Chemistry: A Volatile History Chemistry: A Volatile History Chemistry: A Volatile History is a 2010 BBC documentary on the history of chemistry presented by Jim Al-Khalili. It was nominated for the 2010 British Academy Television Awards in the category Specialist Factual. Only in the last 200 years have we known what an element is – a substance that cannot be broken down further by chemical reaction. The Ancient Greeks, with no way of breaking open substances, could only base their ideas of the elements on what they could see: Earth, Fire, Water and Air. In the 16th century alchemists were busy trying to turn
Tendency of the rate of profit to fall average rate of profit of industries to fall gradually across long intervals of time. The 20th century Marxist controversies about the TRPF focused on five issues: In addition, philosophers and economists also discussed the sense in which the TRPF could be considered an economic "law", since it seemed unclear how a necessary tendency could be "necessary" or inevitable, if it was only a tendency, in combination with other tendencies. It was not so easy, to model a situation in which a developmental tendency would, after some time, win through despite a variety of counteracting forces that would ordinarily reduce or