Quantum Physics and Max Planck

As a high school student, the study of physics generally meant the study of classical physics. To me, the idea of “Quantum physics” was just theoretical physics that involved exploring subatomic particles. Although quantum physics does involve inspecting the behavior and interaction of small particles such as protons, neutron, electrons and even gluon and quarks, the field of quantum physics is much vaster and is used to explain many unanswered mysteries in history. The study of quantum physics reflects lights of possibilities on ideas that may have been just fictions in the past. Quantum physics brings the universe together; as the great physicist Erwin Schrodinger famously said, 

“Quantum physics thus reveals a basic oneness in the universe.”

History tells many stories about the famous debate amongst physicist that argued light to be a particle or a wave and classical physics resolved this conflict by saying that light only behaved like a wave. It was not until the 20^th century when theoretical physicists Max Planck proposed a new idea that proved both sides of the debate wrong. He explained that light was not a particle or a wave but it behaved like both. This idea of Max Plank gave birth to the world of quantum physics and many more.

Max Planck’s journey:

Max Planck was a young genius who was a talented pianist and very enthusiastic about classical physics. During his time, many believed that physics was already almost fully discovered and there were only some holes here and there to fill in. Planck still decided to further study classical physics just for the sake of learning and exploring.

Figure 1: Max Plank (1858-1947)

In the beginning of 20^th century, when light bulbs started gaining massive popularity, researchers started looking for ways to make these light bulbs more and more efficient and Max Planck was also investigating on this issue. Classical physics assumed that as a body got hotter, its radiation in form of light must also increase. However, closer inspection proved this theory to be wrong or inadequate. For example, if steel is heated, it glows in different colors according to its temperature. So, it goes from red to yellow, till blue; but if the frequency just kept going higher and higher with temperature, the steel at some point would radiate Ultraviolet, which is not visible (making the steel invisible). However, this assumption of classical physics could not be confirmed by any experiment, as the steel always remained visible. Planck spent five years trying to explain it with classical physics but found no satisfactory solution. In desperation, he threw out all previous ideas and assumed instead that the radiation was not emitted continuously but in forms of discrete packets of energy known as quanta. An analogy of this quantization of radiation energy is water falling in droplets rather than continuous stream. The total energy then only amounts to a multiple of his quantum of action, a constant designated by a letter ‘h’. Overall, Planks law stated, the radiation energy is the product of the constant h and the frequency of the radiation (supported by experimental evidences of blackbody radiation).

Max Planck was not very confident in his new findings and theory. He was also not comfortable denying the widely accepted concepts of classical physics. However, this was just the beginning of a new era for modern physics which earned him a Noble Prize and was also joined by many well-known physicists, including: Albert Einstein, Arthur Compton, C.V. Raman, Pieter Zeeman, Niels Bohr, Hans Geiger, Ernest Marsden and Ernest Rutherford.

Figure 2: 1927 Solvay conference in Brussels

Noble prize:

The Nobel Prize in Physics 1918 was awarded to Max Planck "in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta".

Modern Quantum Physics:

The word “quantum” derives from Latin, meaning “how great” or “how much”. The discovery of light coming in small packets of energy initiated this field of physics. However, today it underlies the mathematical framework of many fields of physics and chemistry, including condensed matter physics, solid-state physics, atomic physics, molecular physics, computational physics, computational chemistry, quantum chemistry, particle physics, nuclear chemistry, and nuclear physics. Quantum physics traditionally investigated the world of microscopic components. However, it is also needed to explain certain recently investigated macroscopic systems such as superconductors, superfluids, and large organic molecules. The world of quantum physics is wide and expanding every day. Some fundamental aspects of the theory are still actively studied.
Broadly speaking, quantum mechanics incorporates classes of phenomena for which classical physics cannot account. For example:

• Quantization of certain physical properties
• Quantum entanglement 
• Principle of uncertainty
• Wave-Particle duality       

Credits:

1. https://www.youtube.com/watch?v=Ex8EvBTk9LY
2. http://www.forbes.com/forbes/welcome/
3. http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html
4. http://roberta.tevlin.ca/
5. https://www.youtube.com/watch?v=x5wlsIhooms

Photos:

1. http://d3thflcq1yqzn0.cloudfront.net/000795912_prevstill.jpeg
2. http://case.ntu.edu.tw/scinarrator/wordpress/wp-content/uploads/2015/05/planck_g.jpg
3. http://hyperphysics.phy-astr.gsu.edu/hbase/imgmod/plnck.gif
4. https://upload.wikimedia.org/wikipedia/commons/6/6e/Solvay_conference_1927.jpg
5. http://spectrum.ieee.org/image/1711890