Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: DoctorBeaver on 28/06/2007 19:57:26

Title: When did modern chemistry start?
Post by: DoctorBeaver on 28/06/2007 19:57:26
Is there a definitive event that can be pointed to as being the start of modern chemistry as opposed to medieval alchemy?
Title: When did modern chemistry start?
Post by: another_someone on 28/06/2007 20:20:22
What do you regard as chemistry?

Many would regard cookery as a form of chemistry.

What about metallurgy?

What about drugs, or the production of pigments and dyes?
Title: When did modern chemistry start?
Post by: Bored chemist on 28/06/2007 20:57:40
Well, it's a matter of definition but both Boyle and Lavoisier get called the father of modern chemistry.
Title: When did modern chemistry start?
Post by: DoctorBeaver on 28/06/2007 21:25:07
I suppose I should have said "...of what's known as chemistry...". I would include in the definition that there needs to be at least a basic understanding of what's going on. Hence, early dye-making would not count. Similarly, I would not class cooking as chemistry although, obviously, there are chemical processes involved.
Title: When did modern chemistry start?
Post by: another_someone on 29/06/2007 00:32:45
I suppose I should have said "...of what's known as chemistry...". I would include in the definition that there needs to be at least a basic understanding of what's going on. Hence, early dye-making would not count. Similarly, I would not class cooking as chemistry although, obviously, there are chemical processes involved.

What do you mean by "a basic understanding of what's going on"?

Are you talking about the development of the periodic table, or an understanding of how electrons behave in chemical reactions?  Would you disallow people who believed in the phlogiston theory, because it is not the current theory of chemical reactions (Boyle was I believe a proponent of the phlogiston theory, which was debunked by Mikhail Lomonosov in 1753 - Lavoisier was also involved in the debunking of phlogiston , so he probably has more legitimacy than Boyle, unless you allow proponents of the phlogiston theory to call themselves chemists).
Title: When did modern chemistry start?
Post by: DoctorBeaver on 29/06/2007 07:00:31
I'm sorry I asked  [:(]
Title: When did modern chemistry start?
Post by: eric l on 29/06/2007 10:30:27
I'm sorry I asked  [:(]
I am glad you asked, but you can not expect a straight or simple answer.  On the one hand, it is a bit like asking "when did the modern era in history start ?" - most of the things evolve gradually, and even revolutions have their roots in things going on well before.  Pointing out a single date or event is rather arbitrary.
On the other hand, how to define "modern chemistry" - or even "how do we define chemistry ?".  I think it is universal that with your first lessons in chemistry they teach you that "physical processes are reversible, while chemical processes are not".  But later, you learn that most chemical reactions are reversible, depending on conditions etc...  So the definition of chemistry we got in that classroom can not be correct.
So instead of indicating a start, one could agree on some milestones like
You see that the third milestone is nothing like a single event, but learning about previous models is almost necessary if we want to understand the currently accepted one.
Title: When did modern chemistry start?
Post by: DoctorBeaver on 29/06/2007 18:19:42
I appreciate what you're saying, but I was just wondering if there was something that could be pointed to as that which dragged chemistry out of medieval alchemy into the modern era.
Title: When did modern chemistry start?
Post by: another_someone on 30/06/2007 01:48:45
I appreciate what you're saying, but I was just wondering if there was something that could be pointed to as that which dragged chemistry out of medieval alchemy into the modern era.

That is too Hollywood, and not real life.

Nor do I think it is quite fair to condemn chemistry in the middle ages in such terms.  Knowledge is, like all things in the real world, more about evolution than revolution (although we do like to imagine landmarks in our backward look at the evolution of knowledge, but those landmarks are more for our own maps than really having been recognised by the people at the time).
Title: When did modern chemistry start?
Post by: DoctorBeaver on 30/06/2007 14:15:38
I'm talking about looking back. For instance, geometry can be said to have started with Euclid (as near as dammit); calculus with Newton.

