Traveling to other solar systems seem pretty easy in the movies, but in real life, it could get quite complicated. First of all, the closest star system to us is Alpha Centauri, which is 4.37 light-years away, which is very far from us even if we can travel at the speed of light. But even traveling close to that speed is a problem. The fastest manmade object in history was the Parker Solar Probe that reached speeds of 430,000 miles per hour using the gravity of the sun to accelerate it. That speed is only 0.064% of the speed of light! So maybe we could just use normal rockets to get there? Well, accelerating a spaceship to a tenth of the speed of light would take 4.50×1017 joules, which is about twice the yield of a hydrogen bomb. So reaching a fraction of the speed of light requires a dangerous amount of energy, so it seems like visiting the closest star system is impossible at the moment, let alone other galaxies.

From a TA: There was a proposal in 2016 called Breakthrough Starshot where many tiny probes would be launched into space and accelerated by lasers on Earth towards Alpha Centauri. With this method, the probes are expected to fly by Alpha Centauri in a timespan of ~ 20 years. https://breakthroughinitiatives.org/initiative/3
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