Lord Kelvin

    Image 1 Caption: Kelvin young: Scottish physicist William Thomson, Lord Kelvin (1824--1907)---another furry 19th century scientist.

    Image 2 Caption: Kelvin old.

    Features:

    1. Lord Kelvin was a pioneer of thermodynamics (see Wikipedia: Lord Kelvin: Thermodynamics) and the Kelvin temperature scale was named in honor of his work in that field.

      Lord Kelvin also invented the original idea of the heat death of the universe in 1854. He was a cheery Scot.

    2. Lord Kelvin was the first to suggest something like dark matter existed to explain the Milky Way rotation though his evidence may have been insignificant or spurious (see Wikipedia: Dark matter: Early history).

      lord_kelvin_young cartoon of photons

    3. Image 3 Caption: The modern idea of the of the heat death of the universe according to the Λ-CDM model plus other ingredients illustrated cartoonishly.

      The idea is that by a cosmic time of order 10**100 years, the black holes may have evaporated and the vastly expanded universe could be only a very dim, dilute gas of electrons, positrons, neutrinos, photons, and dark matter particles.

      Some hypothetical dark matter particles decay to baryonic matter with very long half-lives (see Wikipedia: Dark matter: Indirect detection). So maybe the dark matter particles will be gone too by of order 10**100 years ??? in the Λ-CDM-model cosmic future.

    4. The ultimate fate of the universe may be dismal---but it's all wild extrapolation.

    Images:
    1. Credit/Permission: Anonymous photographer, circa 1900 (uploaded to Wikipedia by User:Fastfission, 2005) / Public domain.
      Image link: Wikipedia: File:Lord Kelvin photograph.jpg.
    2. Credit/Permission: Anonymous photographer, circa 1860 / Public domain.
      Download site: St. Andrews Mathemetican Biographies: Lord Kelvin.
      Image link: Itself.
    3. Credit/Permission: © User:Zalasur, 2005 (uploaded to Wikipedia by User:Maksim, 2006) / Creative Commons CC BY-SA 3.0.
    Local file: local link: lord_kelvin.html.
    File: Astronomer file: lord_kelvin.html.