About the Minimal Resolution of Space-Time Grains in Experimental Quantum Gravity

TL;DR

This paper critically examines thought experiments on the limits of space-time measurement at the Planck scale, revealing how quantum device design can improve measurement precision and impact quantum gravity models.

Contribution

It provides a detailed analysis of measurement device quantum nature, showing how to circumvent constraints and reduce fluctuations, advancing understanding of space-time measurement limits.

Findings

Quantum fluctuations in measuring devices can be minimized with better design.

Certain measurement constraints like Schwarzschild can be bypassed.

Implications for phenomenological quantum gravity models are discussed.

Abstract

We critically analyse and compare various recent thought experiments, performed by Amelino-Camelia, Ng et al., Baez et al., Adler et al., and ourselves, concerning the (thought)experimental accessibility of the Planck scale by space-time measurements. We show that a closer inspection of the working of the measuring devices, by taking their microscopic quantum many-body nature in due account, leads to deeper insights concerning the extreme limits of the precision of space-time measurements. Among other things, we show how certain constraints like e.g. the Schwarzschild constraint can be circumvented and that quantum fluctuations being present in the measuring devices can be reduced by designing more intelligent measuring instruments. Consequences for various phenomenological quantum gravity models are discussed.