scientist with beakers
Quantum theory is a way to explain the nature of matter and how it behaves at the atomic and even subatomic level. Closely related is quantum mechanics, which is a description of matter at the atomic and subatomic levels. The theory posits that all matter is composed of individual quantifiable units. It was developed in 1900 by the German physicist Max Planck. He presented his theory to the German Physical Society. While much of the theory continues to generate much debate and some controversy, there are parts that are almost universally accepted based on available evidence.
Quantum theory has been used in popular fiction to explain many different things. Popular TV shows like “Sliders” and “Quantum Leap” generated great interest. It even plays a role in Dan Brown’s novel Angels and Demons, during a part explaining the existence and meaning of antimatter. In most cases, this and other works of fiction examine one of the two main theories related to the reality of the natural world to build their premises. These theories are respectively called the Copenhagen Interpretation and the Many Worlds Theory.
The Many Worlds Theory posits that once an object exists in any state, the universe around that object transforms into multiple parallel universes. The number of parallel universes is determined by the number of possible universes in which it is possible for this object to exist. This number is impossible to know, at least as it is now with modern scientific instruments. At some point, instruments may be developed that can more explicitly display the principles of quantum theory.
The Copenhagen interpretation of quantum theory suggests that a particle cannot be assumed to exist until it is measured. So once that happens, it’s whatever you measure. Although it seems like a simple suggestion, this interpretation of quantum theory says that a particle is in all possible states until it is specifically measured and observed.
This is often illustrated by an example known as Schrödinger’s cat. If a cat, in a hypothetical example, is caught and thrown into a box, it is safe to assume that he is alive, at least for a certain period of time. If a vial of cyanide is dropped into this box, it may have broken and killed the cat. Or it may have been unharmed and saved from the cat. While this is unknown, the Copenhagen Interpretation of quantum theory would posit that the cat is in both states, i.e. alive and dead, at the same time.
One of the biggest critics of quantum theory is Albert Einstein. Einstein could not agree that a single particle could exist in more than one universe, as suggested by the many worlds theory. The physicist, however, accepted some aspects of the theory. For example, he understood that energy can exist in quantifiable units and suggested that this was true not only of energy, but also of radiation.