When and Where did the Atomic Theory Come From?

[Rev. Rye]

This is actually a very complicated question:

• Leucippus (his historicity possible, but not proven) and his student Democritus developed the theory of the atom around the fifth century BC in an attempt at reconciling Heraclitus and Parmenides. Aristotle rejected atomic theory and so, with his ascendancy, atomic theory becomes dormant for over a millennium.
  
• Surprisingly, thinkers in India, most notably Kanada (and yes, that was his name), author of the Vaisesika Sutra, stumbled upon a very similar atomic theory to that of Democritus, and possibly even doing so before Democritus. That said, since Atoms weren't mentoned in the Vedas, it did not catch on in India until later.
  
• Near the end of the 18th Century, John Dalton, emboldened by the discovery of the Law of Conservation of Mass, starts work on figuring out the various elements, and even begins to figure out what they're made of and their relative size differences. He first does an oral presentation in 1803, publishes a paper in 1805, and fleshes it all out in 1808's A New System of Chemical Philosophy.
  
• And shit just gets more complicated from there...
  

[Edwardo Piet]

Atomic theory comes from the ancient Greek Atomists.

What we nowadays call an atom isn't actually an atom

Science can never find an atom. Even if they eventually are unable to find any smaller building blocks... there could still be smaller building blocks that they were unable to detect.

[Gawdzilla Sama]

Atomic theory comes from the ancient Greek Atomists.

What we nowadays call an atom isn't actually an atom

Science can never find an atom. Even if they eventually are unable to find any smaller building blocks... there could still be smaller building blocks that they were unable to detect.

Oh, he's been found:

[Edwardo Piet]

Wut? What does Adam Ant have to do with anything???? Wut wut wut!

[Rev. Rye]

You know perfectly well his name isn't Atom.

You're probably thinking of this Atom:





Or maybe even this Atom, though I admit I'd be impressed if you knew him:

[Edwardo Piet]

Yeah that makes more sense lol.

[Gawdzilla Sama]

Sense when do we have to make sense?

[Angrboda]

The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. However, these ideas were founded in philosophical and theological reasoning rather than evidence and experimentation. Because of this, they could not convince everybody, so atomism was but one of a number of competing theories on the nature of matter. It was not until the 19th century that the idea was embraced and refined by scientists, as the blossoming science of chemistry produced discoveries that could easily be explained using the concept of atoms.

https://en.wikipedia.org/wiki/Atomic_theory

[GrandizerII]

The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. However, these ideas were founded in philosophical and theological reasoning rather than evidence and experimentation. Because of this, they could not convince everybody, so atomism was but one of a number of competing theories on the nature of matter. It was not until the 19th century that the idea was embraced and refined by scientists, as the blossoming science of chemistry produced discoveries that could easily be explained using the concept of atoms.

https://en.wikipedia.org/wiki/Atomic_theory

Yeah, a number of posters here were thinking of the scientific notion of the atom rather than the ancient Greek philosophical notion of it, and the OP made it very clear.

I still think Rhondazvouz may have gotten an incorrect date from the source she was reading. That, or the confusion may be due to the lack of scholarly consensus regarding the relevant ancient dates?

[Rhondazvous]

This is actually a very complicated question:

• Leucippus (his historicity possible, but not proven) and his student Democritus developed the theory of the atom around the fifth century BC in an attempt at reconciling Heraclitus and Parmenides. Aristotle rejected atomic theory and so, with his ascendancy, atomic theory becomes dormant for over a millennium.
  
• Surprisingly, thinkers in India, most notably Kanada (and yes, that was his name), author of the Vaisesika Sutra, stumbled upon a very similar atomic theory to that of Democritus, and possibly even doing so before Democritus. That said, since Atoms weren't mentoned in the Vedas, it did not catch on in India until later.
  
• Near the end of the 18th Century, John Dalton, emboldened by the discovery of the Law of Conservation of Mass, starts work on figuring out the various elements, and even begins to figure out what they're made of and their relative size differences. He first does an oral presentation in 1803, publishes a paper in 1805, and fleshes it all out in 1808's A New System of Chemical Philosophy.
  
• And shit just gets more complicated from there...
  

Thanks. Rev. You've given me something I can work with. What about the work of Heraclitus and Parmenides was Democritus trying to reconcile that led him to think in terms of atoms?