The thing about black holes is...
Discussion
Flibble said:
From the perspective of the person falling into the black hole time passes normally though. Time dilation is relative to an external observer, not absolute.
Let's ignore the awkward gravitational effects, not to mention any stray radiation, which might cause problems for the person falling into the singularity and assume they make it to the event horizon. The will be travelling at almost the speed of light and still accelerating. So to them, the time dilation is total. The universe, however, is on the outside and there is no time dilation and everything goes on as normal. Time passes, for everyone but the person travelling at the speed of light and still accelerating, or would be had time dilation not stopped everything for him/her. After a few weeks or so all the stars go out, the universe has continued its every increasing expansion, and the laws of physics have become guidelines, then a wish list and finally history. What's holding the singularity together loses out and the whole thing falls apart. (This is according to an article in the New Scientist, although I've stripped it of all the words that confused me, and I think the author.)
So for the poor sap trying to enter the singularity, just as he got to the speed of light and still under gravitational pull, the singularity winks out and he/she is presented with a dead universe with nothing but temperature in it. Right up until she/she falls apart. But at the time the singularity exploded he or she had, to all intents and purposes, lived forever because there's nothing left, not even time. Immortal exploded.
Or have I missed something?
ash73 said:
Yes I think so, different things flex in different frames (except c). A person falling into the black hole will experience time as normal, but the proper distance to the singularity will contract to zero, whereas an observer will see them travelling the normal distance but their time will dilate to infinity. The end result is the same; they take no time to get there.
My understanding from a casual read on the subject is that the event horizon stops us seeing an object, or in this hypothetical case, a person, travelling at the speed on light. Gravity still has an influence on the object which, the theory states, is travelling at the speed of light as it crossing the event horizon. Paraphrased. So whilst distance is compressed to zero, it would be improper for us to be able to see/get information from such an event. The event in event horizon is there to show that we can't see what's going on. I know that black holes are a little fuzzy in modern theories, but in essence by the time the object/person reaches the 'centre of the black hole' it is the end of the universe.
They will take 'no time' to get there because the object/person is everywhere as its mass is infinite. But as it is beyond the event horizon, it is not in our universe. Until such times as the universe is so diffuse as to make it impossible for it to maintain its existence.
There was a book, the one Stargate was based on, which developed the life expectancy of a person falling into the black hole. I've forgotten its name.
I used to belong to a reading group and the premise of the book gave rise to loads of emails - pre forums (such a time did exist, and now will go on forever, or until black holes explode) - and theories. Great fun and I wish I'd stayed with it. But time, with a change in role at work, was suddenly dilated. I had to be everywhere at once.
OK, I'm afraid this is a bit basic, but when I were a lad we were assured of death were we to ever approach a black hole due to the effects of spaghettification, but to my mind, it wouldn't matter that your feet ant legs would be several light years longer than your torso because it is the space that they exist in that is stretched, not the legs themselves?
ash73 said:
Yes I think so, different things flex in different frames (except c). A person falling into the black hole will experience time as normal, but the proper distance to the singularity will contract to zero, whereas an observer will see them travelling the normal distance but their time will dilate to infinity. The end result is the same; they take no time to get there.
Yeah, the passage of time entirely relativeThe person "falling" into the "hole" will experinece time in their local space in apparent normality. But those objects outside of their reference frame (i.e the rest of the Universe) will appear to speed up
As the faller you would never reach the event horizon because, as others have already said, the Universe would expire before you got there, even though the distance would appear to contract.
To the external observer (outside of extreme gravitational effects), it would take infinite time for the person you are watching to reach the event horizon, so it can never be witnessed
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