Subbranches of science

Acoustics

Acoustic basically deals with the study of sounds therefore it is called Science of sounds. So, we can say that Acoustic is a branch of science that deals with the production, transmission and reception. it also includes the study of musical instruments. Other than this, it also studies the other topics related to sounds such as noise control, SONAR, thermoacoustic refrigeration, ultrasounds, bio acoustics and seismology etc.

Acrobatics

It basically deals with the art of performing acrobatic feats that are known as gymnastics.

Aerodynamics

It deals with the motion of gases and air. It also includes the the study of motion and control of solid bodies, like aircraft, missiles, etc, in the air.

Aeronautics: 

It is known as the science of flights

Aerostatics

The branch of statics that deals with gases in equilibrium and with gas and bodies in them.

Maser And Lasers

Maser is stands for Microwave Amplification by Stimulated emission of Radiation. A class of amplifiers and oscillators that make use of internal energy of atom and molecules to obtain low noise level amplification and micro wave oscillation of precisely determined frequencies. Stimulated emission, which is the basic principal n which these devices work, is emission the emission by an atom in an excited quantum state of photon, as the result of the impact of photon from outside of exactly equal energy. Thus stimulating photon, or wave, is augmented by the one emitted by the excited atom. A maser consists of an "active medium"in most of the atoms can optically pumped to an excited state by subjecting the system to electromegnatic radiation of different frequencies to that of stimulating frequency. An active medium is enclosed in a resonant cavity so that wave is build up with only one mode of oscillation, which is equivalent to a single output frequency. Maser can also be made to operate at optical frequencies, when referred to as optical maser or laser.

The term laser derived from the technical name for the process ; light Amplification by Stimulated Emission of Radiation.  Stimulation emission is the emission of a photon (a particle of light). Laser is an instrument  which produces a beam of light. However, laser light is much more powerful than ordinary light. It has such high energy that it can cut through very hard substances such as metal and diamond. metal are also joined together or welded , using laser.   

Temprature and Heat

Temperature of something refers to how hot it is?To measure the temperature some scales are discovered. The temperature scales are divided into the degrees.

Celsius Scale:

The most common scale is Celsius scale that was discovered by Anders Celsius, in 1742. The Celsius scale measure the temperature in centigrade. A degree centigrade is often shown as C. On this scale , the temperature at which ice turns to water (melting point.) is 0 degree centigrade, and the point at which water turns to steam (boiling point) is 100 degree centigrade, at normal air pressure.

Fahrenheit Scale:

 The other temperature scale  that is most common in use is Fahrenheit scale, by Gabriel Fahrenheit in 1714. It is shown as F. According to this scale the melting point of ice is 32degree Fahrenheit and the boiling point of water is 212 degree Fahrenheit, at normal air pressure.
To change the centigrade into Fahrenheit, multiply the given temperature by 915 and add 32. To change the  degree Fahrenheit into centigrade, subtract 32 and multiply by 5/9.

Kelvin Scale:

Another scale that is used to measure the temperature is Kelvin scale.  It is mostly used in scientific work. The melting point of ice is over 273 degree Kelvin, and boiling point of water is 373 degree Kelvin, at normal air pressure.

Heat

The energy that transferred from one body or system to another as a result of  temperature difference is known as heat.  heat is measured in joules, like the all other forms of energy, in SI units.In c.g.s units, it is measured in calories. In imperial units it is measured in British thermal  units

Big Bang Theory

Big Bang is a theory about the beginning of the universe. It is said that all the matter was packed close together, or, in other words that everything that we know today was present in a form of single body. Round about 15,000 to 20,000 million years ago, there was a huge explosion and all the matter was scattered in the space. That explosion is known as Big Bang. In the result of that big bang all the galaxies were formed and they are still moving away from each other  till now. Most of the astronomers agree with the theory.
Observation of galaxies proves that theses galaxies are still moving far from each other. And the universe is expanding with the passage of time.
The big bang consider the age of universe also. The explanations of big bang theory shows that at a time the universe was too hot and dense, therefore it began to expand rapidly. But after the initial expansion, it started to be cooled in such a way that the energy can be transformed into subatomic particles , such as electrons, neutrons etc. It is said that the first nuclei was formed within next few minutes after that great explosion that is known as Big Bang.
In short Big Bang theory is a scientific theory and is accepted by scientific communities of the world. There are other theories also about the universe such as, Steady State. But the Big Bang is most popular among all other theories. 

