A ground-breaking study released in the journal Physical Review Letters (arXiv.org version) offers what its authors call ‘the first observational evidence that the Universe could be a complex hologram.’ The study, led by University of Waterloo Professor Niayesh Afshordi, may lead to new beliefs on the Big Bang theory and quantum gravity.
Hubble Frontier Fields view of a distant galaxy cluster. Image credit: NASA / ESA / HST Frontier Fields Team / STScI.
Prof. Afshordi and his colleagues from UK, Canada and Italy, investigating irregularities in the Cosmic Microwave Background (CMB), the ‘afterglow’ of the Big Bang, have found there is substantial evidence supporting a holographic explanation of the Universe.
“We are proposing using this holographic Universe, which is a very different model of the Big Bang than the popularly accepted one that relies on gravity and inflation,” Prof. Afshordi said.
“Each of these models makes distinct predictions that we can test as we refine our data and improve our theoretical understanding — all within the next five years.”
A holographic Universe, an idea first suggested in the 1990s, is one where all the information, which makes up our 3D ‘reality’ (plus time) is contained in a 2D surface on its boundaries.
“Imagine that everything you see, feel and hear in three dimensions — and your perception of time — in fact emanates from a flat two-dimensional field,” explained co-author Prof. Kostas Skenderis, from the University of Southampton, UK.
“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. However, this time, the entire Universe is encoded!”
Although not an example with holographic properties, it could be thought of as rather like watching a 3D film in a cinema.
“We see the pictures as having height, width and crucially, depth – when in fact it all originates from a flat 2D screen. The difference, in our 3D Universe, is that we can touch objects and the ‘projection’ is ‘real’ from our perspective,” the researchers said.
A sketch of the timeline of the holographic Universe: time runs from left to right; the far left denotes the holographic phase and the image is blurry because space and time are not yet well defined; at the end of this phase (denoted by the black fluctuating ellipse) the Universe enters a geometric phase, which can now be described by Einstein’s equations; the CMB was emitted about 375,000 years later; patterns imprinted in it carry information about the very early Universe and seed the development of structures of stars and galaxies in the late time Universe (far right). Image credit: Paul McFadden.
In recent years, advances in telescopes and sensing equipment have allowed scientists to detect a vast amount of data hidden in the microwaves left over from the moment the Universe was created.
Using this information, Prof. Afshordi, Prof. Skenderis and co-authors were able to make complex comparisons between networks of features in the data and quantum field theory.
They found that some of the simplest quantum field theories could explain nearly all cosmological observations of the early Universe.
“The key to understanding quantum gravity is understanding field theory in one lower dimension. Holography is like a Rosetta Stone, translating between known theories of quantum fields without gravity and the uncharted territory of quantum gravity itself,” Prof. Afshordi said.
“Holography is a huge leap forward in the way we think about the structure and creation of the Universe,” Prof. Skenderis added.
“Einstein’s theory of general relativity explains almost everything large scale in the Universe very well, but starts to unravel when examining its origins and mechanisms at quantum level.”
“Scientists have been working for decades to combine Einstein’s theory of gravity and quantum theory. Some believe the concept of a holographic Universe has the potential to reconcile the two. I hope our research takes us another step towards this.”
The authors now hope their work will open the door to further our understanding of the early Universe and explain how space and time emerged.
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Niayesh Afshordi et al. 2017. From Planck Data to Planck Era: Observational Tests of Holographic Cosmology. Phys. Rev. Lett. 118 (4): 041301; doi: 10.1103/PhysRevLett.118.041301
