When in the car with my daughter, we noticed that wiht only one window open, travelling at about 40mph+, there was a sort of pulsing noise in the car, sometimes quite unpleasant on the ears.  Usually opening another window stops it, especially if on the opposite side of the car.  My daughter sits in the back, but the same effect happens whether it is her window or mine.  I guess this must be some sort of pressure wave, but we wondered what caused it.

When in the car with my daughter, we noticed that wiht only one window open, travelling at about 40mph+, there was a sort of pulsing noise in the car, sometimes quite unpleasant on the ears.  Usually opening another window stops it, especially if on the opposite side of the car.  My daughter sits in the back, but the same effect happens whether it is her window or mine.  I guess this must be some sort of pressure wave, but we wondered what caused it.

Curtains are traditionally made about 50% wider than the window opening, so they are thrown into folds or pleats. My friend says this is necessary to obtain optimum heat insulation. I say that the folds will just provide more surface area for air and heat to pass through. Who is right? What is the optimum configuration for a set of curtains?

Since Windows 3.0, the system has included at least one version of Patience (Solitaire). Can  anyone speculate as to:

• The number of man hours lost world wide to playing the game, as opposed to actually doing useful work.

• What could have been achieved if all the above lost time were used constructively to achieve a single goal, e.g. eradicating world hunger etc.

On looking at windows and car windscreens when it rains, I have noticed that raindrops tend to follow the previous paths of other drips when falling down the glass surface. Why is this?