British astrophysicist, Lord Martin Rees, founder of the Center for the Study of Existential Risk, famous for his contributions to black hole formation and the evolution of the universe, has observed that contrary to popular perception, the vacuum of space is not an empty void. The vacuum, Rees states, has in it “all the forces and particles that govern the physical world.” And he adds, it’s possible that the vacuum we can observe is in reality “fragile and unstable.”
The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma. Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons.
The Big Bang, which caused the entire universe to emerge instantaneously, was a change of state that can’t be explained as happening in one place or at one specific time, observe Deepak Chopra and quantum physicist Menas Kafatos in You are the Universe. “During the Planck era,” they write, “everywhere and nowhere were the same, as were before and after. Despite the wall that prevents us from witnessing the Planck era, we could call it a phase transition whereby one state transformed into another and the virtual became manifest.
During the Planck era, the authors write, the incredibly minute timescale when the big bang began, “Nature wasn’t so recognizable, because the familiar constants and forces were either very different or didn’t yet exist. In the so-called Planck dimension, space becomes “foamy,” an indistinct state where any sense of direction, such as up and down, comes to an end. In terms of duration, Planck time—the characteristic scale of the Planck era—is more than 30 orders of magnitude faster than the fastest timescales of present-day nanoscience, where a nanosecond is a billionth of a second.”
“It’s quite peculiar,” they continue, “sitting here where the clocks tick, to realize that, just like an electron popping into a new shell, the entire creation did the same almost 14 billion years ago. But if we can imagine it, at least this tells us how something as tiny as an electron and something as large as the cosmos are linked. Neither one is on clock time; therefore, entirely new ways of thinking must be adopted”.
Yesterday, Phys.org reported that international researchers have been investigating the black holes detected in 2015 by the LIGO/Virgo collaboration that generated gravitational waves arising from a binary black hole merger using the two detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) examining whether they could be of primordial origin –produced in the early universe before stars and galaxies were formed.
A new theory proposed by Hooman Davoudiasl, a theoretical physicist at the Brookhaven National Laboratory in New York, suggests that these primordial black holes (PBH) were created by an abrupt cosmological phase transition, which is somewhat similar to the transition from vapor to liquid that occurs when water condenses on a cold surface. An example of this phase transition in the early universe could be the cooling of hot plasma made up of quarks and gluons, which might have occurred as the universe expanded, and they began binding into protons and neutrons.
Davoudiasi suggests that the black holes observed by the LIGO/Virgo collaboration originate from a first order quark confinement phase transition. In his paper, published in Physical Review Letters, Davoudiasl implemented this idea using a light scalar that could turn out to be a good dark matter candidate.
“The general subject of non-standard cosmologies is worth thinking about further,” Davoudiasl said. “Modifying some of our usual assumptions regarding the early universe could potentially lead to new insights about open questions in physics and cosmology.”
Fast forward to contemporary planet Earth, in October 2018, Rees observed Earth could be crushed to the size of a soccer field by particle accelerator experiments where the possibility exists that quarks would reassemble themselves into compressed objects called strangelets. That in itself would be harmless. However under some hypotheses a strangelet could, by contagion, convert anything else it encounters into a new form of matter, transforming the entire earth in a hyperdense sphere about one hundred meters across –the size of a soccer field.
“Many of us are inclined to dismiss these risks as science fiction, but given the stakes they could not be ignored, even if deemed highly improbable,” Rees concluded, quickly countered by Stephen Hawking who observed that “collisions releasing greater energy occur millions of times a day in the earth’s atmosphere and nothing terrible happens.”
The Daily Galaxy, Sam Cabot, via Phys.org, University of Munster, You Are The Universe
Image credit: With thanks to DESY, an artist’s impression of the active galactic nucleus