During our first grading period in Advanced Physics, I learned about the nature of Physics. The world is full
of experiences that cry out for explanations. Think, for example, of the colors of rainbows and soap bubbles, the
vapor trails of high-flying aircraft, the fact that liquid water abruptly changes into solid ice at a certain temperature, the
production of lightning and the thunder that follows it in a storm, the beautiful hexagonal symmetry of small
snowflakes; all these, and a limitless list of other phenomena, fall within the province of the science of physics. The
essence of science in general is the observation and exploration of the world around us with a view to identifying
some underlying order or pattern in what we find. And physics is that part of science which deals primarily with the
inanimate world and which furthermore is concerned with trying to identify the most fundamental and unifying
principles. The first of these conditions -- restriction to the inanimate world -- separates physics, at least provisionally,
from biology; the second separates it from chemistry, which, at least in its theoretical aspects, builds on some
specific areas of physics but can ignore some others. Mathematics, of course, although indispensable to the practice
of physics, is an entirely different field of study, since it is self-contained and is ultimately independent of observations
of the real world. The subject of this article could be approached in many different ways. One way of obtaining some
insight into the nature of physics is to look at the story of how physics has developed from its beginnings until now.
That is what this article does, although it makes no attempt to be exhaustive and omits many topics that some might
consider important or even essential. Its main purpose is not to offer a chronological survey for its own sake, but just
to illustrate how the consistent aim of physics is to relate our knowledge of phenomena to a minimal number of
general principles .Physics is a branch of science that involves the study of the physical world; energy, matter, and
how they are related. We study Physics because it is one of the most fundamental of sciences. It is also the
foundation of all engineering and technology. It is an adventure. We can discover many things in learning about
Physics. Albert Einstein, Galileo Galilei, Isaac Newton, Alessandro Volta, James Watt, Benjamin Franklin, Lord
Kelvin, James Prescott Joule, and many more are the scientific giants who laid the foundation of Physics. The
branches of Physics are Astronomy or Astrophysics, Classical Physics, Low Temperature Physics, Plasma Physics,
Quantum Physics, Atomic & Solid State Physics and Relativistic Physics. I also learned about waves and its
properties. Mechanical waves can be classified as transverse waves and longitudinal waves. I can’t forget the song
that Sir Sonny discussed to us, the Electromagnetic Waves Song. Radio waves, microwaves, infrared, visible light,
ultraviolet rays, x-rays and gamma rays are mentioned in that song. Sound waves are compressional waves. When a
noise is made, such as when a locker door slams shut and vibrates, nearby air molecules are pushed together by the
vibrations. The speed of a wave depends on the properties of the medium it is traveling trough. It travels the fastest in
empty space and slowest through solids. In calculating the speed of a wave, multiply the wavelength and the
frequency. The wavelength is the distance between one point on a wave and the nearest point. The frequency is the
number of waves that pass a given point each second. It is expressed in Hertz (Hz). I also learned about Reflection,
Refraction and Diffraction. The Law of Reflection states that the angle of incidence is equal to the angle of reflection.
I tried to strike a laser in a mirror and it’s proven that the angle of incidence is equal to the angle of reflection. When
sound waves hit an object, they reflect and come back to you. You hear the sound multiple times, it is called the
echo. Refraction is the wave that bents. The light waves travel slower in water than air. This causes light waves to
change direction and bend towards the normal line. Diffraction is an object that causes a wave to change direction
and bend around it. I learned about Light. Light is a form of energy which is invisible to the human eye that is radiated
by moving charged. It is the reason why we can see things. Light is absorbed by the object and reflects in our eyes.
The real nature of light is dualistic in nature. Light behaves like a particle and a wave. The particle theory of light is
proposed by Isaac Newton while the wave theory of light is proposed by Christian Huygens. The sources of light are
incandescent and luminescent. A laser is a special kind of light source that produces very regular waves that permit
the light to be very tightly focused. Laser is an acronym for Light Amplification by Stimulating Emission of Radiation.
Light travels at a speed of 300,000 km/s. When light reaches an object, it is absorbed, reflected, or passes through it.
