The Natural Sciences and the Definition of Truth

On November 9, 2014, renowned American physicist Neil deGrasse Tyson tweeted the following.

This statement by deGrasse Tyson intrigues me. Although he is a physicist and therefore calls the natural sciences home, and I am an historian and call the liberal arts my home, there are a number of scientific principles shared by all scholars. These principles concern, for example, the terms “truth” and “theory.” However, the above tweet would indicate that deGrasse Tyson doesn’t adhere to these principles. So, let’s unpack his statement.

By making a statement about the truth of scientific theories on Twitter, deGrasse Tyson does himself a disservice. Tweets are limited to 140 characters including blank spaces. Therefore, I would argue that Twitter might not be the best forum for making statements that require certain nuance and contextualization. What deGrasse Tyson did by choosing Twitter is that he put himself forward as a scientist who believes that scientific results equal truth, which is inaccurate and, in fact, bad science. I believe this to be an unfortunate consequence of the limitations imposed by the tweet format, because I have come to regard deGrasse Tyson as a scientist well deserving of his good reputation.

Let’s return to the actual tweet.

deGrasse Tyson states that five scientific theories are true, whether or not people choose to believe in them. As I have stated before on The Boomerang, there is no such thing as “truth” in research. Instead, research results are judged based on their “validity.”

In historical research, the reason why it’s not possible to speak of “truth” is because as soon as a moment has passed, the truth of that moment is lost. All we can do is try and recreate that moment to the best of our ability through research. Or, as French historian Marc Bloch once stated—the past doesn’t change, but our knowledge of it does.

With a minor modification, Bloch’s statement can be applied to the natural sciences. The universe doesn’t change, but our knowledge of it does. Therefore, whenever a new discovery is made about the universe, we discover something about the world we live in that we didn’t know before. But does that mean that we have revealed the truth about our world? No. If we knew the truth about our world, there would be no need for science and both deGrasse Tyson and I would be out of a job.

Historical science and physics base their research on established methodologies and theories. In historical science, the theories applied to historical documents are, for example, theories of structuralization; theories of social networks; or theories of urbanization. None of these theories are considered to harbor any kind of truth. Theories in historical research are used because they provide a plausible framework within which to analyze the process of human activities in retrospect so that valid research results can be presented.

The Andromeda Galaxy, Milky Way's next-door neighbor.

The Andromeda Galaxy, Milky Way’s next-door neighbor.

The same goes for theories in the natural sciences. The theories used in natural sciences provide plausible frameworks in which to analyze, for example, the origin of the species on Earth or the Creation of the Universe. The theories themselves do not provide the conclusions; they help contextualize the data and make them valid. These valid data are then presented as research results. They are not presented as truth, because as soon as another discovery is made, the results are likely to change.

Moreover, as stated by Stephen Hawking and Michio Kaku, theories in physics are used to make predictions about the universe through mathematical calculations. For example, the theory of hyperspace states that our world consists of ten dimensions. However, we as humans are only able to experience four of those dimensions. Mathematical calculations are used to make predictions about the other six.

So, if there is no such thing as “truth” in scientific research, only valid results that are likely to change, how can we claim to know what we know?

My answer to that question is that when the valid results are analyzed together, they present a picture of our world that is plausible based on our experiences as human beings living in this universe. Therefore I am a believer in the theories mentioned by deGrasse Tyson. But I don’t believe in them because they are true. I believe in them because they are the most valid.

In the words of my friend, the Australian, I shall return.

March Bloch The Historian’s Craft (Manchester University Press, 1954)
Stephen Hawking A Brief History of Time (Bantam Books, 1998)
Michio Kaku Hyperspace. A Scientific Odyssey Through Parallel Universes, Time Warps, and the 10th Dimension (Anchor Books, 1995)

Image of the Andromeda Galaxy has been downloaded from Wikipedia.