Tikalon Blog by Dev Gualtieri

A Limit to Science?

November 12, 2010

In a previous article (Basic Research, October 22, 2010) I remarked that this year marks the 65th anniversary of the publication of Vannevar Bush's report, "Science, The Endless Frontier ." There's no question that when this report was written in 1945 the frontiers of science seemed endless, and that idea appears to be the case today as well. As many articles on this blog, from graphene to the cosmic microwave background, will attest, scientists find something new everywhere they look.

There have been naysayers to this idea of endless science. It's possible that William Thomson, a.k.a., Lord Kelvin , for whom the eponymous temperature scale is named, was one of these. He is reputed to have said the following at the 1900 meeting of the British Association for the Advancement of Science ,

"There is nothing new to be discovered in physics now. All that remains is more and more precise measurement."

It's uncertain whether he said this, since no primary reference has been found.[1] I think it's credible that he did say this, since this comment is akin to his other pronouncements. Furthermore, in 1894, six years before Kelvin's speech, Albert Michelson of Michelson-Morley experiment purportedly referred to Kelvin when he said,

"An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals."

In that age, before quantum mechanics , it was easy for physicists to believe that they had the universe explained. Their view was the same as that of Pierre-Simon Laplace , who introduced what's called Laplace's demon , a close cousin of Maxwell's demon . Laplace reasoned that if some entity (his demon) knew the exact location and momentum of every atom in the universe, then all the past and future states of the universe could be calculated. Quantum mechanics, expressed by Heisenberg's uncertainty principle , killed that idea entirely.

Clockwork Universe Sculpture
by Tim Wetherell.

In 1980, just 35 years after the "Endless Frontier," Stephen Hawking had his own doubts about endless science. His inaugural lecture as Lucasian Professor of Mathematics at Cambridge University was entitled, "Is the end in sight for theoretical physics?" Hawking said that there was a 50-50 chance of finding a unified theory within twenty years. However, in a subsequent talk in 1998, he said he still held to that estimate, but the twenty year clock would start then.[2] Will we have such a theory by 2018, after the next twenty year interval?

Russell Stannard , an emeritus professor of physics at the Open University (United Kingdom ), says that the problem is not that it will be impossible to build the next particle accelerator to replace the nine billion dollar Large Hadron Collider , for example. The problem is that the human mind has its own limits that cannot be transcended.[3-7] If you're thinking of the B-movie phrase, "There are some things that man was not meant to know," that's what came to my mind, also. Stannard can't be dismissed as just another crank, since he has the credentials to espouse such speculation. He was invested with an OBE and was given the Bragg Medal from the Institute of Physics . His thoughts on this matter are contained in his latest book, "The End of Discovery: Are We Approaching the Boundaries of the Knowable?"[3]

In the beginning, physics was discovered through simple experiments, such as Galileo's swinging pendulums and rolling balls down inclined planes . One man could perform such experiments and make sense of the collected data. After such simple experiments revealed the general picture of the physical world, more complicated experiments were required to dig more deeply; and now you have huge teams of people performing very complicated experiments to elucidate increasingly impenetrable phenomena. The time is nigh when a human mind could not devise that next experiment or understand its result. Even today, most of our investigations of nature are far beyond the natural environment in which we live. We have no reference points. Stannard lists as questions of a very deep nature, such as free will , the nature of space, time, and matter and the existence of extraterrestrial life .[3]

There's also the problem of motivation. Stannard writes that

"...one presumably does not want to devote one's entire career to addressing a question that cannot be answered - especially if one could have opted for a different line of research more amenable to producing a worthwhile result."[5]

Many scientists take a middle stance. Martin Rees , president of the Royal Society , agrees with some of Stannard's points, but disputes others. Rees thinks that there may be some questions we're incapable of formulating, and things we can't understand. Says Rees,

"Just as a monkey doesn't worry about how it evolved, whereas we understand Darwinism, there may be a problem which we haven't been able to conceive."[4]

Rees thinks there's plenty more life left in science before we need to worry. He also believes that we may get an assist from computers.

I'll end with the following from Stannard:

"There is, after all, no way of proving that a particular question is, for whatever reason, unanswerable. Which leaves us with an uncomfortable thought. I have said that fundamental science will come to an end. But how will we know that the scientific age has ended? We, or more likely our descendents, will not know. Looking back, they might note the lack of any recent significant advances... I suppose when it is noted that the physics text books have not required updating for the past millennium the penny might drop."[5]

A Limit to Science?

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