Featured Research

from universities, journals, and other organizations

Vanquishing Infinity: Old Methods Lead To New Approach To Finding Quantum Theory Of Gravity

Date:
August 21, 2009
Source:
American Physical Society
Summary:
Quantum mechanics and Einstein's theory of general relativity are both extremely accurate theories of how the universe works, but all attempts to combine the two into a unified theory have ended in failure. Now physicists have found a way to carry out a new set of gravity calculations with the help of an older theory that has been around since the 1980s.

In the 1940s, Richard Feynman devised a graphical method for carrying out calculations. Bern et al. use different kinds of diagrams that permit large calculations. Owing to their resemblance to the work of artist Piet Mondrian, these graphical computational devices are sometimes referred to as Mondrian diagrams.
Credit: Adapted from Bern et al., Phys. Rev. D 76, 125020 (2007)]

Quantum mechanics and Einstein's theory of general relativity are both extremely accurate theories of how the universe works, but all attempts to combine the two into a unified theory have ended in failure. When physicists try to calculate the properties of a quantum theory of gravity, they find quantities that become infinite -- infinities that are so bad they can't be removed by mathematical gambits that work in other areas of physics.

Related Articles


Now, Zvi Bern, John Carrasco, and Henrik Johanssen at UCLA, Lance Dixon at the Stanford Linear Accelerator Center, and Radu Roiban at Pennsylvania State University have found a way to carry out a new set of gravity calculations with the help of an older theory that has been known since the 1980s to be finite.

Their new results are reported in Physical Review Letters and highlighted in a commentary by Hermann Nicolai at the Max Planck Institute for Gravitational Physics in Potsdam, Germany, in Physics.

Previous attempts at removing the fatal infinities in quantum gravity calculations collapsed when researchers discovered that you would need an infinite number of parameters. The problem stems from the point-like and thus infinitesimally small fundamental particles in the theories, so some physicists have developed string theory as a possible approach: instead of point particles, the fundamental entities are vibrating loops of string. But string theory is beset with its own difficulties, as it lays out a "landscape" of possibilities with an astronomical number of scenarios.

The new paper by Bern et al. shows that by combining desirable aspects of string theory and point-like particles, they can use cancellations in the calculations - done with the help of graphical computational methods called Feynman diagrams (and later elaborations) - to escape the problem of infinities. While not a solution to the problem of quantum gravity, nor a result that knocks string theory aside, the findings of Bern et al. show that theories thought to be dead ends may still show the way forward.


Story Source:

The above story is based on materials provided by American Physical Society. Note: Materials may be edited for content and length.


Cite This Page:

American Physical Society. "Vanquishing Infinity: Old Methods Lead To New Approach To Finding Quantum Theory Of Gravity." ScienceDaily. ScienceDaily, 21 August 2009. <www.sciencedaily.com/releases/2009/08/090817143556.htm>.
American Physical Society. (2009, August 21). Vanquishing Infinity: Old Methods Lead To New Approach To Finding Quantum Theory Of Gravity. ScienceDaily. Retrieved March 1, 2015 from www.sciencedaily.com/releases/2009/08/090817143556.htm
American Physical Society. "Vanquishing Infinity: Old Methods Lead To New Approach To Finding Quantum Theory Of Gravity." ScienceDaily. www.sciencedaily.com/releases/2009/08/090817143556.htm (accessed March 1, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, March 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

HTC And Valve Team Up For Virtual Reality Headset

HTC And Valve Team Up For Virtual Reality Headset

Newsy (Mar. 1, 2015) HTC unveiled Vive, its new virtual reality headset, Sunday. The device is supported by gaming company Valve, which has made a push into the market. Video provided by Newsy
Powered by NewsLook.com
Rehab Robot Helps Restore Damaged Muscles and Nerves

Rehab Robot Helps Restore Damaged Muscles and Nerves

Reuters - Innovations Video Online (Mar. 1, 2015) A rehabilitation robot prototype to help restore deteriorated nerves and muscles using electromyography and computer games. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins