The STEAM Blog

Shaja Samefa
Edited by: Lilly Hale

Quantum mechanics reveals the complex behaviors of matter and light at atomic scales, with its origins tracing back to Planck, Einstein, and Bohr and extending to modern advancements.Concepts like wave-particle duality and the uncertainty principle challenge classical physics and promise revolutionary applications in computing and cryptography. Its ongoing evolution captivates scientists and holds immense potential for future technological breakthroughs.

What is Quantum Mechanics?

Quantum mechanics studies how matter and light behave at the atomic and subatomic levels. Consequently, it aims to explain the properties of particles such as electrons, protons, and quarks, as well as their interactions in atoms and molecules. Moreover, Gluons are particles that help hold quarks together to make protons, neutrons, and other particles.Unlike electrons or photons, gluons are never found alone but are essential for understanding how matter sticks together at the smallest scales of the universe.

The History of Quantum Mechanics

• 1900s-1910s: Early Beginnings
  
  • Max Planck (1900): Introduced the concept of quantization of energy, suggesting that energy can only be absorbed or emitted in discrete amounts, or quanta.
  • Albert Einstein (1905): Proposed the photon theory of light, suggesting that light consists of particles called photons, each carrying a quantum of energy.
  • Niels Bohr (1913): Developed the Bohr model of the atom where electrons orbit the nucleus in discrete energy levels, explaining atomic spectra.
• 1920s: Formulation of Quantum Mechanics
  • Louis de Broglie (1924): Proposed that particles like electrons could also exhibit wave-like properties, leading to the concept of wave-particle duality.
  • Werner Heisenberg (1925): Formulated matrix mechanics, a fundamental formulation of quantum mechanics using matrices to describe physical quantities.
  • Erwin Schrödinger (1926): Developed wave mechanics, providing a wave equation (Schrödinger equation) that describes the behavior of quantum systems.
• Late 1920s-1930s: Further Developments
  
  • Paul Dirac (1928): Formulated the Dirac equation, unifying quantum mechanics with special relativity and predicting the existence of antimatter.
  • Max Born, Pascual Jordan, and others: Contributed to the development of       quantum field theory and the interpretation of quantum mechanics.
• Mid-20th Century: Quantum Field Theory and Modern Formulations
  
  • Richard Feynman, Julian Schwinger, and Sin-Itiro Tomonaga (1940s-1950s): Developed quantum electrodynamics (QED), a relativistic quantum field theory describing interactions between light and matter.
  • Murray Gell-Mann, George Zweig (1960s): Proposed the quark model to explain the structure of hadrons, introducing the concept of quarks and gluons.
• Late 20th Century to Present: Applications and Advancements
  
  • Quantum Information Theory: Explores the application of quantum mechanics to information processing, cryptography, and computing.
  • Quantum Computing: Advances in manipulating quantum states to perform computations that classical computers find difficult or impossible.

Key Concepts in Quantum Mechanics

Wave-particle duality

In quantum mechanics, wave-particle duality proposes to exhibit both wave-like and particle-like behaviors.

Particle Nature:  (photoelectric effect)

• The Photoelectric Effect: demonstrated photons behave as discrete particles.

Wave Nature: (young double-slits experiment)

• The double-slit experiment: showed interference patterns, confirming the wave-like behavior of particles.

Quantization

Max Plank

Max Planck introduced the concept of quantization in the year 1900. Quantization in physics restricts properties like energy or angular momentum to specific discrete amounts, not continuous values. Consequently, it’s a fundamental concept in quantum mechanics, reflecting how certain physical quantities behave in discrete increments rather than continuously.

Photoelectric effect

• When light (photons) shines on a metal surface, it interacts with electrons in the metal.
• According to classical physics, increasing the intensity of light (more photons) should eject more electrons and increase their kinetic energy.
• However, the photoelectric effect experiments in the early 20th century demonstrated that ejected electron energy depends solely on light frequency.
• Light does not emit electrons below a certain threshold frequency, regardless of intensity.
• When exceeding this threshold, electrons emit instantly with kinetic energy proportional to photon frequency.
• Classical wave theory fails to explain this observation, suggesting inadequate continuous energy absorption.

Significance:

• Einstein proposed light as photons, each with energy ( E = hv ), supporting Planck’s quantization theory of energy in quanta.
• The photoelectric effect offers evidence by showing that electrons’ energy depends on light’s frequency in discrete steps.

Uncertainty Principle

Werner Heisenberg

The Uncertainty Principle, formulated by the German physicist Werner Heisenberg in 1927, is a fundamental concept in quantum mechanics. It states that it is impossible to precisely and simultaneously measure the position and momentum of a particle.

