Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















TIME AND SPACE
Researchers demonstrate 'quantum surrealism'
by Staff Writers
Toronto, Canada (SPX) Feb 25, 2016


File image.

New research demonstrates that particles at the quantum level can in fact be seen as behaving something like billiard balls rolling along a table, and not merely as the probabilistic smears that the standard interpretation of quantum mechanics suggests. But there's a catch - the tracks the particles follow do not always behave as one would expect from "realistic" trajectories, but often in a fashion that has been termed "surrealistic."

In a new version of an old experiment, CIFAR Senior Fellow Aephraim Steinberg (University of Toronto) and colleagues tracked the trajectories of photons as the particles traced a path through one of two slits and onto a screen. But the researchers went further, and observed the "nonlocal" influence of another photon that the first photon had been entangled with.

The results counter a long-standing criticism of an interpretation of quantum mechanics called the De Broglie-Bohm theory. Detractors of this interpretation had faulted it for failing to explain the behaviour of entangled photons realistically. For Steinberg, the results are important because they give us a way of visualizing quantum mechanics that's just as valid as the standard interpretation, and perhaps more intuitive.

"I'm less interested in focusing on the philosophical question of what's 'really' out there. I think the fruitful question is more down to earth. Rather than thinking about different metaphysical interpretations, I would phrase it in terms of having different pictures. Different pictures can be useful. They can help shape better intuitions."

At stake is what is "really" happening at the quantum level. The uncertainty principle tells us that we can never know both a particle's position and momentum with complete certainty. And when we do interact with a quantum system, for instance by measuring it, we disturb the system. So if we fire a photon at a screen and want to know where it will hit, we'll never know for sure exactly where it will hit or what path it will take to get there.

The standard interpretation of quantum mechanics holds that this uncertainty means that there is no "real" trajectory between the light source and the screen. The best we can do is to calculate a "wave function" that shows the odds of the photon being in any one place at any time, but won't tell us where it is until we make a measurement.

Yet another interpretation, called the De Broglie-Bohm theory, says that the photons do have real trajectories that are guided by a "pilot wave" that accompanies the particle. The wave is still probabilistic, but the particle takes a real trajectory from source to target. It doesn't simply "collapse" into a particular location once it's measured.

In 2011 Steinberg and his colleagues showed that they could follow trajectories for photons by subjecting many identical particles to measurements so weak that the particles were barely disturbed, and then averaging out the information. This method showed trajectories that looked similar to classical ones - say, those of balls flying through the air.

But critics had pointed out a problem with this viewpoint. Quantum mechanics also tells us that two particles can be entangled, so that a measurement of one particle affects the other.

The critics complained that in some cases, a measurement of one particle would lead to an incorrect prediction of the trajectory of the entangled particle. They coined the term "surreal trajectories" to describe them.

In the most recent experiment, Steinberg and colleagues showed that the surrealism was a consequence of non-locality - the fact that the particles were able to influence one another instantaneously at a distance.

In fact, the "incorrect" predictions of trajectories by the entangled photon were actually a consequence of where in their course the entangled particles were measured. Considering both particles together, the measurements made sense and were consistent with real trajectories.

Steinberg points out that both the standard interpretation of quantum mechanics and the De Broglie-Bohm interpretation are consistent with experimental evidence, and are mathematically equivalent. But it is helpful in some circumstances to visualize real trajectories, rather than wave function collapses, he says.

The paper, "Experimental Nonlocal and Surreal Bohmian Trajectories," will be published Feb. 19 in Science Advances.

.


Related Links
Canadian Institute for Advanced Research
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
TIME AND SPACE
Canonical transformation provides insights into many-particle physics
Klosterneuburg, Austria (SPX) Feb 18, 2016
The concepts of rotation and angular momentum play a crucial role in many areas of physics, ranging from nuclear spectroscopy to molecular collisions and precision measurements. In a paper appearing in the leading physics journal Physical Review X on February 12, 2016, Mikhail Lemeshko, Professor at the Institute of Science and Technology Austria (IST Austria), and Richard Schmidt, Postdoc ... read more


TIME AND SPACE
NASA chooses ASU to design and operate special satellite

Chinese scientists invent leak detection system for moon exploration

Aldrin recounts successes and challenges of historic space journey

Edgar Mitchell, astronaut who walked on Moon, dead at 85

TIME AND SPACE
Russia plans return to Mars, Moon despite money woes

Opportunity Taking Panoramic Views and Prepping for Science

NASA to simulate growing potatoes on Mars in Peru

Somewhere between Earth and Mars Science Fiction Became Science Fact

TIME AND SPACE
Virgin Galactic unveils new spaceship 16 months after deadly crash

NASA sees record number of astronaut applications

Visions of the future unleashed at TED

Engineer Makes Sure Commercial Crew Craft Will Make Smooth Landing

TIME AND SPACE
China Conducts Final Tests on Most Powerful Homegrown Rocket

Last Launch for Long March 2F/G

China aims for the Moon with new rockets

China shoots for first landing on far side of the moon

TIME AND SPACE
Black Mold Found in Cargo Prepared for ISS, Resupply Mission Delayed

Putting the Public in the Shoes of Space Station Science

Russians spacewalk to retrieve biological samples

Russia to Deliver Three Advanced Spacesuits to ISS in 2016

TIME AND SPACE
JAXA Launches X-ray Astronomy Satellite

ULA Launches NROL-45 Payload for the National Reconnaissance Office

SES-9 Launch Targeting Late February

Spaceflight Awarded First GSA Schedule Contract for Satellite Launch Services

TIME AND SPACE
Astronomers take images of an exoplanet changing over time

First detection of super-earth atmosphere

Hubble Directly Measures Rotation of Cloudy 'Super-Jupiter'

Volcanoes Light Up Atmospheres of Small Exoplanets

TIME AND SPACE
New research introduces 'pause button' for boiling

Mystery of Dracula orchids' mimicry is unraveled with a 3-D printer

Shrinking 3-D technology for comfortable smart phone viewing

Modified laser cutter prints 3-D objects from powder




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.