Jean-Paul Marat
Découvertes sur la Lumière

In Marat's time, Newton 's views on light and colour were regarded almost universally as definitive, yet Marat's explicit purpose in his second major work Découvertes sur la Lumière (Discoveries on Light) was to demonstrate that in certain key areas, Newton was wrong.

The focus of Marat's work was the study of how light bends around objects, and his main argument was that while Newton held that white light was broken down into colours by refraction, the colours were actually caused by diffraction. When a beam of sunlight shone through an aperture, passed through a prism and projected colour onto a wall, the splitting of the light into colours took place not in the prism, as Newton maintained, but at the edges of the aperture itself. Marat sought to demonstrate that there are only three primary colours, rather than seven as Newton had argued.

Once again, Marat requested the Academy of Sciences review his work, and it set up a commission to do so. Over a period of seven months, from June 1779 to January 1780, Marat performed his experiments in the presence of the commissioners so that they could appraise his methods and conclusions. The drafting of their final report was assigned to Jean-Baptiste Le Roy. The report was finally produced after many delays in May 1780, and consisted of just three short paragraphs. Significantly, the report concluded that "these experiments are so very numerous......they do not appear to us to prove what the author believes they establish". The Academy declined to endorse Marat's work. When it was published, Découvertes sur la lumière did not carry the royal approbation. According to the title page, it was printed in London, so that either, Marat could not get the official censor to approve it, or, he did not want to spend the time and effort to do so.
language:response_language[Polish], keywords:forbidden_words, startend:quotation