What is light?
Good question.
https://www.amazon.com/Philosophy-Light-Steven-Brutus-ebook/dp/B0H66Q6N1P/ref=sr_1_1?dib=eyJ2IjoiMSJ9.VAvc_4VnAjgavvE8RiRUtjId2lftRg8f-Mwoz8SS4MX1qZKBzVqMEkEPx1JmbDRgcijL7i87OQ7I4IECp8AKxK_YEsAx9EtQThezLKZjQH7GwXJRHoaYEDawBwOGovaJ17eJooIG7mMn5WZWPT9VyQ.v9VfcMIwOD_58-wXtSDf1SgaJNCDk4o4nhA-4c9z7Ok&dib_tag=se&qid=1784496622&refinements=p_27%3ASteven+Brutus&s=books&sr=1-1