Physicists say they have detected a fifth force of nature

Physics can be pretty intense at times, but one of the most straightforward aspects is that everything in the Universe is controlled by just four fundamental forces: gravity, electromagnetic, and strong and weak nuclear forces.

Now physicists in Hungary think they might have found evidence of a mysterious fifth force of nature.

Before we get into that, let’s go back to those four forces for a second, because they’re significantly important.

They’re a fundamental part of the standard model of physics, which explain all the behaviour and particles we see in the Universe.

Starting from the larger end of the scale, gravity is responsible for holding together the planets and gravity, and the electromagnetic force is in charge of keeping our molecules together.

“At the smallest level are the two other forces: the strong nuclear force is the glue for atomic nuclei, and the weak nuclear force helps some atoms go through radioactive decay,” writes Ryan F. Mandelbaum for Popular Science.

“These forces seemed to explain the physics we can observe, more or less.”

Evidence of this fifth force was spotted last year when a team from the Hungarian Academy of Science reported that they’d fired protons at lithium-7, and in the fallout, had detected a brand new super-light boson that was only 34 times heavier than an electron.

As exciting as that sounds, the paper was mostly overlooked, until a team in the US published their analysis of the data at the end of last month, on pre-print site arXiv.

The US team, led by Jonathan Feng from the University of California, Irvine, showed that the data didn’t conflict with previous experiments, and calculated that the new boson could indeed be carrying a fifth fundamental force – which is when the science world started to get interested.

As Nature magazine reports, researchers around the world are racing to conduct follow-up tests to verify the Hungarian discovery, and we can expect results within around a year.

If you’re anything like me, you’re probably wondering, what does a super-light boson have to do with a new force of nature?

This isn’t the first time researchers have claimed to detect a fifth force, but the search has heated up over the past decade.

Many scientists think there might be a particle out there called a ‘dark photon,’ which could carry a new force that would explain dark matter – that invisible substance that makes up more than 80 percent of the Universe’s mass.

“According to the standard model, physicists should see that the number of observed pairs drops as the angle separating the trajectory of the electron and positron increases,” Edwin Cartlidge writes for Nature.

This ‘bump’ was evidence of a new particle, according to Krasznahorkay and his team.

They calculated that the mass of this new particle would be around 17 megaelectronvolts, which isn’t what was expected for the ‘dark photon’, but could be evidence of something else entirely.

The analysis by Feng’s team in the US didn’t involve a repeat of the experiment, but merely used calculations to verify that, theoretically at least, the proposed super-light boson Krasznahorkay detected could be capable of carrying a new fundamental force.