Why is red wine served in a glass that is shaped differently from a white wine glass?

Why is red wine served in a glass that is shaped differently from a white wine glass?

Red wine is supposed to be served at room temperature, while white wine should be cool. This means that the smell of red wine is much more important (cold wines don't give off much of a smell). So the glass should be big enough to leave room for the smell to build up over the wine. Many wine experts recommend serving 6 fluid ounces of red wine in a 10 fluid ounce glass. With white wine on the other hand, the glass can be just big enough to take the wine.