I do some voluntary work <a href=" http://manofalvaovoda.hu/narrative-essay-outline-4th-grade.pdf#tend ">history of research paper</a> Some of Kelvin&#039;s theories were proved wrong, most famously his calculation of an upper limit for the age of the Earth. Based on the cooling of the earth, Kelvin estimated its maximum age to be tens of millions years, as Dr Holmes explains: