Max Planck and Quantum Theory

• Max Planck's quantum theory overturned classical physics by demonstrating that energy is emitted in discrete packets called "quanta," revolutionizing the understanding of the subatomic world.

Max Planck: Early Life and Career

• Born in Kiel, Germany, he was the youngest of six children.
• His family relocated to Munich when he was 9.
• He excelled in mechanics, mathematics, and music in school.
• He earned a doctorate from the University of Munich at 21, focusing on the second law of thermodynamics.
• In 1889, he became a professor of theoretical physics at the University of Berlin, where he remained until 1926.

Black Body Radiation

• In the 1890s, physicists were struggling to explain the absorption and emission of light, focusing on "black body" radiation.
• A black body is a hypothetical object that absorbs all electromagnetic radiation.
• When heated, a black body emits energy as electromagnetic waves across various wavelengths, including visible, ultraviolet, and infrared light.
• Experiments revealed that the wavelengths emitted by hot objects deviated from classical thermodynamics predictions.
• Planck began studying black body radiation in 1894, aiming to reconcile theory with observation.

Planck's Breakthrough

• Initially, scientists thought atoms, the sources of radiation, could oscillate continuously at any frequency.
• By 1899, Planck realized atoms could only vibrate at frequencies that were whole-number multiples of a base frequency (h).
• Planck calculated "h," now known as Planck's constant, a fundamental physical constant with the same numerical value throughout the universe.
• Planck proposed that photons release energy not in continuous waves but in discrete packets called "quanta," the smallest possible unit of energy.

Planck's Radiation Law

• Planck's radiation law explained the relationship between an object's temperature and emitted electromagnetic radiation: E = hv.
• E represents the energy in a photon
• v represents its electromagnetic radiation frequency is
• h represents Planck’s constant
• In 1900, he presented his theory of "quantized" energy packets to the German Physical Society.
• This initiated a physics revolution and is considered the origin of quantum theory.
• In 1905, Albert Einstein validated Planck's hypothesis by using it to explain the photoelectric effect.
• Planck's constant allowed for the development of new physical units, including the Planck length (1.6 x 10-35 meters) and Planck time (5 x 10-43 seconds).

Legacy

• Planck supported Albert Einstein's work and created a professorship for him at the University of Berlin in 1914.
• He received the Nobel Prize in Physics in 1919 for discovering energy quanta.
• Planck's quantum theory paved the way for modern technologies such as solar power.
• There are 83 Max Planck Institutes worldwide.

Paul Dirac

• Paul Dirac (1902–1984) is known for his Dirac equation, which predicted antimatter particles like the positron.
• Dirac created quantum field theory by finding parallels between classical particle motion theory and Werner Heisenberg's matrix mechanics paper.
• His equation predicted "antimatter"—particles with similar properties to matter but with opposite electrical charge.
• In 1932, Dirac became Lucasian Professor of Mathematics at Cambridge University.
• He shared the Nobel Prize in Physics with Erwin Schrödinger in 1933.

Explore Max Planck's revolutionary concept of energy quantization, delving into the challenges classical theories faced with black body radiation. Learn about Planck's black body research, his influence on Einstein, and his Nobel Prize-winning contributions to physics that laid the groundwork for quantum mechanics.