Photons are the particles that light up the Universe
Can you imagine a world without light? Light is a fundamental part of our existence because it allows us see, feel and understand the world around us. From the brightness of the sun to the faint glow of a candle, light is an omnipresent element of everyday life. However, have you ever thought about what this resource actually consists of and how we might perceive it?
photons They are the answer to this question: the elementary particles responsible for light and electromagnetic radiation. These small elements are involved in a wide variety of natural processes: from plant photosynthesis to astronomical phenomena occurring in stars and distant galaxies. And although we can’t see them directlyPhotons play a critical role in understanding the universe and in many of the technologies we use every day.
EINSTEIN AND PHOTONS
The concept of the photon arose in the midst of the quantum revolution in the face of the unknown and not knowing how to determine the nature of light: was it a wave or a particle? The final answer included both solutions, assuming that duality who postulated that light behaves in the same way as electromagnetic wave How particle flow: Sometimes it acts as waves that refract and create patterns, such as those that form on water after throwing a stone, and sometimes it acts as particles that can hit and be detected by other objects.
But the history of photons begins in 1905, when Albert Einstein He was immersed in studying photoelectric effect, a phenomenon that occurs when certain materials emit electrons when exposed to light if it has a certain minimum frequency. Thus, Einstein proposed that light consists of particles, which he called “how much light“, which later became known as photons.
Photoelectric effect: the phenomenon that earned Einstein the Nobel Prize
In the 1920s and 1930s, the concept of the photon began to take hold through a series of key experiments: double slit And Compton effect. The first of these, originally designed to demonstrate that it was made entirely of waves, eventually found interference patterns this confirmed two simultaneous behaviors: as a wave and as a particle. For his part, physicist Arthur Compton conducted some X-ray scattering experiments that demonstrated that light could behave like particles, collide and dispersethereby maintaining the existence of photons.
The Compton effect occurs when a photon collides with an electron and the electron changes direction, losing energy in the process. This is proof that photons behave like particles when interacting with matter.
WHAT ARE PHOTONS?
But then, besides behaving like waves and particles at the same time, what else determines photons? Well, an adequate definition for them would be to think of them as basic and fundamental units of light and other forms of electromagnetic radiationrays such as radio waves, x-rays and ultraviolet rays. Moreover, unlike electrons or photons, they have no rest mass and therefore they move at the maximum known speed: 300,000 km/s.
Did you know that the colors we see also depend on photons? Actually, Each shade corresponds to a photon with a specific energy.: Photons that travel at higher energy give rise to colors such as purple or blue, while photons at lower energy give rise to reddish tones. This means that, for example, white light consists of photons of different colors and therefore different energies, which are collected in one beam.
Visible spectrum of light. Red on the right corresponds to the longest wavelength and lowest frequency of photons; while blue is identified with a shorter wavelength and higher frequency of photons.
PHOTONS AND MATTER
What happens when a photon collides with objects and their atoms? There are three possible answers: either they are absorbed, or reflected, or transmitted. For example, when an object appears to be colored a certain color, it is because absorbs some photons and reflects others: a red table will appear this shade because it will absorb photons corresponding to blue and green colors, and will reflect red ones that will reach your eyes and you will identify the object from which they come from by that tone. On the contrary, there are other materials, such as glass, that allow light to pass through. transmission of infection.
The interaction of photons with matter is also important when it comes to understanding various technologies recent years. For example, solar panels use photons to excite atoms to generate electricity through the photovoltaic effect, while optical fiber transmits data using photons of light, allowing for fast and efficient transmission over long distances.