[Robert]

Our next topic-driven chat session will be held on Saturday, October 1st, at 3:00pm Central Standard Time (CST) or GMT-6. Saturday is the continuing winner in the poll and seems to be a reasonable time for most folks. Be sure and vote in this thread's poll so I can know who will be there. Unless we have at least 3 or 4 comitted members, I may need to cancel. If cancelled, that just means that I probably wont be there and a transcript may not be provided. Members are still welcome to meet and discuss anything on or off topic.

The topic is...

Warps in SpaceTime:
Black Holes, White Holes, Wormholes

Anything with mass creates warps in spacetime. However, I'd like the focus of this chat session to be more on what happens to spacetime as matter approaches a singularity. I threw white holes and wormholes in there but expect black holes to be the main topic of discussion. We might also discuss the nature of spacetime.

References:

1. Spacetime - Wikipedia reference
2. Black hole - Wikipedia reference
3. White hole - Wikipedia reference
4. Worm hole - Wikipedia reference

Statistics
This will be chat session #13. Since our last chat we have grown from 734 to 786 members representing 91 countries (up from 8. Also we've had 169 members active over the preceding 30 days which is up from 159; another indicator that we may have a good turnout.

The Usual Timezone Stuff
Ok, the usual stuff... As I already said, the chat session will be held this Saturday at 3:00pm (CST). You can use the timezone converter to convert to your local time. Once there, enter the day and time as specified above, then select US/Central in the "From Time Zone" column and your own location in the "To Time Zone" column, then click Convert. Be sure and unclick the "Use Current Date/Time" option. This will give you the time of the chat meeting in your own local time.

Some other areas:

Texas, U.S. - Saturday, 3:00pm
California, U.S. - Saturday, 1:00pm
India - Sunday, 1:30am
London - Saturday, 9:00pm
Madrid, Spain - Saturday, 10:00pm
Melbourne, Australia - Sunday, 6:00am
New Zealand - Sunday, 8:00am
Sweden - Saturday, 10:00pm
Canada, Eastern - Saturday, 4:00pm
Pakistan - Sunday, 1:00am

Future Chat
These topic-driven chat sessions will continue every other Saturday at 3pm (CST). These will be moderated and a transcript of the chat will be recorded and available for later review. A weekly un-moderated and open-discussion chat will begin in the near future, based on traffic patterns on the website.

We'll meet in Flash Chatroom. See you there!

Regards,
--Robert

[Guille]

This is the one last attempt. I'll be there, or I won't try anymore.


It's a great topic to start aiming a concept-definitioning which is the first step to be done for a TOE.

[Guille]

I just have realised that the Tuesday 4th of October I'm going on a school trip to Prague. We're coming back on saturday the 10th. I think we're leaving in the morning, but maybe we don't come back home until the late afternoon. Anyway, it still looks like I'll manage to be there.

[Robert]

Guille - The chat is October 1st, so there should be no conflict if you leave on October 4th. Also, the 10th is on a Monday, not Saturday. Perhaps you mis-read the date of the chat? I'd hate for you to miss out because of that.

To all - Just to get the discussion going. What would happen if I put on my space suit, rode my space ship to the nearest black hole, and jumped out to fall into the black hole. What would I see? What would you see? (you are watching me fall from a stationary frame of reference to the black hole) Would I make it to the event horizon? What would I see inside? Do I end up in another universe? Lots of questions to ponder.

[Guille]

Originally Posted by Robert Guille - The chat is October 1st, so there should be no conflict if you leave on October 4th. Also, the 10th is on a Monday, not Saturday. Perhaps you mis-read the date of the chat? I'd hate for you to miss out because of that.

TRUE! I did a mathematical error: I thought that the saturday of the chat was not this saturday, but the one after it. Still, it may be that I can't be there at the very egining because I'm going to whach a movie that day, but I tihnk I'll make it.

Originally Posted by Robert To all - Just to get the discussion going. What would happen if I put on my space suit, rode my space ship to the nearest black hole, and jumped out to fall into the black hole. What would I see? What would you see? (you are watching me fall from a stationary frame of reference to the black hole) Would I make it to the event horizon? What would I see inside? Do I end up in another universe? Lots of questions to ponder.

I first want to state that all of what I right in the next paragraph is absolutely hypothetical in the sense that it is not based on empirical either direct or indirect observation, but it does have rationality in it (or I like to think so).

Last year I did a work in physics class about black holes. I found out that there are 8 mayor different ways of dying that will make it absolutely impossible and inprobable for you to arrive at the event horizon, alive. But considering an absolutelly hypothetical case in which you manage to cross the whole black hole alive, what you would see as you go down to the singularity is the blach hole becoming a star, and finally dissapearing. You will also see the universe getting smaller and smaller, until everytihng is condensed, and neither forces, energy or matter are differentiable. About your last question, I believe it to be the mayor question to discuss, I think there are three possible answers:

1. You will arrive at the event horizon, then the particles of your body will start crossing from one side to another, and you iwll be explelled really fast from the now-white-hole, and you will be in another unvierse.
2. You will be converted into anti-matter and become part of the black hole.
3. You will be converted to energy which will be obtaine dby the blakc hle, and then it's event horizon will grow.

I think the three are possible and rational, so I don't really think we can totally choose one in this moment of history.

[Robert]

Originally Posted by Guille But considering an absolutelly hypothetical case in which you manage to cross the whole black hole alive, what you would see as you go down to the singularity is the blach hole becoming a star, and finally dissapearing. You will also see the universe getting smaller and smaller, until everytihng is condensed, and neither forces, energy or matter are differentiable.

