Nav: Home

Bridge between quantum mechanics and general relativity still possible

September 19, 2019

Quantum mechanics and the general theory of relativity form the bedrock of the current understanding of physics - yet the two theories don't seem to work together. Physical phenomena rely on relationship of motion between the observed and the observer. Certain rules hold true across types of observed objects and those observing, but those rules tend to break down at the quantum level, where subatomic particles behave in strange ways.

An international team of researchers developed a unified framework that would account for this apparent break down between classical and quantum physics, and they put it to the test using a quantum satellite called Micius. They published their results ruling out one version of their theory on Sept 19th in Science.

Micius is part of a Chinese research project called Quantum Experiments at Space Scale (QUESS), in which researchers can examine the relationship with quantum and classical physics using light experiments. In this study, the researchers used the satellite to produce and measure two entangled particles.

"Thanks to the advanced technologies made available by Micius, for the first time in human history, we managed to perform a meaningful quantum optical experiment testing the fundamental physics between quantum theory and gravity," said Jian-Wei Pan, paper author and director of the CAS center for Excellence in Quantum Information and Quantum Physics at the University of Science and Technology of China

The theory Pan and the team tested was that the particles would decorrelate from one another as they passed through separate gravitational regions of Earth. The different gravitational pulls would force a quantum interaction that behaved as classical relativism would - the particle in less gravity would move with less constraint than the one in stronger gravity.

According to Pan, this "event formalism" attempts to present a coherent description of quantum fields as they exist in exotic spacetime, which contains closed time-like curves, and ordinary space time. Event formalism standardized behavior across quantum and classical physics.

"If we did observe the deviation, it would mean that event formalism is correct, and we must substantially revise our understanding of the interplay between quantum theory and gravity theory," Pan said. "However, in our experiment, we ruled out the strong version of event formalism, but there are other versions to test."

The researchers did not see the particles deviate from the expected interactions predicted by the quantum understanding of gravity, but they plan to test a version of their theory that allows for a little more flexibility.

"We ruled out the strong version of event formalism, but a modified model remains an open question," Pan said.

To test this version, Pan and the team will launch a new satellite that will orbit 20 to 60 times higher than Micius to test a wider field of gravity strength.

Other authors include Ping Xu, Ji-Gang Ren, Hai-Lin Yong, Sheng-Kai Liao, Juan Yin, Wei-Yue Liu, Wen-Qi Cai, Xuan Han, Hui-Nan Wu, Wei-Yang Wang, Feng-Zhi Li, Meng Yang, Li Li, Jingyun Fan and Cheng-Zhi Peng, all of whom are affiliated with the Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics at the University of Science and Technology of China and the Chinese Academy of Science Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, also at the University of Science and Technology of China. Yiqiu Ma and Yanbei Chen, both of Theoretical Astrophysics at the California Institute of Technology, Timothy C. Ralph of the Center for Quantum Computation and Communication Technology at the School of Mathematics and Physics at The University of Queensland and Feng-Li Lin of the Department of Physics of the National Taiwan Normal University also contributed.
-end-
This work was supported by the Strategic Priority Research Program on Space Science of the Chinese Academy of Sciences and the National Natural Science Foundation of China.

University of Science and Technology of China

Related Quantum Physics Articles:

A platform for stable quantum computing, a playground for exotic physics
Harvard University researchers have demonstrated the first material that can have both strongly correlated electron interactions and topological properties, which not only paves the way for more stable quantum computing but also an entirely new platform to explore the wild world of exotic physics.
A new quantum data classification protocol brings us nearer to a future 'quantum internet'
A new protocol created by researchers at the Universitat Autònoma de Barcelona sorts and classifies quantum data by the state in which they were prepared, with more efficiency than the equivalent classical algorithm.
Quantum physics: Ménage à trois photon-style
When two photons become entangled, the quantum state of the first will correlate perfectly with the quantum state of the second.
Quantum physics -- Simulating fundamental interactions with ultracold atoms
An international team of physicists succeeded in precisely engineering key ingredients to simulate a specific lattice gauge theory using ultracold atoms in optical lattices.
A key piece to understanding how quantum gravity affects low-energy physics
In a new study, led by researchers from SISSA (Scuola Internazionale Superiore di Studi Avanzati), the Complutense University of Madrid and the University of Waterloo, a solid theoretical framework is provided to discuss modifications to the Unruh effect caused by the microstructure of space-time.
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Quantum physics and origami for the ultimate get-well card
The bizarre optical properties of tiny metal particles -- smaller than light waves -- can be captured on paper to detect even a single target molecule in a test sample.
Can artificial intelligence solve the mysteries of quantum physics?
A new study published in Physical Review Letters by Prof.
Brilliant glow of paint-on semiconductors comes from ornate quantum physics
A new wave of semiconductors that can be painted on is on the horizon.
New device could help answer fundamental questions about quantum physics
Researchers have developed a new device that can measure and control a nanoparticle trapped in a laser beam with unprecedented sensitivity.
More Quantum Physics News and Quantum Physics Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#544 Prosperity Without Growth
The societies we live in are organised around growth, objects, and driving forward a constantly expanding economy as benchmarks of success and prosperity. But this growing consumption at all costs is at odds with our understanding of what our planet can support. How do we lower the environmental impact of economic activity? How do we redefine success and prosperity separate from GDP, which politicians and governments have focused on for decades? We speak with ecological economist Tim Jackson, Professor of Sustainable Development at the University of Surrey, Director of the Centre for the Understanding of Sustainable Propserity, and author of...
Now Playing: Radiolab

An Announcement from Radiolab