New fundamental force of nature

Credit: quantumdiaries.org

Scientists are always eager to understand and explore the basic strings of nature and its working to make them public for the benefit of mankind. The forces are controlling the world, and by extension, the visible universe. Forces drive the cosmic narrative and tell its various actors, from particles to planets, how to move and behave – things that would otherwise seem inexplicable. Scientists have deeply understood the different types of forces in nature on which nature works for example attraction of bodies towards earth, attraction and repulsion of electric charges and magnetic poles, confinement of protons and neutrons inside the nucleus.

In physics, there are four observed fundamental forces or interactions that form the basis of all known interactions in nature which are gravity , electromagnetism, the weak and the strong nuclear forces. Gravity and electromagnetism forces are of infinite range whereas week and strong nuclear forces have range of 10-17 & 10-15m respectively. Scientists are trying hard to unify all these four forces to one (i.e., grand unified theory of the universe) but still without success but they claim to explain all natural actions based on these four basic forces of nature. However, scientists only believe in the effects in nature which can be visualized, measured and have repeatability. There are numerous examples of forces of love and hate which human beings always encounter in their daily lives like: family love attraction (particularly mother & child), human to human love or hatred forces, physical attraction between different sexes (sometimes same sexes also) in all these can be combined under forces of biological in nature which scientists so far are not able to conceptualized and quantify.

Living the biological forces aside, it is well assumed that just four fundamental forces keep the nature and cosmic action going on.  However, scientific claim of basic four forces in nature is under debate with the recent scientific evidences about a fifth type of force in nature. Some speculative theories before have also proposed the existence of fifth force in order to explain different strange observations which do not fit in the existing theories and thus, the characteristics of this force depend on the theory being advanced. Some scientists propose a force with strength of gravity (much weaker than electromagnetism or the nuclear forces) having a range of less than a millimeter to cosmological scales whereas other proposes a weak force mediated by W′ and Z′ bosons. The search for a fifth force has attracted more attention in recent decades due to two discoveries in cosmology which are not explained by current theories. These discoveries are the existence of dark matter and it has been discovered that most of the mass of the universe is accounted for by an unknown form of matter called dark matter. Many physicists consider that dark matter consists of undiscovered subatomic particles but some believe that it could be related to an unknown fundamental force. Secondly, it has also recently been discovered that the universe is going through a phenomena of accelerating expansion which has been attributed to a form of energy called dark energy and physicists speculate that a form of dark energy could be a fifth force.

Related to the above discussed two discoveries, dark matter and dark energy, multiple indications seem to be showing that something is manipulating the universe beyond the four basic forces. Hints from theory and experiment are combining to suggest that it might not be just four, but five, six – or maybe even more.  Scientists at the Institute for Nuclear Research at the Hungarian Academy of Sciences (Atomki) claim to have found a new particle that reveals a fifth force of nature. Scientists claim to have discovered a new particle - dubbed X17 (due to its calculated mass of 17 mega-electronvolts) - that requires the existence of a fifth force of nature. Particle X17 could be responsible to connect our visible world with the dark matter and if confirmed further, wouldn't just be any old particle - its characteristics suggest it to be a completely new kind of fundamental boson that hasn't been studied before. This would be a fetching discovery because three of the four known forces governing the natural world are known to have carry bosons, which lend their hand in the physics of attraction and repulsion of objects where as the force of gravity is supposedly carried by a hypothetical particle called the graviton, which scientists have predicted but not yet detected.

The researchers back in 2015 at the Institute for Nuclear Research at the Hungarian Academy of Sciences (Atomki) say that they weren’t looking for the new particle but it popped up as an anomaly in their detector while they were searching for signs of dark matter. Then a group of prominent particle physicists working at the University of California, Irvine (USA), took a closer look and suggested that the Hungarians had stumbled on to a new type of particle that implies an entirely new force of nature. They watched energetic (excited) helium atom release energy by emitting light, before returning to its unexcited state. During this process, the particles seemed to split at an unusual angle in repeated studies — always a 115-degree-angle. A few years ago, the same research team observed an isotope of decaying beryllium leading them to explore the same as they have done with a lighter He atom. Their findings showed that particles were released by beryllium-8 (radioactive) atoms at a 140-degree angle, which was odd, and new. This phenomenon has no fitting explanation on the basis of the four known forces that govern the natural world. This also isn't the first time scientists have claimed a glimpse of the proposed "fifth force" in action, either. The Hungarian scientists in late 2019 released new results suggesting that their signal hadn’t gone away and the anomaly persisted even after they changed the parameters of their experiment and have seen in the same way hundreds of times. That leaves some physicists excited by the prospect of a new force who think the new force could move physics closer to a grand unified theory of the universe, or even help explain dark matter and dark energy. However, more theoretical and experimental studies are further needed to verify and declare the existence of nature’s fifth force as it will affect the whole teaching and learning concepts of physics.

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