Do we live in a 2-D hologram?

New Fermilab experiment will test the nature of the universe

A Fermilab scientist works on the laser beams at the heart of the Holometer experiment. The Holometer will use twin laser interferometers to test whether the universe is a 2-D hologram. Credit: Fermilab

A Fermilab scientist works on the laser beams at the heart of the Holometer experiment. The Holometer will use twin laser interferometers to test whether the universe is a 2-D hologram. Credit: Fermilab

A unique experiment at the U.S. Department of Energy’s Fermi National Accelerator Laboratory called the Holometer has started collecting data that will answer some mind-bending questions about our universe – including whether we live in a hologram.

Much like characters on a television show would not know that their seemingly 3-D world exists only on a 2-D screen, we could be clueless that our 3-D space is just an illusion. The information about everything in our universe could actually be encoded in tiny packets in two dimensions.

Get close enough to your TV screen and you’ll see pixels, small points of data that make a seamless image if you stand back. Scientists think that the universe’s information may be contained in the same way and that the natural “pixel size” of space is roughly 10 trillion trillion times smaller than an atom, a distance that physicists refer to as the Planck scale.

“We want to find out whether space-time is a quantum system just like matter is,” said Craig Hogan, director of Fermilab’s Center for Particle Astrophysics and the developer of the holographic noise theory. “If we see something, it will completely change ideas about space we’ve used for thousands of years.”

Quantum theory suggests that it is impossible to know both the exact location and the exact speed of subatomic particles. If space comes in 2-D bits with limited information about the precise location of objects, then space itself would fall under the same theory of uncertainty. The same way that matter continues to jiggle (as quantum waves) even when cooled to absolute zero, this digitized space should have built-in vibrations even in its lowest energy state.

Essentially, the experiment probes the limits of the universe’s ability to store information. If there is a set number of bits that tell you where something is, it eventually becomes impossible to find more specific information about the location – even in principle. The instrument testing these limits is Fermilab’s Holometer, or holographic interferometer, the most sensitive device ever created to measure the quantum jitter of space itself.

Now operating at full power, the Holometer uses a pair of interferometers placed close to one another. Each one sends a one-kilowatt laser beam (the equivalent of 200,000 laser pointers) at a beam splitter and down two perpendicular 40-meter arms. The light is then reflected back to the beam splitter where the two beams recombine, creating fluctuations in brightness if there is motion. Researchers analyze these fluctuations in the returning light to see if the beam splitter is moving in a certain way – being carried along on a jitter of space itself.

“Holographic noise” is expected to be present at all frequencies, but the scientists’ challenge is not to be fooled by other sources of vibrations. The Holometer is testing a frequency so high – millions of cycles per second – that motions of normal matter are not likely to cause problems. Rather, the dominant background noise is more often due to radio waves emitted by nearby electronics. The Holometer experiment is designed to identify and eliminate noise from such conventional sources.

“If we find a noise we can’t get rid of, we might be detecting something fundamental about nature – a noise that is intrinsic to space-time,” said Fermilab physicist Aaron Chou, lead scientist and project manager for the Holometer. “It’s an exciting moment for physics. A positive result will open a whole new avenue of questioning about how space works.”

The Holometer experiment, funded by the U.S. Department of Energy Office of Science and other sources, is expected to gather data over the coming year.
Read more at www.fnal.gov

New mathematical model links space-time theories

A ‘black string’ black hole phenomenon

A ‘black string’ black hole phenomenon

Researchers at the University of Southampton have taken a significant step in a project to unravel the secrets of the structure of our Universe.

Professor Kostas Skenderis, Chair in Mathematical Physics at the University, comments: “One of the main recent advances in theoretical physics is the holographic principle. According to this idea, our Universe may be thought of as a hologram and we would like to understand how to formulate the laws of physics for such a holographic Universe.”

A new paper released by Professor Skenderis and Dr Marco Caldarelli from the University of Southampton, Dr Joan Camps from the University of Cambridge and Dr Blaise Goutéraux from the Nordic Institute for Theoretical Physics, Sweden published in the Rapid Communication section of Physical Review D, makes connections between negatively curved space-time and flat space-time.

Space-time is usually understood to describe space existing in three dimensions, with time playing the role of a fourth dimension and all four coming together to form a continuum, or a state in which the four elements can’t be distinguished from each other.

Flat space-time and negative space-time describe an environment in which the Universe is non-compact, with space extending infinitely, forever in time, in any direction. The gravitational forces, such as the ones produced by a star, are best described by flat-space time. Negatively curved space-time describes a Universe filled with negative vacuum energy. The mathematics of holography is best understood for negatively curved space-times.

Professor Skenderis has developed a mathematic model which finds striking similarities between flat space-time and negatively curved space-time, with the latter however formulated in a negative number of dimensions, beyond our realm of physical perception.

He comments: “According to holography, at a fundamental level the universe has one less dimension than we perceive in everyday life and is governed by laws similar to electromagnetism. The idea is similar to that of ordinary holograms where a three-dimensional image is encoded in a two-dimensional surface, such as in the hologram on a credit card, but now it is the entire Universe that is encoded in such a fashion.

“Our research is ongoing, and we hope to find more connections between flat space-time, negatively curved space-time and holography. Traditional theories about how the Universe operates go some way individually to describing its very nature, but each fall short in different areas. It is our ultimate goal to find a new combined understanding of the Universe, which works across the board.”

The paper AdS/Ricci-flat correspondence and the Gregory-Laflamme instability specifically explains what is known as the Gregory Laflamme instability, where certain types of black hole break up into smaller black holes when disturbed – rather like a thin stream of water breaking into little droplets when you touch it with your finger. This black hole phenomenon has previously been shown to exist through computer simulations and this work provides a deeper theoretical explanation.

In October 2012, Professor Skenderis was named among 20 other prominent scientists around the world to receive an award from the New Frontiers in Astronomy and Cosmology international grant competition. He received $175,000 to explore the question, ‘Was there a beginning of time and space?’’.

Read more at http://www.southampton.ac.uk/mediacentre/news/2013/may/13_96.shtml