The Last Question and The Last Answer by Issac Asimov. I like how you can read a lot of his short stories in under 30 minutes, but they address really existential concepts and make your brain hurt for a good while afterwards.

If we assume a linearly proportional scaling on the EmDrive (3kW per N), and we assume that Lockheed Martin's Fusion Reactor actually works and gets built in the next 15 years, we could realistically see spacecraft with pseudo-unlimited energy generation powering an EmDrive at over 30,000 N of thrust... Even at lower efficiencies it could theoretically generate enough thrust to escape Earth's gravity well.

* I'm not a rocket scientist or anything but we could totally see long-distance space travel become reality in the next 100 years!