Buzz
For centuries, humanity has sought to unravel the mysteries of the universe's composition. The Ancient Greeks were the first to propose the concept of atoms, which they believed to be the universe's fundamental particles—the very 'building blocks' of everything. For around 1,500 years, this was the extent of our understanding of matter. Then, in 1897, the discovery of the electron shook the scientific community to its core. Just as molecules were made of atoms, atoms were now found to have their own components.
The deeper we delved, the more elusive the answers became, always slipping just out of our grasp. Even protons and neutrons—the core components of atoms—are made up of even tinier pieces called quarks. With every breakthrough, more questions arose. Could time and space simply be clusters of minuscule charged particles too small to observe? Perhaps—but these ten theoretical particles might hold the answers to everything. If we could ever detect them:
10. Strangelets
Let’s begin with something familiar to us—quarks. There are six distinct types of quarks. The most common are the 'up' and 'down' quarks, which form the protons and neutrons that make up atoms. On the other hand, 'strange' quarks are far less common. When strange quarks combine in equal numbers with up and down quarks, they create a particle known as a strangelet. These strangelets are the delicate fragments that form strange matter.
According to the strange matter theory, strangelets are produced in nature when a massive neutron star—a star that has collapsed under its own weight—builds so much pressure that the electrons and protons in its core merge, further collapsing into a dense quark bubble known as strange matter. Since large strangelets could theoretically exist outside of these extreme stellar environments, it’s possible that they have drifted away from such stars, entering other solar systems, including our own.
Now, here’s where things get really wild: if these strangelets existed, a large one could convert an atom's nucleus into another strangelet by colliding with it. This new strangelet could then keep colliding with more nuclei, triggering a chain reaction that would eventually turn all matter on Earth into strange matter. In fact, the Large Hadron Collider had to release a statement assuring the public that they were unlikely to accidentally create strangelets capable of destroying the planet. That’s how seriously the scientific community takes the potential of strangelets.
9. Sparticles
Supersymmetry theory proposes that every particle in the universe has a counterpart—an opposite twin known as a supersymmetric particle, or sparticle. For each quark, there exists a partner, a 'squark,' that mirrors it perfectly. For every photon, there is a corresponding 'photino.' This symmetry extends to all sixty-one elementary particles we know. With so many of these particles, why haven’t we discovered a single sparticle yet?
Here’s the explanation: in particle physics, heavier particles decay more quickly than lighter ones. When a particle becomes sufficiently massive, it decays almost instantaneously after being created. If sparticles are as heavy as theorized, they would disintegrate in the blink of an eye, while their superpartners—the particles we can observe—persist. This could also account for the abundance of regular matter in the universe and the scarcity of dark matter, as sparticles might make up dark matter, existing in a field that is currently undetectable.
8. Antiparticles
Matter consists of particles, and similarly, antimatter is composed of antiparticles. This concept makes sense, right? Antiparticles share the same mass as regular particles but possess opposite charges and angular momentum (spin). While this aligns with supersymmetry theory, antiparticles behave just like particles, even forming anti-elements like antihydrogen. Essentially, for every type of matter, there exists a corresponding antimatter counterpart.
Or at least, it should. That’s the issue—there's plenty of matter around, but antimatter doesn’t seem to appear anywhere. (Except for the Large Hadron Collider—just to clarify, antiparticles have been discovered and are no longer just a theory).
During the Big Bang, an equal number of particles and antiparticles should have been created. The theory is that all matter in the universe originated at that moment. Therefore, antimatter must have been created simultaneously. One theory suggests that there are regions of the universe entirely made of antimatter. While everything visible to us, even the most distant stars, consists mostly of matter, our observable universe might only be a small section of the whole. Antimatter planets, suns, and galaxies could be existing in another part of the universe, like opposite-charged electrons and protons revolving around each other in an atom.
