Big freeze
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A group of theoretical physicists at the University of Melbourne and RMIT University have proposed a new theory on the origin of the universe that could overturn the Big Bang model. This new idea, which piggybacks off the nascent field of quantum graphity, suggests that the early universe went through a dramatic transformation, or phase shift, in a manner similar to how a liquid turns to a solid. To prove their theory, however, the researchers will have to find the crack in the ice.

According to lead researcher James Quach, the early universe can be compared to a liquid - a state of matter that has no definable form. As it cools, it "crystallizes" into the three spatial and one time dimension that characterizes our universe today. It's the cooling of the universe, says Quach, that gives it its structure. Consequently, Quach and his team are making the case that the start of the universe should not be modeled as a Big Bang, but rather like a Big Freeze - akin to water transforming into ice.

A driving force behind Quach's work is his contention that the Big Bang theory is inadequate. Speaking to the Sydney Morning Herald, Quach had this to say:
The biggest problem with the big bang model is the bang itself. At the bang, physics breaks down. The model cannot make any predictions at what occurs at the big bang. You can't use any of the mathematics [or] any of the theories."
This is where quantum graphity could come to the rescue. Writing in Space, Natalie Wolchover explains how the theory fits in:
The notion that space and time are emergent properties that suddenly materialized out of an amorphous state was first put forth by physicists at Canada's Perimeter Institute in 2006. Called "quantum graphity," the theory holds that the four-dimensional geometry of space-time discovered by Albert Einstein is not fundamental; instead, space-time is more like a lattice constructed of discrete space-time building blocks, just like matter looks continuous, but is actually made of building blocks called atoms.
According to this theory - which is still a kind of holy grail of physics - space is made of indivisible chunks that function much like pixels do on a computer screen. Consequently, in order for this theory to be proved right, the researchers will have to demonstrate that these building blocks truly exist.

Again, the states-of-matter analogy could help. When liquids turn to ice, they crystallize and form cracks. What Quach and his team need to do now is find the cosmological equivalent of these "cracks," or defects.

And indeed, they believe this might be possible. According to Quach, light and other particles might bend or reflect off such defects - an effect that could be measured. Looking ahead to this possibility, the team has already performed some calculations and are claiming that the math looks right. The key now will be in setting up the appropriate experiment. As Wolchover notes, the team needs to figure out the average distance between cracks: "It isn't known whether they are microscopic, or light-years apart."

The next step for the researchers, therefore, will be in figuring out if they need to use a telescope or a microscope.

The entire study appears in Physical Review D.

Sources: Space and the Sydney Morning Herald.