It all started with the big bang, er… Einstein
The equation has far-reaching implications even to this day, one of which is the equivalence of mass and energy.
The equation, as is obvious, says that energy (represented by E) is equal to mass (represented by m.) Precisely how they are equated is another matter altogether, but what we need to gather from this equation at the moment is that Einstein
said showed that mass and energy are inter-convertible i.e. he showed that at some level they are pretty much the same!
Now this cropped up a new problem. If energy and mass are so easily converted into one another, what makes mass stay as mass? And what prevents it from just zipping around as energy? To understand that we will take a quick look at mass and energy.
Mass and energy and various attractions
Following Einstein’s work came that of Hawking et al. who proved that the story of the universe starting with a big bang was truer than we thought. So imagine this: the universe has just begun and the first particles have been created and anti-particles have disappeared (we do not really know where they went yet) and mass is clumping together to form bigger masses and bigger masses are becoming stars and planets and galaxies and so on; and all of these are in a state of continuous motion.
Two important questions come to mind here: One, what makes these masses move? Two, what makes smaller masses clump together to form larger masses?
The first question is easily answered. Energy that was available to these masses just after the big bang is what makes them zip around. (Now that is a scientifically meaningless sentence because there was nothing before the big bang, but let us concentrate on getting the point across first.) So now we know how this works pretty well. Like salt in water or dirt in a pond, the particles just kept moving about in space. The only difference is that this movement was perhaps not as random, but the underlying principle is quite analogous.
So far we have masses moving about, which is all well and good. Now we come to our more fundamental second question, what makes masses clump together?
The common understanding in physics is that the presence of mass creates attraction. This is why the earth and sun attract, why two stars attract and so on. They are all massive i.e. have mass. They all contain some substance that gives them the property of mass (whatever that substance is, we do not yet know, but we will come to that soon.)
So now you realise that this thing called mass is important to keeps everything stable or else all the mass would have become energy and things would have just been zipping around the universe because the energy that is already present is not going anywhere. (Remember the saying, energy can neither be created nor be destroyed? It is actually a law of Physics.) We will now see how the Higgs boson — or the God Particle as the media call it for some reason which is beyond me — will actually help us answer this question.
Nothing in physics happens without reason. To be precise, we try to find a reason for everything and the next looming question was, what gives particles this property called mass? The answer is the Higgs particle.
The PRL Symmetry Breaking Papers and the Higgs boson
In 1964, three teams of two physicists each independently — within just a couple of months of each other — published papers now called the PRL Symmetry Breaking Papers. In a sentence, these papers all addressed different approaches to the same problem of mass could arise in the circumstance we have just talked about. Of these teams one consisted of American physicist Gerald Guralnik and British physicist Peter Higgs (hence Higgs boson.)
Their solution was simple: Higgs and Guralnik attributed the presence of mass to an as yet undiscovered particle. This was not all about building castles in the air. Their mathematical working had resulted in a strong conclusion that the presence (or addition) of a particle with certain characteristics would solve the mass problem. Further investigation revealed that the particle ought to have properties that put it under a certain category of particles called bosons (i.e. particles which obeyed the Bose-Einstein statistics. In relation, another category of particles, which obey Fermi-Dirac statistics are dubbed fermions.) And this boson came to me known as the Higgs boson.
But the problem (mathematically, again,) was that the Higgs boson appeared briefly (for a fraction of a second) seconds after the big bang and then disappeared. In other words, you do not find Higgs bosons floating around to detect them like you would an electron, or a proton or a car on the road. So the only solution that lay before physicists was to experimentally re-create the Higgs boson by re-creating the big bang, the very phenomenon that kick started our entire universe.
Thus began the LHC project at CERN: a 50-year long, trial and error experiment surpassing an entire generation of experimental physicists trying to get particles to reach 99.99% the unattainable speed of light (because Einstein said so,) and getting those terribly fast moving atoms to collide — much like two rocks colliding — and break up into a million fragments — much like two rock breaking — and look for the Higgs boson among those fragments — like looking for a needle in a haystack.
And we found the needle. That is physics.