Is there a point before which you can say that what was practised was not chemistry as we know it, but more superstitious dallying?
Title: When did modern chemistry start?
Post by: another_someone on 30/06/2007 15:51:54
I'm talking about looking back. For instance, geometry can be said to have started with Euclid (as near as dammit); calculus with Newton.

http://en.wikipedia.org/wiki/Calculus
Quote
The history of calculus falls into several distinct periods, most notably the ancient, medieval, and modern periods

The ancient period introduced some of the ideas of integral calculus, but does not seem to have developed these ideas in a rigorous or systematic way. Calculating volumes and areas, the basic function of integral calculus, can be traced back to the Egyptian Moscow papyrus (c. 1800 BC), in which an Egyptian worked out the volume of a pyramidal frustrum [1] [2] Eudoxus (c. 408-355 BC) used the method of exhaustion, which prefigures the concept of the limit, to calculate areas and volumes. Archimedes (c. 287-212 BC) developed this idea further, inventing heuristics which resemble integral calculus.[3] The method of exhaustion was rediscovered in China by Liu Hui in the 3rd century AD, who used it to find the area of a circle. It was also used by Zu Chongzhi in the 5th century AD, who used it to find the volume of a sphere.[2]

In the medieval period, the Indian mathematician Aryabhata used the notion of infinitesimals in 499 AD and expressed an astronomical problem in the form of a basic differential equation.[4] This equation eventually led Bhāskara II in the 12th century to develop an early derivative representing infinitesimal change, and he described an early form of "Rolle's theorem".[5] Around 1000 AD, the Iraqi mathematician Ibn al-Haytham (Alhazen) was the first to derive the formula for the sum of the fourth powers, and using mathematical induction, he developed a method for determining the general formula for the sum of any integral powers, which was fundamental to the development of integral calculus.[6] In the 12th century, the Persian mathematician Sharaf al-Din al-Tusi discovered the derivative of cubic polynomials, an important result in differential calculus.[7] In the 14th century, Madhava of Sangamagrama, along with other mathematician-astronomers of the Kerala school of astronomy and mathematics, described special cases of Taylor series,[8] which are treated in the text Yuktibhasa.[9][10][11]

In the modern period, independent discoveries in calculus were being made in early 17th century Japan, by mathematicians such as Seki Kowa, who expanded upon the method of exhaustion. In Europe, the second half of the 17th century was a time of major innovation. Calculus provided a new opportunity in mathematical physics to solve long-standing problems. Several mathematicians contributed to these breakthroughs, notably John Wallis and Isaac Barrow. James Gregory proved a special case of the second fundamental theorem of calculus in 1668.

Leibniz and Newton pulled these ideas together into a coherent whole and they are usually credited with the independent and nearly simultaneous invention of calculus. Newton was the first to apply calculus to general physics and Leibniz developed much of the notation used in calculus today; he often spent days determining appropriate symbols for concepts. The basic insight that both Newton and Leibniz had was the fundamental theorem of calculus.

When Newton and Leibniz first published their results, there was great controversy over which mathematician (and therefore which country) deserved credit. Newton derived his results first, but Leibniz published first. Newton claimed Leibniz stole ideas from his unpublished notes, which Newton had shared with a few members of the Royal Society. This controversy divided English-speaking mathematicians from continental mathematicians for many years, to the detriment of English mathematics. A careful examination of the papers of Leibniz and Newton shows that they arrived at their results independently, with Leibniz starting first with integration and Newton with differentiation. Today, both Newton and Leibniz are given credit for developing calculus independently. It is Leibniz, however, who gave the new discipline its name. Newton called his calculus the "the science of fluxions".

Since the time of Leibniz and Newton, many mathematicians have contributed to the continuing development of calculus. In the 19th century, calculus was put on a much more rigorous footing by mathematicians such as Cauchy, Riemann, and Weierstrass. It was also during this period that the ideas of calculus were generalized to Euclidean space and the complex plane. Lebesgue further generalized the notion of the integral.

So, yes, Newton and Leibniz were responsible for the modern cohesive structure of calculus, but the ideas they used were not original to them, and it is certainly unfair to suggest that those before them were practising some superstitious dallying.  What Newton, and probably even more, Leibniz, created was the modern language of calculus.

