Yesterday, the noise my car was making got worrisome enough for me to drop it off at the repair shop. They offer a shuttle service so you don't have to sit around between tires and unidentifiable metal pieces all day. The shuttle driver asks for an address. "31 Caroline North," I say. "Aaah, Perimeter Institute! I watch your lectures when I can't sleep at night!" Interesting approach, I think, but some of them can put you to sleep very efficiently indeed.
"I've read Brian Greenes' book!" Here we go. "And Stephen Hawkings' book." Sure. And he hasn't even yet pulled out of the driveway. "Black Holes are SO fascinating. What are you working on?" We make it onto King Street. "Quantum Gravity?" - "Aaah, that is the thing with light going, like, around things, right?" He draws with his hands what I identify as the unavoidable marble on the rubber sheet with a bent trajectory around it, and almost drives headon into the oncoming traffic. "Oohm, no, actually, that's got nothing to do with Quantum Gravity, that's..." - "Then that's what String Theory is about, eh?" - "No not really, it's..." - "No? Then what is String Theory about?" Excellent question. How do you explain what physicists are doing at the beginning of the 21st century when the vast majority of people hasn't yet understood what physicists were doing at the beginning of the 20st century?
So I explain what by the 3rd semester every student of physics has heard so many times they can repeat it in their sleep. "We know that all the physics we observe is described by 4 forces. Three of them are quantized. Quantization is the story with the particle-wave stuff and the double-slit experiment and that kinda thing, I believe Greene and Hawking wrote something about that." - "Yes!" - "Okay. Now gravity is what makes apples fall and tells us how planets move around the sun etc. But it doesn't have any quantum properties." - "That's so exciting!" Gee, that light was very very dark yellow already. I really wish he would look at the street and not at me. "Yes. But it's a problem because we know quantum objects fall, yet we don't know how they do it. That's why everybody is trying to 'quantize' gravity, and that yet-to-be-found theory is called 'quantum gravity'."
"Aah! So that's what String Theory is about?" - "At least that's the hope," I say. "You mean, like, I think I read there's some problems with it?" Some problem? "Did you read Lee Smolin's book by any chance?" - "Lee Who?" - "Well, you see, if there were no problems and all was easy what would you need theoretical physicists for?" - "Hahaha, that must be so interesting, to work on that stuff." - "I'm not a String Theorist, but yes, it's interesting."
"I read there's like really many black holes! Even in our galaxy!" He is basically jumping up and down now in the driver's seat. "Yes, we have good evidence for that." - "Black holes are so interesting! I am reading Hawkings' book again." - "Did you read Lenny Susskind's recent book?" - "Lenny Who?" So at least ignorance is evenly distributed. "And they have like, different sizes and isn't that complicated?"
He is so excited, I feel really sorry for my personal disenchantment with the wonders of physics. Last week I was at Starbucks and a guy asked me what I'm doing. I tell him I'm a physicist. If I want to fly to the moon he wants to know. "Why would I want to be shot through the atmosphere in a metal box to stand on a dusty piece of rock? No, of course I don't want to fly to the moon." - "But wouldn't that be interesting?" - "What? There's nothing up there! Not even air. If you want interesting, you better stay down here." - "But you know when you dig 4 feet deep into the moon it's made of cheese!" I think Chad's dog might like that.
The shuttle driver eventually arrives at PI. He asks me to write down the names of the books I mentioned. I kinda forget about Susskind's book. He wishes me good luck with my research. Thanks, I say, thinking I really have to make the travel reimbursement for the APS meeting.