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lol Or would you notice?


I didn't say I was being scientific.

And I feel like I am repeating myself when I say that I know nothing (scientific) about black holes.

But that doesn't mean I can't answer the question that was proposed on the first page about black holes.

Obiously Time Travel through blackholes isn't scientific, but it's something I just believe can happen, not in the sence that is Time Travel that we think of....like in the movies, but a sort of "shortcut" through space...folding space persay to get from one point to another even faster than a straight line.
LIke folding a paper, to make the two opposite points meet.

A white hole is pretty much the oppisite only complicated. In simplifed terms it instead of sucking everything in, It spits everything out! blaugh

I have to agree with Emily that people probably did suggest that Monkey's would fly out their a** before the Wright Brothers would fly. Things that were deemed a waste of time and impossible became the opposite.

Science has to be based on belief. You have to believe something is true to have the will to pursue it and prove that it is true. Why would you bother with something unless you believe it to be?

Until we can build a faster spaceship we won't really know much about black holes besides what we can observe from where we are. It takes us what, 6-7 months to get to Mars? *doesn't know for sure* We got a long ways to until we know much about black holes. We can theorize in labs and try to simulate what goes on in them, but it’s all we can do for now.

My astronomy indergrad course was weak. But yes I'm aware of sign and constelation differences. Astrological signs are invariable, however we are each born under a constelation that is different from our sign. That'll get you a more defined meaning. Hence, I am emotional, sensitive and sensible but I'm also strong willed, and dun't open up easily.

I bought the book, 'cause I can take it to the field. My laptop isn't a Mac (I get mine for lab work around summer!). Yup, I've looked at the websites.

VoijaRisa:
I think it cool that you do research. Unlike some people may think, Astronomy is not an easy major. Good luck with everything!

Ok a couple of things that will help you understand a little more about black holes.

1. equation for the gravitational force.

F.g = Force due to gravity
m.1 = mass of one object
m.2 = mass of another object
r = distance between two objects
G = A constant (used to make units balance)

F.g = (G * m.1*m.2)/r^2

What this means is that the strength of gravitational attaction depends on the total mass of the objects involved and goes up very rapidly the closer they get. (example everytime you halve the distance the force does up by a factor of four times)

This is an appoximate formula for a real world situation you have to consider the distribution of mass and a bunch of other stuff, but it can give you the basic idea if you have a math background.

2. Basically to get a black hole you need not only a large mass (like that from a dying star) but you also need that mass to be really really condensed. For this reason not just anything can become a black hole (not all stars do). This doesn't normally happen because subatomic forces will act to keep the density from reaching this level.

Here is an example of how a black hole could form ( pretty much know they can form this way there are theories with a lot less support that they can form in other ways)
You pretty much need something along the Lines of a blue giant star. This will burn through its hydrogen fuel relativly fast at which point you will have mostly He, which due to the massive mass of the star will move towards the center and Fuse there, then after awhile you will have oxygen which will also fuse. The star doesn't burn through all of any given type of fuel in a single go so it starts to look sort of like an onion with the heavier elements in the center and the lighter ones forming shells around them, all undergoing fusion. Now Fusion releases a tremendous about of energy but is dependent on the materials fusing, up until you reach Iron (the basic idea is that when the central part of the star fuses its way to iron, it can't go any farther because at low pressures iron 56 has the highest binding energy per nucleon of any element, so fusion or fission of iron 56 requires an energy input.) This means that the center of the star is no longer undergoing a controlled nuclear explosion thus forcing everything else out and maintaining the struction of the star. So it holds steady for a moment (so to speak) and then collapses on its core. At this point the whole star fuses at once and you get a Type II supernova (http://www.pbs.org/wgbh/nova/universe/super2.html nice flash thing showing what I am talking about if I am making no sense)
Scientists think this mass fusion is how we get everything above Iron on the periodic table. In any case sometimes during this explosion enough of the force is concentrated intward (as well as outward) to overcome all the forces that would normally stop matter from becoming that dense and you get a black hole left where the core of the star used to be.

3. Light cannot escape from a black hole, photons have no mass, gravity depends on mass, ... huh?

To understand this you need to get Einstein's General Relativity. Which heavily heavily (and probably slightly incorrectly) paraphrased states that really strong gravitation forces bend space and time. Picture a Sheet being held tight at all four corners and then having a bowling ball set on it, the sheet is space/time and the reason things move towards the ball is that it bends space/time so that they will roll towards it. Using this analogy a Black hole is like a hole in the sheet, rather than just bending it things fall completely into it. Also note that time is deformed basically coming to a stop as you approach the event horizon (not totally sure on the details here).

4. So there are a few problems with using a black hole for time travel.
a. You would have to deal with Tidal Forces. Basically as you get near a black hole parts of you would be being pulled harder than other parts of you. (imagine you have two friends carrying you, one holding your hands and the other your feet, they are both moving in the same direction but the one holding your hands is pulling 4 times harder and trying to go faster than the one holding your feet) The technical term I have heard used is "Spaghettification" but basically it gets to the point as you get near the event horizon (the boundary that light can't escape) that the differences in force and acceleration will overcome subatomic forces and rip the atoms composing your apart (again not 100% on this but pretty sure).
b. You would have to deal with time dilation. Basically we don't know what would happen to you if you actually crossed the event horizon but to an observer time would appear to slow down for object (assuming it managed to stay in one piece) and the time it would take to reach the event horizon would be effectivly infinite.

5. Good news for time travelers. We still don't totally understand how gravity works, we cannot create it (other than though gross manipulation of mass) and we cannot detect the force carriers that allow for attaction between objects. Theories abound on what is actually going on but basically we don't know. So it is "possible" that if we had a more advanced understanding of gravity we might be able to somehow mitigate the tidal forces around a black hole and go into one. Moreover if we could manipulate gravity it "might" be possible to manipulate time in some way as well allowing you to overcome the time dilation near a black hole. Now if we could do all this it becomes somewhat questionable as to rather we would actually need to go into a black hole to time travel, but hey whatever floats your boat. Also it would be more like a stasis then unfreeze at some point in the future as opposed to going back in time (although some physicist think they may have managed to send light particles back in time at least that is one theory for what is going in this experiment http://www.livescience.com/technology/050819_fastlight.html).

6. In short there is a lot to consider. I believe that it might be possible to go forward in time (using black holes or not) but I do not "believe" that it is possible to go backward in time. Violation of causality, and subsequent paradoxes and questions about free will are just more than I am even willing to consider, though if someone ever shows me some hard evidence to the contrary i could at least consider it.

7. I think this is my longest post ever.

I have a fancy telescope that finds the stars and planets for you and can do all these other nifty things. It works really well and let me tell you. Saturn is so beautiful!

Oooh Yay Funness!

I know I don't know what happened?
The guild seems deadish too..
and we have double more mebers?
o.o

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