Conversation so far:
what is the si unit of thermal capacity
The SI unit of heat capacity is joule per kelvin
What is the kelvin unit
The kelvin is the base unit of temperature in the International System of Units (SI), having the unit symbol K.
Where did the kelvin unit get its name
It is named after the Belfast-born, Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin.

Question: who is the engineer and physicist
Self-contained rewrite: who is william thomson, 1st baron kelvin