if we bend the stick in a circle (so to speak) the ant can simply jump from one end to the other in the blink of an eye. But then again the energy requirements are not just monumental they are beyond human scale so far.
Now the bigger question can anyone travel more than speed of light, there isn't too much of a conflict between religion and science its only that the religious fraternity has always been ignorant (so to speak regardless of which religion they are from), Prophet PBUH during mairaj travelled to 7th sky, but when he came back the water he used for oblution before Jibrail knocked was still flowing and that travel did cost him 27 years of his life. What happened did the time become zero means the universe stopped or did he travel at a speed beyond human imagination or scientific proof, some points to ponder about. All three major religion with scripture based upon "revelation" speak about 7 skies, but Quran also mention that what we see in the sky (the stars etc) is the first sky so what actually are 7 skies, may be 7 dimensions.....
Personally I think space travel is extremely inefficient over large distances, may be we see singularity linked gates (black hole) or quantum teleportation linked gates, linking one planet to the other, just few thoughts....
