Critiquing dark matter

It was considered the “breakthrough of the year” by the reputable journal Science in 1998 when astronomers peered into the universe and found that it was “flying apart ever faster."

By Mark Ferguson

The expansion of the universe suggested that Einstein was right when he described a mysterious energy that fills the “empty” space that occupies most of the universe: dark matter. “Not only is there too little matter in the universe to ever halt the expansion on its own, but the outward motion appears to be speeding up, not slowing down,” wrote James Glanz in his Science article. “At the same time, the finding raises such profound questions about the nature of space that cosmologists are wondering whether the ultimate fate of the universe can ever be known for certain.”

Professor Robert Hudson in the Department of Philosophy
Professor Robert Hudson in the Department of Philosophy

Professor Robert Hudson in the Department of Philosophy has been studying dark matter for years and he wonders whether scientists were able to come to their conclusions accurately about dark matter and the expansion of the universe. He described that by observing far-off exploding stars called supernovae, scientists were finding that they were becoming ever dimmer over time. They explained the changing luminousness of the supernovae through acceleration - sweeping them to unexpectedly large distances from the Earth.

Hudson questions this kind of finding as he is busy working on his latest book with a working title of Seeing Things: the philosophy of reliable observation in which he describes as a philosophical critique of experimental science.

"Newton, Einstein, Darwin – those men described big theories," said Hudson. "But I look at the experimentalism of theories and how we have come to the conclusions that we do."

Hudson points to one of his scientific philosophical peers, Allan Franklin, who wrote a book called The Neglect of Experiment around the same time as the discovery that the universe was expanding. Franklin's key argument in the book is the problems with experiments scientists face when coming to confirming theories in elementary particle physics. Essentially, he is asking us how one comes to believe rationally in experimental results.

When it comes to believing, or not believing, in the expansion of the universe and the existence of dark matter, Hudson is skeptical to believe it. As a philosopher though, his proof is not necessarily in the pudding.

"I am a scientific realist. I come to the idea that science arrives at the truth of theoretical entities – like the universe … It is the unobserved reality underlying our observations."

This might sound confusing, but Hudson explains it quite simply. Essentially, how can we come to a conclusion that the universe is expanding based on a man-made experiment? We look at supernovae millions of light years away one day, and the next decide that they have moved further away into the darkness of space. "I am studying this kind of research and how they reason, the instruments they use, the supernovae they monitor."

As a realist, Hudson thinks that dark matter could be explained, but getting the experiments right could be a ways off.

"The luminous matter that we see in the universe (stars, galaxies, etc.) makes up a very small percentage of what's out there. The rest is dark matter and dark energy, or at least, that's what scientists are trying to prove."