In ancient times, humans still use birds as a medium of long-distance communication intermediaries. In contrast to today, technological advancements are gradually increasing. Humans have been facilitated by sophisticated tools such as telephones, radios, ultrasound devices. Where the use of this equipment cannot be separated from the wave. the presence of wave.

A wave is a disturbance that transfers energy through matter or space. There are two main types of waves. Mechanical waves propagate through a medium, and the substance of this medium is deformed. Restoring forces then reverse the deformation. For example, sound waves propagate via air molecules colliding with their neighbours. When the molecules collide, they also bounce away from each other (a restoring force). This keeps the molecules from continuing to travel in the direction of the wave. [1]

The second main type, electromagnetic waves, do not require a medium. Instead, they consist of periodic oscillations of electrical and magnetic fields originally generated by charged particles, and can, therefore, travel through a vacuum. These types vary in wavelength and include radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. [2]

Suppose the telephone, in its use, used sound waves as its propagation medium. The sound produced by the caller will be received by satellite and then it will be reflected back to the receiver. So long-distance communication can be done in seconds. Means indirectly, the waves are already attached to humans in their daily life.

In addition, the sun as the centre of the solar system can radiate its light to the earth because of the wave. Where the light beam that falls to earth has a certain speed in time t seconds. Therefore, the authors raised a paper titled 'Lighting the Sun as the Application of the Wave Ball'.

Wave

Waves can be interpreted as vibrating energy that propagates. In everyday life many people think that the propagation in waves is the vibration or the particles, this is a bit incorrect because the wave propagation is the energy that the vibration has. From here arises really the medium used the wave does not come creeping? when in fact there is a vast water flow in the sea.

The mechanism of energy transport through a medium involves the absorption and reemission of the wave energy by the atoms of the material. When an electromagnetic wave impinges upon the atoms of a material, the energy of that wave is absorbed. The absorption of energy causes the electrons within the atoms to undergo vibrations. After a short period of vibrational motion, the vibrating electrons create a new electromagnetic wave with the same frequency as the first electromagnetic wave. While these vibrations occur for only a very short time, they delay the motion of the wave through the medium. Once the energy of the electromagnetic wave is reemitted by an atom, it travels through a small region of space between atoms. Once it reaches the next atom, the electromagnetic wave is absorbed, transformed into electron vibrations and then re-emitted as an electromagnetic wave. While the electromagnetic wave will travel at a speed of c (3 x 108 m/s) through the vacuum of interatomic space, the absorption and re-emission process causes the net speed of the electromagnetic wave to be less than c. This is observed in the picture below. [3]

According to the water flow at sea it is not caused by waves but rather caused by the temperature difference in seawater. But there may also be a displacement of medium particles when the wave through the gas substance medium bonding between the particles is very weak then it is possible that the air particle is moved position because it is exposed to wave energy. Although the displacement of particles will not be far it can be said that the medium particles move along.

Waves based on the medium can be divided into 2 kinds:

1. The mechanical wave is a wave that in its propagation needs a medium. Examples of mechanical waves are sound waves.
2. Electromagnetic waves are waves that in its propagation do not need a medium. Examples of electromagnetic waves are light waves.

Waves based on the direction of propagation can be divided into 2 kinds

1. A Longitudinal wave is a wave whose propagation direction parallel to the direction of vibration. An example is sound waves.
2. Transverse waves are waves whose direction is perpendicular to the direction of vibration. For example light waves.

The easiest illustration to describe the spherical wave is the case of a point of light that emits uniformly uniform light radiation, with a spherical wave face.

Why the Sunlight can be said Including Wave Ball

First. we must understand the definition of the ball wave first. Wave ball is the propagation of energy vibrations that are emitted in all directions so as to form a surface like a ball.
Illustration of sunlight irradiation in all directions to form the surface of the ball.

Sunlight can be classified as a ball wave. Because the spreading is shaped like a spherical surface. Spread of light (example of a spherical wave)

When the sunlight shines on the earth, the beam of light will affect the entire surface of the earth (other than the part of the earth with its back to the sun). In the process of irradiation, sunlight does not require propagating medium, so its wavelength does not affect the exposure of sunlight to the earth.

In the polar coordinate system above where: r represents the distance between the points against the source
Ө is the angle formed by r with the vertical axis z ɸ is the angle formed by the projection r with the vertical plane illustrated that sunlight is at the coordinate centre point (0,0,0). Look at the picture on the right
Mathematically expressed by:

Because the spherical surface of the wave is then the equation can be reduced to a one-dimensional case that depends only on r alone.

Conclusion

Can be concluded that the wave is a vibration that propagates. Sunlight includes a spherical wave. The spherical equation (spherical) can be searched using polar coordinates.
Sunlight is an application of the principle of spherical waves because the light emission forms a spherical surface

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Reference

EndNote:

1. Wikipedia source
2. Wave Wikipedia source
3. Waves source

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