Things not part of a complex system:
Physical phenomena: light, gravity, time, sound, electromagnetic radiation, gravity, time, Heat, temperature, Pressure, Electricity, magnetism, electromagnetic fields, Wave-particle duality, uncertainty principle
Mathematical concepts: numbers, geometry, algebra, logic, Trigonometry, calculus, differential equations, Combinatorics, probability, statistics, Fractals, chaos theory
Fundamental particles: electrons, protons, neutrons, quarks, Photons, neutrinos, gluons, Higgs boson, W and Z bosons, Dark matter, dark energy
Physical constants: the speed of light, the gravitational constant, the Planck constant, The fine-structure constant, the Coulomb constant, The Rydberg constant, the Boltzmann constant, The Avogadro constant, the Faraday constant
Natural phenomena: sunsets, sunrises, rainbows, aurora, Earthquakes, volcanic eruptions, Tornadoes, hurricanes, typhoons, Solar eclipses, lunar eclipses