Is there a point before which you can say that what was practised was not chemistry as we know it, but more superstitious dallying?

The difference between calculus and chemistry is that calculus is a very narrow field, and not the whole of mathematics; so it is relatively easier to discuss who created the language we use today in discussing a very narrow topic like calculus, then saying the same for the whole of chemistry.

I certainly think it unfair to claim that people preparing gunpowder in ancient China, or experimenting with early metallurgy, were indulging any more in superstitious dallying.  Even today, although ever more we begin to use powerful computers to try and model chemical reactions, but certainly in the pre-computer age, much of chemistry (particularly the complex organic chemistry used in pharmaceuticals) was as much educated guesswork and laboratory trial and error.  Only now, with the advent of very powerful computers, can we say we can actually start to design drugs for a purpose, rather than simply look through all of the folk knowledge that was accumulated through 'superstitious dallying' that provided the basis for drugs such as aspirin and quinine.

I suppose if one wanted to look for point where past knowledge of chemistry was brought together into a single structure in the way that Newton and Liebnitz broght together past ideas of infinitesimals and limits into a single cohesive structure, then maybe one could look at the creation of the periodic table:

http://en.wikipedia.org/wiki/Periodic_table
Quote
The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although earlier precursors exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869. Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior.

In Ancient Greece, the influential Greek philosopher Aristotle proposed that there were four main elements: air, fire, earth and water. All of these elements could be reacted to create another one; e.g., earth and fire combined to form lava. However, this theory was dismissed when the real chemical elements started being discovered. Scientists needed an easily accessible, well organized database with which information about the elements could be recorded and accessed. This was to be known as the periodic table.

The original table was created before the discovery of subatomic particles or the formulation of current quantum mechanical theories of atomic structure. If one orders the elements by atomic mass, and then plots certain other properties against atomic mass, one sees an undulation or periodicity to these properties as a function of atomic mass. The first to recognize these regularities was the German chemist Johann Wolfgang Döbereiner who, in 1829, noticed a number of triads of similar elements:

In 1829 Döbereiner proposed the Law of Triads: The middle element in the triad had atomic weight that was the average of the other two members. The densities of some triads followed a similar pattern. Soon other scientists found chemical relationships extended beyond triads. Fluorine was added to Cl/Br/I group; sulfur, oxygen, selenium and tellurium were grouped into a family; nitrogen, phosphorus, arsenic, antimony, and bismuth were classified as another group.

This was followed by the English chemist John Newlands, who noticed in 1865 that when placed in order of increasing atomic weight, elements of similar physical and chemical properties recurred at intervals of eight[citation needed], which he likened to the octaves of music, though his law of octaves was ridiculed by his contemporaries. However, while successful for some elements, Newlands' law of octaves failed for two reasons:
  •    1. It was not valid for elements that had atomic masses higher than Ca.
  •    2. When further elements were discovered, such as the noble gases (He, Ne, Ar), they could not be accommodated in his table.

Finally, in 1869 the Russian chemistry professor Dmitri Ivanovich Mendeleev and four months later the German Julius Lothar Meyer independently developed the first periodic table, arranging the elements by mass. However, Mendeleev plotted a few elements out of strict mass sequence in order to make a better match to the properties of their neighbors in the table, corrected mistakes in the values of several atomic masses, and predicted the existence and properties of a few new elements in the empty cells of his table. Mendeleev was later vindicated by the discovery of the electronic structure of the elements in the late 19th and early 20th century.

Earlier attempts to list the elements to show the relationships between them (for example by Newlands) had usually involved putting them in order of atomic mass. Mendeleev's key insight in devising the periodic table was to lay out the elements to illustrate recurring ("periodic") chemical properties (even if this meant some of them were not in mass order), and to leave gaps for "missing" elements. Mendeleev used his table to predict the properties of these "missing elements", and many of them were indeed discovered and fit the predictions well.

With the development of theories of atomic structure (for instance by Henry Moseley) it became apparent that Mendeleev had listed the elements in order of increasing atomic number (i.e. the net amount of positive charge on the atomic nucleus). This sequence is nearly identical to that resulting from ascending atomic mass.

