The Student and The Barometer

Some time ago I received a call from a colleague. He was about to give a student a zero for his answer to a physics question, while the student claimed a perfect score. The instructor and the student agreed to an impartial arbiter, and I was selected.

I read the examination question: "Show how it is possible to determine the height of a tall building with the aid of a barometer." The student had answered: "Take the barometer to the top of the building, attach a long rope to it, lower it to the street, and then bring it up, measuring the length of the rope. The length of the rope is the height of the building."

The student really had a strong case for full credit since he had really answered the question completely and correctly! On the other hand, if full credit were given, it could well contribute to a high grade in his physics course and certify competence in physics, but the answer did not confirm this.

I suggested that the student have another try. I gave the student six minutes to answer the question with the warning that the answer should show some knowledge of physics. At the end of five minutes, he hadn't written anything. I asked if he wished to give up, but he said he had many answers to this problem; he was just thinking of the best one. I excused myself for interrupting him and asked him to please go on.

In the next minute, he dashed off his answer, which read: "Take the barometer to the top of the building and lean over the edge of the roof. Drop the barometer, timing its fall with a stopwatch. Then, using the formula x=0.5*a*t^2, calculate the height of the building." At this point, I asked my colleague if he would give up. He conceded, and gave the student almost full credit.

While leaving my colleague's office, I recalled that the student had said that he had other answers to the problem, so I asked him what they were. "Well," said the student, "there are many ways of getting the height of a tall building with the aid of a barometer. For example,if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.

"Fine," I said, "and others?"

"Yes," said the student, "there is a very basic measurement method you will like. In this method, you take the barometer and begin to walk up the stairs. As you climb the stairs, you mark off the length of the barometer along the wall. You then count the number of marks, and this will give you the height of the building in barometer units." "A very direct method."

"Of course. If you want a more sophisticated method, you can tie the barometer to the end of a string, swing it as a pendulum, and determine the value of g [gravity] at the street level and at the top of the building. From the difference between the two values of g, the height of the building, in principle, can be calculated."

"On this same tack, you could take the barometer to the top of the building, attach a long rope to it, lower it to just above the street, and then swing it as a pendulum. You could then calculate the height of the building by the period of the precession".

"Finally," he concluded, "there are many other ways of solving the problem. Probably the best," he said, "is to take the barometer to the basement and knock on the superintendent's door. When the superintendent answers, you speak to him as follows: 'Mr. Superintendent, here is a fine barometer. If you will tell me the height of the building, I will give you this barometer."

At this point, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school and college instructors trying to teach him how to think.

The name of the student was Niels Bohr, who later received the Nobel prize for Physics.

An old occupation
What happens when people of different occupations get old.

- Old accountants never die, they just lose their balance.

- Old actors never die, they just drop apart.

- Old archers never die, they just bow and quiver.

- Old architects never die, they just lose their structures.

- Old bankers never die, they just lose interest.

- Old basketball players never die, they just go on dribbling.

- Old beekeepers never die, they just buzz off.

- Old bookkeepers never die, they just lose their figures.

- Old bosses never die, much as you want them to.

- Old cashiers never die, they just check out.

- Old chauffeurs never die, they just lose their drive.

- Old chemists never die, they just fail to react.

- Old cleaning people never die, they just kick the bucket.

- Old cooks never die, they just get deranged.

- Old daredevils never die, they just get discouraged.

- Old deans never die, they just lose their faculties.

- Old doctors never die, they just lose their patience.

- Old electricians never die, they just lose contact.

- Old farmers never die, they just go to seed.

- Old garagemen never die, they just retire.

- Old hackers never die, they just go to bits.

- Old hardware engineers never die, they just cache in their chips.

- Old hippies never die, they just smell that way.

- Old horticulturists never die, they just go to pot.

- Old hypochondriacs never die, they just lose their grippe.

- Old investors never die, they just roll over.

- Old journalists never die, they just get de-pressed.

- Old knights in chain mail never die, they just shuffle off their metal coils.

- Old laser physicists never die, they just become incoherent.

- Old lawyers never die, they just lose their appeal.

- Old limbo dancers never die, they just go under.

- Old mathematicians never die, they just disintegrate.

- Old milkmaids never die, they just lose their whey.

- Old ministers never die, they just get put out to pastor...

- Old musicians never die, they just get played out.

- Old number theorists never die, they just get past their prime.

- Old numerical analysts never die, they just get disarrayed.

- Old owls never die, they just don't give a hoot.

- Old pacifists never die, they just go to peaces.

- Old perfessers never die, they just lose their class.

- Old photographers never die, they just stop developing.

- Old pilots never die, they just go to a higher plane.

- Old policemen never die, they just cop out.

- Old preachers never die, they just ramble on, and on, and on, and on....

- Old printers never die, they're just not the type.

- Old programmers never die, they just branch to a new address.

- Old programming wizards never die, they just recurse.

- Old quarterbacks never die, they just pass away.

- Old schools never die, they just lose their principals.

- Old sculptors never die, they just lose their marbles.

- Old seers never die, they just lose their vision.

- Old sewage workers never die, they just waste away.

- Old skateboarders never die, they just lose their bearings.

- Old sailors never die, they just get a little dingy.

- Old Soldiers never die. Young ones do.

- Old steelmakers never die, they just lose their temper.

- Old students never die, they just get degraded.

- Old tanners never die, they just go into hiding.

- Old typists never die, they just lose their justification.

- Walt Disney didn't die. He's in suspended animation.

- Old white water rafters never die, they just get disgorged.

- Old wrestlers never die, they just lose their grip.