An ultra-high-resolution simulation of a small part of the universe – a million times smaller than a proton – revealed the very first structures that ever existed. And these dense structures are strange.
The first trillionth of a second after the Big explosion, the universe was a hot, soupy place, place, heated to more than a trillion degrees. Although scientists cannot directly observe this moment, they can reconstruct it using powerful computer simulations.
The new simulations, more detailed than ever before, showed how gravity in this first case causes quantum particles, known as inflatons, to coincide. The results showed for the first time how these lumps then form complex and dense structures that weighed between a few grams and 20 kilograms – about heavier than a postage stamp, but lighter than a bulldog – in a space smaller than ‘ an elementary particle.
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The simulations are the first to show enough detail that scientists can decipher the variety of sizes and shapes of these baby structures. In addition, the results elegantly matched a simple theoretical model that is nearly 40 years old, said study co-author Richard Easther, a physics professor at the University of Auckland.
“We are discovering this incredibly complex phase in the early universe, which is only now beginning to be well understood.”
The simulations modeled a time at the end of inflation, a period in which the universe was largely in balloons. At that time, the universe contained only energy and inflatables – a kind of quantum substance that formed from the energy field that filled the entire space after the big bang.
Physicists think that the inflation structures seen in the simulations stem from fluctuations in that energy field immediately after the big bang. The same field probably created the large-scale galactic structures seen in the universe today that are billions of light-years away.
The dense, inflatons-filled structures seen in the simulations probably did not last long, as they probably changed into elementary particles within fractions of a second. But with their high densities – which are as much as 100,000 times denser the surrounding space – their movements and interactions can cause wrinkles in the tissue of space-time called gravitational waves. The new simulations will help scientists calculate exactly how large the gravitational waves could be, which will help future experiments to look for similar ripples in the universe.
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The small buds may also have collapsed under their own weight, creating the universe’s first black holes, called primary black holes. Some scientists think that such black holes could be a candidate for dark matter – the mysterious substance that no one has seen directly, but which currently makes up 85% of matter in the universe. The physicists did not see any black holes in their simulations, but they plan to run longer, more detailed simulations in the future that could show such objects.
“The primordial black holes are an interesting possibility at this point – it could lead to new behaviors, but would also provide new handles for testing the model,” Easther wrote in an email to Live Science. Since some original black holes must continue into the modern universe, finding one can help verify scientists’ models of these early moments in infancy.
Easther and his colleagues published an article describing the simulations on March 22 in the journal Physical Review D.
Originally published on Live Science.