@eb6c2683 On aliens as intelligent, technological creatures from other star systems - again, known Physics hints in every which way that emergence of life wherever anyhow possible will happen and that life will constantly evolve to more&more complex forms. Aliens certainly exist. Even current human tech' have already found completely Physical method for essentially unlimited travel speed - Alcubierre  Drive. We just have no tech to create it but, as it is possible someone out there certainly did