[originaltext]M: Have you heard that in another few years you may be able to bu

M: Have you heard that in another few years you may be able to buy a car that changes colors every day to match the outfit you are wearing?
W: Oh, please be serious!  I suppose they will change shapes as well. If you want a big car to take all your friends camping, I suppose you’ll just be able to snap your fingers and make it happen. Or if you want a sporty two-seater, you could just tell the car what you wanted, and it would do the rest. Is that how it will work?
M: No, I am serious. They have found a way to alter the surface of metals so that they can reflect different colors just by passing a small amount of electricity over them.
W: Oh, I see. So anything that touches the outside of the car will get a shock. That sounds lovely.
M: It’s only a tiny amount of electricity. It wouldn’t be enough to shock anybody.
W: Well, it sounds pretty difficult to believe.
M: Yes, it’s quite amazing. The important thing you have to remember is that the color of an object is really just an illusion created by the way light bounces off its surface. Engineers have been able to produce a car that changes colors at the touch of a button by slightly rearranging the position of the particles on the surface of the metal.
W: It sounds so amazing. But I guess it could be possible.
M: It is possible today. The only problem is that it is very expensive. To produce a car with a surface that changed colors would cost almost twice as much as what a regular car costs. For that much money you could just by the car and have it repainted twenty times, so it’s not very practical yet.
W: Yes, but in other ways it could be more practical. If you took your car to be painted twenty times, it would use quite a bit of polluting chemicals, and it would take a long time.
M: You’re right there, but how many people really get their car repainted that many time?
W: Hmm, I suppose you’re right, but I sure would love to have my car match my outfit every day.