American Scientist

Each discipline of science has its own debates in which evidence for one side or the other may not be particularly clear, because evidence can often be interpreted from different perspectives to support diverging conclusions. Sometimes there is more than one answer and both sides are right. And sometimes neither side is correct; the answer may lie at a point in between—or somewhere else entirely. The best approach that scientists can take is to give space to all theories that have sufficient evidence to merit serious consideration, and to expect that future work will continue to build the cases for and against those theories. At times, the debate itself can lead to advances.

In this issue’s Perspective column, “(Don’t) Shut Your π-Hole”, Dean J. Tantillo informs us about one such debate within the world of chemistry. Molecules that have a neutral charge overall are nonetheless made up of elements and electrical bonds that create regions with more or less positive charge. Areas that are lacking electrons are termed either π-holes or σ-holes, depending on their shapes. But what causes “passion-filled debates,” as Tantillo says, is defining what areas of the molecule really constitute a π-hole or a σ-hole, and determining how much these areas really mediate interactions between molecules. Tantillo believes that these debates are not only acceptable, but also fruitful, because they lead researchers to create new predictions that are then testable and can lead to new experiments, which in turn can have important practical outcomes, such as the development of a new cancer drug.

Research into communication itself was behind the imaging development that David M. Pepper and Todd W. Murray discuss in their article “Seeing’ into Opaque Materials with Light and Sound”. Pepper and Murray discuss an early invention of Alexander Graham Bell, the photophone, which used sunlight to transmit voices. Bell observed what later came to be known as the photoacoustic effect, the formation of sound waves by the rapid thermal expansion and contraction of the air over a periodically heated surface. This effect underlies a current technique, laser-based ultrasound, which uses lasers to generate ultrasonic waves within opaque materials, the echoes of which are detectable at the material’s surface and can be used to create images of what’s inside.

In “How Herman Hollerith Counted America and the World”, Ainissa Ramirez recounts how a chance conversation played an important role in events that contributed to modern computing. At a cocktail party, Hollerith, an inventor with an interest in tabulating machines, connected with a prominent member of the U.S. Census Office, and they ended up discussing the technology needed for counting the population. Eventually, after years of experimentation and a number of setbacks, Hollerith realized his dream of creating a tabulating machine that would modernize the processes of the Census. His system, which used punch cards, tabulated the results of the 1890 census, and drastically shortened the amount of time it took to come up with a rough count of the census, from seven years to six weeks. Hollerith’s company later became part of IBM and the computer revolution.

The history of science is full of stories in which a random encounter or a new perspective kicked off a major innovation or resolved a long-standing enigma. Have you ever had a serendipitous experience or an unexpected result that changed the direction of your research? Join us on social media or write us a message through our website to tell us about it.