The Quantum Era Begins

Let's take a look at some of the initial experiments, the beginning of the quantum era and see what led scientists to embrace these seemingly bizarre ideas on the nature of reality. Isaac Newton’s treatise Philosophiae Naturalis Principia Mathematica, published in 1687, described universal gravitation and the three laws of motion, laying the groundwork for classical mechanics. In the early 20th century, Newtonian physics was still the science of the day, describing everyday events and objects such as gravity and orbits of planets with near perfection, but new experiments on a much smaller scale were showing results which could not be explained by classical physics.

For example, it was well known that electrons orbited the nucleus of an atom. However, if they did so in a manner which resembled the planets orbiting the sun (the prevailing view of the time), classical physics predicted that the electrons would spiral in and crash into the nucleus within a fraction of a second. Obviously that doesn't happen, or every electron in every atom of the universe would spiral into every nucleus and the universe would cease to exist instantly. That incorrect prediction, along with other experiments that failed classical predictions, showed scientists that something new was needed to explain events at the atomic level.

In 1900 Max Planck suggests that radiation is quantized (it comes in discrete amounts), discovering what is now called Planck’s Constant. This discovery describes a phenomenon occurring in microscopic particles such as electrons and photons in which certain physical properties occur in fixed amounts rather than assuming a continuous range of possible values. It is this very property that allows a physical universe and matter to exist at all. With Max Planck’s discovery of Planck’s Constant, the era of quantum physics is born.