如今已经发现了大量系外行星,而一旦我们得以区分出其化学组成,那时人类或许将会尝试派出恒星际飞行器前往查探,以便寻找生命存在的最佳候选星体。但是梦想归梦想,当考虑进行一次这样的考察之旅将会耗费多少能量时,就会感到大吃一惊。或许在遥远的未来真的会出现非常先进的,现在无法想象的推进技术,但是在这里,我们仍然使用基于牛顿物理的“作用-反作用”引擎为基础进行讨论。 Many extrasolar planets have now been discovered, and once we have been able to distinguish their chemical composition, mankind may try to send out a stellar aircraft to search for the best candidate for life. But dreams go to dreams, and when you consider how much energy you spend on such a tour, you’ll be taken aback. There may really be very advanced, unimaginable propulsion technologies in the distant future, but here we are still discussing based on the Newtonian physics-effect-reaction engine.