Imagine a world where a trip to the moon is as easy as running to the grocery store. Visiting nearby stars might be a routine cross-galaxy flight, and you may even have a layover at a galactic travel hub on a place like Batuu from Star Wars. In this imaginary universe, many stars and planets would be connected, and their societies could communicate as a part of a galactic civilization.
Given our limited spaceflight capabilities, it might seem obvious at first why this hasn’t happened. It took even one of our fastest small probes (New Horizons, which visited Pluto in 2015) almost 10 years to get to the outer solar system, and we haven’t yet sent humans any further than the moon (and that was back in the 1970s). With our current technology, it would take around 100 human lifetimes to cross the unimaginably large four light years to our nearest neighbor star, Proxima Centauri.