PRO-box thinking

One day Ernectu Rutherford, president of the Royal Academy, asked a colleague for help. He was going to put the lowest rating on the physics of one of its ...



One day Ernectu Rutherford, president of the Royal Academy, asked a colleague for help. He was going to put the lowest rating on the physics of one of his students, while he claimed to be a perfect score. Both - a teacher and a student - have agreed to rely on the judgment of a third party, disinterested arbitrator. The choice fell on Rutherford. I read the examination question: "Show how it is possible to measure the height of a building using a barometer?».


The student had answered: "Take the barometer to the roof of the building to pull down the barometer on a long rope, and then bring it up, measuring the length of the rope, which show the exact height of the building».

The case was really complicated, because the answer was absolutely full and faithful! On the other hand, the exam was in physics, and the answer has little to do with the application of knowledge in this area.

Rutherford suggested that the student try to answer again. Giving him six minutes to prepare, he warned him that the answer should show some knowledge of physics. After five minutes the student has not written anything in the examination sheet. Rutherford asked him if he gives up, but he said that he has a few solutions to the problem, and he just chooses the best.

Intrigued, Rutherford asked a young man to begin to answer without waiting for the allotted period.

A new response to a question read: "Take the barometer to the roof and throw it down, measuring the fall. Then, using the formula, calculate the height of the building ».

Then Rutherford asked his colleague teacher, if he was satisfied with this answer. He finally gave up, recognizing the response satisfactory. However, a student mentioned that he had other answers, and he was asked to open them.

- There are several ways to measure the height of a building using a barometer, - said the student. - For example, you can go outside on a sunny day and measure the height of the barometer and his shadow, and measure the length of the shadow of the building. Then, deciding simple proportion, determine the height of the building.
- Bad, - said Rutherford. - There are other ways?
- Yes. There is a very simple way, which, I am sure you will enjoy. You take the barometer up and climb the stairs, putting the barometer to the wall and making a mark. Count the number of marks, and multiplying it by the size of the barometer, you will get the height of the building. It is quite obvious method.
- If you want a more sophisticated way - he continued - that tie the barometer to a string, swing it like a pendulum, and determine the value of gravity at the base of the building and on its roof. From the difference between these quantities, in principle, it is possible to calculate the height of the building. In this case, however, tied to barometer lace, you can climb to the roof of your pendulum and swing it to calculate the height of the building over a period of precession.
- Finally - he concluded - among many other ways to solve this problem better, perhaps, is this: Take the barometer with, get the manager and tell him: "Mr. Manager, I have a wonderful barometer. It's yours, if you tell me the height of this building ».

Then Rutherford asked the student if he really did not know the conventional answer to this problem. He admitted that he did, but said that fed up with high school and college instructors trying to teach him how to think, which is not always accept non-standard solutions.

This student was Niels Bohr (1885-1962), Danish physicist and Nobel laureate 1922