Lavoisier was a French chemist. He correctly explained the role of oxygen in combustion.
By carefully weighing and analyzing materials after burning,
he showed that burned materials are heavier than unburned materials.
This was because of the addition of a gas , discovered by scheele and Priestley. Lavoisier named it oxygen.
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Boyle was an Irish scientist. He founded the study of chemistry as a separate science and aimed to 'improve natural knowledge by experiment'.
He is known for his experiments on gases and was the first chemist to isolate and collect a gas.
He formulated Boyle's law:
A Volume of gas at a constant temperature varies inversely with the pressure applied to the gas.
He showed that air is absorbed in the process of combustion and that only one part of air, oxygen, is necessary for breathing.
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Crookes was a British physicist and chemist. In 1861, he discovered the element thallium.
His studies on electrical discharges in vacuum tubes resulted in the Crookes tube, an early cathode ray tube,
in 1880 he found that 'cathode rays' cast shadows and traveled in straight lines, which could be deflected by a magnet.
He believed that cathode rays were made up of negatively charged particles (electrons).
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Tycho Brahe
A Danish astronomer, lived before the telescope was invented and made the most accurate observations with the naked eye ever known.
Like most astronomers of the time, he was employed by his king as an astrologer who had to cast horoscopes,
but his real interest was the movement of the planets.
He believed that the planets orbit the sun , but he also thought that the sun orbits the earth,
and that our planet was the center of the universe.
Brahe set out to prove this by observing the positions of the planet
After His death the observations reached the hands of Johannes Kepler, who was studying the same problem.
Brahe's naked-eye observations helped Kepler prove that the earth also revolves around the sun,
and that the planets move in ellipses, not circles.
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Linus Pauling A united states chemist, Linus Pauling won the 1954 Nobel Prize for chemistry for his work on chemical bonding
He Calculated the energies needed to bind atoms in a molecule,
the distance between the atoms and the angles at which bonds form .
Also he won the Nobel prize for Peace in 1962
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Hawking is a British theoretical physicist.
He is best known for his theories about black holes, which are invisible bodies in space with strong gravitational forces.
He has shown that they give off particles and radiation until they explode and disappear.
Hawking is generally thought to have made some of the most important finds about gravity since Einstein's theory of general relativity.
He is currently working on combining gravity and a branch of physics known as quantum mechanics in a single theory that can explain the origin and structure of the universe.
He holds the post of lucasian professor of physics at Cambridge University,
a post Sir Isaac Newton once held. Hawking has suffered from an incurable disease of the nervous system since the 1960s.
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Alexander Graham Bell Was born and educated in Scotland but lived for most of his life in the United States of America.
Before he left Scotland, Bell began teaching deaf children using a code of symbols invented by his father.
His interest in the human voice, and the realization that speech produces around waves vibrating in air,
led him to become the first person to successfully transmit speech by means of electrified wire .
In 1876, he announced the world's first workable Telephone. It had certain disadvantages;
it had to be moved quickly from mouth to earand the sound was very faint even when the speaker shouted.
The American inventor Edison soon produced a much more powerful and successful telephone.
In 1880, Bell brought out the Gramophone which was an improved version of Edison's phonograph,
a machine which recorded speech and played it back
Though Bell will always be associated with the invention of the telephone,
he would rather have been remembered as a teacher of the deaf.
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Torricelli was an Italian mathematician and physicist.
He discovered the principle of the barometer.
He put a long Mercury-filled glass tube, closed at one end, upside-down in a cup of mercury.
The air pressure on the surface of the mercury in the cup held the column of mercury in the tube at a height of 760 mm.
The weight of the column of mercury was equal to the pressure of the atmosphere.
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Baird was a Scottish engineer.
In 1924 he became the first person ever to transmit a television picture by radio waves.
He was also the first to transmit a picture across the Atlantic (in 1928),
and in the same year he transmitted colour television picture.
Baird's first television apparatus, set up in his attic workshop at Hastings, England,
included a tea chest, a biscuit tin, the front lenses from a number of bicycle lamps, bits of wood,
darning needles, string, and sealing-wax.
This crude camera transmitted a blurred image of a cross to a receiver at the other end of the attic.
