８ｔｈ： Sir Isaac Newton's universal gravitation

Universal gravitation is the attraction which everything has as the name suggests. All the substances of a world have the attraction which pays well mutually. Newton is seen fall an apple and it is said that that an apple falls obtained an idea called the body pulled to gravitation attraction of the earth. And he considered the attraction with if the moon over there and the sun are far reached not only in the apple.

As for movement of the heavenly body, the law was explained by Kepler. However, Kepler's laws of planetary motion had three, and the law was a little complicated for considering it as the ultimate principles of a nature. Universal gravitation which Newton considered. If the law is right and is a more fundamental law, all of three laws of Kepler should be drawn from universal gravitation. As a result, it arrives at the idea that the power committed between two objects is decided by the mass of a substance, and distance between objects. If its mass is large, it is large, and if the strength of gravitation which works between two objects has a small distance, it is large. 

Newton is writing the equation which describes quantitatively the strength of gravitation which works between two more objects. According to the equation, the attraction committed between two objects is proportional to the product of objective mass, and in inverse proportion to the square of distance. By this law of gravitation, it succeeded also in drawing three laws of Kepler. 

It means discovery of a briefer and more fundamental law. This theory also comes to be called the general relativity which makes the special relativity of Einstein who talked to the second, and a pair. 

7th: Ampere's law

French physicist Andre Marie Ampere discovered in 1820.
Ampere observed the power committed between two current in an experiment, and summarized the experimental result to Ampere's law, and it succeeded in explaining the phenomenon of the electromagnetism discovered before it. When current was sent, it discovered that a magnetic field produced in the direction around which the right screw turns as a direction to which the right screw follows the direction of current.
This is called "law of Ampere's right screw."

The law showing the relation between current and the magnetic field made to the surroundings of it is called "Ampere's law."
The result of adding the size of the magnetic field in accordance with the closed course is proportional to the sum of the current which pierces through the closed course.
Since it carries out by a curvilinear integral that a magnetic field adds, it is also called "the law of Ampere's circumference integration."

6th:Michael Faraday's law of induction

H.C. Oersted had discovered the magnetism by current in 1820, and Faraday had proved in 1831 that current flowed by the relative motion of a magnet and a coil.

It was a phenomenon of electromagnetic induction, when the magnet was taken in and out of a coil, current flowed into the coil, and when current was conversely sent through the coil, it discovered that power arose to a magnet.

That is, if magnetic flux is changed, an electric charge can be moved(current is sent) , and it has become a principle of a dynamo or an electric motor by the phenomenon which a magnetic field will occur and will exert power on a magnet if an electric charge moves.

5th: Doppler effect

Doesn't it have the experience which you thought that how for a siren to be heard is different in the time of keeping away from oneself?
Moreover, if sound of "being a can with a clang" of a crossing is heard out of a train, isn't there any experience thought that how to be heard in the time of keeping away with the time of approaching a crossing is different?
These are the phenomena which physicist Doppler of Austria discovered in the mid-1800s and which are called the "Doppler effect."

It is said that the old person conducted the experiment using a drum and fife corps in order to confirm the Doppler effect of this sound.
It actually verified about the case where assign a drum and fife corps in a station, it is made to play, a watcher takes a train, and sound is observed, and the case (when a sound source moves and the watcher is standing it still) where put on the train which runs a drum and fife corps, it is made to perform (when a watcher moves and the sound source is standing it still), and a watcher observes sound at a station.

About the case where a watcher moves and a sound source stands it still, verification will be possible even now (if lucky) ., for example, the person "high speed may ride on high speed and may pass through the station which does not stop although a local train draws up", has a chance -- there is a place where the signal at the time of leaving now  is using what is called not bell sound but a melody.
If it passes through the station with a rapid train (while the melody of the highball is sounding), and . which the melody becomes amusing and hears it by the Doppler effect will also be carried out and it will meet with such a situation just before another train leaves a station, please strain and listen to an ear.

4th:Kirchhoffsches Strahlungsgesetz

In 1845, Gustav Kirchhoff who is a physicist discovered this law.
[The first law]
It is a law about current and "total of the current which flows into certain one on a circuit, and total of the current which flows out of there are equal" becomes the first law.Please see the following figure, 



 When there is a circuit as shown in the upper figure and I4 is current which flows out of A point with the current with which from I1 to I3 flows into A point , it is the following formula.
I4 =I1 +I2 +I3
The idea that moreover, total of the current of a   "A point will be set to 0 if an upper type is transformed" is also made.




[The second law]
It is a law about voltage and "total of the power supply voltage (electromotive force) of a certain closed circuit and total of the voltage (voltage drop) consumed by load are equal" becomes the second law.


When there is a circuit as shown in the upper figure, it is the second law that a next type is realized.
I1･R1 +I2･R2 =E1 +E2

3rd：Charles Augustin de Coulomb's law

Coulomb's law
The law called "Coulomb's law" serves as a starting point of electricity and magnetism.
A French physicist called Coulomb (Charles Augustin de Coulomb) discovered this law with a measuring device called a balance.

 When there is two point charge called q_1 and q_2 according to Coulomb's law , it is between the electric charge.



 This power works.
This power is called coulomb force.
Discovery of this law was very important and the research of the electric phenomenon which had stopped for a long time was able to go a new era by discovery of this law.
the power committed with Coulomb's law  also having if there is nothing and it does not become a size of an astronomical scale in the power of saying  that it is large . gravity, it cannot understand, but in a substance, electric charge distribution only has a little gaps, and such mere big power generates electric power that man can understand.
A glint of light and roll of thunder of lightning are also born by the electric charge distribution in the air having shifted just for a moment.

2nd ALbert Einstein's Special relativity

There are "special relativity" and "general theory of relativity" in Einstein's theory of relativity.
First of all, let's explain the special relativity. There are two big pillars in the special relativity.
The 1st is  "special principle of relativity."
The 2nd is "a principle with the invariable speed of light."
The special principle of relativity is a law referred to as "A natural law is similarly realized no matter it may move by what speed."
"The natural laws" said here is all laws including fall of a thing.
Even if it is moving and the phenomenon which happens when start a chemical reaction and a nuclear reaction, burn a thing, electricity is sent or power is applied has stopped, it is said that it is completely the same. 
The principle with another invariable speed of light is a law said "The velocity of light does not change no matter it may move by what speed."
 This says, "The speed of light is the same for anyone."
Speed of light is set to speed per second 299,792.458 km. That is, it is about 300,000 km/s (in the case of in a vacuum). This  say that this speed does not change for any persons.