William Thomson, known as Lord Kelvin, was a prominent physicist and engineer born in 1824 in Belfast, Ireland. He is best known for his work in thermodynamics, particularly the formulation of the absolute temperature scale, which is now called the Kelvin scale. His contributions laid the groundwork for modern physics and engineering. Thomson also played a significant role in the development of the telegraph and made advancements in electrical engineering. He was a key figure in the establishment of the second law of thermodynamics and contributed to the understanding of heat transfer and energy conservation. His legacy continues to influence science and technology today.