Question: The Tyndall crater was named after John Tyndall, what was John Tyndall famous for?

Context paragraphs:
Tyndall effect: The Tyndall effect, also known as Willis-Tyndall scattering, is light scattering by particles in a colloid or else particles in a very fine suspension.  It is named after the 19th-century physicist John Tyndall.  It is similar to Rayleigh scattering, in that the intensity of the scattered light depends on the fourth power of the frequency, so blue light is scattered much more strongly than red light.  An example in everyday life is the blue colour sometimes seen in the smoke emitted by motorcycles, in particular two-stroke machines where the burnt engine oil provides these

Tyndall Medal: The Tyndall Medal is a prize from the Institute of Acoustics awarded every two years to a citizen of the UK, preferably under the age of 40, for "achievement and services in the field of acoustics".  The prize is named after John Tyndall.

John Tyndall: John Tyndall FRS (2 August 1820 – 4 December 1893) was a prominent 19th-century Irish physicist.  His initial scientific fame arose in the 1850s from his study of diamagnetism.  Later he made discoveries in the realms of infrared radiation and the physical properties of air.  Tyndall also published more than a dozen science books which brought state-of-the-art 19th century experimental physics to a wide audience.  From 1853 to 1887 he was professor of physics at the Royal Institution of Great Britain in London.

Tyndall Centre: The centre, named after the 19th-century UK scientist John Tyndall (born in Ireland) and founded in 2000, has eight core partners: the University of East Anglia, University of Cambridge, Cardiff University, University of Manchester, Newcastle University, University of Oxford, University of Southampton, and the University of Sussex.  Fudan University joined the Tyndall Centre partnership in May 2011.

Tyndall Mountains: Tyndall Mountains ( ) is a mountains close south of Avsyuk Glacier in central Arrowsmith Peninsula, Graham Land.  Mapped by Falkland Islands Dependencies Survey (FIDS) from surveys and air photos, 1948-59.  Named by United Kingdom Antarctic Place-Names Committee (UK-APC) for John Tyndall (1820–93), Irish mountaineer and pioneer glaciologist, author of many works on glaciers and the physical properties of ice.

Pic Tyndall: Pic Tyndall (from French: lit, "Tyndall Peak") is a minor summit below the Matterhorn (western shoulder) in the Pennine Alps, on the boundary between Aosta Valley (northern Italy) and Switzerland.  Because of its small prominence it was included in the enlarged list of alpine four-thousanders.  It was named in honour of John Tyndall who made the first ascent.

Tyndall Glacier (Chile): Tyndall Glacier or Geike Glacier is one of the largest glaciers in the Southern Patagonian Ice Field.  It is located in the Torres del Paine National Park, Chile.  The glacier has its main calving front in Geikie Lake and like its neighbor, Grey Glacier, it has been significantly retreating for the last years.  The glacier is named after the Irish glaciologist John Tyndall.

Mount Tyndall: Mount Tyndall is a peak in the Mount Whitney region of the Sierra Nevada in the U.S. state of California.  It rises to 14025 ft , and is the tenth highest peak in the state.  The mountain was named in honor of the Irish scientist and mountaineer, John Tyndall.

Tyndall (Martian crater): Tyndall is an impact crater in the Cebrenia quadrangle of Mars, located at 40.0°N latitude and 190.1°W longitude.  It measures approximately 87 kilometers in diameter and was named after Irish physicist John Tyndall (1820–1893).  The name was approved in 1973, by the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature.

John Tyndall Award: The John Tyndall Award is given to the "individual who has made pioneering, highly significant, or continuing technical or leadership contributions to fiber optics technology".  The award is named after John Tyndall (1820-1893), who demonstrated for the first time internal reflection.

Supporting paragraphs: Tyndall (Martian crater) John Tyndall
Answer: his study of diamagnetism