His two areas of significant research were electricity and caloric theory.

This was a direct challenge to the caloric theory which held that heat could neither be created nor destroyed.

The caloric theory is now also remembered for the naming of the calorie.

In fact, to some of his contemporaries, the results added to the understanding of caloric theory.

Historically, however, it was based on contemporary caloric theory and preceded the establishment of the second law.

These observations solved the weight paradox and set the stage for the new caloric theory of combustion.

A main aspect of the struggle was to deal with the previously proposed caloric theory of heat.

In later combination with the law of energy conservation, the caloric theory still shows a very valuable physical insight into some aspects of heat.

Rumford argued that the seemingly indefinite generation of heat was incompatible with the caloric theory.

There is one version of the caloric theory that was introduced by Antoine Lavoisier.

He proposed instead the caloric theory which saw heat as a type of weightless, invisible fluid that moved when out of equilibrium.

Its replacement by caloric theory in the 18th century is one of the historical markers of the transition from alchemy to chemistry.

- But a footnote signalled his first doubts about the caloric theory, referring to Joule's very remarkable discoveries.

Since heat was a material substance in caloric theory, and therefore could neither be created nor destroyed, conservation of heat was a central assumption.

Caloric theory had dominated thinking in the science of heat since it was introduced by Antoine Lavoisier in 1783.

Though formulated in terms of caloric (see the obsolete caloric theory), rather than entropy, this was an early insight into the second law.

Besides the caloric theory, another theory existed in the late eighteenth century that could explain the phenomena of heat: the kinetic theory.

Though Carnot had developed a compelling analysis of a generalised heat engine, he had employed the clumsy and already unfashionable caloric theory.

Caloric theory (Calorifics)

Joule's more exact measurements on equivalence were pivotal in establishing the kinetic theory at the expense of the Caloric theory.

Carnot believed in the incorrect caloric theory of heat that was popular during his time, but his thought experiment nevertheless described a fundamental limit of nature.

Count Rumford (born Benjamin Thompson) showed, about 1797, that mechanical action can generate indefinitely large amounts of heat, so challenging the caloric theory.

The introduction of the Caloric theory was also influenced by the experiments of Joseph Black related to the thermal properties of materials.

His results were not seen as a "threat" to caloric theory at the time, as this theory was considered to be equivalent to the alternative kinetic theory.

Topics here include electricity, radio engineering, caloric theory, fixed star parallax, Doppler effect, space and time, as well as genetic engineering and the nuclear energy.