## Saturday, August 08, 2020

### [lmibdzwc] General relativistic map projection

Gravity bends light emitted from the back a massive sphere toward a viewer in front.  For example, someone observing a neutron star from far away would see more than half its surface.

What formulae define this azimuthal map projection?  (It is no longer an orthographic or near-side perspective projection.)  What would the earth look like if all but one point were projected this way onto a disc?  (Physically, such a scenario corresponds to the Earth's surface being a thin shell magically hovering just above the event horizon of a 2157.284 solar mass intermediate-mass black hole.)