First off, there are many adversities faced when the topic of interstellar travel rises. There are just too many issues to make interstellar travel viable, in our life times and possibly, ever. There is the issue of propulsion, as our traditional means of getting from point A to point B doesn't really cut it when moving across the vast distances of space. There are viable methods, like wormholes and Alcubierre drives, but they're entirely theoretical. Other problems like protecting the shuttle from radiation and space debris and something known as The Wait Calculation really don't make things better. The list goes on, which brings me back to my question...
Is it probable?
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Yes... Just think, we used to think it was impossible to get to the moon, but we did. We thought the earth was the center of the solar system, but we proved otherwise. We used to think earthquakes and volcanic eruptions happened because we pissed off the gods... Everything we doubt is impossible is only because our current limit in technology and intelligence. 100 years from now, I guarantee that we'll have accomplished something that we currently think is impossible. As long as we don't end up killing each other and the planet first, we can do anything.