The Opposite of Infinity - Numberphile (youtube.com)
Continuing to talk Infinitesimals, this time with Dr James Grime.- John Walter Gregory (Wikipedia)
John Walter Gregory, FRS, FRSE, FGS (27 January 1864 – 2 June 1932) was a British geologist and explorer, known principally for his work on glacial geology and on the geography and geology of Australia and East Africa.
- Abraham Robinson (Wikipedia)
Abraham Robinson (born Robinsohn; October 6, 1918 – April 11, 1974) was a mathematician who is most widely known for development of nonstandard analysis, a mathematically rigorous system whereby infinitesimal and infinite numbers were reincorporated into modern mathematics. Nearly half of Robinson’s papers were in applied mathematics rather than in pure mathematics.