Simplify the following text for a Grade 8 native English-speaking person.
Original: The Kelvin scale is named after the Belfast-born engineer and physicist William Thomson , 1st Baron Kelvin ( 1824 â `` 1907 ) , who wrote of the need for an `` absolute thermometric scale '' .
Simplified: It is named in honor of the physicist William Thomson , the first Lord Kelvin ( 1824 â `` 1907 ) .