What kind of substance is light, and is it anything like sound?

Light is a special substance with the dual properties of wave and particle. Light can undergo diffraction and interference in the characteristic phenomenon of waves, and sound can also occur. But light is essentially an electromagnetic wave, and propagation does not require a medium, so it can also propagate in a vacuum, but sound waves are mechanical waves, and propagation must be a medium, and it cannot propagate in a vacuum.

To be precise, light is a probability wave. It has wave-particle 2 imagery. Essentially, it is an electromagnetic wave. Electromagnetic waves are all probability waves

It has the same properties as mechanical wave sound, such as interference, diffraction. There are also properties that are the same as particles, such as probability.

In conclusion, light is an electromagnetic wave. In fact, electromagnetic waves are a difficult thing to study because of their speed .

Upstairs it's all about it.

There is also a point where the rest mass of the photon is 0

To add: the theory of relativity has been proved, and the greater the speed, the greater the mass. An object with a speed of light has an infinite mass, which is why it is impossible for an object to exceed the speed of light.

This is because if you accelerate an object with infinite mass, the acceleration is also infinite, and the energy required is also infinite, which is impossible.

The aether is an outdated theory, and it was once wanted to verify the motion of the entire universe through the absolutely stationary aether. It turns out that there is no such thing as aether.

As long as light is not absorbed and transformed, it can spread indefinitely. That's why we can see 10 billion light-years of unexpected stars.

Light is an electromagnetic wave, and sound is just a sound wave of an object vibrating, which is not the same.

Light is an electromagnetic wave that is both wave-like (interference and diffraction phenomena) and particulate (photoelectric effect). Whereas, sound is a mechanical wave that requires a medium to propagate.

Light is an electromagnetic wave, and sound waves are mechanical waves, both are waves.

But light is both particle and fluctuating and does not require medium propagation; Whereas, sound waves are mechanical waves that can only propagate through a medium!

Light is an electromagnetic pluck, but it is also particle-based, composed of photons, sound is a material wave, light is a transverse wave, and sound is. Longitudinal waves

Light is a segment of electromagnetic waves, visible light, which is microns, and is also a particle, a photon.

Sound waves are mechanical waves due to vibrations, and they all adhere to the wave theory, but light is also particle-like.

The essence of their production is also different.

Wave-particle duality is both a wave and a particle.

In physics, as long as it exists objectively, it can be called matter, such as electric fields, magnetic fields, etc., which we cannot see, and we can see.

To be precise, sound belongs to mechanical waves, which are transverse waves, so the propagation of sound requires an elastic medium, which cannot be transmitted in true failure, but electromagnetic waves do, and the changing electric field produces a changing magnetic field, which is transmitted to the distance.

Are air, electricity, fire, and sound substances?

Do you know if air, electricity, fire, and sound are substances?

First of all, we need to understand what is a substance? There are two definitions of matter:1 Narrow definition:

Matter is the physical object, field and other objective things that make up all things in the universe; It is a form of aggregation of energy. For example, air and water, food and cotton, coal and oil, iron and steel, copper, aluminum, as well as various energy waves (such as light, trembling, heat) and fields (electricity, magnetism, gravity), and even higher forms, such as people and their groups, nations, nations, etc., are all matter. In short, in the world, all the objective beings around us are material.

2 Broad definition: Matter is natural existence. Matter is an objective existence that does not depend on consciousness.

From the above definition, it can be seen that air, fire, electricity, and sound are all substances.

Air: It is composed of atoms composed of a mixture of oxygen, nitrogen, carbon dioxide, etc. It is a physical object.

Fire: is the plasma state of a flammable substance at high temperatures, composed of particles. It is a physical object. Laugh off.

Electricity: Consists of electrons moving directionally under an electric field. It is a physical object.

Sound: It is the vibration of a sound source that causes hearing. It is energy that travels in the form of waves. Belongs to the wave. It also belongs to substances.

Light and sound have the same thing: they both travel in the form of waves.

Light and sound are different:

1. The propagation medium is different

Light is essentially a stream of photons in a specific frequency band. A light source emits light because the electrons in the light source gain extra energy. If the energy is not enough to make it jump to a more outer orbit, the electrons undergo an accelerated motion and release the energy in the form of a wave.

Light can propagate without a medium and can propagate in a vacuum in space.

Sound requires a medium to propagate and cannot be propagated in a vacuum. Sound is a wave phenomenon that is transmitted through a medium (air or solid, liquid) and can be perceived by the auditory organs of humans or animals.

2. The speed of propagation is different

The propagation speed of sound in different media is generally solid liquid gas (exceptions: cork 500m s, less than kerosene (25), distilled water (25), etc.), and the propagation speed of sound is related to the type of medium and the temperature of the mediator.

The speed at which sound travels through various types of objects:

Vacuum 0m s (i.e. no propagation), air (0) 331m s, air (15) 340m s, air (25) 346m s, cork 500m s, kerosene (25) 1324m s, distilled water (25) 1497m s, sea water (25) 1531m s, ice 3230m s.

