{
  "id": 14674867,
  "title": "Quantum sensor could measure how Earth drags spacetime",
  "url": "https://urgent.news/2026/10/15/quantum-sensor-could-measure-how-earth-drags-spacetime",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-15T10:40:01.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-10-quantum-sensor-earth-spacetime.html"
  },
  "original_language": "en",
  "account": "Quantum sensor researchers at UC Berkeley, the Austrian Academy of Sciences, and Caltech have proposed a novel experiment to measure Earth's frame-dragging effect—a tiny phenomenon where a rotating object, like our planet, subtly influences the surrounding spacetime. This effect, predicted by Einstein's general relativity, causes gyroscopes to slightly precess or change orientation as they rotate relative to distant stars.\n\nThe experiment involves cooling helium to a superfluid state, which allows it to flow with no friction, using a gyrometer (a device measuring rotation). The researchers envision filling a doughnut-shaped tube with superfluid helium-4 and detecting changes in its flow through a Josephson junction—a barrier with tiny holes. When the device rotates, it generates a quantum mechanical phase difference across the junction, which can be measured by tracking the motion of a mechanical diaphragm connected to the loop of superfluid.\n\nWhile previous experiments at UC Berkeley have measured Earth's rotation using superfluid helium, detecting the minute frame-dragging effect remains challenging due to thermal noise. To address this, the researchers conducted an analysis of the thermal noise properties of the proposed device, guided by Keith Schwab's expertise in superfluid devices. Their findings suggest that cooling the superfluid rotation sensor far below the superfluid transition temperature (around 10 mK) could significantly mitigate thermal noise, potentially matching or surpassing the sensitivity of existing frame-dragging measurements within less time.\n\nThis approach not only aims to enhance the precision of detecting Earth's frame-dragging but also offers a new way to study how gravity influences time, testing aspects of Einstein's general relativity. By observing changes in the helium that reflect minute differences in time passage around the sensor's loop, scientists could probe physical processes on scales comparable to the Planck time, an important quantum gravity threshold. This laboratory-based proposal stands out for its feasibility and potential to offer insights into the intersection of quantum mechanics and general relativity.",
  "summary": "Einstein's theory of general relativity describes gravity as the bending of spacetime, a mathematical model that combines three-dimensional space and time into a single, four-dimensional continuum. The theory also predicts that a rotating object, such as Earth, slightly drags the surrounding spacetime as it rotates, a phenomenon known as frame-dragging.",
  "key_points": [
    "Experiment uses superfluid helium-4 in doughnut-shaped tube to detect Earth's frame-dragging effect.",
    "Cooling superfluid to 10 mK could enhance sensitivity to measure spacetime dragging."
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}