APR 28, 2015 9:26 AM PDT

Mathematical Equation of Universe Suggests a Giant, Cosmic Holograph

WRITTEN BY: Will Hector
At first glance, there is not the slightest doubt: to us, the universe looks three dimensional. But one of the most fruitful theories of theoretical physics in the last two decades is challenging this assumption. The "holographic principle" asserts that a mathematical description of the universe actually requires one fewer dimension than it seems. What we perceive as three dimensional may just be the image of two dimensional processes on a huge cosmic horizon.

Up until now, this principle has only been studied in exotic spaces with negative curvature. This is interesting from a theoretical point of view, but such spaces are quite different from the space in our own universe. Results obtained by scientists at TU Wien (Vienna) now suggest that the holographic principle even holds in a flat spacetime.
Is our universe a hologram?
Everybody knows holograms from credit cards or banknotes. They are two dimensional, but to us they appear three dimensional. Our universe could behave quite similarly: "In 1997, the physicist Juan Maldacena proposed the idea that there is a correspondence between gravitational theories in curved anti-de-sitter spaces on the one hand and quantum field theories in spaces with one fewer dimension on the other," says Daniel Grumiller (TU Wien).

Gravitational phenomena are described in a theory with three spatial dimensions, the behaviour of quantum particles is calculated in a theory with just two spatial dimensions -- and the results of both calculations can be mapped onto each other. Such a correspondence is quite surprising. It is like finding out that equations from an astronomy textbook can also be used to repair a CD-player. But this method has proven to be very successful. More than ten thousand scientific papers about Maldacena's "AdS-CFT-correspondence" have been published to date.

For theoretical physics, this is extremely important, but it does not seem to have much to do with our own universe. Apparently, we do not live in such an anti-de-sitter-space. These spaces have quite peculiar properties. They are negatively curved, any object thrown away on a straight line will eventually return. "Our universe, in contrast, is quite flat -- and on astronomic distances, it has positive curvature," says Daniel Grumiller.

However, Grumiller has suspected for quite some time that a correspondence principle could also hold true for our real universe. To test this hypothesis, gravitational theories have to be constructed, which do not require exotic anti-de-sitter spaces, but live in a flat space. For three years, he and his team at TU Wien (Vienna) have been working on that, in cooperation with the University of Edinburgh, Harvard, IISER Pune, the MIT and the University of Kyoto. Now Grumiller and colleagues from India and Japan have published an article in the journal Physical Review Letters, confirming the validity of the correspondence principle in a flat universe.

"If quantum gravity in a flat space allows for a holographic description by a standard quantum theory, then there must by physical quantities, which can be calculated in both theories -- and the results must agree," says Grumiller. Especially one key feature of quantum mechanics -quantum entanglement -- has to appear in the gravitational theory.

When quantum particles are entangled, they cannot be described individually. They form a single quantum object, even if they are located far apart. There is a measure for the amount of entanglement in a quantum system, called "entropy of entanglement." Together with Arjun Bagchi, Rudranil Basu and Max Riegler, Daniel Grumiller managed to show that this entropy of entanglement takes the same value in flat quantum gravity and in a low dimension quantum field theory.

"This calculation affirms our assumption that the holographic principle can also be realized in flat spaces. It is evidence for the validity of this correspondence in our universe," says Max Riegler (TU Wien). "The fact that we can even talk about quantum information and entropy of entanglement in a theory of gravity is astounding in itself, and would hardly have been imaginable only a few years back. That we are now able to use this as a tool to test the validity of the holographic principle, and that this test works out, is quite remarkable," says Daniel Grumiller.

This however, does not yet prove that we are indeed living in a hologram -- but apparently there is growing evidence for the validity of the correspondence principle in our own universe.

(Sources: Vienna University of Technology; Science Daily)
About the Author
  • Will Hector practices psychotherapy at Heart in Balance Counseling Center in Oakland, California. He has substantial training in Attachment Theory, Hakomi Body-Centered Psychotherapy, Psycho-Physical Therapy, and Formative Psychology. To learn more about his practice, click here: http://www.heartinbalancetherapy.com/will-hector.html
You May Also Like
DEC 28, 2020
Space & Astronomy
During a Total Solar Eclipse, a Comet is Spotted Racing Past the Sun
DEC 28, 2020
During a Total Solar Eclipse, a Comet is Spotted Racing Past the Sun
On December 14, 2020, there was a total solar eclipse that could be seen in Chile and Argentina. Now scientists have rev ...
MAR 18, 2021
Space & Astronomy
There May Be More Water-Rich Planets than Previously Thought
MAR 18, 2021
There May Be More Water-Rich Planets than Previously Thought
Researchers have hypothesized that a certain mechanism may mean there are many more water-rich planets with atmospheres ...
APR 21, 2021
Space & Astronomy
Earth-like Planet Discovered Orbiting Red Dwarf Star
APR 21, 2021
Earth-like Planet Discovered Orbiting Red Dwarf Star
Researchers from Spain have discovered an Earth-like planet orbiting the star, GJ-740, a red dwarf star located 36 light ...
MAY 23, 2021
Space & Astronomy
More Accurate Clocks Create More Disorder in the Universe
MAY 23, 2021
More Accurate Clocks Create More Disorder in the Universe
Physicists at the University of Oxford in the UK have conducted an experiment that suggests the more accurately clocks t ...
MAY 29, 2021
Space & Astronomy
First Matter in the Universe Flowed Like Tap Water
MAY 29, 2021
First Matter in the Universe Flowed Like Tap Water
In two separate studies, researchers led by those at the University of Copenhagen and Queen Mary University of London fo ...
JUN 01, 2021
Space & Astronomy
Curiosity Captures Shimmering Martian Clouds
JUN 01, 2021
Curiosity Captures Shimmering Martian Clouds
Mars has a thin atmosphere without much humidity, making cloudy days rare. But clouds can be found sometimes near the Ma ...
Loading Comments...