Approaching a Black Hole

When these happened

27 dated records from 1915 to 2025. Each is drawn as wide as its date is certain — a band is a band because nobody knows the year, not because the drawing is imprecise.

27 shown · 27 dated · 0 cannot be placed on an axis · Approximate or contested. Draw a band and do not sharpen its edges.

In order27

1915-11Einstein presents the field equations of general relativity
It happened, and the record is settled.
1916Schwarzschild solves the field equations for a point mass
It happened, and the record is settled.
1918Heber Curtis records a curious straight ray in Messier 87
It happened, and the record is settled.
1939Oppenheimer and Snyder compute continued gravitational contraction
It happened, and the record is settled.
1963Kerr finds the rotating solution
It happened, and the record is settled.
c. 1964-1968The term "black hole" enters use
Sources disagree, or the dating is contested. Stated, not resolved.
1964A bright X-ray source is found in Cygnus
It happened, and the record is settled.
1965Penrose proves that collapse to a singularity is generic
It happened, and the record is settled.
1971-1972Cygnus X-1 is localised and weighed
It happened, and the record is settled.
1973Bekenstein assigns entropy to a black hole
It happened, and the record is settled.
1974Hawking shows that black holes radiate
It happened, and the record is settled.
1976Hawking argues that information is destroyed
It happened, and the record is settled.
1977A mechanism for extracting energy from a spinning black hole
It happened, and the record is settled.
1993Page states what unitarity requires of the radiation
It happened, and the record is settled.
2002A star is tracked through a complete close approach to the Galactic centre
It was measured or witnessed, with the observation cited.
2004-07Hawking concedes the information bet
It happened, and the record is settled.
2015-09-14 09:50:45 UTCGW150914 - two black holes merge and the signal reaches Earth
It was measured or witnessed, with the observation cited.
2016-02-11The detection is announced and published
It happened, and the record is settled.
2017-04The Event Horizon Telescope observes M87* and Sagittarius A*
It was measured or witnessed, with the observation cited.
2018-05S2 passes pericentre and its light is measurably redshifted
It was measured or witnessed, with the observation cited.
2019-2020The Page curve is reproduced from within semiclassical gravity
It happened, and the record is settled.
2019-04-10The first image of a black hole shadow is published
It was measured or witnessed, with the observation cited.
2020The orbit of S2 is shown to precess as general relativity predicts
It was measured or witnessed, with the observation cited.
2020-10-06The Nobel Prize in Physics recognises black holes twice over
It happened, and the record is settled.
2021-03The M87* ring is imaged in polarised light
It was measured or witnessed, with the observation cited.
2022-05-12The black hole at the centre of our own galaxy is imaged
It was measured or witnessed, with the observation cited.
2024A second epoch shows the ring persists and the bright spot moves
It was measured or witnessed, with the observation cited.