ChickenPox (Varicella) and Cholera

Chickenpox (Varicella):

It is a disease, common in childhood and infectious before four days from the rash appears, until seven days after appearing the rash.Its incubation period usually last for 14 days. The rash, which may be preceded by mild headache or fever. It begins as red spots, and within a few hours raised in such a way, they become clear blister. Within two or three days these blisters becomes opalescent and then scab over, with many corps of blisters that appear over a period of 5 to 7 days. This rash can occur on any part of the body, including mouth and scalp. 

Infect chickenpox is caused by virus called, Herpes zoster. There is specific treatment for this disease. The victim should avoid scratching with dirty hand and nails and to relieve itch. 

Cholera:

Cholera is an acute infection in the intestine of victim. This infection causes profuse watery diarrhea, vomiting and dehydration. It is caused by consuming water or food contaminated by bacterium Vibrio comma, which is found in faeces. It can be prevented by the supply of clean water. Its vaccination is also available; two injections are injected at the interval of two to four months and is also effective for six to nine months, after which booster doses are needed.

AIDS

AIDS (Acquired Immune Deficiency  Syndrome). This fatal disease was first introduced in Los Angeles, in 1981. The virus that cause AIDS is known as HIV (Human Immune-Deficiency Virus). This disease spread through ;

• oral sex or sexual intercourse with someone who carries this virus, especially if it is anal intercourse.
• by the use of infected needles or instruments that contaminated with HIV infected blood.
• by receiving the blood or blood products from someone carrying HIV.
• from the mothers who are carrying HIV which can pass into baby.  

AIDS is spreading so rapidly throughout the western world, and has an epidemic proportion in the eastern and central Africa.
This virus attacks the particular type of white blood cells that reduce the ability to combat infection. It can attack the nervous system also. Therefore acute infection leads to the production of antibodies. When someone acquire that virus, a transient flu-like sickness with gland swelling and muscles aches may occurs.

Infection in Living beings

 Organisms that can cause sickness are present all around us; in air, water, soil, food and in the bodies of other animals and plants. Therefore when some of these harmful organisms pass through the body of a living being, it resulted in infection in that body.
Infection is the diseased condition found in both animals and plants. When harmful micro organisms e.g bacteria, viruses enter the tissue of victim and get multiply. Such micro-organisms are mostly unicellular ; bacteria, viruses and protozoans. Other than these, many kinds of fungus, worms and arthropods.
Trees are often become infected when the bark is damaged by grazing animals or through loss of branches. Spores enters in trees and cause deformities, fruit loss or even death also. Infection also occurs when the roots become damaged and allow soil born organism to enter in the body.
Infection in animals can be caused by wounds and injuries. Some kinds of infection in human beings are passed through the tiny droplets of water that are produced in result of sneezing. The common cold is transmitted to another person in this way.The common cold is caused by a virus which infects the cells of our mouth, nose and throat. Some infection need proper medical treatments and some are cured by the victim's own defense mechanism. 

The ways of transmission of infection in a body:

Air born transmission:

Infection caused by the tiny droplets  that are present in the air from the nose, saliva or dust particles.

contamination:

Infection that is caused by the food and water containing infected materials e.g faeces or urine.

Direct contact:

Infection through the close contact with an infected body. Usually skin infection caused by direct contacts.

Blood Born Transmission:

Infection that passed through the injection of contaminated blood and blood products or by the use of improper sterilized instruments. 

Animal born Transmission:

Infection by the contaminated   saliva, for example, Malaria that is carried through the mosquito's bites and bubonic plague that transmitted through the flea bites