Here’s what bothers me about time travel movies: When faced with someone claiming to be from the future, people will express disbelief for maybe a minute or two. After that, it’s all, “Oh please, Captain Tomorrow, please stop those killer robots from destroying the high school gym and ruining my prom!” Of course, I might also say, here’s what bothers me about the real world: When faced with someone claiming to be from the future, we never, ever believe him. I mean, what if that guy we committed to a psych ward actually were from the 25th century or wherever and had something vitally important to tell us? Where would we be then? I was reminded of this the other day when I read about a would-be saboteur arrested outside the Large Hadron Collider in Switzerland. The suspect, Eloi Cole, claimed he had traveled back in time to prevent the LHC from destroying the world, the website CNET UK reported. “The discovery of the Higgs boson led to limitless power, the elimination of poverty and Kit-Kats for everyone,” Cole said, according to police. “It is a communist chocolate hellhole and I'm here to stop it ever happening.” I didn’t realize at first that the article was published on April Fool’s Day of last year (in all fairness, neither did the person who forwarded it to me), and my initial reaction was, “Hey, what if this guy is for real?” I mean, the bit about Kit-Kats seemed a little far-fetched, but maybe that was somehow code for, “Everyone and everything in this world will be sucked into a black hole created right here.” Anyway, it got me to thinking: What if we could go back in time and prevent or even just witness a particular optics-based invention or innovation? What would we choose? I might travel back to 1976, to a Blue Öyster Cult show on the Agents of Fortune tour, to see guitarist Buck Dharma in one of the very first laser light shows at a rock concert. Mostly just because that would be cool to see. Or maybe I would go back to the invention of the laser pointer and find a way to lock out dumdums who would otherwise think to point them at movies screens and airplanes. Not exactly saving the world, but still a benefit to society. What do you think? Where and when would you go if you could travel back in time, and what would you do?