Snark Posted April 11, 2019 Share Posted April 11, 2019 34 minutes ago, Cassel said: If even the photons are moving away from us, how do we see them? We don't. It's not photons we're talking about all this stuff, it's the gas that emits them. There's a ring of very, very hot gas, orbiting the black hole at very, very high speed. Because it's very hot, it's very bright, and radiates photons in all directions. Obviously, we only see the photons that are emitted in our direction, same as anything else. For the gas that's moving towards us, the photons it emits in our direction are Doppler-shifted up and are therefore brighter. For the gas that's moving away from us, the photons it emits in our direction are Doppler-shifted down and are therefore less bright. 34 minutes ago, Cassel said: I hope you're right. Well, there's also the fact that this black hole has been around for a pretty long time, so if it were gonna be a problem, we wouldn't be here in the first place. 34 minutes ago, Cassel said: after all this ring is orbiting around the black hole Yes, but, 34 minutes ago, Cassel said: so the bottom is the closest to us, the top farthest, and the right and left sides move towards us or on the contrary, move away, depending on which direction the ring rotates. Either the picture is rotated 90 degrees or something does not fit. I'm not totally sure that's the case. I don't know anything about the specific orientation of the disk, nor is its appearance necessarily as simple as you'd think due to gravitational lensing distorting the heck out of things. Quote Link to comment Share on other sites More sharing options...
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