Lights come up on: the living room of Albert Einstein’s small clapboard house near the Princeton Institute of Advanced Study. It is the winter of 1937. For the last three hours Einstein and Niels Bohr have been sitting together in uncomfortable chairs and continuing their debate, begun at the 1927 Solvay Conference in even worse chairs, about whether objects exist when no one is around to observe them. Einstein, now and then giggling as he draws on an unlit pipe and sips from an empty coffee mug, has been maintaining that of course they do, or why pay to insure them? Meanwhile Bohr has grown increasingly exasperated, to the point of wishing he had bypassed Einstein’s and were frolicking in the indoor pool at the Holiday Inn Express down the road. Why wouldn’t the father of relativity admit that without an observer, there were no objects to speak of at all? Einstein, sensing his guest’s rising irritation, decides to change tacks.
EINSTEIN: I propose a little thought experiment, Niels, to clarify the situation.
BOHR: I smell a trap, Albert. I know your thought experiments can be very subtle. I will need to keep my wits about me so as not to be deceived. But I agree to listen.
EINSTEIN: Excellent. Then imagine my closed garage, right outside at the end of my drive. Now imagine it full of light. Now imagine a single photon escaping through the garage window and striking you in the eye. Now picture what you then see: a brand new Squire Drophead Coupe, yellow, with chromium wire wheels.
BOHR: Are you referring to the 1600 model that has a supercharged engine, a live rear axle, four-wheel hydraulic brakes, and reaches a top speed of 115 mph?
EINSTEIN: Nothing else. It’s out there in my garage. And you forgot to mention the custom dual-pipe exhaust. It’s a gas.
BOHR: A gas? You mean it obeys Boyle’s law of pressure and volume? But look here, Albert, are you licensed to drive in New Jersey?
EINSTEIN: I had my papers airmailed from Berlin. But Niels, you miss the point. The car actually exists in my garage, unobserved.
BOHR: Then let’s go for a spin!
EINSTEIN: Alas, I am too tired at the moment. Let’s share a couple of bowls of ice cream and then have a little nap. I’ll feel more rested then.
BOHR: Ice cream! We don’t serve that in Denmark anymore due to the cone shortage. Do you have sprinkles?
EINSTEIN: No, and no cones either. I have bowls and spoons only.
BOHR: In that unfortunate situation, let’s go on talking a while. I have a thought experiment for you to consider too, my dear Albert, while I continue to ponder your coupe.
EINSTEIN (helping himself to tobacco though his doctor has forbidden it): Shoot.
BOHR: Imagine this time there are two cars. One is your magnificent yellow roadster, sitting at rest in your garage, just as you propose. It really is there, of course?
EINSTEIN: Of course. I said it was, didn’t I?
BOHR: Fine. Now imagine that a second car, a sassy red Bugatti Type 57, approaches your car at half the speed of light.
EINSTEIN: Wait a moment. This Bugatti…does it have a horseshoe grille, thermostatically-controlled engine shutters, a twin-cam engine, and a five-year power-train warranty?
BOHR: It is loaded. It’s got all the bells and whistles and an excellent warranty. And now the astonishing thing…it is mine. I parked it not twenty yards from your door when I arrived this morning to visit you. I bought it as soon as I stepped off the boat today in New York, and drove it here in under an hour, tires smoking.
EINSTEIN: I never thought to inquire how you got here. To think there is a car finer than mine in Princeton, and you are its owner! How the hell much does the Institute pay visiting Danish lecturers, anyway?
BOHR: Easy, my friend. Did you really not anticipate my rejoinder?
EINSTEIN: I demand to see this automobile at once!
BOHR (withdraws a folded magazine from his jacket pocket and tosses it Einstein’s way): That’s the latest issue of American Auto, dated January 1937. You’ll find the car on page 31 just as I described it, except the part about its belonging to me and being parked outside. You’ll agree that in the abstract it’s just as much…a gas, as you say?
EINSTEIN (uses the magazine to swat a large fly that has alit on the wall beside him, then tosses it back to Bohr): Very clever, Niels. You had me going there for a moment. I should have realized that a thought experiment is only a thought experiment.
BOHR: I now claim a ride in that yellow coupe of yours. And if you are too tired to drive, I will take the wheel. (Produces a pair of aviator goggles.) I even brought some goggles with me so I can roll the window down. I always bring a pair when I travel in case I have a chance to fly in a biplane.
EINSTEIN: Um, about the coupe. I confess my garage is empty of all matter, even of light. You see, my friend, I actually did purchase that splendid coupe two days ago, but yesterday decided I couldn’t meet the monthly payments and returned it to the dealership, well within the three-day grace period following purchase. I’m sorry if this news comes as a disappointment. (Glances at his watch.) But if you’ll be patient another few seconds…until three o’clock to be precise…I should have a favorable update for you.
(At three precisely there comes a loud knock on the door. Einstein opens it to reveal Heisenberg, a young red-headed man who speaks in a heavy German accent.)
HEISENBERG (standing in the door): Dr Einstein? I’m Heisenberg from the car dealership. We spoke the other day about finding you a preowned car after you returned the yellow coupe. Well, professor, I tried to compare the price of the car to the mileage on the odometer, as you requested, and I made an amazing discovery. I can’t specify the mileage without knowing the price you’ll pay, and I can’t specify the price without knowing the car’s mileage. In other words, I can’t give you both the price and the mileage at the same time.
EINSTEIN: I’m willing to pay up to eight hundred dollars for a car with less than a hundred thousand miles on it. What’s so hard about that, Heisenberg?
HEISENBERG: It depends on what’s on the lot, is all I’m saying. But I should have something for you in a day or two.
BOHR (to Einstein): The sole difficulty I detect would be if you insisted on paying only eight hundred dollars for a Drophead Coupe. Think what sorry shape the tranny would be in!
HEISENBERG (taking in the two men): What about a couple of mopeds for four hundred? I can bring them around tomorrow morning.
EINSTEIN and BOHR (together): Deal!
EINSTEIN: As long as they’re flex-fuel.
HEISENBERG: Flex-fuel? Was ist das?
EINSTEIN: Just a little proposal of mine to be published in next month’s Physics Today.
BOHR: It’ll never work.
(As the scientists move on to other topics and Heisenberg exits: blackout.)