Are photons and waves not matter particles?
Optical quantum (light quanta) is also known as a photon. Einstein first stated this noun in a famous treatise, published in 1905. Due to his great achievements in photon theory, Einstein was awarded the 1921 Nobel Prize in physics.
So what is quantum optics? In daily life, light is the most familiar thing to humans. Without light, humans really can not live. Yet, the man who perceives the nature of light has to go through a tortuous and difficult road.
The theory represented by Newton is that the object laminates because it emits a stream of light particles. The reason we can see the light is that these particles fall into the eye, causing sight. According to this theory, it is explained that the reflection phenomenon of light is a result of the elastic impact of light particles on the reflective surface. However, Huygens, a contemporary of Newton, thought that an object’s light was a wave motion. This type of wave motion is different from water waves and sound waves we often observe – they both have a medium for transmitting waves. That medium is water for water waves, air or liquids, and other solids for sound waves. But light waves propagate in a vacuum, which also means that vacuum is the medium of light waves.
These two theories were in conflict at the outset, but since Newton was more prestigious in the scientific world, the particle theory of light held an important position for a very long time. It was not until the early nineteenth century, when Young, Fresnel, and Fraunhofer made discoveries about the interference and polarization of light, they were very well suited to Huygens’ wave theory of light. But Newton’s particle theory of light can not explain this.
As the evolution of optical devices developed, the optical theory also evolved greatly. After Maxwell demonstrated that light waves are a type of electromagnetic wave, the wave theory of light has been almost completely experimented with. The theory of light is wave motion and also widely accepted.
But this theory, when faced with the experimental results of the photoelectric effect, always proved powerless. The so-called photoelectric effect indicates that: When light shines on the metal surface, electrons will be thrown out. As early as 1872, Stoletov of the Moscow State University discovered this phenomenon. Later German physicists, Hertz, and their colleagues worked on this problem and achieved many successes.
When one sought to use the wave motion theory of light to explain the photoelectric effect, the conclusion was that: as the light intensity increased, the speed of electrons being thrown out of the metal must also increase. But the experimental results show that, when using the light of the same illumination frequency, all observed electrons have the same speed regardless of the light intensity. Also, the speed of electrons being thrown out of the metal has no relation to the intensity of the light! Moreover, when the frequency of light reaches a certain extreme value, it can cause electrons to be thrown out of the metal in the light of the incident. Besides, whether electrons in the metal can be knocked out or not, this issue is related to the light’s frequency, meaning that the rate at which electrons are ejected when using bright purple light is greater than when using red light shine! So the wave-motion theory of light fell into a difficult situation with the experimental results.
With his creative mindset, Einstein investigated the photoelectric effect from a completely different angle. He proposed the theory of light and photonics. According to this theory, light’s energy is due to the discontinuity of each smallest singular energy yield. The magnitude of that mononuclear energy is just exactly proportional to the frequency of the light. The light still has the same frequency (or wavelength) as the wave motion, but it also has the property of tiny “particles” – single energy units. Thus, light is simply a beam of energy streams, in which the first unitary energy is called photonics. When light is illuminated on the metal surface, it gives the energy of photolumines to electrons, photonics immediately disappears, and electrons receive the energy of photons, plus its energy out of the metal. Since photonics’ energy is only related to light, only light with a frequency greater than a certain value can provide the full energy to cause electrons in the metal to turn on and go out. Thus, the quantum optoelectronic theory has used a clear, concise method of explaining the photoelectric effect.
This success earned him a Nobel Prize. But quantum optical theory leads to a debate about the nature of light that occurred 100 years ago. After all, what is light? Is it a wave motion or a particle?
The development of physics made it impossible not to accept the argument that sometimes light appears as a wave motion (such as interference and diffraction of light). Sometimes, it appears as particles (such as the arrival and reflection of light). Still, the light is neither a wave motion like a water wave or sound wave nor a matter particle like a tiny point matter; light has two aspects of wave-particle motion: wave-particle duality.
Why is the sunlight or light emitted by other light sources that we always see stable and continuous, not partial? This is because the photonic energy is so small. Its representation in mathematical form is the famous Planck system E = hv, where E is the photon energy, v is the frequency of light, h is the Planck’s constant is 6.62618 X 10-34 Js. Although that number is so small, its effect on the development of physics, on human perception of light’s nature is very great. Suppose we turn on a 25 W electric bulb and treat the emitted light as yellow light. That beam of light immediately consists of 6 X 1019 energy units of quantum optics, or say, The beam of light emits 6 X 1019 quantum optics; that is, every second emits 60 billion energy unit ratios. Because the human eye has the property of temporarily retaining the vision, such a large optical number comes at such a fast rate. The human eye can not recognize quantum photons at each rate one by one; just see it as a continuous beam.
Therefore, it can be seen that photonic quantum is the smallest unit of energy. It is not a matter of matter. Although the photonic quantum’s energy magnitude is related to frequency, which is not the usual wave motion that we see.