* Radioactivity: He was one of the first to propose that radioactivity could be a significant source of heat within the Earth, influencing its internal temperature and geological processes. This was a pivotal idea in the development of our understanding of Earth's evolution.
* Geochronology: He developed methods to estimate the age of the Earth based on the rate of salt accumulation in the oceans. While these methods were later proven inaccurate, they were important steps in the development of geochronology.
* Meteorology: He studied the dynamics of the atmosphere, particularly the role of radiation and convection.
* Oceanography: He investigated the properties and circulation of the oceans.
Note: There's also another John Joly who was a 19th-century architect and was known for designing the National Gallery of Ireland.
To understand John Joly's writings better, you could look for books or articles that focus on his contributions to:
* The Age of the Earth: His research on the salt content of the oceans and its implications for the Earth's age.
* Radioactivity and Earth's Heat: His ideas on how radioactive decay might contribute to the Earth's internal heat.
* Atmospheric Physics: His research on atmospheric processes like radiation and convection.
Let me know if you'd like me to help you find specific publications by John Joly!