In Brief
Scientists at the British University of Columbia have argued that constantly fluctuating space-time is responsible for universal expansion rather than dark energy. This may be an answer to one of the fundamental problems in cosmology.

Einstein + Quantum Physics

Scientists at the University of British Columbia have proposed a radical new theory to explain the exponentially increasing size of the universe. Ultimately, it seeks to reconcile two different concepts in physics: Quantum Mechanics and Einstein’s Theory of General Relativity. the researchers argue that instead of dark energy causing the universe’s growth, it could be explained by constant quantum fluctuations of vacuum energy.

In their work, the researchers argue that, instead of dark energy causing the universe’s growth, it could be explained by constant quantum fluctuations of vacuum energy. The paper claims — if their findings are true — that “the old cosmological constant problem would be resolved.” The press release notes the potentially transformative nature of the work: “Their calculations provide a completely different physical picture of the universe.”

Similarly, Bill Unruh, the physics and astronomy professor who supervised P.H.D student Qingdi Wang’s work, stated that the research offers an entirely new take on old problems: “This is a new idea in a field where there hasn’t been a lot of new ideas that try to address this issue.” In the end, their calculations provide a fundamentally different picture of the universe: one in which space-time is “constantly moving,” fluctuating between contraction and expansion. It’s the small net effect towards expansion, though, that drives the expansion of the universe.

Unruh uses the sea as an analogy to explain why we cannot feel the effects: “It’s similar to the waves we see on the ocean […] They are not affected by the intense dance of the individual atoms that make up the water on which those waves ride.”

The Big Why

Previous belief has held that the universe is expanding steadily due to dark energy pushing other matter further and further away. When we apply quantum theories to vacuum energy, it results in an increasing density which could in turn result in universal explosion — due to the gravitational effect of the density.

The discovery that the universe is expanding was made simultaneously by two independent teams in 1998: Supernova Cosmology Project and the High-Z Supernova Search Team. Three members of the two teams have since won Nobel prizes for their work, which measured light using ‘standard candles.’ Since that discovery was made, scientists have tried to work out exactly what this energy is that’s driving the cosmos apart.

Despite the fact that it has been a compelling mystery for decades, there haven’t been that many theories posed. So, while the work of Wang and Unruh may not provide the ultimate answer, they present a new, potential solution to one of the most fundamental problems in cosmology.

Editor’s note: This article has been updated. A previous version mistakenly referred to “dark energy” as “dark matter.”