13.77 billion years. That’s how old the universe is.
If you were to compress the time the universe has existed into 24 hours, with the Big Bang occurring at the stroke of midnight, humans crash the party late – at 11:59:56pm, just four seconds before the end of the day!
Our insatiable curiosity about our origins has only provoked questions on top of more questions, including: What happened seconds after the Big Bang?
Astrophysicists are keen on winding back the clock to learn more about the very early universe. Now, a mysterious, hypothetical particle could mean finding out for the first time what took place just ONE second after the birth of the universe!
Searching for baby universe.
But wait, how far can astronomers peer back at the universe’s history?
With modern scientific equipment, researchers can look at what happened 400,000 years after the Big Bang, through observations of the Cosmic Microwave Background (CMB) on the electromagnetic spectrum. During this time, the universe was sufficiently cooled for hydrogen to form through the combination of protons and electrons, kickstarting the evolution of the cosmos.
Going deeper into the abyss proved to be quite challenging as scientists can’t observe any photons before those 400,000 years.
Enter the realm of axions, hypothetical particles that may have been released one second after the universe’s birthday.
Published in the journal Physical Review D, physicists propose to seek an axion counterpart of the CMB, called the Cosmic Axion Background, or CAB. They have yet to prove that axions exist, but they strongly believe it’s only a matter of time before the particles reveal themselves!
Wherefore art thou Axion!
Axions have long been on the radar of theoretical physicists. Take string theory for example. Axions are predicted to be a significant part of the theory, where physicists turn to quantum mechanics to explain the mechanisms of gravity. The existence of the axion could also unravel the mystery of why the negative and positive charges inside a neutron are so hard to measure. More recently, axions have also become intertwined with the theory of dark matter, and researchers are rushing to search for axion dark matter.
In the paper, the physicists indicate that as more sensitive instruments are innovated to search for dark matter, they might finally be able to encounter axions in the form of CAB. And if that happens, it would be a major discovery that shakes up the world of physics. Not only would it establish the existence of the axion, but scientists all over the world would have spanking new information about the very early universe, revolutionising the way we comprehend its evolution.
It’s mind-boggling to wrap our heads around humankind’s achievements thus far in understanding the universe. To put things in perspective, though we have only existed a mere four seconds on the 86400-second (24-hour) cosmic scale, we are now gearing towards finding out what exactly happened right after the Big Bang.
Truly astonishing, isn’t it?