Light travels extremely fast. 299792458 3 10 ms in a vacuum, slower in air. In media with a larger refractive index, such as water or glass, the propagation speed is even slower.

Expand the information of the survey:

The effect of light

1. Photoelectric effect.

When ultraviolet light hits the surface of a metal, free electrons inside the metal escape from the metal surface, and the photoelectron emission of this ultraviolet light forms part of the photoelectric effect of ultraviolet light. The photoelectric effect of ultraviolet light is a way in which light energy is converted into electrical energy. The photoelectric effect is divided into external photoelectric effect, internal photoelectric effect, and photogenerated volt effect.

In addition to metals and semiconductors, there are also certain gases and some chemicals that can produce photoelectric effects when irradiated by ultraviolet rays, and humans, animals and plants can also produce photoelectric effects after being irradiated.

2. Photochemical effect.

Ultraviolet light can produce photochemical reactions when irradiating certain substances. The energy (3 6 EV) of ultraviolet light with a wavelength of 200 400 nm is exactly the energy required to produce a photochemical reaction after absorption by many grinding substances (the chemical bond energy is also in the range of 3 6 EV). In particular, short-wave ultraviolet light has a large photon energy, which is particularly effective for photochemical reactions, and can directly cause the synthesis and decomposition of some substances.

3. Acousto-optic effect.

When there is elastic stress or strain in the medium, the optical properties (refractive index) of the medium will change, which is known as the elastic effect. When the ultrasonic wave propagates in the medium, because the ultrasonic wave is an elastic wave, it will cause the sparse alternating change of the medium, or the elastic deformation, and due to the elastic light effect, it will cause the optical properties of the medium to change, thus affecting the propagation characteristics of the light in it.

Usually, the bounce effect caused by ultrasonic waves is called the acousto-optic effect.

Sound is not matter, sound is a form of motion of matter.

Sound is a sound wave produced by the vibration of an object. It is a wave phenomenon that propagates through a medium (air or solid, liquid) and can be perceived by the auditory organs of humans or animals. Sound travels in the form of waves that vibrate (vibrate). Sound is the motion formed by the propagation of sound waves through any substance.

For the human body, sound is generated by vibrating objects (vibration sources), transmitted to human auditory organs through elastic media (such as air, water, wires, etc.), converted into neural signals and transmitted to the brain, and can be recognized by our brain (frequency between 20-20,000 Hz). Therefore, sound is a physical + physiological phenomenon, and sound in the narrow sense is the vibration between 20 and 20,000 hertz that can be received and recognized by the auditory organs. The propagation of sound propagates in the form of waves, the wave itself is the propagation in the form of motion, and sound is a form of motion of matter, not a substance.

Similarities: they are all waves, and waves are characterized by both light and sound.

Differences: Light is a type of electromagnetic wave that propagates by electromagnetic force and needs to be in a field to exist. Light has a sporty mass.

Sound is the result of the vibration of matter, which is propagated by intermolecular forces, and cannot be transmitted without matter. The sound has no quality.

Light is faster than sound, so every time it rains, we see lightning first and then hear thunder

In layman's terms.

The light is visible!

The sound is audible!

How to distinguish between material and immaterial.

According to the definition of matter in physics: matter is the physical object that makes up all objects in the universe and it can be concluded that everything that can be perceived in real existence is matter (such as magnets, and magnetic fields are considered substances), but what does not exist in real life and is hypothetical for the convenience of physics research is not massless. For example:

Inductance lines. Cultural heritage is generally divided into tangible cultural heritage and intangible cultural heritage, tangible cultural heritage refers to the cultural relics left over from history, which are specific physical objects, and the prominent focus is also the history and value of the items themselves, while intangible cultural heritage, most of which do not exist in kind, are classified as intangible cultural heritage.

First of all, it is one-sided. The question is very simple, and those who have studied Marx's philosophy must know that the only characteristic of matter is objective reality. More specifically, matter is an objective existence that does not depend on human consciousness and can be reflected by people.

Sound, light, etc., do not depend on human consciousness to exist, and you can feel them, so they must be material.

First of all, it is necessary to clarify the definition of substance.

Matter is the physical objects and fields that make up all objects in the universe. In addition to the physical objects that we can see and touch, light, electromagnetic fields, etc., are also substances, and they are substances that appear in the form of fields.

Then let's clarify the definition of light.

The object that is emitting light is called a light source, and the condition of "being" must be met, and the light source can be natural or artificial. In physics, it refers to an object that can emit electromagnetic waves in a certain wavelength range (including visible light, ultraviolet, infrared, X-rays and other invisible light).

Therefore, light is also matter.

Let's take another look at what sound is.

Sound is a kind of pressure wave: when playing a musical instrument, slapping a door or knocking on the tabletop, their vibration will cause the vibration of the medium, if the sound wave propagates in the air, it is the rhythmic vibration of the air molecules, so that the surrounding air produces dense changes, forming a dense longitudinal wave, which produces sound waves, and this phenomenon will continue until the vibration disappears.

So sound is different from light, sound waves are also different from light waves, sound is not matter, but a manifestation of the vibration of matter.