I was listening to Quirks and Quarks the other day and heard a story about the Event Horizon Telescope project where they take a half dozen telescopes from around the world, some atomic clocks and a few computers and take a picture of the black hole at the center of the galaxy. Just a wee fellow with the mass of 4 million suns and 26k light years away. Even while the thing itself is totally black and emits no light it is surrounded by a cloud of billion degree gas that is the brightest thing around. Apparently we will get a look at the shadow of the thing in a year or so.
Mind = blown.
Anyway, my question is how do you see through that cloud of gas?
Of course but isn't the cloud of gas emitting the brightest radio signal? How do you see something dark that lies directly behind something that is very bright?
Is this the same principle that is used to detect exoplanets only in reverse?