Moreover, according to this principle, the more precisely we know the position of a particle, the less precisely we can know its momentum, and vice versa. This uncertainty does not arise from technical limitations of measurement; rather, it reflects the intrinsic nature of quantum systems.

Schrödinger Equation

Erwin Schrödinger

This principle states that the more precisely we know the position of a particle, the less precisely we can know its momentum, and vice versa. It describes how the quantum state of a physical system evolves. 

Where 𝑡 is time, |Ψ(𝑡)⟩ is the state vector of the quantum system (Ψ being the Greek letter psi), and  is an observable, the Hamiltonian operator.

The Schrödinger equation is a core component of quantum mechanics and is widely used in theoretical physics. It finds applications in atomic physics, quantum chemistry, and condensed matter physics. For instance, in atomic physics, it calculates the energy levels of electrons in a hydrogen atom and predicts the distinct spectral lines seen in hydrogen’s emission and absorption spectra.

Quantum Cloud: Bridging Art and Quantum Mechanics through Antony Gormley’s Sculpture

“Quantum Cloud” by Antony Gormley is a significant work of art that explores intersections between art and quantum mechanics. Through sculptural installations, Gormley delves into the complex concepts of quantum physics, particularly focusing on ideas of indeterminacy, the interplay of energy fields, and the relationship between physical presence and perception. This exploration challenges viewers to contemplate the deeper implications of existence and reality through a visual and conceptual lens.

Words of Antony Gormley 

How can you convey the fact that the presence of somebody is greater or different from their appearance?

The Domains allowed me to evoke the internal space of the body as a field, but are still bound by an invisible skin: I wanted to extend or ignore the skin.

The Quantum Clouds continue the matrix of the Domains into outer space through the continuation of the branching connections, positioning the original body-field within a wider field.

The indeterminacy of the skin summons active involvement of the projection and finding force in the eye of the beholder.

It is an open question in the Quantum Clouds – whether the body is emerging from a chaotic energy field, or the field from the body.

Simplified Interpretation

Antony’s artwork intriguingly parallels concepts from quantum mechanics, particularly through its exploration of boundaries, essence, and perception. The Schrödinger equation, which is fundamental in quantum mechanics, calculates the wave functions of particles and predicts their behavior at atomic scales. In Antony’s work, this mathematical framework can be seen as a metaphor for the interplay between physical form and internal essence.

The particles discussed, such as electrons and quarks, exist in probabilistic states defined by wave functions. Similarly, Antony’s artwork delves into how a person’s essence may transcend physical boundaries, much like how particles exist in a cloud of probability rather than fixed locations. The Domains in the artwork evoke internal spaces constrained by invisible boundaries, akin to the quantum mechanical concept where particles are defined by their wave functions and uncertainties.

Quantum Clouds in the artwork extend this idea into a cosmic scale, reflecting the broader context of human essence and its interactions with the universe. Just as quantum mechanics deals with the uncertainty of particles’ positions and energies, Antony’s art invites viewers to question and interpret the nature of boundaries and essence. This engagement mirrors the observer effect in quantum mechanics, where the act of observation influences the state of the observed.

Ultimately, Antony’s work prompts viewers to ponder whether the essence of the body originates from a chaotic field of energy, akin to the probabilistic nature of quantum particles, or if the field itself emerges from the body’s essence. This dynamic interplay mirrors the deep questions posed by quantum mechanics about the nature of reality and observation.

References

• Explore physics | Institute of Physics. (n.d.). Explore physics. [online] Available at: https://www.iop.org/explore-physics.
• Coolman, R. (2014). What Is Quantum Mechanics? [online] Live Science. Available at: https://www.livescience.com/33816-quantum-mechanics-explanation.html.
• Bhuyan, S. (2023, September 19). Wave-Particle Duality: Definition, Theory, and Examples. Science Facts. https://www.sciencefacts.net/wave-particle-duality.html#:~:text=Wave-particle%20duality%20is%20a%20fundamental%20concept%20in%20physics
• Physics LibreTexts. (2016). 7.3: The Heisenberg Uncertainty Principle. [online] Available at: https://phys.libretexts.org/Bookshelves/University_Physics/University_Physics_(OpenStax)/University_Physics_III_-_Optics_and_Modern_Physics_(OpenStax)/07%3A_Quantum_Mechanics/7.03%3A_The_Heisenberg_Uncertainty_Principle.
• Encyclopedia Britannica. (n.d.). Schrodinger equation | Explanation & Facts. [online] Available at: https://www.britannica.com/science/Schrodinger-equation.
• Elert, G. (2019). Photoelectric Effect. [online] The Physics Hypertextbook. Available at: https://physics.info/photoelectric/.www.antonygormley.com. (n.d.). Quantum Clouds – Sculpture Series – Antony Gormley. [online] Available at: https://www.antonygormley.com/works/sculpture/series/quantum-cloud.