Wonders of the Universe

SUB-ATOMIC PARTICLES

Our understanding of the structure of matter has increased in the last century. Originally, atoms were thought to be the basic building blocks of life, but Rutherford’s famous diffraction experiment proved that matter consisted mainly of space, with each atom containing a very small dense nucleus surrounded by a cloud of electrons. Further investigation showed that each nucleus was composed of protons and neutrons and that each proton was composed of up and down quarks. We have now reached what is believed to be the smallest particles possible – scientists have now discovered that all matter is composed of 9 particles and 4 forces, plus the hypothetical Higgs Boson. The search for the basic building blocks of matter has used matter colliders, which can produce the very high energies that are required to recreate the temperatures in the early Universe, when these sub-atomic particles originally existed.

Nathalie Lees © HarperCollins