Ancient Neutrinos Could Put String Theory and Quantum Loop Gravity to the Test

Sep 14, 2005

The distribution of ancient neutrinos may eliminate some of the most promising theories linking gravity and quantum mechanics, according to a theoretical analysis put forth at the Perimeter Institute in Canada. Many physicists believe that combining gravity and quantum mechanics into a single theory is one of the most important problems in science today.

Leading attempts to create a unified theory of gravity and quantum mechanics, such as string theory and loop quantum gravity, make sense in a universe in which gravity is subordinate to the laws of quantum mechanics. However, problems with these sorts of theories have led some to propose that gravity and quantum mechanics are equal contributors to the final unified theory.

According to this hypothesis, gravity breaks down the quantum nature of objects. The heavier the object, the quicker gravity leads to the breakdown â€" that is one reason that large objects, such as baseballs, obey the classical physics of Newton, while light objects such as electrons and other particles obey the counterintuitive laws of quantum mechanics. The new research suggests that this idea can be tested using neutrinos created in the early universe.

If gravity breaks down the quantum nature of neutrinos, this should be evident in ratios of the types of neutrinos detected at next generation neutrino experiments such as IceCube, a one cubic kilometer neutrino detector currently being built beneath the ice of Antarctica. Such a result would require physicists to rethink popular theories including string theory and quantum loop gravity. It would also mean that the physics of the early universe was fundamentally different than it is today.

J. Christian
Physical Review Letters (upcoming article)

Source: American Physical Society

Explore further: Invisibility cloak aspirations inspire new metasurface material

Related Stories

Einstein saves the quantum cat

Jun 16, 2015

Einstein's theory of time and space will celebrate its 100th anniversary this year. Even today it captures the imagination of scientists. In an international collaboration, researchers from the universities ...

How mathematics reveals the nature of the cosmos

Jun 08, 2015

Let us discuss the very nature of the cosmos. What you may find in this discussion is not what you expect. Going into a conversation about the universe as a whole, you would imagine a story full of wondrous ...

How spacetime is built by quantum entanglement

May 27, 2015

A collaboration of physicists and a mathematician has made a significant step toward unifying general relativity and quantum mechanics by explaining how spacetime emerges from quantum entanglement in a more ...

Scientist provides new fluid dynamics insights

May 27, 2015

New calculations by a theoretical astrophysicist at The University of Alabama in Huntsville (UAH) provide tools that open a door to exploring the history of events in astrophysical flows and in plasma fusion ...

Recommended for you

Could your smartphone one day tell you you're pregnant?

9 hours ago

Researchers at the Hanover Centre for Optical Technologies (HOT), University of Hanover, Germany, have developed a self-contained fiber optic sensor for smartphones with the potential for use in a wide variety ...

Restoration of NIST's million-pound deadweight machine

18 hours ago

Restoration is well underway for NIST's 4.45-million newton (equivalent to one million pounds-force) deadweight machine, the largest in the world. The three-story-tall deadweight, comprising a stack of stainless ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.