Despite improvements made by Baird,
in 1937 the British Broadcasting Corporation chose for its broadcasts a rival system that used a Cathode Ray Tube.
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Charles Babbage
Resigned as professor of Mathematics at Cambridge to work on designing a mechanical calculating machine.
Despite the invention of logarithms, the need for accurate and complicated calculations had outgrown the existing simple machines,
such as the Abacus.
Babbage's aim was to use sets of gears that moved each other to produce columns of figures.
These figures would then be printed out automatically.
His difference Engine, as he called it, was never finished,
but the beautifully-machined parts can be seen in the Science Museum, London.
He abandoned it for the Analytical Engine, Which was intended to solve algebraic problems as well as do direct calculations,
but he could not find enough money to complete it. He is now respected as a computing pioneer born before his time.
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Amedeo Avogadro
Was an Italian physicist.
He is famous for his gas law, known as Avogadro's law,
Which states that when each one of a set of identical glass jars is filled with a different Gas,
at the same temperature and pressure, they each contain the same number of molecules of gas.
To discover the actual number of molecules requires the use of Avogadro's number.
It is usually written as 6.0220 X 10²³ which is a short way of writing
602,200,000,000,000,000,000,000. This is about the number of molecules of any gas,
including AIR, that would be contained in 22.4 litres.
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Berzelius was a Swedish chemist. He classified different substances by calculating their atomic weights.
By 1818 he had accurately calculated the atomic weights of 45 elements and suggested a new way of naming the elements
by using the first letter or letters of their names, O = oxygen
Combinations of elements are represented by putting the letters together CO2 = Carbon dioxide, one carbon atom joined to two oxygen atoms.
Source : Wikipedia
Dalton was an English chemist. He is best known for his atomic theory to explain the structure of matter. It became one of foundations of modern chemistry. He was first to calculate weights of the atoms of several elements. He worked out of table of atomic weights of elements but it was later found to be inaccurate.
Bohr was Danish physicist who contributed greatly to the development of modern nuclear physics. For his work on the structure of the atom he won the 1922 Nobel Prize for Physics. In 1943 he worked as an advisor to scientist developing the nuclear bomb.
Lister was a British surgeon who radically changed surgical practice with the introduction of antiseptics. They reduced the risk of bacterial infection during surgery. Lister’s antiseptic solution of carbolic acid was used to clean wounds and surgical cuts and to scrub surgeons’ hands. Lister believed that infection was caused by airborne dust particles, so he also sprayed the air with carbolic acid. The equipment was heated to a high temperature to make it bacteria free. His discoveries met with initial resistance but had become widely accepted by the 1880s when he introduced antiseptic catgut ligatures. Ligatures are the strong threads used to sew surgical wounds together. He also devised new operations and invented several surgical instruments.
Fleming was a British bacteriologist in 1928. He noticed that a spot of green mould stopped the growth of some bacteria, he was cultivating the antibiotic drug penicillin was developed from the mould. Fleming won the 1945 Nobel prize for medicine which he shared with Howard florey and Ernst chain the scientists who developed the use of the drug.
This American inventor pioneered wireless telegraphy and radio broadcasting.
He invented a vacuum tube that amplified electrical symbol, which was to be significant in the development of radio and television communication.
Ampere was a French physicist. He is famous for his work with electricity and magnetism. Ampere discovered that parallel electric currents attract each other if they move in the same direction and repel each other if they move in opposite directions. He discovered that when electricity produces magnetism and that when electricity is passed through a coiled wire it acts like a magnet. The unit used to measure the size of an electric current was named Ampere or AMP in his honour. ==========>>>
An English monk and Alchemist, Bacon become known as the founder of experimental science. He believed that doing experiments for your self was the way to learn about nature rather than accepting what other people tell you.
His most important work was the opus maius in which he wrote about the scientific method of learning. he did many Experiments. He showed how rainbows are made by the effect of water drops on sunlight, and how lenses could be used to help people with weak sight. More reading
Carver was an American educator and agricultural scientist. he worked to improve crop production and agricultural methods. he encouraged farmers of the Southern States to grow soil enriching peanuts and sweet potatoes. He discovered many uses for the new crops from peanuts. He made over 300 products including soap and Ink.
Source :Wikipedia