Yet another bad problem we need to keep in mind is the resulting needed big vessel size to transport many decades or centuries of supplies. (At least a little protectively, make the vessel quite long and not very wide.) Such a big high speed vessel would be at bad risk of a crash into any significant not small interstellar space junk. At any wanted speed being a significant fraction of light speed, that would likely badly destroy the vessel and kill all not yet aged to death.
Or traveling slower would mean all would certainly uselessly age to death after many boring centuries confined in the vessel. So it would be stupidly useless to attempt such a futile voyage. Of course pre-2000 SF (science fiction) had never wanted to accept such bad realities. To survive sellable to many fans, SF had to instead dream up wishful false nonsense unrealities like magical jumps across space, or unrealistic interstellar leaps far faster than light speed. (SF wasn't confined to doable realities. It was primarily just entertaining fiction, something almost like magical children’s' fairy tales, but here dreamed up for adults.)
But when "moderns" (genetically advanced beyond old natural humans) may become developed, initially to acquire perfect health, then to slow, then halt aging, then to even nicely reverse ages back to good healthy mid 20s, by then an eventual way to escape some far space risky travel problems might be to next devise a noncellular life form which "moderns" may transform into, a life form which has no living aging cells forever needing new replacements, while gaining needed living energy converted from average body temperature heat, thus not needing any daily grown food. There seems no reason why such a new extremely efficient invented alternative life form should forever be impossible.
Also this might become a life form which can basically turn off living for even decades, a bit like some winter frozen animals, letting such new more advanced noncellular moderns then travel effectively shut down for centuries. Similarly for advanced interstellar aliens. Why should anyone argue that no effective life forms can ever allow anything except only evolved Earth type or alien home planet type mortal aging cellular life forms? Internal body details should matter little. It's conscious thinking brain functions which lets us do as we like, and continually happily live well and technologically advance.
This is a guest post. Ask Iwas.A.Member@gmail.com .If interested in much more about advanced future folks living quite well in space, ask for DOS compressed email attached FBW.Z
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