Adios Black Hole, hello a MECO?

More astro nonsense.

More astro nonsense.

I find that to be a very short sighted response. Trying to understand the fundamental structure of the Universe may not be interesting or understandable to you but others see it is the ultimate challenge. To understand the actual fabric of time, matter, energy and space gives us great insight and broadens our perspective on everything.

Another theory is its just a mirage

think inside the square

This theory could explain that black holes exist.

Matter entering a black hole goes through to the 'other' side - into another universe (or time).

The MECO is the entry of matter into our universe from a black hole on the other side.

The two might be joined together as a continuous loop of string (the string theory) with matter passing along the string.

The string itself (wound evenly or just a tangled mass) in one huge ball - in which our universe is but a thin slice at any one angle through the centre.

Matter continually passes along the string to enter or leave our universe (our slice) - but we cannot see the 'string' - we just see manifestation of this as black holes and white holes.

At the same time our slice is not static but slowly rotating about the centre of the ball progressively to pass through every angle (in three dimensions) on the x, y and z axis - but also with a 'spin' in the disc of the slice - which is the fourth dimension.

My theory might have holes in it, but at least I can visualize it.

Hmmmm that's an interesting theory and explanation Horace...

I quite like the picture of the universe intersecting a ball of string...

That's also a good way to describe the theory... Nice!

John.

horace04....you say that matter passes through to the other side.....i find that hard to believe, since the essence of a black hole is that nothing escapes from it once passing the event horizon.

"nothing escapes from it once passing the event horizon"

...Except Hawking radiation, of course.

Hi horace40 your theory that

Matter entering a black hole goes through to the 'other' side - into another universe (or time).

Has a few serious holes (pun intentional) in it. The biggest one is that if the matter that fell into a black hole disappeared then the black hole would cease being a black hole. The gravity that makes a black hole exist is derived from the matter that is in and that falls into it. If the matter disappears to somewhere or when else then the gravity driving the black hole would cease and it would no longer be a black hole.

Also, we have to consider the extreme gravitational forces of a "black hole". It's possible that massive black holes were the "condensation" causitive that condensed galaxies around each of them. We apparently "see" a massive black hole at the center of almost all galaxies. If a MECO had that much gravitational force, wouldn't it just be another form of a black hole, e.g., a "fuzzy" black hole? If the MECO had even a tiny fraction of the mass of a massive black hole, how can radiation pressure maintain it as a discrete physical body, which radiates massive amounts of radiation? Too many concrete theories and math that support black hole existance. Don't lose sight of the fact that massive black holes may have a mass of several million normal stars. How can one's theory support a radiative body of that much mass that doesn't appear in large telescope searches of the center of nearby galaxies, including our own?

This is what I understand.

The black hole comes about because as a super giant star starts to collapse the gravity increases to a point that matter can no longer resist gravity and it collapses to a singularity. The result is an escape velocity greater than the speed of light and an event horizon that seems to gobble everything up that gets too close.

It is however possible that matter can always resist gravity and therefore the singularity never forms and the escape velocity remains below light speed. The result is an object that has very strong gravity and keeps sucking in everything that gets too close.

The thing is that both would look pretty much the same and appear as an ever expanding region that steadily gobbles up everything that gets too close.

My knowledge of things like this has holes in it the size of the black variety and I may have it all wrong. Jorrie understands this better than I and he may be able to either confirm or correct this if he is watching.

Good thoughts, MASU. I have read many of your replys and you are usually ahead of the crowd. There was/is a very nice program on NOVA, wherein astronomers were unable to reconcile the amount of energy being released by gamma ray burst events back 9 to 12 Billion light years ago, where the energy observed in one gamma ray burst emission seemed to be equal to the energy of all the observable galaxies. They finally realized that this release of energy was (1) from very massive stars, formed early in the history of the Universe, which had short life-times due to their mass and the rate at which they burned their hydrogen fuel, and (2) that the energy seen as gamma ray bursts was being emitted in rather narrow beams in two opposite jets from the collapsing star. Thus the observed energy was only a small fraction of what had been thought to be a spherical emission of gamma rays. Thus were massive black holes created, and which then fed off surrounding matter. The infalling matter rotates around the massive gravitational center in "rings", and the matter rotates so fast that the friction causes x-ray emission, much like in a conventional x-ray tube using fast electrons. There is a wealth of math for black hole creation and their properties. The understanding of black holes in our Universe loses comprehension when one realizes that a massive black hole (as seen in almost all galactic cores) may contain millions of stellar masses! If the density of a simple neutron star is millions of tons per fluid ounce, how can we measure a black hole's material density? I don't think there is any "proof" that singularities exist either, which would be close to a real time definition of infinite mass. Could we ever find a way to abstract energy from the energetic ring of matter surrounding a "feeding" black hole? Don't overlook the X-ray flux associated with the ring of heated matter. Any thoughts you have on the subject of black holes would be appreciated, as I always welcome other insight!

