0 Members and 1 Guest are viewing this topic.
Very big black holes (billions of solar masses) have soft enough event horizons to avoid disrupting whole stars as they cross the event horizon and so are quite likely to be less active when material is falling into them.
The technical term for getting ripped apart by gravity in the vicinity of a Black Hole is (and I'm not kidding here) : Spaghettification.
OK a luminous object would not instantly vanish the moment it crosses the even horizon it would just fade out after a brief period if you watched it.
Yes they can and you are quite familiar with them in everyday life when similar things happen. Consider a conventional filament lamp, for example, a car headlamp bulb it is turned on and emits a bright light. You turn it off and the light does not go out instantly it gradually fades and if it is dark and you have not looked at the bright like you can still see it glowing a couple of seconds after you switched off the bulb if you used an infra red camera you might still be able to detect it after ten or fifteen seconds and if you used very sensitive resistance measurements on the filament you could detect that it had been turned on and was still cooling maybe fifteen minutes after it had been turned off in theory it will be cooling off for ever because that's what the equations say, but the difference eventually becomes too small to detect. When objects fall into black holes if they are hot and emitting light and you can see them this light is red shifted continuously becoming infra red microwave and eventually radio waves just like the filament cooling. In theory this goes on for ever but you would not be able to see this or even detect it after a brief period of decay.For some stupid reason the "gee whizz" side of science publicity tends to latch on to this and get normal people totally confused. It really annoys me and I wish science publicists would tell people things properly as they are in ways that they would be familiar with and not try to give what are perfectly normal things spurious air of mysticism.OK a luminous object would not instantly vanish the moment it crosses the even horizon it would just fade out after a brief period if you watched it.
I agree imatfaal We are always talking about what an outside observer would see and not what the object at a distance would experience. This I believe is the biggest problem because most people do not believe that what they see as an outside observer is very different from what the traveller that they are observing would experience. The traveller always thinks things are perfectly normal locally with the exception of local temperatures and gravity gradients of course. Distant objects of course are distorted for them though.