A question of Black holes.

[oscar1]

Perception is of course not at all the same as the real thing. I perceive what a photograph shows me as being two-dimensional, but all the particles the image is made of, are three-dimensional. And since the photograph will eventually decay, it is actually three-dimensional plus one.

 

[daniko]

Although most of the posts here mention that - it's a four dimentional space we live-in, I doubt there is understanding what follows from it.<br /><br />The example with the rubber sheet must be understood not as 3D abstraction but as 3D & Time abstraction.<br /><br />For example - the lower you fall below the surface of the rubber plane - the slower time flows. In that row of thoughts - in a Black Hole's bottom ( which is on infinite depth ) time must be stopped.<br /><br />If we think of the two approaching Black Holes - as closer they become - the more slower their common time will become (compared to the normal - non distorted space). From here we wouldn't be able to *see* the merger of the two Black Holes, because it is going to happen after all the time in the normal non distorted space has passed !<br /><br />

 

[weeman]

<font color="yellow"> From here we wouldn't be able to *see* the merger of the two Black Holes, because it is going to happen after all the time in the normal non distorted space has passed ! </font><br /><br />This would be the same consequence with the event horizon. If you are in a ship that is outside of the event horizon, and your friend decides he is going to take a trip into the black hole, you will never see him actually disappear into the black hole. You will see him get closer and closer to the horizon, yet he will seem to infinitely stay at the horizon, it will seem as if he never crosses that barrier.<br /><br />Just before your friend crosses the horizon, he will emit his last photons. This is the light that will appear to you for an essentially infinte amount of time. Thats because it will take virtually all the time in the non distorted space for the last photons to reach your ship. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[alokmohan]

Precisely .You never know the reality beyond signal long,long back.Epistemology matter.

 

[oscar1]

"If we think of the two approaching Black Holes - as closer they become - the more slower their common time will become (compared to the normal - non distorted space). From here we wouldn't be able to *see* the merger of the two Black Holes, because it is going to happen after all the time in the normal non distorted space has passed !"<br /><br />I don't think we know enough about gravity to determine that. For one, as the Black Holes aproach eachother, there would have to be a barrycentre somewhere, which may very well displace enough of the gravity going around, to make the actual collision event visable 'in time'. Who knows?<br />

 

[why06]

<img src="/images/icons/cool.gif" /> So time would slow infinitely before the holes collided, <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[oscar1]

I merely mentioned an additional factor that may or may not bear some influence when (or 'if' rather) the hypothetical occasion occurs.

 

[R1]

Time should definitely slow down close to a black hole.<br />the clocks near the black holes barely tick at all. I would think 30 billion years might elapse near the earth and the hand on the clock at the black hole barely<br />moved a fraction of a second.<br />If there's an alleged black hole at the center of the Milky Way, or<br />even just a supergravitational area, wouldn't everything near it<br />still be way in the past? the earth, being near the Milky Way outer <br />fingertips, has aged quite considerably, but what is the realistic age of the area <br />near the center? <br />In other words, if 5 billion years elapse (here on earth)at the outer parts of the Milky way, is it more like the age of the part close to center is <br />only about 5 seconds old? are we looking at the way the Milky way center looks<br />like on its first minute of existence when we look at its center?<br />has anyone computed time at various locations in the universe? is the formula simple? <div class="Discussion_UserSignature"> </div>

 

[R1]

another question, wouldnt this time-slowing close to the balck hole<br />create a reverse looking spiral of stuff going towards it, by reverse<br />I mean the stuff closest to the black hole begins to freeze in time, but<br />the outer spiral arms would continue to move quickly because time is less<br />slowed down since the distance to the black hole is greater. <div class="Discussion_UserSignature"> </div>

 

[enigma10]

Time would not stop. Outside of that, yes, time would slow.<br /><br /> <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[alokmohan]

In Kip Thornes book he opens with an imaginary journey to black holes.The monitor is world Geographical society .When the crew for journey start they advise the monitors to go to hybernation.As time for reporting back may be million years. But the crew gets thirty years older fo thirty year voyage.Near black hole you are immortal sort of.

 

[daniko]

Hey there! I like how responsive all of you are!<br />It's good to see that not everyone is bored with this theme!<br /><br /><font color="green"><b>To weeman:</b></font><br /> I'll put just some clarifications on how gravity affects light. Gravity does not slow down the speed of light propagation. It just changes it's energy (i.e. it's frequency decreases). So we see it red-shifted.<br />The reason we see processes near strong gravity are slow is not that our Space Video Player is turned to slow framerate.<br />The framerate is the same - it's the reality framerate that is slower. In strong gravity all physical processes happen in slower rate. In this count:<br />- the spin of the electrons around the nucleus;<br />- the speed of nuclear reactions;<br />- the speed of falling of an object;<br />- the speed of chemical reactions;<br />- ...<br /><br />But if we are in strong gravity - everything will move in normal speed for us. The thing that for the outside observer things are going slowly - does not mean that in local time they go slow.<br />From here - when I speculate that the two black holes will never merge in our time-space does not mean that something will stop them from doing this.<br />The crash will happen - but in timely fassion - it will be outside our universe<br /><br /><font color="green"><b>To Oscar1:</b></font><br />I think that gravity must not be accepted as a force shield. It is not something that could be produced, amplified, distorted or redirected, emmited or recieved.<br />The gravity is just a property of the matter. Like size of the rock or the full energy of a material object.<br />The gravity comes with the matter and goes with the matter. They are undividable.<br />I think that with the case of two approaching black holes - all the strange things that happen are with the space-time.

