The Standard Model of particle physics is brilliant and completely flawed – ABC Online

Every time physicists find a new particle, the Standard Model gets one step closer to becoming a Super Model.

There's always talk of whether the new arrival fits in, or stands out, or matches the model's predictions. Everything gets related back to this "Bible of quantum physics".

The Standard Model isn't mystical, however. It's purely, beautifully mathematical.

Yet for all its predictive power, it's not perfect it can't explain gravity, dark matter or dark energy. The real goal of particle-smashing physicists is to break it.

Only by finding new particles that weren't predicted by the Standard Model, and can't fit inside it, will we move to a new and improved model one that doesn't have big gaps where gravity and the dark parts of physics should be.

Forty years ago scientists pulled everything they knew about quantum physics into one massive equation the Standard Model of particle physics.

If you can follow the maths, the Standard Model is a stunning piece of work. It's like a how-to guide for the particles and forces that operate at the tiny quantum scale including all the atoms that makes up people, plants, planets and stars.

(Luckily for the non-physicists among us, it also comes in handy table form and our handy video above.)

The really big deal with the Standard Model is that it didn't just describe particles that were already known, like the electron and quarks that make up atoms.

It did something much more important it predicted some new particles too, including the Higgs boson.

Testing predictions is at the heart of science, and every one of the particles that the Standard Model predicted has since been discovered. The Higgs was the last to be found, in 2012.

That ability to predict and explain every aspect of the quantum world makes the Standard Model a bit of a superstar.

But while it's undeniably brilliant, no one has ever pretended the Standard Model is perfect.

The most obvious flaw in the Standard Model was there from the beginning it could never account for gravity, the force that rules at the macro scale. That's not the Standard Model's fault; quantum theory and Einstein's gravitational theory just don't work together.

But gravity's not the only thing missing from the model.

The Standard Model can't account for the dark matter and dark energy that make up a cool 95 per cent of the universe either.

And most bizarre of all, it comes right out and says that universe shouldn't exist at least not the way it is. The Model predicts that matter and antimatter should have been produced in equal amounts at the birth of the universe and annihilated immediately thereafter, leaving one enormous sea of light.

Thankfully that hasn't exactly gone to plan either; there's matter all over the place, including little old you and me.

Some of the Standard Model's other shortcomings are on a much less grand and galactic scale.

One of the best-known problems is that it predicts that one family of particles neutrinos should have zero mass. But as the recipients of the 2015 Nobel Prize in Physics can attest, these ridiculously small particles that travel at near light speed have very tiny, but not zero, masses.

Far from being considered a failure for its shortcomings, the Standard Model has always been appreciated by physicists for what it is: a great start to understanding and possibly unifying all of physics.

And in the decades since it appeared, theoretical physicists have thrown up a pile of possible additions to the Model, trying to account for the things it can't explain.

These mostly involve new particles that are much heavier than the known quarks, leptons and bosons. In supersymmetry, the best known 'upgrade' to the model, every particle has a much heavier partner, called a sparticle, which helps patch the current gaps.

Theories are great, but if we want to find out which, if any, of the various upgrades to the Standard Model are right, we really need to find new particles. And that's where particle accelerators come in.

The Higgs boson was found at the Large Hadron Collider in 2012. With higher energy collisions heavier particles could also be discovered.

(www.cern.ch)

The Higgs boson was found at the Large Hadron Collider in 2012. With higher energy collisions heavier particles could also be discovered.

Particle accelerators smash together tiny bits of matter everything from electrons to whole atoms at almost light speed. When that happens, the energy of the collision can be converted into matter. (Einstein's E=mc2 tells us that mass and energy are two sides of the same deal).

And if there's enough energy it can form a heavier particle than we've ever observed.

Heavy particles made in colliders are generally unstable they only exist for an incredibly short time before breaking down into lighter, more stable bits. But those telltale leftovers are exactly the thing physicists look for in particle accelerator experiments all over the world.

So far, new particles haven't been able to 'break' the Standard Model; they just keep opening new chapters of it.

Knowing the mass and energy of these particles will favour some of the new theoretical additions, and knock others out of contention.

The more new particles we find, the narrower the field for refinements to the model.

Any new, heavy particles that are found will result in some new characters in the Standard Model equation, and the beginnings of an extra row or column in the accompanying table. This 'Standard Model Plus' could account for the mass of neutrinos, the antimatter/matter issue, dark matter and dark energy.

But accounting for gravity won't happen without shifting to a new theory altogether one that accounts for all known particles and phenomena as well as the current model does, but that can work with gravity as well.

And theories of quantum gravity won't be validated by particle accelerators any time soon. The energies required to test them are well beyond the range of even the very biggest atom smashers.

For now, a grand unified theory of the universe that ties in quantum and gravitational scales appears to be out of reach. If we ever find it, we'll be in serious Super Model territory.

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The Standard Model of particle physics is brilliant and completely flawed - ABC Online