The law of Refraction states that the incident ray, refracted ray and the normal line lie on the same plane. The index
of refraction is a dimensionless or unitless constant that can be obtained by dividing the speed light in a vacuum and
by the speed of light in a material. In water, the speed of light is 75% that in vacuum or ¾. The index of refraction is
always greater than 1. When light passes through an object, it is transparent. When light is blocked by an object and
dark shadow is cast, it is opaque. When some light passes through but not all and a light shadow is present, it is
translucent. The total internal reflection is the phenomenon of light where the angle of incidence is greater than 90
degrees, instead of refracting; it will undergo total internal reflection. I learned about plane mirror. Plane mirror is
mirror with a planar reflective surface. I also learned on how to locate an image on a plane mirror. Sir Sonny gave us
an activity about that. We locate an image on a plane mirror using a ruler and measuring the distances of the figures.
A virtual image is an image formed when the outgoing rays from a point on an object always diverge. The image
appears to be located at the point of apparent divergence. Because the rays never really converge, a virtual image
cannot be projected onto a screen. In diagrams of optical systems, virtual rays are conventionally represented by
dotted lines. Virtual images are located by tracing the real rays that emerge from an optical device (lens, mirror, or
some combination) backward to a perceived point of origin. A real image is an image which is located in the plane of
convergence for the light rays that originate from a given object. If a screen is placed in the plane of a real image the
image will generally become visible on the screen. Examples of real images include the image seen on a cinema
screen (the source being the projector), the image produced on a detector in the rear of a camera, and the image
produced on an eyeball retina (the camera and eye focus light through an internal convex lens). In ray diagrams
(such as the images on the right), real rays of light are always represented by full, solid lines; perceived or
extrapolated rays of light are represented by dashed lines. A real image occurs where rays converge, whereas a
virtual image occurs where rays only appear to converge. The size of a plane mirror is the same as the object that is
in front of the mirror. The attitude is upright. The location is behind the mirror. The type is virtual image. The mirror
does not reverse images from left to right; it reverses them from front to back relative to the front of the mirror. Stand
facing a mirror. Point to one side. You and your mirror image are pointing in the same direction. Point to the front.
Your mirror image is pointing in the opposite direction to you. Point upwards. You both point in the same direction.
Now stand sideways on to the mirror and repeat. You are now pointing in opposite directions when you point
sideways. Place the mirror on the floor and stand on it. This time you point in opposite directions when you point
upwards and your upside down image points downwards. In all cases the direction reverses only when you point
towards or away from the mirror. The answer stems from the fact that a reflection is not the same as a rotation. Our
bodies have strong left-right symmetry, and we try to interpret the reflection as a rotation about a central vertical axis.
We imagine the world in front of the mirror has been rotated through 180¡ about the mirror's vertical axis, and it has
arrived behind the mirror where we see the image. Such a rotation would put the head and feet where we expect
them, but leaves the left and right sides of the body on opposite sides to where they appear in the reflection. But if
instead we imagine the world to have been rotated about a horizontal axis running across the mirror, this would leave
you standing on your head, but would keep the left and right sides of your body in the expected positions. The image
would then appear top/bottom inverted, but not left-right. So whether you see the image as left-right inverted or topbottom inverted, or for that matter inverted about any other axis, depends upon which axis you unconsciously (and
erroneously) imagine the world has been rotated about. If you lie on the floor in front of a mirror you can observe both
effects at once. The room appears left-right reflected about its vertical axis, while you interpret your body as being
left-right reflected about a horizontal axis running from head to foot. And lastly, I learned about Spherical mirrors. A
spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface. The most common nonspherical type are parabolic reflectors, found in optical devices such as reflecting telescopes that need to image
distant objects, since spherical mirror systems, like spherical lenses, suffer from spherical aberration. One advantage
that mirror optics has over lens optics is that mirrors do not introduce chromatic aberration. There are two types of
spherical mirrors: concave and convex. The most commonly occurring examples of concave mirrors are shaving
mirrors and makeup mirrors. As is well-known, these types of mirrors magnify objects placed close to them. The most
commonly occurring examples of convex mirrors are the passenger-side wing mirrors of cars. These type of mirrors
have wider fields of view than equivalent flat mirrors, but objects which appear in them generally look smaller (and,
therefore, farther away) than they actually are. Principal axis is a line through the center of the spherical mirror that
intersects the mirror at the vertex of the spherical section. Center of curvature is the point on the optic axis that
corresponds to the center of the sphere of which the mirror forms a section. Radius of curvature is the distance frin
the vertex to the center of curvature.