A relatively brief introduction to modern physics

What is Modern Physics?

There are two major branches of modern physics, one dealing with events on a cosmic scale, and the other dealing with events on subatomic scales. General relativity is the foundation of modern cosmology, and quantum mechanics is the foundation of subatomic physics. Each theory has been heavily tested and has been shown to be unfathomably accurate. The fact that these theories are mutually incompatible has perplexed physicists for the past several decades

The idea that the universe is governed by two sets of laws, one for massive objects, and the other for subatomic objects, is dubious and unsatisfactory. For years, physicists have been working on making these two theories concordant with each other, but with little success. Einstein went as far as rejecting many of the axioms derived from quantum theory, and doubted the validity of the theory altogether. Nevertheless, both theories have withstood the test of time thus far.

The Greeks hypothesized that all matter is made of fundamental, indivisible units. Not too long ago, these parts were thought to be atoms. In the 20th century we discovered that atoms could be further broken down into protons, neutrons, and electrons. Later, we learned that protons and neutrons could be further broken down into quarks. The majority of matter that we encounter is composed of quarks and electrons. Many contemporary physicists believe that quarks and electrons can not be broken down any further. String theory, or superstring theory, claims otherwise. According to string theory all fundamental particles of matter consist of a tiny, vibrating, one-dimensional loop. The properties of fundamental particles are a consequence of the different ways a string can vibrate. Looking at matter as such may reconcile the differences between quantum mechanics and general relativity. Furthermore, string theory may soon be able to put up the claim as being the elusive “theory of everything” as it describes and unifies the fundamental particles and forces of the universe.