Critical Reasoning (CR) | Re: Because there are no habitable planets other than Earth in

Because there are no habitable planets other than Earth in our solar system and because it is unlikely we will ever have the capability to reach other systems, the conclusion that humankind will never colonize outer space seems justified. Consider, however, that every planet lies at the bottom of a deep gravity well. It not only takes energy to lift people and material out of such wells; it also takes considerable energy to lower them to the bottom in good working condition. Human beings need