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parallaxicality
2016-Oct-16, 05:11 PM
I'm in the research phase at the moment but I'm getting a bit overwhelmed. It would help, I think, if you could give your opinions on the things the public most needs to know about them.

Thanks in advance.

Hornblower
2016-Oct-16, 06:09 PM
I would say the public at large should be informed that black holes do not "suck" in neighboring bodies any more than do stars or planets of the same mass. That appears to be the number one misconception spread by bad popular media writing on this topic.

01101001
2016-Oct-16, 08:19 PM
Black holes have both inflow and outflow.

parallaxicality
2016-Oct-16, 08:24 PM
Do you mean Hawking radiation? Or relativistic jets?

Buttercup
2016-Oct-16, 09:43 PM
Why some scientists seem to talk about black holes as though they're proven, while apparently they're still theory.

Unless I'm confused (again).

Cougar
2016-Oct-16, 09:43 PM
...opinions on the things the public most needs to know about them....



It is the space around them that is highly "warped."




When they're spinning, they drag the space around with them - frame dragging.




These weird effects only happen very close to the hole; otherwise, as mentioned by Hornblower, objects far enough away will orbit a black hole much as if it's just a massive star.

AFJ
2016-Oct-20, 06:23 PM
Can you make animations? Might be helpful to start with an animated model of the Solar system. At some point replace the Sun by a same mass black hole, and let the planets happily revolve further without any disturbance.

Maybe cool too to see stars whipping about around the SMBH of the Milky Way.

schlaugh
2016-Oct-20, 06:41 PM
You might discuss:
- The differences between (hypothetical) primordial black holes vs. those created from stellar collapse.
- Why black holes do not attract their nearest neighbors anymore than when they were fully-functioning stars (an expansion on Hornblower's point)
- The nearest black holes are ____ far away
- The differences between stellar-mass BHs and the SMBH that resides in the center of the Milky Way

mkline55
2016-Oct-20, 07:59 PM
Describe how mass and radius are related.
Show the observable universe's estimated mass and explain what radius a black hole of that mass would have.

parallaxicality
2016-Oct-20, 09:28 PM
I discovered while doing some intense researching that most of these issues are already covered on Youtube, particularly by PBS Space Time. So I'm putting this series on the back burner for the moment. Thanks for the input though :-)

publiusr
2016-Oct-22, 08:03 PM
I might lead up to black holes with mention of magnetars and how they may be harder to orbit than a true black hole. Then about quark stars, gravastars, then black holes proper.

Strange
2016-Oct-26, 09:11 AM
Why some scientists seem to talk about black holes as though they're proven, while apparently they're still theory.

Unless I'm confused (again).

So it sounds like the evidence for the existence of black holes would be an important thing to cover. :)

Doing something on the orbits of the stars around Sagittarius a* would perhaps be interesting in its own right.

Another thing to cover: the reason light cannot escape is NOT because of escape velocity.

And (given a recent thread) the reason gravity can "escape" is ...