7. Gravitons
Currently, antiparticles present a significant challenge in particle physics theories. Want to hear about another issue? Gravity. Compared to other forces, like electromagnetism, gravity is weaker than sneezing your way through a fist fight. It also seems to behave differently depending on the mass of an object—gravity is easy to observe in planets and stars, but at the molecular level, it behaves unpredictably. And on top of all that, gravity doesn’t even have a particle to carry it, like photons carry light.
This is where the graviton comes into play. The graviton is the theoretical particle that would—sort of—make gravity fit within the same framework as all other observable forces. Since gravity exerts a weak pull on every object, regardless of distance, it would have to be massless. But that’s not the issue—photons are massless, and we’ve already discovered them. We’ve even defined the exact parameters that a graviton would need to match, and as soon as we find a particle—any particle—that fits those criteria, we’ll have found the graviton.
Discovering it would be crucial because, right now, general relativity and quantum physics don’t align. But at a very specific energy level, known as the Planck scale, gravity stops following the rules of relativity and switches to quantum behavior. So solving the gravity conundrum could unlock the key to a unified theory.
6. Graviphotons
There’s another fascinating theoretical particle related to gravity: the graviphoton. This particle would be generated when the gravitational field is excited within a fifth dimension. It stems from the Kaluza Klein theory, which suggests that electromagnetism and gravity could be unified into a single force, provided there are more than four dimensions in spacetime. A graviphoton would have the properties of a graviton but also carry the characteristics of a photon, creating what physicists refer to as a 'fifth force' (currently, there are only four fundamental forces).
Other theories suggest that a graviphoton could be a superpartner (like a sparticle) of gravitons, but with a unique twist: it would both attract and repel simultaneously. This could allow gravitons to potentially create anti-gravity. And this is just within the fifth dimension—supergravity theory goes even further, proposing the existence of graviphotons and allowing for up to eleven dimensions.
5. Preons
What exactly are quarks made of? First, let's understand the scale. The nucleus of a gold atom contains seventy-nine protons, and each proton consists of three quarks. The width of that gold atom's nucleus is around eight femtometers—eight millionths of a nanometer, and a nanometer is already one billionth of a meter. So, suffice it to say that quarks are incredibly tiny, and preons—particles even smaller than quarks—would be so minuscule that no current scale could measure them.
There are other terms for the theoretical components of quarks, such as primons, subquarks, quinks, and tweedles, but 'preon' is the most commonly accepted. Preons are crucial because quarks are currently considered fundamental particles—they represent the smallest possible units. If quarks are found to be made of smaller pieces, it could open up a multitude of new theories. One current theory even proposes that the universe's elusive antimatter could be hidden within preons, meaning everything contains a bit of antimatter. According to this theory, you yourself are partly antimatter—you just can't see it because the matter components combine to form larger structures.
4. Tachyons
Tachyons are the particles that most directly challenge the established laws of relativity. They are theorized to move faster than light, which, if proven true, would mean that the lightspeed limit is no longer a boundary. In fact, it would imply that the speed of light isn't a limit at all but merely the middle point—just as particles can come to a complete halt, tachyons on the other side of that boundary could theoretically travel at infinite speed.
Strangely, the relationship between tachyons and the speed of light is reversed compared to that of normal particles. In simple terms, when a regular particle speeds up, its energy requirements grow. To break the lightspeed barrier, a normal particle would need an infinite amount of energy. However, for a tachyon, the opposite is true: the slower it moves, the more energy it needs. As it approaches the speed of light from the opposite side, its energy demand rises exponentially. But as it accelerates, its energy needs diminish, eventually reaching a point where it requires no energy at all to achieve infinite speed.
Imagine two magnets: one stuck to a wall and the other in your hand. When you push the hand-held magnet towards the one on the wall with the poles aligned, the magnets repel each other. The closer you get, the harder you push. Now picture another magnet on the other side of the wall doing the same thing. The wall magnet represents the speed of light, while the hand-held magnet represents the normal particles, and the distant one represents tachyons. Even if tachyons existed, they'd forever be stuck on the other side of a barrier we can't pass. But it's worth mentioning that they might just be able to send messages backward in time.
