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The 2,400 year search for the atom...

Added Jun 09, 2017 •

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what do an ancient Greek philosopher in an Century Quaker have in common with Nobel prize-winning scientists  although they are separated over 2400 Gears of History each of them contributed to answering the Eternal question what is stuff made of it was around 4:40 BCE that the test first proposed that everything in the world was made up of tiny particles surrounded by empty space and he even speculated that they've the in size and shape depending on the substance they can post he called these particles a Tomos Greek for indivisible  is I he is opposed by the more popular philosophers of his debt Aristotle for instance disagree completely stating instead that matter was made of 4 L earth wind water and fire and most later scientists follow suit  atoms would remain all but forgotten until 1808  when a Quaker teacher named John Dalton sought to challenge Aristotelian Theory where as democritus's atomism purely theoretical Dalton showed that common substances always broke down into the same elements in the same proportions he concluded that the very compounds were combinations of atoms of different elements each of a particular size and mass that could neither be created nor destroyed though he received many honors for his work as a Quaker Dalton live modestly until the end of his days atomic theory was no accepted by the scientific Community but the next major advancement would not come until nearly a century later with a physicist JJ Thomson's 1897 discovery of the electron what we might call the chocolate chip cookie model of the atom he showed atoms as uniformly packed spheres of positive matter filled with negatively charged electrons Thompson won a Nobel Prize in 1906 for his electron Discovery but his model of the atom didn't stick around long this was because he had add some pretty smart students including a certain Ernest Rutherford who would become known as the father of the nuclear age well studying the effects of x-rays on gases Rutherford decided to investigate Adams more closely by shooting small positively charged alpha particles at a sheet of gold foil under Thompson's model the atoms thinly dispersed positive charge would not be enough to deflect the particles in any place the effect would have been like a bunch of tennis balls punching through a thin paper screen but while most of the particles did pass through some bounced right suggesting that the foil was more like a thick neck with a very large mesh Rutherford concluded that atoms consisted largely of empty space just a few electrons while most of the mass was concentrated in the center which he termed the nucleus the alpha particles pass through the gaps but back from the dense positively charged nucleus but the atomic theory wasn't complete just yet in 1913 another of Thompson stood the name of Niels Bohr expanded on Rutherford's nuclear model drawing on earlier work by Max Planck and Albert Einstein he stipulated that electron orbit the nucleus at fixed energies and distances able to jump from one level to another but not to exist in the space between boars planetary model took Center Stage but soon it to encountered some complications experiments that shown that rather than simply being discreet particles electron simultaneously behaved like waves not being confined to a particular point in space and in formulating his famous uncertain principal furner Heisenberg showed it was impossible to determine both the exact position and speed of electrons as they moved around an atom the idea that electrons cannot be pinpointed but exists within a range of possible locations gave rise to the current Quantum model of the atom fascinating Theory with a whole new set of complexities whose implications have yet to be fully grasp even though our understanding of atoms keeps changing the base fact of atoms remains so let's celebrate the Triumph of atomic theory with some fireworks as electrons circling an atom shift between energy levels they absorb or release energy in the form of specific wavelengths of light resulting in all the marvelous colors we see and we can imagine Democritus watch from somewhere satisfied that over two Millennia later he turned out to have been right all along

Uploaded by Michelle Martin.

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The 2,400 year search for the atom...

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