James Clerk Maxwell
In 1864 James Clerk Maxwell took all the pieces of the electricity and magnetism puzzle and put them together. His mathematical laws of electromagnetism are known as Maxwell’s equations:
E
lectricity
and magnetism are two different aspects of the same force.Every electrical charge has an electrical field around it. This field attracts opposite charges and repels like charges.
A moving electrical charge or field generates a magnetic field.
A moving magnetic field generates an electrical field.
As Maxwell considered his discovery, he realized something else that was very interesting. A charge in an electrical field creates a charge in a magnetic field. But a charge in a magnetic field then creates a charge in an electric field. This process can continue on and on. So a single charge in an electric or magnetic field spreads out very rapidly, creating an electromagnetic wave effect.
Maxwell calculated how quickly this electromagnetic wave would move through space. His results said that it would travel at 300,000 kilometers per second (186,000 miles per second). But that is a well-known speed. It is the speed of light. Could it be that light is a form of electromagnetic energy?
Yes. Maxwell discovered that light is an electromagnetic wave. More recent discoveries have shown that light radiation is actually generated by the rapid vibration of electrons in atoms. And it wasn’t long after Maxwell’s laws were published that other new forms of electromagnetic radiation were discovered.
In 1889 Heinrich Hertz discovered the existence of radio waves. These are electromagnetic waves with much longer wavelengths than visible light. In 1895 Wilhelm Roentgen discovered X rays.
In 1897 J. J. Thomson discovered the existence of a negatively charged particle smaller than an atom. This particle became known as the electron. Scientists realized that it is the motion of electrons that carries electrical energy.
Lodygin
T
he
creation of the first incandescent lamp is closely connected with the
name of the well-known Russian scientist and inventor, Alexander
Nicolayevitch Lodygin.
Lodygin created the first incandescent lamp and laid the foundation for the production of the present-day incandescent lamps that are much more economical than the lamps with carbon electrodes. Lodygin was the first to turn a laboratory device into a means of electric lighting. He was also the first inventor to discover the advantages of the metal wire filaments in comparison with other filaments.
Lodygin’s great achievements paved the way for further successful work of a number of other Russian electrical engineers.
He was born in Tambov region on October 18, 1847. His parents gave him a military education as they wanted him to join the army. However, military service did not interest him at all. So, he resigned soon and devoted all his time to the study of engineering and the solving of technical problems.
In 1872 Lodygin constructed a number of incandescent lamps, these first lamps consisting of a glass bulb with a carbon rod serving as a filament.
In 1873 he produced an improved lamp having two carbon electrodes instead of a one and a longer life (about 2 hours and even 2 hours and a half). That very year Lodygin demonstrated his invention in several Petersburg streets, lighting them by means of his electric lamps. It was the first practical application of the incandescent lamp for lighting purposes. Lots of people went out into the street to see electric light for the first time in their life and, as a matter of fact, for the first time in the world.
Lodygin was never satisfied with his achievements and continued to perfect his invention. Indeed, a more perfect lamp designed by him appeared in 1875. the interest in Lodygin’s lamp greatly increased. However, under very hard economic conditions existing in tsarist Russia he got neither the help nor the necessary support to realize his plans. He himself was practically without money, having spent all he had on his numerous experiments.
Lodygin’s study of metal filaments having a high melting point is a work of world importance. It is he who introduced tungsten filaments in a vacuum. He received a patent for his invention in America. Tungsten is still considered to be very metal that should be used for filament production. The electric lamps that light your room doubtless have tungsten filaments.
Lodygin died on the 16th of March, 1923, at the age of 76. Death carried away a great Russian scientist, the first to have used the incandescent lamp as a means of lighting.