“If it doesn’t agree with experiment, it’s wrong. That’s all there is to it”

This a guest post from Jeremy Leaf, a third year PhD student in the School of Physics and Astronomy at the University of Nottingham and a member of the ENTHUSE project team.


It is one of our first electronics sessions. An Ethiopian teacher is learning how to use a multimeter and breadboard. Having measured the resistance of a number of discrete resistors using a multimeter, I suggest he try to measure them in series using the breadboard. He chooses two resistors and, on paper, calculates what the total resistance should be. He then carefully measures across both resistors in series. The teacher’s face lights up as he breaks into a wide smile. The theory is correct.

The process of learning a physical theory, and then observing it manifest itself in an experiment, is a vital pathway to understanding physics. It allows us to grasp difficult concepts and truly understand their nature. Unfortunately, in Ethiopia, physics education stops at the textbook. The education system has neither the funds nor expertise to employ physical experiments in their schools. Our assignment was to show how experimental physics could be taught using locally available materials. We also employed some more advanced apparatus, such as multimeters and breadboards, in the hope that they would be able to acquire these in time.

Simple apparatus and experimental concepts that we take for granted are often totally new to many physics teachers in Ethiopia.  This project was an exciting opportunity to make a small but meaningful impact on the futures of those who go to school here, as well as forge a link between our two countries. Education is key for this country to develop a generation of young Ethiopians that can think critically and creatively. I feel immensely privileged to have been a part of that process.

Author: Philip Moriarty

Physicist. Rush fan. Father of three. (Not Rush fans. Yet.) Rants not restricted to the key of E minor...

3 thoughts on ““If it doesn’t agree with experiment, it’s wrong. That’s all there is to it””

  1. I sympathize with the intent of the title, but it is too simple. The opposite extreme is Eddington’s quip that no experiment should be believed until it has been confirmed by theory.

    The point is that some experiments are wrong. Sometimes the interpretation is wrong. Sometimes everything is OK but one just happens to have observed an outlier.


  2. “Experiment” shouldn’t be interpreted literally in the sense of a single experiment (and it’s clear from Feynman’s quote that he didn’t mean this). The key thing is that if a body of experimental evidence rules out a particular theory, it’s dead or it needs reworking.

    Experiment/nature is the final arbiter. Otherwise, we can postulate whatever fanciful theories we like and we’re into the realms of philosophy, metaphysics, or religion rather than physics.


    1. I agree completely, of course. However, in popular media the impression is often created that one single finding can “cause the textbooks to be rewritten” and so on, which is usually not true.


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