AI illustration of the proposed experiment—Time-Resolved and Superradiantly Amplified Unruh Effect. Credit: Navdeep Arya
Researchers from Stockholm University and the Indian Institute of Science Education and Research (IISER) Mohali have reported a practical way to spot one of physics’ strangest predictions: the Unruh effect, which says that an object speeding up (accelerating) would perceive empty space as faintly warm. But, trying to heat something up by accelerating it unimaginably fast is a nonstarter in the…
AI illustration of the proposed experiment—Time-Resolved and Superradiantly Amplified Unruh Effect. Credit: Navdeep Arya
Researchers from Stockholm University and the Indian Institute of Science Education and Research (IISER) Mohali have reported a practical way to spot one of physics’ strangest predictions: the Unruh effect, which says that an object speeding up (accelerating) would perceive empty space as faintly warm. But, trying to heat something up by accelerating it unimaginably fast is a nonstarter in the lab. The team has shown how to convert that tiny effect into a clear, timestamped flash of light.
Here’s the simple picture. Imagine a group of atoms between two parallel mirrors. The mirrors can either speed up or slow down light emission from the atoms. When these atoms cooperate, they can emit together like a choir—much louder than solo singers. This collective outburst is called superradiance.
The new study explains how the acceleration-induced warmth of empty space, if experienced by the atoms, quietly nudges them so that the choir’s burst happens earlier than it would for atoms sitting still. That earlier-than-expected flash becomes a clean, easy-to-spot signature of the Unruh effect. The work, co-authored with Kinjalk Lochan and Sandeep K. Goyal of IISER Mohali, is now published in Physical Review Letters.
“We’ve found a way to turn the Unruh effect’s whisper into a shout,” said Akhil Deswal, a Ph.D. student at IISER Mohali. “By using carefully spaced high-quality mirrors, we make ordinary background signals quieter while the acceleration-seeded burst comes out early and clean.”
Crucially, the proposal demands significantly lower acceleration compared to the requirement in the absence of high-quality mirrors.
“Timing is the key,” added Navdeep Arya, a postdoctoral researcher at Stockholm University. “The choir of atoms is not only louder but also shouts earlier if they feel the faint Unruh effect-related warmth of empty space. That simple clock-like marker can make it easier to separate the Unruh signal from everyday noise.”
By theoretically addressing a decades-old detection challenge, the idea opens a bridge between available laboratory devices and phenomena usually linked to extreme conditions. Because acceleration and gravity are closely related, similar timing tricks might one day help researchers probe subtle, gravity-driven quantum effects—right on the lab bench.
More information: Akhil Deswal et al, Time-Resolved and Superradiantly Amplified Unruh Effect, Physical Review Letters (2025). DOI: 10.1103/6z1l-kkmk
Citation: Turning the faint quantum ‘glow’ of empty space into a measurable flash (2025, November 10) retrieved 10 November 2025 from https://phys.org/news/2025-11-faint-quantum-space.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.