About the best a time-traveler can hope for is to metaphorically step on a butterfly that doesn’t have too big an effect on the future. As such, let’s take a moment to commemorate these ...

It's a lot like the Time Traveler game you just played. Let's try it out with a pair of pretend twins, Al and Bert, both of whom are 10 years old in their highly futuristic universe. Al's parents ...