3. God Particle
The Higgs boson, often called the God particle, was tentatively detected on March 14, 2013, within the Large Hadron Collider (9). To give a bit of context, the Higgs boson was first theorized in the 1960s as the particle responsible for imparting mass to other particles.
At its core, the God particle is created within the Higgs field, which was proposed as a mechanism to explain why some particles that should theoretically have mass are instead massless. This Higgs field, which had never been observed before, would need to span the entire universe and provide the force necessary for particles to gain mass. If proven true, it would help fill in major gaps in the Standard Model, which serves as the framework for understanding the universe—except, of course, for gravity.
The discovery of the Higgs boson is crucial because it not only validates the existence of the Higgs field but also explains how energy within that field can transform into mass. But its significance extends beyond that—it sets an important precedent. Prior to its discovery, the Higgs boson existed only as a theoretical concept, with mathematical models and physical parameters that outlined its potential existence and properties, such as its spin. The discovery confirmed that the particle we hypothesized was indeed real, and it was the smallest known entity in the universe that fit the bill.
If we were able to achieve it once, who’s to say that particles like tachyons, strangelets, and gravitons couldn’t be real? These theoretical particles have the potential to upend everything we know about existence and the universe, bringing us closer to truly understanding the very building blocks of our world.
2. Branes
To grasp a true understanding of gravity, one must turn to M-theory, or Membrane theory. Branes, short for membranes, are particles capable of spanning multiple dimensions. A 0-brane, for instance, exists in zero dimensions, much like a quark, while a 1-brane represents a one-dimensional string. A 2-brane is a two-dimensional membrane, and so forth. These higher-dimensional branes can vary in size, giving rise to the notion that our entire universe is one enormous brane with four dimensions, existing as a fragment within a larger multi-dimensional space.
As for gravity, our four-dimensional brane cannot contain it entirely. Instead, the energy of gravity leaks into other branes as it moves through the multi-dimensional space. What remains in our brane is just a fraction of that energy, which explains why gravity seems so weak compared to other forces.
Building on that, it's logical to imagine countless branes moving through infinite space—endless branes in an infinite universe. This idea leads to multiverse and cyclic universe theories. The cyclic model suggests that the universe is caught in a repetitive cycle: it begins with the Big Bang, expanding from pure energy, then gravity eventually pulls everything back into a singularity for the Big Crunch. The energy from that compression triggers another Big Bang, propelling the universe into a new cycle, much like a living cell that flares into existence only to die.
1. Strings
Up to this point, most of the particles we've discussed are considered point particles; quarks and photons are thought of as minuscule, zero-dimensional points. String theory challenges this by proposing that these fundamental particles aren't really points at all. Instead, they're one-dimensional strands, or 'strings.' Essentially, string theory is a Theory of Everything that manages to work within both the realm of gravity and quantum physics—a feat that current theories struggle to achieve, as gravity doesn't mesh with quantum mechanics at the microscopic level.
In the grand scheme of things, string theory could be seen as a quantum theory of gravity. To put it in perspective, strings would serve as the foundational elements of quarks, replacing preons while maintaining all other aspects of the theory. In string theory, the form of the string determines what particle it becomes. If it's an open strand, it becomes a photon. If the ends connect to form a loop, it becomes a graviton—much like how a single piece of wood could become either a house or a flute, depending on how it's shaped.
There are actually several variations of string theory, each proposing a different number of dimensions. While most suggest ten or eleven dimensions, Bosonic string theory (or superstring theory) goes further, positing as many as twenty-six. In these extra dimensions, gravity would be as strong as or even stronger than the other fundamental forces, which helps to explain why gravity appears so weak in our three-dimensional space.