In order to illustrate recurring properties, Mendeleev began new rows in his table so that elements with similar properties fell into the same vertical columns ("groups").

With the development of modern quantum mechanical theories of electron configuration within atoms, it became apparent that each horizontal row ("period") in the table corresponded to the filling of a quantum shell of electrons. In Mendeleev's original table, each period was the same length. Modern tables have progressively longer periods further down the table, and group the elements into s-, p-, d- and f-blocks to reflect our understanding of their electron configuration.

In the 1940s Glenn T. Seaborg identified the transuranic lanthanides and the actinides, which may be placed within the table, or below (as shown above). Element 106, seaborgium, is the only element that was named after a then living person.
Title: When did modern chemistry start?
Post by: eric l on 30/06/2007 16:06:36
I'm talking about looking back. For instance, geometry can be said to have started with Euclid (as near as dammit); calculus with Newton.

Is there a point before which you can say that what was practised was not chemistry as we know it, but more superstitious dallying?
Paracelsus (http://en.wikipedia.org/wiki/Paracelsus) mixed repeating older ideas with own observations and experiments.  Would that make him a chemist or an alchemist ?  A similar thing can be said about Roger Bacon (http://en.wikipedia.org/wiki/Roger_Bacon) who clearly worked in the alchemist tradition, but was very much a modern scientist.
Title: When did modern chemistry start?
Post by: DoctorBeaver on 30/06/2007 17:19:33
OK, point taken. I'll shut up now  [:-X]
Title: When did modern chemistry start?
Post by: i am bored on 07/07/2007 04:49:47
now what i think (keep in mind this is coming out of the fingers of a fourteen year old so bear with me) is if you want to find the age when modern chemistry started you need to define alchemy as a little bit more than transmuting lead into gold then take the properties that are alchemy and chemistry and compare them because in my understanding of the two subjects there is not much difference between them both contain knowledge of elements and how to use them just in different ways however by comparing the differences between the two maybe it was more current that you maybe have thought.
Title: When did modern chemistry start?
Post by: DoctorBeaver on 07/07/2007 12:08:33
Alchemists had it all wrong anyway. True alchemy was nothing to do with metals. That was allegorical - but they didn't realise.

Alchemy was about becoming 1 with the Godhead. The human body was referred to as base, and the Godhead as gold.
Title: When did modern chemistry start?
Post by: i am bored on 07/07/2007 21:28:39
ok well my knoledge of alchemy is limited so can you explain to me what a godhead is?
Title: When did modern chemistry start?
Post by: another_someone on 08/07/2007 23:41:53
http://en.wikipedia.org/wiki/Alchemy
Quote
Alchemy as an investigation of Nature

The common perception of alchemists is that they were pseudo-scientists, who attempted to turn lead into gold, believing that the universe was composed of the four elements of earth, water, fire, air, and spent most of their time concocting miraculous remedies, poisons, and magic potions.

Most alchemists were well-meaning and intelligent men and distinguished scientists, such as Isaac Newton and Robert Boyle. These innovators attempted to explore the nature of chemical substances and processes. They had to rely on experimentation, traditional know-how, rules of thumb and speculative thought in their attempts to uncover the mysteries of the physical universe.

At the same time, it was clear to the alchemists that "something" was generally being conserved in chemical processes, even in the most dramatic changes of physical state and appearance; that is, that substances contained some "principles" that could be hidden under many outer forms, and revealed by proper manipulation. Throughout the history of the discipline, alchemists struggled to understand the nature of these principles, and find some order and sense in the results of their chemical experiments—which were often undermined by impure or poorly characterized reagents, the lack of quantitative measurements, and confusing and inconsistent nomenclature.

Alchemy as a philosophical and spiritual discipline

Alchemy was known as the spagyric art after Greek words meaning to separate and to join together. Compare this with the primary dictum of Alchemy in Latin: SOLVE ET COAGULA — Separate, and Join Together.

