Comte was proven wrong in his claim that we could never learn the composition of stars. What do we know today that Comte did not know when making his claim, and that makes it possible for us to learn the chemical compositions of stars?

Comte did not make proper observation of the visual spectra of sparks and flames in the laboratory. An understanding of this could have given him an idea of the visual spectra of stars, hence an idea of their compositions.

An advantage we have over Comte is the invention of the spectroscope in the 19th century. Comte did not know that the elements in the sun absorb light at specific wavelengths which make it possible for us to study its composition.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.