Patrick Guilfoile: Oops, I thought those diamonds were real
Most of us have a hard time accepting that we are wrong. Consequently, one of the challenging things about doing science is constantly subjecting yourself to being proven wrong. Scientists publish their work knowing that other scientists could reproduce their observations or experiments and find out they goofed. In most cases, when findings are retested, all is well and they hold up. In other cases, another group demonstrates that the original work was flawed. Although potentially embarrassing, this is one of the hallmarks of science; it is self-correcting, and always subject to change as new evidence comes in.
In 2007, scientists reported that they had found diamonds in Australian minerals that were over 4 billion years old. This was a significant finding, as it suggested that the earth’s crust was already very thick at that time, based on what is known about how diamonds form. Consequently, the prevailing wisdom of the earth being a wickedly hot place four billion years ago, with molten rock covering the earth’s surface, was called into question.
However, other scientists who had worked with these minerals before had never found diamonds, and they were skeptical. They requested a sample from the researchers for further analysis, this time using a much more powerful microscope, and other tools. Their analysis revealed that the diamonds present in the sample were very sharp and angular. The scientists also found evidence of unusual minerals and epoxy resin associated with the diamonds.
In the original report describing diamonds, the scientists had used diamond paste to cut open the rocks. The diamond paste consists of sharp, angular diamonds, epoxy resin, and the same type of unusual minerals identified in the samples. Therefore, it appears that the diamonds identified by the original researchers were from the diamond paste, rather than a part of the original mineral.
While this was embarrassing for the scientists who initially published these results, this whole episode demonstrates the importance of self-correction in science. Scientists get closer and closer to understanding the natural world both by accurately interpreting evidence and experiments, and by correcting errors in earlier work. This lack of dogma in science can be frustrating when we hear conflicting claims about the value of medical procedures or the nutritional benefits of certain foods. Ultimately, though, the ability to revisit experiments and ensure the findings are accurate is a key strength of scientific research.
More information is available in: “Diamonds in Earth’s oldest zircons from Jack Hills conglomerate, Australia, are contamination”. Earth and Planetary Science Letters, Volume 387, 1 February 2014, Pages 212-218. by Larissa Dobrzhinetskaya, Richard Wirth, Harry Green and “Whoops! Earth’s Oldest ‘Diamonds’ Actually Polishing Grit” by Becky Oskin available at: http://www.livescience.com/42192-earths-oldest-diamonds-scientific-error...
PATRICK GUILFOILE has a doctorate in bacteriology and is the associate vice president at Bemidji State University.