"the singularity never forms and the escape velocity remains below light speed"

To form a black hole, matter doesn't need to make a singularity, it just has to compress to within its event horizon - that is, the radius at which its mass has an escape velocity equal to the speed of light. What's inside the event horizon is a matter of great debate! Maybe a singularity, maybe not... But how can we tell, if we can't see past the horizon? I predict that the theorists will be busy for a long time yet.

To form a black hole, matter doesn't need to make a singularity, it just has to compress to within its event horizon - that is, the radius at which its mass has an escape velocity equal to the speed of light.

This is true as well and according to Einstein since nothing can ever travel or propagate faster than the speed of light we can never know what lies beyond the event horizon.

Another thing to consider is that any abject falling into a black hole will technically attain the speed of light at the event horizon. But if you do attain the speed of light you mass increases infinitely and time dilates to zero so you can never actually fall into the black hole. You get as far as the event horizon and then get stuck frozen in time for eternity along with everything else that has fallen into the black hole.

However from what I understand and I may be wrong, as a black hole sucks matter in the event horizon expands so what dose that mean for all the matter that is already stuck at the event horizon. Dose this matter move backwards, stay where it is or what?

Another thing is that since the matter can never actually reach the black hole and it's mass increases to infinity as it approaches the black hole what effect dose the gravity of all the infinite masses stuck at the event horizon have on the black hole itself.

If there wasn't a black hole at the center and rather just a really massive lump that had and escape velocity close to but not actually the speed of light it would look to us from outside pretty much the same, I think, or would it?

Strange things these black holes, if they do exist and nothing ever escapes from them then wouldn't the universes fate be to get sucked into one of the existing black holes never to be seen again? Then again there is Hawkins radiation that supposedly can boil off the black hole and I have not even the slightest of inkling of how this works.

The concept of a black hole seems to create more conundrums than it fixes and I am not sure if the universe is easier to understand with or without them. I love this stuff, lots of answers that can probably never be proven true or false and every answer poses three or four even more unbelievable questions.

I think you are confusing what an outside observer sees, watching a particular bit of matter approaching an event horizon, and what actually happens. If matter did not pass thru the event horizon, how does a black hole increase so tremendously in size and mass? And yes, the event horizon increases in size (radius distance from the core) as the black hole increases in mass. ( Think of your own visual horizon here on Earth. As you move, your "horizon" also moves. It's not a real "thing" in space). Don't lose sight of the fact that this "growth" of the massive black hole has been going on for billions of years!! Millions of stellar masses may be concentrated inside the event horizon, at the core of the black hole. It may take a million years for a black hole to ingest a close star. You say that "Another thing is that since matter can never actually reach the black hole and its mass increases to infinity...". I believe that matter does cascade rather violently thru the event horizon and into the black hole. The event horizon is just an area in space that defines the "one way only" traffic into the black hole. We'd have to have a thread discussion of the meaning of infinity to discuss that portion of your thoughts. The old saying: "Give me the largest number you know, and I'll give you a larger number" tells you something about Infinity. All the matter in the Universe is small, compared to "infinite" mass. Also, we can never "see" an actual black hole. We see things via reflected light and since light cannot pass outward thru the event horizon... . I believe Hawking's radiation is theoretically for tiny black holes, where virtual particles are constantly created from the energy of space, bubbling like oatmeal in a pot, and appear and disappear extremely rapidly. If one of the dual particles thus formed falls into the black hole, then supposedly the 2nd virtual particle become real, and in that sense, draws energy from a small (microscopic ?) black hole. I can only marvel at a mind like Hawking's! What a gift!

I believe that matter does cascade rather violently thru the event horizon and into the black hole. The event horizon is just an area in space that defines the "one way only" traffic into the black hole.

There is another property of the event horizon an that is time dilates to non existence. I don't believe that the physics that we are all so familiar with can actually apply inside the event horizon. From what I have been told in other discussions on black holes if you ever get sucked into one the universe will appear to age faster and faster as you get closer to the event horizon. Once you get to the event horizon you will see all the other things that have ever been sucked in frozen in time at the event horizon just like you.

