Interstellar travel is a delusional pipe dream. Microgravity does terrible things to the human body. Unless we figure out a way to make artificial gravity (no, a spinning disk is not enough) humans will likely never travel to another star system. Interstellar travel is not practical and not plausible because biological life forms are fragile and inefficient. Humans are not evolved for space. Even inside a spacecraft we’re at the mercy of gravity (microgravity) and the effects of that on our bodies. We could not survive a generation-long trip to another star system, and even if we did survive, we’d be unhealthy and likely pass that one to the next generation of humans born aboard the spaceship. We don’t even know if humans can gestate in microgravity. How would that affect the fetus? We don’t know. Interstellar travel is a pipe dream and humans will likely never see another star system. It’s NOT that it’s impossible. It’s that biological life is too fragile and inefficient. Biological life is not evolved for prolonged exposure to microgravity. And that’s just ONE of the major problems. Radiation, vacuum, extreme heat and cold, dangers of impact with meteoroids/asteroids/comets. Air, food, water, and nutrition. All problems, though solvable, they’re highly impractical and cost prohibitive long term. Then you have the time dilation problem. That’s a BIG one if you’re expecting a round-trip. HAHAHAHA! People have no idea. We are stranded on earth and trapped within our solar system. Escape is futile. At least for biological life. Genetically engineered, technologically augmented, pharmaceutically enhanced humans MIGHT be able to travel to another star system, but we’re a long way away from that point technologically speaking. This is why I think that if aliens exist (which I think they do) and they have interstellar travel capability, then they are likely not biological life forms; or if they are…they are highly genetically/technologically and pharmaceutically engineered. Which over the long term, makes no sense. The biological portion of their bodies would be inefficient and would post a long term risk to survival and failure of mission to reach another star system. Danger and risk of failure and inefficiency would dictate such civilizations would evolve themselves into machines. Likely enhanced by AI. It’s the only logical hypothesis without creating anti-gravity. So which is more likely? Antigravity or merging with technology to become technologically immortal? Technological immortality would solve the biological fragility and impracticality problem. Merging with AI and evolving into machines would negate and solve the time dilation problem, and every other problem that biological entities would have. Logic and physics, chemistry and biology and the economics of interstellar travel dictate that biological technologically advanced civilizations evolve into machines to achieve the capability of interstellar travel. This is why I think humans will never reach another star system. It’s not that I think interstellar travel is impossible. It’s clearly possible. I just think it doesn’t make logical sense for biological life forms. Too many hurdles to over come and merging with technology becomes the easier and faster way to get the another star system. We will be forced by physics to evolve or die.