Concave and Convex

In the last experiment, you saw how a car's curved passenger-side mirror changes the way that a reflection looks. Let's play around with curved mirrors again.


Find a large metal serving spoon whose surface is smooth enough that you can see your reflection. Hold the inside of the spoon toward your face and look at your reflection. What do you see? Surfaces that are curved in this way are called concave (remember this word by thinking of the inside curve as a "cave"). Now turn the spoon around and look at your reflection on the outside (convex) part of the spoon. Does it look different from the concave reflection?


Which side of the spoon looks most like what you saw in the car's passenger mirror reflection? Is that mirror concave or convex? Which side would be better as a magnifying mirror?