According to quantum physicists, there is no such thing as empty space – instead there is only a “quantum foam” everywhere. Using the latest telescopes from NASA, the race is on to find it.
But there is a catch; we can’t ever hope to observe the quantum foam directly.
Eric Perlman of the Florida Institute of Technology explains, “The ‘bubbles’ in the quantum foam are quadrillions of times smaller than atomic nuclei and last for infinitesimal fractions of a second – or in quantum-speak, the size of a Planck Length for a Planck Time. According to string theorists, this requires an additional six dimensions. Space-time itself is fluctuating in these regions. Because these bubbles are so small and last for such a short time, they can never be observed directly.”
The weird world of quantum mechanics describes how matter and light behave on a scale smaller than the nuclei of an atom. The best quantum gravity models predict space-time to be a seething foam where minuscule new dimensions spontaneously appear and disappear in the blink of an eye.
In order for scientists to try and prove the quantum foam exists they intended to observe its effect on light. The theory is that each photons path would be slightly different as it made its way through the quantum foam. As a result, the distance each photon traveled would be different. It sounds doable, but it’s incredibly hard to observe the photons.
Perlman explains, “Over the cosmological distances that the photons travel from these distant sources, the effects of the fluctuations the photons encounter will accumulate. The more they accumulate, the more out of phase the light will get. Creating an image from a collection of such photons would be like trying to distinguish what one person is saying in a huge crowd of people talking. So it would be physically impossible to get a clear picture.”
Perlman and his team recently attempted to prove the foam is there by using X-ray and gamma-ray observations of distant quasars. The team used the Chandra X-ray Observatory, Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System, or VERITAS.
The results seem to go against the quantum foam theory; Perlman said, “It seems space-time has to be smooth, at least at the level of 1000x times smaller than an atom, and space-time must be much less foamy than most models predict.”
However, Perlman leaves some hope for quantum foam: “This investigation does not go as far down as the Planck Length. So there is still some hope for the tiniest of bubbles.”