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Physics/Black holes appearance

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Question
Hello, I would like to know what would show that a black hole was moving farther away from you?

My specific wonders would be how light around the hole would act, how its shape would change, or if the black hole would start to reflect less and less light?

Thanks in advance from a curious and pondering teenager,

Billy

PS. It would be great to include web links so I can research further and as to where you got information to see if it is credible. :))

Answer
Black holes have accretion discs which are some of the brightest objects in the universe.  Those would exhibit a definite Doppler shift if the black hole were receding from you, very easy to measure precisely.  Black holes do not reflect light, they absorb it.  So research the Doppler shift and accretion disks, these are the things we use to observe black holes, not the black hole itself...in general gravitational lensing uses whole galaxies.

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Dr. Stephen O. Nelson

Expertise

I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

Experience

I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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