Look at the sky long enough and the universe begins to resemble a city at night. Galaxies take on the features of streetlamps that clog neighborhoods of dark matter, connected by gas pathways that line the banks of the intergalactic nothingness.
This map of the Universe was predetermined, drawn up in the tiniest shivers of quantum physics, shortly after the Big Bang began expanding space and time some 13.8 billion years ago.
But exactly what those fluctuations were, and how they set in motion the physics that would see atoms converge in the vast cosmic structures we see today is far from clear.
A new mathematical analysis of the moments after a period called the inflationary age reveals that some sort of structure may even have existed in the swirling quantum furnace that filled the young universe, and it could help us lay out the present day. out of it.
Astrophysicists from the University of Göttingen in Germany and the University of Auckland in New Zealand used a mix of particle motion simulations and some sort of gravity / quantum modeling to predict how structures might form in the condensation of particles after inflation occurred.
The scale of these types of models is a bit astounding. We are talking about masses of up to 20 kilograms in a space of barely 10-20 meters wide, at a time when the universe was only 10-24 seconds old.
“The physical space suggested by our simulation would fit a million times into a single proton,” said astrophysicist Jens Niemeyer of the University of Göttingen.
“It is probably the largest simulation of the smallest area of the Universe to date.”
Most of what we know about this early stage of the universe’s existence is based on exactly these kinds of mathematical quests. The oldest light that we can still see flickering through the universe is the Cosmic Background Radiation (CMB), and the entire show had been underway for some 300,000 years.
But within that faint echo of old radiation, there are some clues as to what was going on.
The light from the CMB was emitted as base particles combined into atoms from the hot, dense energy soup, in what is known as the era of recombination.
A map of this background radiation in the sky shows that our universe already had some sort of structure a few hundred thousand years old. There were slightly cooler bits and slightly warmer bits that could push matter into regions where stars would eventually ignite, galaxies would spiral out, and masses would gather in the cosmic city we see today.
This raises a question.
The space that makes up our universe is getting bigger, which means the universe must have been a lot smaller at one time. So it makes sense that everything we see around us now was once crammed into a volume too limited for such warm and cool places to appear.
Like a cup of coffee in an oven, no part could cool down before heating up again.
The inflation period has been presented as a way to solve this problem. Within trillionths of a second of the big bang, our universe jumped in size by an insane amount, essentially freezing all variations on the quantum scale.
To say this happened in the blink of an eye still wouldn’t do it justice. It would have started around 1036 seconds after the big bang, and ended with 1032 seconds. But it was long enough for the room to lock into proportions, preventing minor temperature swings from disappearing again.
The researchers’ calculations focus on this short moment after the inflation, showing how elementary particles that congeal from the foam of quantum ripples at that point could have generated short halos of matter dense enough to ripple spacetime itself.
“The formation of such structures, as well as their movements and interactions, must have generated a background noise of gravitational waves,” said astrophysicist Benedikt Eggemeier of the University of Göttingen, lead author of the study.
“Our simulations allow us to calculate the strength of this gravitational wave signal, which may be measurable in the future.”
In some cases, the intense masses of such objects could have drawn matter into primal black holes, objects believed to contribute to the mysterious pull of dark matter.
The fact that the behavior of these structures mimics the large-scale clumping of our universe today does not necessarily mean that it is directly responsible for the current distribution of stars, gas, and galaxies.
But the complex physics unfolding between those freshly baked particles may still be visible in the sky, among that rolling landscape of twinkling lights and dark voids we call the universe.
This research is published in Physical assessment D