# Methodology of Scientific Research

## The first story I read in the University

In my first day of classes, the student union gave us a newspaper with this story in the first page:

The following concerns a question in a physics degree exam at the University of Copenhagen:

“How could you measure the height of a tall building, using a barometer?”

## One students gave the following answers

“You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof to the ground.

The length of the string plus the length of the barometer will equal the height of the building.”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“Take the barometer up to the roof, drop it over the edge, and measure the time it takes to reach the ground.

The height of the building can then be worked out from the formula $$h = gt^2/2$$

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“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 building’s shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height.”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper.

The height is worked out by the difference in the gravitational restoring force $$T =2π\sqrt{l /g}$$.”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“Tying a piece of string to the barometer, which is as long as the height of the building, and swinging it like a pendulum, and from the swing period, calculate the pendulum length.”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“Or if the skyscraper has an outside emergency staircase, it would be easier to walk up it and mark off the height of the skyscraper in barometer lengths, then add them up.”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

“I would go to the building superintendent and offer him a brand-new barometer if he will tell me the height of the building!”

The professor said: “the answer is technically correct but does not demonstrate a knowledge of physics”

Measuring the pressure difference between ground and roof and calculating the height difference

This is how planes measure altitude

Air pressure reduces when we go up

## The story’s moral

• The same attribute can be measured through different physical properties

• Thinking “out of the box” enables measuring things that were not easy to measure before

## Homework

Read the short story “Funes the Memorious” (by Jorge Luis Borges).

You can find it on the web.

• Write the key ideas of the story
• In particular, answer the question: Do you want to have perfect memory? Why?