In January 2023, the government of Canada promised $360 million to support the work of quantum scientists all across the country (CBC).
But what is quantum physics? And why is it interesting?
Quantum physics is “the study of matter and energy at its most fundamental level. It aims to uncover the properties and behaviors of the very building blocks of nature” (Caltech). Basically, it focuses on the tiny world of atoms and their constituents, how they work, and the relationships between them. Quantum physics is used in many scientific domains, such as biology, chemistry, astronomy, and the understanding of materials.
A bit of history…
Quantum physics research began in the 19th century. It was discovered that energy and matter could be divided into quanta, which are “discrete quantities of energy proportional in magnitude to the frequency of the radiation associated with it ” (Caltech). The information obtained from quantum physics helped build the first concept of the atom, in which electrons orbited around a nucleus.
However, because atoms are very small, scientists found it difficult to study them. They had to juggle concepts such as the wave-particle duality, superposition, the uncertainty principle, and entanglement.
Quantum physics also deals with fundamental forces of nature, such as electromagnetism, the strong nuclear force, and the weak force. Combining the three gives the theory of the “standard model” (New scientist).
By understanding quantum physics, brilliant scientists, for example, Schrödinger, famous for his cat experiment, discovered complex equations that would later be used for many purposes, for example, lasers and superconductivity.
Waves
The basic element of quantum physics is “wave[s] associated with the motion of all matter, including electrons in an atom” (Scientific American). The waves are associated with the inability to locate a quantum particle and measure its velocity at the same time. Quantum particles do not act the same as particles in the everyday world, and many things seem to work differently in the quantum world. Quantum particles are able to influence one another, even at great distances (known as entanglement). Quantum theory holds the basics on which quantum cryptography and quantum computing were started.
There are still discoveries left to be made about Quantum physics, there are still mysteries to be solved. For example, gravity is difficult to connect with quantum physics because at first sight quantum physics is incompatible with Einstein’s theory of relativity since this theory does not involve particles in the fundamental gravitational force.
Reviewed by Denis Carrier (Physics teacher at St-Lawrence)
Sources:
https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-physics
https://www.newscientist.com/definition/quantum-physics/
https://www.scientificamerican.com/article/everyday-quantum-physics/
