Creativity and humour: barometer and goalkeeper.

Translator: Gordon Burt


Niels Bohr was one of the great physicists of the twentieth century; perhaps the most profound thinker. And he liked football. His brother Harald won a silver medal at the 1908 Olympic Games. Niels played goalkeeper, not too badly.

However, he had certain "shortcomings" which worried his teams supporters; and his very teammates.

It is said that in a game against a German team, dominated completely by Niels’ side, the ball rolled toward the Danish goal. Niels had not noticed: hewas absorbed, making note of something on one of the posts, unaware. The public behind the goal, always alert to his eccentricities, started to shout. At the very last moment, Niels returned to reality and stopped the ball.

Later, embarrassed, he apologised in the changing rooms, explaining that a very interesting mathematical formulation had come to mind and he was unable to overcome the compulsion to write the verification down, forgetting about the game.

Niels has gone down in history thanks to his many merits. He set up the world’s most important laboratory, his contributions won him the Nobel prize and, as a person, he was simple and friendly. As well, he had a sense of humour.

When a young, unknown student, Niels was asked, "How would you measure the height of a skyscraper using a barometer?" He replied, «tie a long string to the barometer and hang from the top of the building. When it reaches the ground, measure the string and the barometer, and the figure is the height of the building».

Understandably, the teacher felt that the response made fun of him, and he failed Niels. The student protested, arguing that his proposal was completely logical. A board found that, while the answer was formally correct, it did not demonstrate even minimum understanding of physical science, and decided to summon him and give him 6 minutes to see if he had the correct response.

After 5 of the 6 minutes, Niels seemed to be absent, silent. A teacher, by now nervous, called on him to say something. The student emerged from his engrossment and apologised: the problem was that he had several answers and did not know which to choose.

"In the first place, the barometer could be taken to the top of the skyscraper and dropp

ed over the side, measuring the time it takes to reach the ground. The height of the building could then be calculated using the formula H=0.5gt2. But it would be the end of the barometer!

Or if the sun is shining, the height of the barometer could be measured, then standing it on its end and measuring the length of the shadow. Measure the length of the skyscraper’s shadow and it is then a simple question of proportional arithmetic to calculate the skyscraper’s height.

But, if one wished to be very scientific, a short length of cord could be attached to the barometer, allowing it to swing like a pendulum, first at ground level and then on the top of the skyscraper, calculating the height by the difference in the gravitational restoring force T=2π(l/g)1/2.

Or if there is an outside emergency staircase on the skyscraper, it would be easier to go up, mark the height of the skyscraper in barometer lengths, and then add them up.

Of course, if you simply want to be tedious and orthodox, the barometer could be used to measure the air pressure at the top of the skyscraper and on the ground, converting the difference in millibars to metres to find out how high the building is.

However, as we are continuously urged to display mental independence and apply scientific methods, no doubt the best procedure would be to knock on the caretaker’s door and say, «if you’d like a nice new barometer, I’ll give you this one if you’ll tell me the height of this skyscraper»".

This and many more anecdotes can be found in the book "Eurekas and Euphorias" by Walter Gratzer (translated by Javier García Sanz), Ed. Crítica, Drakontos collection.

Antonio Carrillo