 

[alokmohan]

Gravity bends light .Why make so much of it?

 

[daniko]

<b>alokmohan:</b>"Gravity bends light .Why make so much of it?"<br /><br />Really it's matter of view point.<br />The essence of Einstein's perception for the Universe is that not the light is that bends - but the space is deformated. It is his base assumption on which he grew his theory.<br />The basic of his understanding is that light <b>always</b> travels at <b>c</b> and it <b>always</b> travels in straight direction.<br />The Space and The Time are - that twist and curve

 

[alokmohan]

One of the basic postulates of general theory of relativity is that star lights bend because gravity acts on it. At the time it looked absurd proposition.To test this scientists had to wait for the next total eclipse.Arthur Eddinton in 1919 solar eclipse experimentally verified it.

 

[enigma10]

I think Steve33 answered this question best back in october.<br /><br /> An informative posting by Steve33 concerning light and gravity <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[daniko]

The bending of light passing near objects with strong gravity is not a postulate - it is an experiment which demonstrates some of the effects of Relativity Theory.<br /><br />The observed effect is not because gravity acts as force on the light. The effect appears because gravity stretches the space on the way of light.<br /><br />If you have a circle in space with no gravitational body inside it - you can derive it's diameter <b>Do</b> form it's perimeter <b>P</b> by the expression: <b>Do = P / Pi</b><br /><br />If you put a gravitational body in the center - it virtually creates additional space inside this circle (condensed space) due to gravitational distortion. If we suppose that the perimeter of the circle is far enough to be affected by gravity - its perimeter <b>P</b> remains the same. From here we could expect that hte diameter would still be <b>Do = P / Pi</b>. But if we strech a space-ruler cross the circle's center we will measure that diameter is <b>Dgr</b> and <b>Dgr > Do</b>.<br /><br />If we pick two light rays that pass by this gravitational body - one crossing the circle and other passing otside. Let the two rays travel head-to-head. When they reach the gravity zone the inner will pass throug <b>L1</b> segment and the outer through <b>L2</b> segment.<br /><br />If in absence of gravity we measure that <b>L1 = L2</b> - after placing the gravitational body it will appear that <b>L1 > L2</b>.<br />So after passing by the gravitational body - the inner light ray will occur a little behind the outer one. This will turn the wave front to the left and the light will continue with changed direction.

 

[search]

There is two main reasons why light is affected by mass in spacetime:<br />First the presence of any mass like planets, stars and galaxies deform the fabric of spacetime. Energy also deforms spacetime fabric.<br /><br />Matter and energy in motion twist this curved shaped structure. Because a bigger mass deforms more the spacetime fabric, when a smaller mass is passing by it will curve towards the bigger mass. The smaller mass is not attracted to the bigger mass by any force it just follows the spacetime curve near the larger mass.This is what is happening to our planets in the solar system for example.<br /><br />This is a legacy of Einstein and his theory of general relativity.<br /><br />There is another way mass can deform spacetime and that is through frame-dragging. Rotation is the key word. Any rotating mass twists the spacetime fabric. This means not only spacetime is curved around the mass but it is also twisted around the rotating mass.<br /><br />This is a legacy of Joseph Lense and Hans Thirring <br /><br />Einstein proposed three phenomena to explain the spacetime curve:<br />Starlight deflection, Mercury's orbital precession difference between Newton's predictions and actual observation, and gravitational redshift. <br /><br />Arthur Eddington during a solar eclipse confirmed Einstein's prediction to within about 20%. Stars that should be behind the sun at the moment of the observation could still be seen because light was being deflected following the curve of space around the sun. Later experiments came confirm the prediction to within 0.1%.<br /><br />Mercury orbit slowly precesses, in the direction of its revolution. Newton did not completely predicted this, Einstein predited and was later confirmed to be correct.<br /><br />According to Einstein predictions light loses energy passing near a gravitational field causing its wavelength to became longer shifting its colour towards the red (Redshift). Pound-Rebka Experiment initially and NASA's Gravity Probe later conf

 

[alokmohan]

SEARCH has added a new dimenstion to the thread.I never knew Shapiro effect and never bothered about gravity B probe.I have only one anecdote to add.When Eddington made that historic confirmation,Einstein was not moved.Asked if he is happy,he replied he knew it will prove correct.What if test failed?He said he would infer instrument was wrong.

