Quantum Gravity - Testing Time for Theories

TL;DR

This paper argues that quantum gravity research is experimentally accessible using current and near-future technologies like neutron, atomic interferometry, and gravity wave detectors, challenging the belief that it is beyond terrestrial testing.

Contribution

It demonstrates that experiments such as neutron and atomic interferometry, along with gravity wave interferometers, can probe quantum gravity effects, making the field experimentally testable.

Findings

Neutron and atomic interferometry experiments can test quantum gravity.

Gravity wave interferometers can probe space-time fuzziness at Planck scale.

Quantum gravity effects may be detectable with current experimental setups.

Abstract

The extreme smallness of both the Planck length, on the one side, and the ratio of the gravitational to the electrical forces between, say, two electrons, on the other side has led to a widespread belief that the realm of quantum gravity is beyond terrestrial experiments. A series of classical and quantum arguments are put forward to dispel this view. It is concluded that whereas the smallness of the Planck length and the ratio of gravitational to electrical forces, does play its own essential role in nature, it does not make quantum gravity a science where humans cannot venture to probe her secrets. In particular attention is drawn to the latest neutron and atomic interferometry experiments, and to gravity wave interferometers. The latter, as Giovanni Amelino-Camelia argues [Nature 398, 216 (1999)], can be treated as probes of space-time fuzziness down to Planck length for certain quantum-gravity models.