The best known goals of the alchemists were the transmutation of common metals into gold or silver (less well known is plant alchemy, or "Spagyric"), and the creation of a "panacea," a remedy that supposedly would cure all diseases and prolong life indefinitely. Although these were not the only uses for the science, they were the ones most documented and well known. Starting with the Middle Ages, European alchemists invested much effort on the search for the "philosopher's stone", a legendary substance that was believed to be an essential ingredient for either or both of those goals. The philosopher's stone was believed to mystically amplify the user's knowledge of alchemy so much that anything was attainable. Alchemists enjoyed prestige and support through the centuries, though not for their pursuit of those goals, nor the mystic and philosophical speculation that dominates their literature. Rather it was for their mundane contributions to the "chemical" industries of the day—the invention of gunpowder, ore testing and refining, metalworking, production of ink, dyes, paints, and cosmetics, leather tanning, ceramics and glass manufacture, preparation of extracts and liquors, and so on (It seems that the preparation of aqua vitae, the "water of life", was a fairly popular "experiment" among European alchemists).

Indeed, from antiquity until well into the Modern Age, a physics devoid of metaphysical insight would have been as unsatisfying as a metaphysics devoid of physical manifestation. For one thing, the lack of common words for chemical concepts and processes, as well as the need for secrecy, led alchemists to borrow the terms and symbols of biblical and pagan mythology, astrology, kabbalah, and other mystic and esoteric fields; so that even the plainest chemical recipe ended up reading like an abstruse magic incantation. Moreover, alchemists sought in those fields the theoretical frameworks into which they could fit their growing collection of disjointed experimental facts.

Starting with the Middle Ages, some alchemists increasingly came to view these metaphysical aspects as the true foundation of alchemy; and chemical substances, physical states, and material processes as mere metaphors for spiritual entities, states and transformations. In this sense, the literal meanings of alchemical formulas were a blind hiding their true spiritual philosophy, which being at odds with the Medieval Church was a necessity that could have otherwise lead them to the "stake and rack" of the Inquisition under charges of heresy. Thus, both the transmutation of common metals into gold and the universal panacea symbolized evolution from an imperfect, diseased, corruptible and ephemeral state towards a perfect, healthy, incorruptible and everlasting state; and the philosopher's stone then represented some mystic key that would make this evolution possible. Applied to the alchemist himself, the twin goal symbolized his evolution from ignorance to enlightenment, and the stone represented some hidden spiritual truth or power that would lead to that goal. In texts that are written according to this view, the cryptic alchemical symbols, diagrams, and textual imagery of late alchemical works typically contain multiple layers of meanings, allegories, and references to other equally cryptic works; and must be laboriously "decoded" in order to discover their true meaning.

In his Alchemical Catechism, Paracelsus clearly denotes that his usage of the metals was a symbol:
    “Q. When the Philosophers speak of gold and silver, from which they extract their matter, are we to suppose that they refer to the vulgar gold and silver?

    A. By no means; vulgar silver and gold are dead, while those of the Philosophers are full of life.”

Up to the 16th century, alchemy was considered serious science in Europe; for instance, Isaac Newton devoted considerably more of his time and writing to the study of alchemy (see Isaac Newton's occult studies) than he did to either optics or physics, for which he is famous. Other eminent alchemists of the Western world are Roger Bacon, Saint Thomas Aquinas, Tycho Brahe, Thomas Browne, and Parmigianino.
Title: When did modern chemistry start?
Post by: i am bored on 09/07/2007 02:21:56
ok now things are a little bit clearer thanks another someone
http://en.wikipedia.org/wiki/Alchemy
Quote
Alchemy as an investigation of Nature

The common perception of alchemists is that they were pseudo-scientists, who attempted to turn lead into gold, believing that the universe was composed of the four elements of earth, water, fire, air, and spent most of their time concocting miraculous remedies, poisons, and magic potions.

Most alchemists were well-meaning and intelligent men and distinguished scientists, such as Isaac Newton and Robert Boyle. These innovators attempted to explore the nature of chemical substances and processes. They had to rely on experimentation, traditional know-how, rules of thumb and speculative thought in their attempts to uncover the mysteries of the physical universe.

