TIME was when physicists dreamed of a final theory, a perfect set of equations that would describe every force and particle in nature. Today that dream is being overtaken by the suspicion that there is no such thing as a theory of everything (see 鈥淎re we nearly there yet?鈥�). Some even fear that all our attempts at a deeper understanding of nature, even string theory, are dead ends.
This will be grist to the mill for those who have long claimed fundamental physics is a waste of time and money. Projects such as the Large Hadron Collider (LHC), which will be the world鈥檚 most powerful particle accelerator when it is switched on at CERN in Geneva in 2007, are an expensive irrelevance, these critics insist. With the LHC, physicists hope to discover the Higgs boson and other more exotic particles that should give us clues to a deeper theory. To the sceptics, however, it will provide at most some possible answers to abstruse questions that only a few people understand or care about.
There are two issues here. First, does the doubt and uncertainty about a theory of everything undermine high-energy physics as a scientific pursuit? The answer is clearly no. It makes no difference if the truths that physicists seek turn out to be more complex and messy than they once hoped. It could even make the search more intriguing. There are as many profound questions out there as there have ever been, and to answer them physicists need the kind of hard experimental evidence that can only come from high-energy experiments such as the LHC.
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The second question is more difficult: can we justify spending the huge sums of money that particle accelerators demand? The LHC will cost several billion dollars, money that would save many lives were it spent on medical research or famine relief. 鈥淔ind the Higgs or feed the starving鈥� sounds like a no-brainer, but it isn鈥檛. Rich nations can afford to spend a lot more on aid without having to cut their tiny pure science budgets. What it boils down to is whether we think the search for fundamental truths, such as the nature of time and space and the origin and fate of the universe, is important.
And the answer, surely, is yes. This quest for knowledge is a defining human quality. It is hard to quantify how our lives have been 鈥渋mproved鈥� by it. There have been plenty of technological spin-offs from the space race and high-energy experiments. But the spin-offs are not the point. In showing us how the universe works, fundamental physics could also tell us something profound about ourselves. And for that, a few billion dollars would be a small price to pay.
