The John Dalton's contributions to science and society Are multiple and very valuable. Thanks to his numerous investigations, he was able to mark a before and after in the world of science.
John Dalton was born on September 6, 1766 in Eaglesfield ( Cumberland, England) and died 26 of July of 1844 in Manchester (England). Chemist, scientist and meteorologist, he emphasized from a very young age for his different way of seeing the world.
He was a passionate meteorologist from where he began to develop his researches discovering that have established the fundamental pillars of science as we know it today.
He was considered as a precocious genius, ahead of his time. From the age of 12 he began teaching at a school in his city. In 1787 he and his brother and his cousin directed a school in Kendal. He spent the rest of his life teaching in Manchester, first at New College and later as a private teacher.
The contributions of John Dalton did not come from his original ideas, but he was dedicated to study hypotheses already existing in his time and, through Quantitative experiments , To demonstrate one by one such theories.
The 7 main contributions of John Dalton
1- Theory of the atom or atomic
This was his most important contribution to science. Although some of his investigations have been shown to be not quite true, his theory that matter consists of atoms of different masses that combine in simple proportions to form compounds Is the fundamental pillar of modern physical science.
This theory contributes to the current research in nanotechnology which is based mainly on the manipulation of atoms.
He came to the conclusion that every form of matter (solid, liquid, or gas) is made up of small individual particles, and each particle called it an atom inspired by the theory of the Greek philosopher Democritus .
John Dalton became the first scientist to explain the behavior of atoms by their weight.
His theory was that atoms of different elements could be distinguished based on their different atomic weights. Their masses were not entirely accurate but they form the basis of the current periodic classification of the elements.
2- Atomic weights
In his investigations he discovered that the atoms could not be created, nor destroyed, nor divided. He found that the molecules of an element always consist of the same proportions except the water molecules.
The atoms of the same element are equal to each other and the atoms of different elements have different weights.
These theories finally proved that they were not true, since it was possible to divide atoms through the process of nuclear fission. It was also shown that not all atoms of the same element have the same mass, since there are different isotopes.
Calculated the atomic weights of the percent compositions of the compounds. For this he used an arbitrary system that determined the atomic structure of each compound.
John Dalton was the one who made the first system of symbols of the elements and composed the table of atomic weights.
3- Law of multiple proportions
Of all the studies, investigations and observations he made on gases and meteorology, he arrived at the theory of the law of multiple proportions, which established that the weights of the elements always combine with each other in more than a proportion with an amount Fixed forming different compounds.
If the fixed quantity of an element is combined with different variable amounts of another element, the relationship between them is always simple whole numbers.
4- Law of the partial pressures (Law of the gases)
In 1803 he formulated this law that summarizes the quantum laws of the chemistry . Thanks to his numerous trials and experiments he was able to make known to the world his theory that if two gases mix with each other, they behave as if they were independent.
The first gas does not attract or repel the second gas, it only behaves as if this second gas does not exist. He concluded that if several gases that do not react together are mixed together, the total pressure of them is the sum of the pressures of each gas.
Today, divers use Dalton principles to assess how pressure levels at different depths of the ocean will affect air and nitrogen In their tanks.
5- The meteorology: The atmospheric pressure
It was he who first proved the theory that rain is not produced by a change in atmospheric pressure but by a decrease in temperature.
It carried daily records of the meteorological conditions throughout his life arriving to collect more than 200,000 annotations on the climate of Manchester. The first book he published was in this field, he published it in 1793 under the title Meteorological observations and tests.
He developed several instruments and studied aurora boreales concluding that these are caused by the magnetism that the Earth exercises.
6- The Daltonismo
Color blindness was first described by John Dalton himself in 1808. At the age of 26 he discovered that both he and his brother suffered from this genetic alteration that prevented them from perceiving colors such as red and green.
This illness made many of his experiments could not prove them because it confused the flasks of the reagents, something that did not prevent him to advance in his investigations.
He left written that when he died he wanted to donate his eyes to investigate the disease and thanks to their studies and their DNA could be studied what is known as"blindness of colors"giving rise to what today we know as Colour blindness , Name that was placed in his honor.
He was a Quaker and one of the best-known anecdotes is that he appeared before King William IV dressed in red when he always wore simple clothes and dark color, the reason was that he saw his gray suit. His eyes are preserved today in the museum of science and industry of Manchester.
7- British Association for the Advancement of Science
John Dalton was one of the founders of the British Association for the Advancement of Science. He was also elected a member of the Royal Society of London in 1822 and in 1826 received the gold medal of the Royal Society of London.
The legacy after his death
After his death, John Dalton left all his wisdom and research embodied in his books and essays. In honor of all his research, many chemists today use the Dalton (Da) unit to designate an atomic mass unit.
The division of the atom in the 20th century might not have been possible without his research into the atomic composition of molecules. A lunar crater bears its name: The Dalton Crater.
Featured Works
- Observations and tests (1793)
- Elements of English grammar (1801)
- Extraordinary facts related to the vision of colors (1794)
- A new system of chemical philosophy (1808)
References
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