At the Large Hadron Collider at CERN in Geneva, two beams of protons shoot in opposite directions around a 27km long ring,
crossing paths at several points inside massive detectors. When they collide (with roughly 1 billion collisions per second),
the energy inside the detector results in the production of other particles. The mountains of data collected by those detectors
is evaluated by physicists working with the experiments at CERN, searching for signs of new physics
(and making sure we understand the physics we’ve already seen).
Particle physicists are not easily satisfied. Our guiding text, the Standard Model, is arguably the most successful theory of all time,
marrying quantum mechanics with special relativity and detailing the properties and interactions of the most fundamental particles of
nature, along with three of the four known forces. It has been built, bit by bit, by tens of thousands of scientists in the last
fifty-something years, and is now being tested to its limit at experiment sites around the world. The precision measurements we make at
colliders like the Large Hadron Collider at CERN, where protons are smashed together to create sprays of new particles, have all been
perfectly and devastatingly in agreement (within uncertainty, of course) with predictions made by the Standard Model (edit: recent results here and here display hints of new physics but should, for now, be treated with caution). We have discovered
every particle it demands, the last of which was the Higgs boson in 2012. The most precise measurement of the theory is the electron
magnetic moment, which has been recorded with the precision of one part in a billion. So, shall we call it a day then? Not quite. The
hunt for physics Beyond the Standard Model is in full swing, with physicists searching to fill the holes that the theory has left.
How would you feel if I told you that we can only identify 5% of the energy and matter in the universe? The atoms in your body are made up of the same substance
as the ground beneath your feet and the stars in the galaxies, and all of this can be fully, beautifully and precisely described by the Standard Model of
particle physics. The celestial bodies spread across the night sky are visible because they interact electromagnetically as light bounces off them and into our eyes or telescopes, through one of the three forces encoded in the Standard Model. But for all the success of that theory, we are still pretty much stumped as to the nature of the other 95% of the stuff out there.