I think I would notice the Universe speed up as I approach the event horizon, while you would see me slow down and freeze forever just above the event horizon. But to me there would be no delay as I fall through the event horizon. But once through the event horizon are you saying that I would see the black hole grow younger?

Once inside the event horizon you would think the light, originating from inside the black hole, would slow down and stop as it reaches the EH boundary. From my frame of reference, however, I must be approaching the speed of light as I enter the black hole, so the stationary light, to you, would appear to me to be moving at the speed of light. So right when I cross over light is flowing outward at the speed of light yet never gets past the EH. Weird.

Originally Posted by Guille 1. You will arrive at the event horizon, then the particles of your body will start crossing from one side to another, and you iwll be explelled really fast from the now-white-hole, and you will be in another unvierse.

I wonder what would happen if you were in a really powerful hovercraft, just inches over the EH. If you stuck your hand through the EH could you pull it back?

If I were to fall backwards into a black home. i.e. looking outward, what would I see as I passed the EH? Seems like I could still view the outside universe; the EH is like a one-way mirror-you can see out but not in.

Of course, in reality I would be long dead by the time I get to the EH, but in principle, I wonder if these things are possible and what could be observed. Perhaps, for a really big black hole the tital forces would not rip me apart immediately.

This is getting confusing. Got to think about think about it some more.

[Guille]

Originally Posted by Robert I think I would notice the Universe speed up as I approach the event horizon, while you would see me slow down and freeze forever just above the event horizon. But to me there would be no delay as I fall through the event horizon. But once through the event horizon are you saying that I would see the black hole grow younger?

I think yes, you will. Oh no! I have jsut realised that you will be in the same gravity force as the black hole itself, so you will both my parallel, and, thus, for you, the black hole won0't grow younge,r and neither ewoudl you grow younger for the black hole (if in any case the black hole had eyes).

Originally Posted by Robert I wonder what would happen if you were in a really powerful hovercraft, just inches over the EH. If you stuck your hand through the EH could you pull it back?

I wonder the exact same thing. I don't know the answer. someone help us, please.

I think that maybe you will always fall down, because for example, imagen a black hole grows and a star nearby enters the bh's horizon. Then, imagne the star is being pulled on the opposite way fro the bh, by a gravitational atraction, around a much bigger star. Then, the star would end up faling down to the bh. this is because the gravity produced by the bh is much bigger than the one produced by the big star, or than enything else in the unvierse (apart form other bigger bh). So I think you can get out of a bh's non-return horizon by having another bigger force than the one that the bh's gravity has on you. This force would need to me gigantic.

Originally Posted by Robert If I were to fall backwards into a black home. i.e. looking outward, what would I see as I passed the EH? Seems like I could still view the outside universe; the EH is like a one-way mirror-you can see out but not in.

I'm not sure about this one either. As I said in the other post, I think that you would see the universe getting smalle,r going back in time, matter and energy becoming 1, galaxies compacting.....i.e. you would see the birth of the unverse. But this is very very very very contradictory, abstract and paradoxical. So I think this idea to be wrong. But I don't ahve a solution to it.

[Robert]

Originally Posted by Guille I think that maybe you will always fall down, because for example, imagen a black hole grows and a star nearby enters the bh's horizon. Then, imagne the star is being pulled on the opposite way fro the bh, by a gravitational atraction, around a much bigger star. Then, the star would end up faling down to the bh. this is because the gravity produced by the bh is much bigger than the one produced by the big star, or than enything else in the unvierse (apart form other bigger bh). So I think you can get out of a bh's non-return horizon by having another bigger force than the one that the bh's gravity has on you. This force would need to me gigantic.

But the gravity of a black hole depends on its size, or rather its mass, and this will vary among black holes. I wonder if you could find a Lagrangian Point in a double black hole system--a smaller black hole orbiting around a larger for instance--where an observer could be positioned slightly above the EH of the smaller black hole.

Now when I stick my hand into the Event Horizon, I should not be able to pull it back out regardless of the size of the force helping me to pull back since nothing can escape a black hole. There is the exception that there could be some quantum tunneling taking place at the surface. BTW, is this quantum tunneling what is meant by evaporation of a black hole. I have read that black holes will eventually evaporate and disappear over trillions of years.

Another thought, could I go into orbit just above the Event Horizon? I'd have to be moving incredibly fast, yet I would be in free fall, so no forces would be ripping my body apart or anything, right? Hmmm. Then what happens if I try to scoop up some of that blackness. Maybe loose a hand? Need to take into account who is observing, reference frames, and effects of time and space distortions since I would be moving very fast while inside a huge warp in a the spacetime fabric.

[Guille]

I have just realised something.


What I said in my other post is wrong. You can't go back at all no matter what if a part of you enters the event horizon, you will fall, no matter what. Now, if you are in the zone of gravitational atraction of the black hole, then you CAN get out, by having a force bigger towards somewhere else. This is because although you are atracted to the black hole, it's not impplyed that you can't go other ways.

[Robert]

My people predictor index, based on the poll, is predicting 3.25 people in chat today. I hope we have a good turnout because this is a very interesting topic.

I have been under quite a lot of pressure lately to meet a deadline in my other job so I'll be working most of the weekend--including now. I'll pop in and out of chat today but may be unable to attend full time. I will publish a transcript of the chat for others the see or review. See you later!