At the same time, it was clear to the alchemists that "something" was generally being conserved in chemical processes, even in the most dramatic changes of physical state and appearance; that is, that substances contained some "principles" that could be hidden under many outer forms, and revealed by proper manipulation. Throughout the history of the discipline, alchemists struggled to understand the nature of these principles, and find some order and sense in the results of their chemical experiments—which were often undermined by impure or poorly characterized reagents, the lack of quantitative measurements, and confusing and inconsistent nomenclature.

Alchemy as a philosophical and spiritual discipline

Alchemy was known as the spagyric art after Greek words meaning to separate and to join together. Compare this with the primary dictum of Alchemy in Latin: SOLVE ET COAGULA — Separate, and Join Together.

The best known goals of the alchemists were the transmutation of common metals into gold or silver (less well known is plant alchemy, or "Spagyric"), and the creation of a "panacea," a remedy that supposedly would cure all diseases and prolong life indefinitely. Although these were not the only uses for the science, they were the ones most documented and well known. Starting with the Middle Ages, European alchemists invested much effort on the search for the "philosopher's stone", a legendary substance that was believed to be an essential ingredient for either or both of those goals. The philosopher's stone was believed to mystically amplify the user's knowledge of alchemy so much that anything was attainable. Alchemists enjoyed prestige and support through the centuries, though not for their pursuit of those goals, nor the mystic and philosophical speculation that dominates their literature. Rather it was for their mundane contributions to the "chemical" industries of the day—the invention of gunpowder, ore testing and refining, metalworking, production of ink, dyes, paints, and cosmetics, leather tanning, ceramics and glass manufacture, preparation of extracts and liquors, and so on (It seems that the preparation of aqua vitae, the "water of life", was a fairly popular "experiment" among European alchemists).

Indeed, from antiquity until well into the Modern Age, a physics devoid of metaphysical insight would have been as unsatisfying as a metaphysics devoid of physical manifestation. For one thing, the lack of common words for chemical concepts and processes, as well as the need for secrecy, led alchemists to borrow the terms and symbols of biblical and pagan mythology, astrology, kabbalah, and other mystic and esoteric fields; so that even the plainest chemical recipe ended up reading like an abstruse magic incantation. Moreover, alchemists sought in those fields the theoretical frameworks into which they could fit their growing collection of disjointed experimental facts.

Starting with the Middle Ages, some alchemists increasingly came to view these metaphysical aspects as the true foundation of alchemy; and chemical substances, physical states, and material processes as mere metaphors for spiritual entities, states and transformations. In this sense, the literal meanings of alchemical formulas were a blind hiding their true spiritual philosophy, which being at odds with the Medieval Church was a necessity that could have otherwise lead them to the "stake and rack" of the Inquisition under charges of heresy. Thus, both the transmutation of common metals into gold and the universal panacea symbolized evolution from an imperfect, diseased, corruptible and ephemeral state towards a perfect, healthy, incorruptible and everlasting state; and the philosopher's stone then represented some mystic key that would make this evolution possible. Applied to the alchemist himself, the twin goal symbolized his evolution from ignorance to enlightenment, and the stone represented some hidden spiritual truth or power that would lead to that goal. In texts that are written according to this view, the cryptic alchemical symbols, diagrams, and textual imagery of late alchemical works typically contain multiple layers of meanings, allegories, and references to other equally cryptic works; and must be laboriously "decoded" in order to discover their true meaning.

In his Alchemical Catechism, Paracelsus clearly denotes that his usage of the metals was a symbol:
    “Q. When the Philosophers speak of gold and silver, from which they extract their matter, are we to suppose that they refer to the vulgar gold and silver?

    A. By no means; vulgar silver and gold are dead, while those of the Philosophers are full of life.”

Up to the 16th century, alchemy was considered serious science in Europe; for instance, Isaac Newton devoted considerably more of his time and writing to the study of alchemy (see Isaac Newton's occult studies) than he did to either optics or physics, for which he is famous. Other eminent alchemists of the Western world are Roger Bacon, Saint Thomas Aquinas, Tycho Brahe, Thomas Browne, and Parmigianino.