In very simple terms, physicists have to break stuff to find stuff. They get to use the scientific principles of a 2 year old toddler and smash things together to see what comes off…..albeit in a much more controlled environment.
Particle physicists have a fun job. Sure they are dealing with some very heady principles, and are trying to prove what has been postulated after years of thought experiments and enough math to make an intelligent person go insane, but ultimately they are trying to break things to find the smallest parts that they can. They use real big tools to do it too. The most famous is the Large Hadron Collider (LHC) built at CERN in Geneva, Switzerland (well part of it is in France as well) is an underground ring measuring 17 miles in circumference. It’s designed to take two opposing beams of particles, accelerate them to just under the speed of light and smash them into each other. These collisions, although small, are very powerful. The explosions are aimed to occur within very large detectors that try to capture the evidence of subatomic particle, which decay very quickly.
As you might imagine these are not experiments that can be conducted inside university labs due to the size of the tools and the cost to operate them. Consider that the entire 17 mile ring is lined with very expensive super conducting magnets each kept just above absolute zero, and the energy needed to accelerate the beams to near the speed of light, that these are not tests to be conducted on a shoestring budget. The LHC had a construction budget of over 7 billion euros, which makes it one of the most expensive machines ever constructed.
So using these big expensive machines, top particle physicists break stuff in the hopes that what falls out can be identified to help explain the questions of the universe. Simple and heady.