The start of the Universe should be modeled not as a Big Bang but more like water freezing into ice, according to a team of theoretical physicists at the University of Melbourne and RMIT University. They explore the formation of metastable defects at domain boundaries and the effects of domain structures on the propagation of bosons. They show that these structures should have observable background-independent consequences including scattering, double imaging, and gravitational lensing-like effects.
They have suggested that by investigating the cracks and crevices common to all crystals – including ice – our understanding of the nature of the Universe could be revolutionised.
Lead researcher on the project, James Quach said current theorising is the latest in a long quest by humans to understand the origins and nature of the Universe.
“A new theory, known as Quantum Graphity, suggests that space may be made up of indivisible building blocks, like tiny atoms. These indivisible blocks can be thought about as similar to pixels that make up an image on a screen. The challenge has been that these building blocks of space are very small, and so impossible to see directly.”
(Color online – right two pictures) Simulation of the propagation of a boson wavepacket over time. Different time instances, t, are superimposed; each instance is labeled with ( t,M). For clearer presentation, populations are multiplied by factor M so that the peak value at each time instant is approximately the same. a) The boson is initialized in domain-0 with k0 = (−1.6,−0.5). As the boson propagates through the domain boundary it undergoes refraction with angle of refraction | R| ≈ 8.8o . b) The boson is initialized in the domain. As this mode can not couple to resonant modes in domain-0 the boson will be completely reflected. Inset: Zoomed depictions of the domain boundary
However James Quach and his colleagues believe they may have figured out a way to see them indirectly.
“Think of the early universe as being like a liquid,” he said. “Then as the universe cools, it ‘crystallises’ into the three spatial and one time dimension that we see today. Theorised this way, as the Universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice.”
RMIT University research team member Associate Professor Andrew Greentree said some of these defects might be visible.
“Light and other particles would bend or reflect off such defects, and therefore in theory we should be able to detect these effects,” he said.
The team has calculated some of these effects and if their predictions are experimentally verified, the question as to whether space is smooth or constructed out of tiny indivisible parts will be solved once and for all.
The team is supported by the Australian Research Council, and their research was published in the latest edition of the journal Physical Review D.
ABSTRACT – Quantum graphity offers the intriguing notion that space emerges in the low energy states of the spatial degrees of freedom of a dynamical lattice. Here we investigate metastable domain structures which are likely to exist in the low energy phase of lattice evolution. Through an annealing process we explore the formation of metastable defects at domain boundaries and the effects of domain structures on the propagation of bosons. We show that these structures should have observable background independent consequences including scattering, double imaging, and gravitational lensing-like effects.