All you need for this trick is a twenty-five-cent piece and a small postage stamp. Put the stamp on the desk and hold the quarter horizontally about half an inch above the stamp. Now blow hard down onto the quarter.Now blow hard down onto the quarter.
The most famous tunnel is the thirty mile “Chunnel” between England and France. Thirty miles of air is a lot to push around, so engineers have come up with a clever solution. The Chunnel is actually two separate tunnels, connected by cross passages.