# Often asked: Why Is Plancks Constant H?

The Planck constant (denoted h) is a natural constant named after Max Planck, one of the founders of quantum theory. He found that **the energy of this electromagnetic radiation consists of quanta of energy hν**, where ν is the frequency of the radiation. These quanta are now called photons.

## Is Planck constant h?

Planck’s constant, (symbol h), fundamental physical constant characteristic of the mathematical formulations of quantum mechanics, which describes the behaviour of particles and waves on the atomic scale, including the particle aspect of light.

## How was Planck’s constant derived?

Planck’s constant is a measured quantity that relates the frequency of any quantum mechanical oscillator (e.g., a photon) to its energy. The original determination of Planck’s constant was made by fitting the spectrum of a blackbody radiator, but several other more accurate methods are used today.

## What does Planck’s constant signify?

Planck’s constant, symbolized h, relates the energy in one quantum (photon) of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 x 10^{–}^{34} joule-seconds.

## What if Planck’s constant was zero?

if Planck constant is zero, both momentum and position can be known simultaneously. if Planck constant is zero, all quantum behavior will become classical behavior, where energy will become continuous, momentum will become zero (which means it is known exactly) and etc.

## Why is Planck’s constant so small?

So why is the Planck length thought to be the smallest possible length? The simple summary of Mead’s answer is that it is impossible, using the known laws of quantum mechanics and the known behavior of gravity, to determine a position to a precision smaller than the Planck length.

## How is Planck’s constant useful to engineers?

Planck’s Constant relates the energy of light photons to their frequency. It also shows up in de Broglie’s relation for the wavelength of matter waves and Schrödinger’s Equation. A common device, the light emitting diode or LED, could be designed only because some engineers understood quantum science.

## What if Planck’s constant was larger?

Some students think that if Planck’s constant were to have a larger value than it has now, the quantum effect would only become observable in a world with a larger size, whereas the macroscopic world might remain almost unchanged.