Tag Archives: Event Horizon Telescope

Optics of the Event Horizon Telescope

Gravitational bending of light rays near objects of size approaching 2MG/c2 (gravitational radius or ‘event horizon’) is known to be severe.  Light rays circle indefinitely at 3MG/c2  as Charles Darwin (the grandson) described in 1958.  Gravitational lensing causes more distant … Continue reading

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Gravitational collapse without black holes

The contemporary notion of black holes originates in Oppenheimer and Snyder’s 1939 article “On Continued Gravitational Contraction” (Phys. Rev. 56:455, 1939).  Later Roger Penrose (Phys. Rev. Lett. 14:57, 1965)  showed that the O&S metric gave rise to trapped surfaces, ie. … Continue reading

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