Gerard 't Hooft, a theoretical physicist at Utrecht University in the Netherlands, does not like the uncertainty of quantum mechanics. Neither did Albert Einstein, who spent half his life searching for an alternative. Einstein's failure led many researchers to accept that the statistical nature of quantum physics describes the real universe, but 't Hooft argues in a new paper that his colleagues are missing a deeper level of reality. "The ultimate theory of nature is not quantum mechanical; quantum mechanics is simply how the ultimate theory of nature is revealed to us," he says.


Fuzzy statistical laws shape the subatomic world, including these 36 cobalt atoms viewed here through a scanning tunneling microscope.
Photograph courtesy of IBM.

The heart of the problem is gravity. General relativity describes the way gravity operates on large scales but does not explain its origin. Quantum mechanics describes the subatomic world where the forces of nature arise, but it turns increasingly vague over extremely small distances. Quantum theory falls apart entirely at the Planck length—an unimaginably minuscule distance some 10-20 times the size of a proton—which is precisely where gravity holds sway.

In 't Hooft's view, the universe follows orderly rules at the Planck length but in such a way that information disappears on its way out to a larger world. Information loss makes it impossible to reconstruct the past state of the inner world based on our studies of particles and fields, leading to quantum weirdness such as electrons being in two places at the same time. "At present I cannot test my theory. But if you move along these lines, maybe you'll get a better picture of what is actually going on," 't Hooft says.