Brain Teasers

1. Will a candle burn in a space ship where everything is weightless? (Due Week Two)

2. A glass flask of an irregular shape contains a certain amount of liquid.  Is it possible to tell, without any measuring device or container, whether the flask is less than half full? (Due Week Three)

3. A spiral made of 35 matchsticks is wound clockwise.  Shift four matches to rewind it counterclockwise. (Due Week Four)

4. Sea captains wouldn't fill their holds completely when they transported cotton from Australia to England.  It would have been to their advantage to take as much as they could, but they didn't.  Why not? (Due Week Five)

5. A steel ball floats in mercury.  Will the depth of the immersion increase or decrease as the temperature rises?  Why? (Due week Six)

6. A scuba diver loses his bearings deep in the ocean.  How can he tell which way to go to get to the surface? (Due Week Seven)

7. The smoke we see consists of small particles of unburned fuel.  Each of the particles is much heavier than air.  So why do they fly upward? (Due Week Eight)

8. Once you got lost in a forest.  You were going to make a fire and spend the night, but fortunately, you found a water pipe.  Obviously you should go along the pipe, but in what direction?  In the direction of the water flow, since the water goes to people.  But how could you determine in which direction the water was flowing? (Due Week Nine)

9.  In some antique clocks intended for operation in the open air, the pendulum was a long tube with a container of mercury at the bottom.  What was the purpose of the design? (Due Week Ten)

10. Can astronauts use a ballpoint pen on board a spacecraft?  What about a fountain pen?  What design would you recommend for a "space pen"? (Due Week Eleven)

11.  Mountaineers say that high up in the mountains, twilight is noticeably shorter than down on the plains. What is your opinion for the reason for this? (Due Week Twelve)

12.  Two identical laboratory pipettes are filled with water to the same level.  The water is cold in one pipette and hot in the other.  As the pipettes are emptied, the drops are counted.  From which pipette will more drops fall? (Due Week Thirteen)