|Photo by Miroslav Duchacek CC-BY-SA-3.0|
Have you ever tried NOT THINKING ABOUT GIRAFFES? It's just hopeless. So here you go:
In special relativity, the passage of time depends on your frame of reference. Time is relative, and simultaneity of events can't be defined except relative to their respective reference frames.
So suppose I take a book with me on a spaceship that moves at 99.99% the speed of light relative to your reference frame. Then every day that elapses for me is about 71 days for you. In two years or so, the book goes out of copyright, and the next planet I visit, I can make copies for every sentient being I can find.
Seems a lot of trouble when I can just put it on BitTorrent.
Ah, but imagine that I'm a world-famous trillionaire author, and I'm worried about the day when my best-selling novel goes out of copyright, and everyone can just rip me off? All I have to do is buy myself a spaceship and go for a vacation. Since my copyright won't expire till 70 years after my death, my hypervelocity excursion will dilate my copyright term for a long, long time. When I get back a year from now (in my reference frame), 71 years will have elapsed on earth, and with the royalties I'll have earned (plus interest) I can probably acquire every other book on the planet. And both houses of Congress. I won't have aged much, so I'll just go on another interstellar jaunt. Rinse and repeat.
Start saving up, Jo Rowling.
For the rest of us, the bright side of this is that we can be pretty sure that copyright law will get be updated at least before interstellar drives are perfected.