 

[alokmohan]

Never cross event horizon.

 

[daniko]

Thanks <b>SEARCH</b> for the post! It was much helpfull.<br />I also never took in account that rotating masses could infere space-time deformation which is different from static gravity deformation.<br /><br />But I must add that gravity as a force is not replaced by space-time deformation. In fact Newtonian theory is based on the gravity force.<br />Space-Time deformation is an additional effect from the gravity foreseen by Einstein.<br />Mercury's orbit is mainly determined by gravital force but on its path around the sun - there is a little depression in the 3D space near the sun.<br />The effect is that crossing of that depression takes a few seconds more to cross compared to if no depression was available. That's because the distance through this gravital depression is a little longer. This doesn't generate any push or pool to the planet but adds a few more seconds of gravital attraction. This bends it's orbit almost invisibly toward the sun.<br />With time this effect accumulates and is observable as rotation of the orbital elipse orientation around the sun.

 

[alokmohan]

Very intense, low-frequency, gravitational wave sources can be expected from gravitational waves associated with the merger of massive black holes.<br /><br />Scientists have long argued that massive black holes are inevitable in the cores of young galaxies. There is very strong evidence that such black holes exist in many objects, with masses ranging from 106 to 109 solar masses. Galactic mergers are likely to give rise to such black hole mergers. So one estimate of the rate of powerful gravity wave events can be obtained by estimating the rate of Galactic mergers. For large galaxies with central black holes, scientists have estimated this rate at about one per century. This does not include the far more frequent mergers of smaller Galaxies for which central black holes have not been confirmed. It is very clear now that the events in the cosmos are well coordinated through the use of very intense low-frequency gravitational wave sources in higher dimension. Gravity detectors in 3D Spatial dimension fail to detect the intense gravity waves.<br /><br />It is also clear that a central command and control structure guides these gravity wave clusters to influence the universe in every part. Black hole collisions are the only opening for us to view the higher dimensions and the gravity wave clusters. <br /><br />It seems that the higher order type IV extraterrestrial civilization is in control from the Hyperspace. <br /><br /><br />--------------------------------------------------------------------------------<br /><br />-----------------------------------------------------------------------

 

[R1]

To me it seems that around the singularity , gravity continues to create space around it by<br />continuing to stretch space-time around it, and yes to me it seems a point can be reached when the singularity could<br />very well explode, or fuse, perhaps, as in fusing bits of space or energy or both into<br />neutrinos, quarks, similar to a big bang condition.<br /> <div class="Discussion_UserSignature"> </div>

 

[R1]

but now, and in terms of the original question, if 2 black holes collide...<br /><br />I'm not sure whether the 2 singularities would merge at all, because of that growth<br />or stretching of space around them. Maybe someone can further <br />contribut with the thought especially as it relates to their speeds, though. <br /><br />For example I wasn't taking into consideration that if a sigularity could exceed C within its own spacetime then ...<br />It would come back out of its event horizon?<br /> but then the stretching of its own<br />space-time could still be faster, in other words can it exeed the speed of its gravity?<br /><br />and then double the question: what if black hole A and B race toward each<br />other at top speed, would singularity A be able to to touch singularity B amidst<br />their own fiercely expanding space-time about them?<br /><br />Or would there be an anti-gravity effect, similar to the way we see distant galaxies <br />almost repelling each other because the space-time between them is quickly expanding?<br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[daniko]

Hey man <b>John1R</b> - I like your thinking <img src="/images/icons/cool.gif" /><br /><br />You hit som really great spots !<br /><br /><font color="orange"><b>"... it seems a point can be reached when the singularity could very well explode ..."</b></font><br />This sparked me.<br />1) I remember that light and other form of pure energy does not have mass and dont create gravity and are not affected by gravity force (not by the force).<br />2) From the BigBang theory we know that energy is suspected to transform into matter in extreme (big bang) conditions<br />3) Matter could transform into energy in extreme (nuke bang) conditions<br /><br />So:<br />1) when a neutron star is about to become BlackHole it's full of matter which produces a hell of a gravity.<br />2) after the neutron star shrinks below the diameter of the Event Horizont - it turns into Black Hole<br />3) Black Hole is Extreme Condition<br /><br />Hipotesis:<br />1) It is possible in the moment of creation of the Black Hole - gravitational pressure to be so dense that all of the forces that hold particles as individual objects to be overwhelmed.<br />2) In that moment all of the matter of the Black Hole could liquify itself into pure energy.<br />3) in that same moment - all the gravital forces will disappear instantly<br />4) this will free the entire amount of energy that's equivalent to the BlackHole mass resulting in BigBang.<br />5) We will never "see" this BigBang in our universe because of the time separation. We will just observe forever the last second of the neutron star.<br /><br />To be continued . . .