Max Planck's ground breaking work in the late 19th and early 20th centuries propelled the development of quantum theory and the establishment of Planck's constant (commonly represented as h) as a fundamental cornerstone in physics. It's crucial to note that Planck's revelation concerning Planck's constant did not stem merely from experimental endeavours. Instead, it emerged from a fusion of his theoretical insights and attempts to elucidate experimental observations.
Planck delved into investigating the enigma of black-body radiation, which denotes the electromagnetic radiation emitted by an ideal absorber or emitter of radiation. His objective was to fathom and explicate the observed spectrum of radiation emitted by objects at varying temperatures.
Initially, Planck approached this conundrum from a theoretical standpoint, endeavouring to reconcile observed experimental data using assumptions grounded in classical physics. However, he encountered a critical hurdle known as the "ultraviolet catastrophe." Classical physics predicted an infinite increase in radiation intensity at shorter wavelengths, contrary to experimental findings.
In response, Planck made a profound theoretical leap by introducing the notion that energy is not continuously emitted or absorbed, as posited by classical physics, but rather in discrete units or quanta. He postulated that the energy of these quanta is directly proportional to the frequency of the radiation, with Planck's constant (h) emerging as the constant of proportionality.
This revolutionary hypothesis led Planck to formulate an equation accurately describing the observed black-body radiation spectrum. Planck's constant emerged as a critical factor in this equation, demonstrating that electromagnetic radiation's energy is quantized and exists solely in multiples of this constant multiplied by the radiation's frequency.
Planck's insights sparked a paradigm shift in physics, laying the groundwork for quantum mechanics and culminating in his receipt of the Nobel Prize in Physics in 1918. His discovery of Planck's constant remains a foundational pillar in modern physics, profoundly impacting our comprehension of matter and energy behaviour at the quantum level.
Max Planck's momentous contribution to physics emerged in 1900 when he proposed his quantum theory, challenging the prevailing classical physics by suggesting that energy is emitted or absorbed in discrete units or "quanta" instead of continuously.
Planck introduced the concept that electromagnetic energy, such as light, is emitted or absorbed in discrete packets or multiples of a fundamental unit known as "quanta" or "quantum" (singular). This theory laid the groundwork for quantum mechanics and gave birth to the concept of Planck's constant (denoted as h), a fundamental constant in nature.
In simpler terms, Planck's constant signifies the minimum energy carried by a single quantum of electromagnetic radiation. This constant establishes a threshold for energy levels and frequencies, signifying that all emitted or absorbed energy exists in multiples of this fundamental value.
For example, according to Planck's theory, one could emit light at 10,000 quanta of energy or at 10,001 quanta but not at a fractional value like 10,000.5 quanta. Energy levels are quantized and cannot exist between whole numbers of quanta.
This discovery revolutionized our comprehension of light and energy behaviour, paving the way for quantum mechanics and significantly contributing to technological advancements like semiconductor technology, lasers, and various other applications in modern physics.
Planck units
Speed
of light |
c = 299792458 ms-1 |
Gravitational
constant |
G = 6.673(10) x 10-11 m3 kg-1 s-2 |
Plank’s
constant |
= h/2π = 1.054571596(82) x 10-34 kg m2 s-1 |
Unit | Scale | Comment |
Planck length | 1.616 x 10−35 m | If a particle or dot about 0.1 mm in size (the diameter of human hair) were magnified in size to be as large as the universe, then inside that universe-sized dot, the Planck length would be roughly the size of an 0.1 mm dot. In other words, it would take more Planck lengths to span a grain of sand than it would take grains of sand to span the observable universe. |
Planck mass | 2.176 x 10−8 kg | An object of such mass would be a quantum black hole created at Planck time, with a Schwarzschild diameter of Planck length. This paper attempts to explain why the Planck mass is so large compared to other fundamental particles. Each time the indivisible particles that make an electron (for example) have travelled the reduced Compton wavelength of the electron, they counter-strike. The electron is therefore in a mass state only a fraction of the time. This is why the Planck mass can be so enormous compared to the electron rest-mass and still make up the electron as well as any other subatomic particle. The number of uncertain transitions between mass and energy for an electron is 7.76 x 1020 times per second. An electron is only 9.109 x 10-31 kg, or 2.389x1022 particles per Planck mass. |
Planck
time |
5.391
x 10−44 s |
In
the Big Bang, the Planck epoch or Planck
era is the earliest stage before the time passed was approximately 10−43 seconds. |
Planck
temperature |
1.417
x 1032 K (kelvin) |
It's
a billion billion times the highest natural temperatures in the current
universe, found in gamma-ray bursts and quasars. This is absolute hot, conceived as an opposite to absolute zero.
Everything 5×10−44 seconds after the Big Bang. Kugelblitzes. |
Planck
area |
10−70 m2 |
Planck
length squared. According to the Bekenstein bound, the entropy of a black hole is
proportional to the number of Planck areas that it would take to cover the
black hole's event horizon. |
Planck
volume |
10−105 m3 |
Planck
length cubed. A quantum black hole is contained within a Planck volume. There
are about 10186 Planck volumes in the universe. |
Planck
energy |
109 J (joules) |
A
quantum black hole must have Planck mass and Planck energy such that its
escape velocity exceeds the speed of light. |
Planck
energy density |
10-29 g/cm3 |
Analogous
to Planck's law which describes the spectral density of electromagnetic radiation emitted by a black body. |
Planck
charge |
10−18 C (coulombs) |
The
electric potential energy of one Planck charge on the surface of a sphere
that is one Planck length in diameter is one Planck energy, |
Planck
force |
1044 N (newtons) |
The
amount of force required to accelerate one Planck mass by one Planck
acceleration |
Planck
density |
1096 kg/m3 |
Equivalent
to the mass of the universe packed
into the volume of a single atomic nucleus. |
Planck
pressure |
10113 Pa (pascals) |
Equal
to one Planck force in one Planck area. It is the gravitational force of
attraction between two equal sized universes all concentrated on one fourth
of Planck Area. |
Planck
acceleration |
1051 m/s2 |
The
acceleration due to gravity at
the surface of a Planck mass or quantum black hole. |
Planck
frequency |
1043 /s |
Upper
bound for the frequency (vibrations per second) of an electromagnetic wave. |