Adrián Ríos, Unilaser Medical Director

Carolina Pardo, Resident III Dermatology Unisanitas-Federico Lleras Acosta Dermatological Institute

Gisela Güiza, Resident II Plastic Surgery Military Hospital-Military University Nueva Granada

At the end of the 19th century, Planck sought to calculate the energy emitted by the hot filaments of a light bulb.

The heating of a material did not seem to have a linear behavior since it was known that light jumped from color to color according to thermal changes.

Planck devised a value to accommodate the energy and frequency of vibration of the waves, resulting from the charge carried by the matter.

A wave with a higher frequency will mean greater energy according to a proportionality linked to a constant value discovered by Planck.

On a descending scale, we can conceive of bacteria and cells a million times smaller, in microns. From microns, 1000 times smaller, we arrive at nanometers (1 in 10 ^{-9} meters), the world of viruses and large molecules, where there are no longer living beings, although there is still light. If we continue a thousand times smaller, we arrive at the world of picometers (1 in 10 ^{-12} meters), where light disappears, only gamma rays fit, and we find particles such as minerals and small molecules such as glucose and adrenaline, in general, the world of chemistry. The next level, 1000 times smaller, is that of femtometers (1 in 10-15 ^{meters} ), where we find the subatomic particles, the neutron and the proton. A thousand times smaller jump in attometers (1 in 10 ^{-18} ) is the dimension of the smallest known particles, quarks and electrons.

We don’t know much more before the last possible measurement, the Planck length, at 10 ^{-34} where space no longer has the geometry we know.

Planck conceived light as a pulsed system and not as a continuous ray.

When pulsed, the energy of the beam was directly related to the frequency of the wave according to a quantum value linked to the value of a number that suited the experiments, Planck’s constant.

The frequency of light, its color, changes according to the temperature reached in the system, the value is so small that the highest temperature cannot affect the final result of energy, linked in light to the movement of particles thousands of times larger.

Einstein used this to explain the photoelectric effect, a phenomenon first observed by Hertz, who had noticed that fewer sparks were produced by electrical induction when there was no light. His student Lenard later concluded that more electrons, i.e. more sparks, were released with the addition of ultraviolet light than with red light from a metal under electrical induction.

The effect was instantaneous and was linked to the greater brightness of the ultraviolet light. The shorter waves were the most energetic according to Planck, and therefore more electrons were released from the metal, Einstein concluded.

The energy, the invisible something that caused the electrons to be released from the metal, increased in value proportional to the frequency of the wave according to a constant value, the Planck number.

A brighter lamp (more photons) would induce more sparks (electrons) with the same individual energy (not brighter sparks). To verify this, it was necessary to measure the electrical charge of the electron, which Millikan achieved 10 years later.

By the end of the 19th century, it was not known what atoms were like; the first diagrams of their composition suggested a system in equilibrium between positive and negative forces, like a pudding with raisins.

There were also skeptics of their existence until Einstein suggested that they were the cause of the continuous and apparently erratic Brownian motion of the pollen particles on the water, to which Einstein gave predictable displacement calculations based on the fact that it was caused by the knocking of the atoms of the water molecules, always in motion, against the light pollen.

Once the electron was discovered, other doubts began to arise about the stability of the atom.

A positive core and negative elements rotating around it should not remain in place as they did in fact.

Order came to the atom with Bohr, who built his structure by postulating fixed energy levels for the different orbits of each electron and the changes in the stationary energy level of each electron between orbits were given by defined jumps of sufficient energy to pass from one level to a higher one, in thresholds countable in whole numbers (quantum).

Bohr knew the calculation of the spectral behavior of objects under heating by Balmer his school teacher and took the Planck number to establish stationary levels which meant that each electronic orbit was proportional in whole numbers to the Planck number.

It was the first explanation of why an atom does not disintegrate and, incidentally, it explained the origin of light. The electrons in the atom that change their level receive specific energy values, integer multiples of the Planck constant. Each level has its own threshold and this energy, once taken, is released by the electron in the form of a photon to maintain the stability of the atom, since in this way an excited electron always returns to its natural energy level. This is how the physical interaction of light with things was conceived.

Electrons and photons could be considered points of higher energy that behave like waves and particles, because they travel in the space that they also occupy, and they are surrounded by magnetic forces that repel electrons from each other and attract photons.

The first part, that of waves and particles, was resolved by De Broglie and Schrödinger by assuming that electrons, like photons, fulfill both characteristics and thus it was possible to calculate probabilities from knowing the mass and energy of an electron or photon.

The intrinsic magnetic forces were later discovered by Otto Stern and Walther Gerlach, thus explaining magnetism as a characteristic of particles (quantum spin). Depending on their spin mode, particles such as bosons (photons) tend to stay together and leptons (electrons) tend to separate.

Finally, Planck’s constant leads us to Heisenberg’s uncertainty principle, which expresses the impossibility of measuring quantum values as if they were visible. A change in energy in a given time must be greater than or equal to Planck’s constant divided by 4 π, therefore, the law of conservation of energy may no longer be fulfilled for very short periods of time. And without this law, no experiment is possible to predict the exact location of an electron or a photon.

*h* =6.626070150 times 10 ^{-34} joule-second is the value of Planck’s constant.

The number where matter as we might conceive it ends.

Its expression in Planck’s formula relates the energy of each photon in Joules (pulsed) by multiplying Planck’s constant by the wave’s displacement frequency. The Planck number (h) compensates in the formula for a maximum value of the wave frequency (f) that would lead to infinite energy values.

E= hf

It was not a mathematical artifice, it was the value of the smallest possible matter, 34 zeros to the left of it in length.