Category Archives: Science

How To Think Like A Scientist

Wilson Greatbatch was an American engineer and inventor, who had more than 150 patents to his name over his lifetime. His most famous invention is the implantable Pacemaker, which has saved countless lives since it came out. But it almost didn’t happen!

Greatbatch was working on a device to record heart sounds, when he accidentally installed the wrong resistor and realized that the device was now giving off rhythmic electrical pulses. He realized at that moment, that he had hit on something important. Pacemakers before that time were bulky devices that worked on power mains, but Greatbatch’s discovery showed that they could work with battery and could be made small enough to be implanted.

While this may seem at the surface to have been an accidental discovery, Greatbatch was really thinking like a good scientist. Kevin Dunbar and Nancy Nersessian, have studied scientists and their thought processes for many years, and have distilled the core thinking patterns that underlie creative scientific thinking. Here are a few strategies and techniques that they believe lead to better scientific accomplishments:

Unexpected Results

Accomplished scientists have often mentioned the role of chance in leading to a discovery. But what distinguishes great scientists from average ones is how they pursue the unexpected results. As Dunbar explains, a good heuristic to go by is, “If the finding is unexpected, then set a goal of discovering the causes of the unexpected finding.

To investigate an unexpected finding, scientists have to pay attention to the finding and recognize that it could lead to some new learning first. It turns out that some scientists have a tendency to make serendipitous discoveries. Sandra Erdelez, a scientist at University of Missouri, has been studying this for many years and found that some people, called the encounterers, have a tendency to stop and “collect” useful or interesting information they bump into. Based on their individual differences in bumping into unexpected information, she classifies people into three types – non-encounterers, occasional encounterers and super-encounterers.

Analogical Thinking

One of the most useful cognitive techniques frequently used in science is analogical thinking. Rutherford-Bohr’s analogy between solar system and atoms or Newton’s analogy between projectiles and moon helped those scientists construct a better model.

Analogies have helped with different aspects of scientific thinking like generating models, designing experiments or formulating hypotheses. As Dunbar explains, “We have found that rather than trying various permutations on a question, the scientists search for a similar problem that has been solved and seek to import its answer to their current problem.” The advantage of analogical thinking, is that it helps the scientists come to a solution quickly by avoiding iterative trials.

Imagistic Reasoning

Imagistic reasoning makes use of images to help in analyzing and understanding a phenomenon. For example, Faraday’s starting point in constructing his field concept was using an image to represent the lines of field like those that form when iron filings are sprinkled around a magnet. By using a more idealized representation through an image, he was able to capture the underlying model.  

Nersessian believes that imagistic reasoning, along with analogical reasoning and thought experiments are part of “abstraction techniques” and help construct a model of a scientific concept.

While most people are familiar with analogical reasoning, As Nersessian explains, “…there are numerous cases that establish the prominence of reasoning from pictorial representations in the constructive practices of scientists who were struggling to articulate new conceptualizations. Such imagistic representations have often been used in conjunction with analogical reasoning in science.


Research in over a decade has demonstrated the significance of these cognitive techniques and strategies in science, and should be included in science education.

We are excited to launch a new middle school science program in partnership with Positive Ally, starting this coming academic year. Our goal is to bring these cognitive techniques to the forefront to build deeper understanding of scientific concepts and help students apply their thinking in solving real world problems.

Thought Experiment: A Creative Exercise in Science

One day at the Cathedral of Pisa, Galileo who was still a teenager, watched a chandelier that a monk had just lit swinging in an arc. Using his medical training, he started timing the motion and discovered that even though the swing got shorter and shorter, the time of each swing stayed the same. That observation so excited him, that he rushed back home to experiment with strings and weights, and it eventually led to a life long fascination with pendulums and motion.

But one of his most interesting discoveries, one that was incorporated in Newton’s first law of motion,  was not the product of direct experimentation. It was his ability to imagine a scenario that was almost impossible to replicate in real life. It’s what Ernst Mach later called as a Gedankenexperiment, or a thought experiment.

Galileo realized that without friction, a ball rolled along a double incline plane will reach its original height on the other side just like a pendulum (Fig. a). He then asks to imagine what would happen if one side of the double inclined plane is made longer. The ball will then travel a longer distance till it retains its original height (Fig. b). In the limiting case of infinite length, the ball would continue rolling since it can’t reach its original height (Fig. c). This completed upended the Aristotelian view of motion that the natural state of a body is that of rest, and motion requires some force.

Thought experiments have played a significant role in the history of Science from Galileo to Einstein. Scientists expand knowledge of a concept, by creating mental models and running virtual experiments on them. In fact, cognitive scientists believe that people reason by carrying out thought experiments on internal mental models.

But more than that, thought experiments are essentially a creative exercise. Creativity at its core is about playing with models – changing different aspects or adding new associations – and iterating to find a better solution. Whether it is using SCAMPER to manipulate an attribute or reversing an assumption, creative thinking provides ways to manipulate mental models in a quest to discover breakthrough ideas.

As Nancy Nersessian, an expert on model-based thinking in Science, explains, “While thought experimenting is a truly creative part of scientific practice, the basic ability to construct and execute a thought experiment is not exceptional. The practice is highly refined extension of a common form of reasoning. It is rooted in our abilities to anticipate, imagine, visualize, and re-experience from memory. That is, it belongs to a species of thinking by means of which we grasp alternatives, make predictions, and draw conclusions about potential real-world situations we are not participating in at that time.

While the role of thought experiments in advancing scientific knowledge is undisputed, what is lesser known is its role as a pedagogical tool up until recently. After dropping out of the rigid school system in Germany, Einstein found the perfect school in Switzerland, where Johann Pestalozzi‘s methods in visual and conceptual understanding were used.

It was there that Einstein first engaged in a thought experiment that would make him the scientific genius of his time. As he told a friend later, “In Aarau I made my first rather childish experiments in thinking that had a direct bearing on the Special Theory. If a person could run after a light wave with the same speed of light, you would have a wave arrangement which could be completely independent of time. Of course, such a thing is impossible.

It’s unfortunate that over time thought experiments as a pedagogical tool have been dropped from science education. Students now spend most of their time learning facts and running predefined experiments as opposed imagining and framing their own thought experiments. Perhaps by re-introducing thought experiments, more students will find science engaging and stimulating, just like Einstein.