Now whether it's actually you frozen at the event horizon or just an after image I don't know but since time doesn't exist inside the event horizon I would suspect that a whole new set of physics needs to be applied.

Do all black holes create the same "warp" of spacetime? or does the warping increase with mass?If it increases, then a more massive balck hole would have a steeper event horizon, and thus sink"deeper" into spacetime, creating a smaller event horizon.Thus, the more massive the black hole, the smaller the event horizon.

I read of a theory similar to Hawking's many years ago, in a book titled "Black holes and warped spacetime" Do not recal the author, but he spoke of microscopic black holes, whose event horizon sucked in 1 of of 2 entangled particles,and emitted energy equivilent to the mass of the particle consumed in order to "Balance the books" of conservation.

This emission of energy was in the form of microwaves.He also specualted that it might be possible in the future to "capture" one of hte "white holes" and beam the energy back to earth.I cannot find the book now, but I have it here somewhere in the miscellaneous file cabinet....

HTRN

I located the book, :"Black holes and warped spacetime"

by William Kaufman, published in 1979.His theory of black holes emitting

radiation predates Hawking's by many years.

Interesting. Thank you.

Guest wrote: "Do all black holes create the same "warp" of spacetime? or does the warping increase with mass?If it increases, then a more massive black hole would have a steeper event horizon, and thus sink "deeper" into spacetime, creating a smaller event horizon.Thus, the more massive the black hole, the smaller the event horizon."

No, its the other way round - the more mass, the larger the event horizon circumference and the 'friendlier' the event horizon becomes. In a way one can say it's because you a farther from the central singularity... See my earlier reply to Astro.

Regards, Jorrie

Are all singularities the same size?

By definition a singularity has no size, so how can one singularity be larger or smaller than another? If all black holes collapse into a singularity, and 2 black holes merge, do you have 2 singularities or one? Will you have one singularity with the combined mass of the black holes, but the same "size" as before the merger? If so, then the event horizon should start to close up at some point,as the frame dragging continues, the way a cyclone in a tub of water collapses after it reaches a certain length.Or it could collapse into a microscopic event horizon, assuming that spacetime is infinitely warpable, the singularity could "sink" infinitely deep.If the speed of the singularity's "warping" of spacetime is limited by the speed of light, the 2nd singularity could never actually collide with the first one, or visa-versa.Presuming they collapsed and formed at different times, they would never be on the same "plane" in spacetime.

"I don't mind hearing voices, I just can't get a concensus on the answers."

/dev/null

Guest no 2(?) asked: "Are all singularities the same size?"

A definite no! Singularities generally describe situations where certain parameters go to infinity. Like density, where either mass is infinite or volume is zero (both are acceptable in the Big Bang instant). Or infinite curvature at the centre of a BH. Or an infinite Lorentz factor: (1-v²/c²)^-0.5

When two identical holes merge, the two singularities quickly become one and the curvature is now 'twice infinity' More seriously, the mass/energy will be more or less double that of one hole (some is radiated away as gravitational waves), the event horizon double the circumference and the gravity at the the same distance doubled.

There are 'bounce' theories that try to avoid a singularity at the centre of a black hole, but it is a quantum mechanical effect that I do not really understand.

Hope it helps, Jorrie

Hi masu, you wrote: "It is however possible that matter can always resist gravity and therefore the singularity never forms and the escape velocity remains below light speed. The result is an object that has very strong gravity and keeps sucking in everything that gets too close."

The limiting mass for a neutron star that could support it's own weight is about 3 solar masses. Above that, the gravitational pull overwhelms the "neutron-degenerate matter" and it must collapse to a black hole. See this Wiki article.

BTW, all masses, even Earth 'sucks in' a lot of matter and grows in diameter! For black holes the effect is a bit more severe, but one can very safely orbit a massive black hole at 3 times the event horizon radius. Below that, you need some propulsion to be safe.

Regards, Jorrie

Hi Jorrie,

I just read the article that you supplied the link to and it has this to say

Because the properties of hypothetical more exotic forms of degenerate matter are even more poorly known than those of neutron-degenerate matter, most astrophysicists assume, in the absence of evidence to the contrary, that a neutron star above the limit collapses directly into a black hole.

The formation of the black hole is dependent on the degeneration of matter and from what I understand this is a somewhat unknown factor. If the matter doesn't degrade the way they have postulated then it may never become dense enough to for a black hole. Mind you it would still be an incredibly massive object with phenomenal gravity it just wouldn't have an escape velocity greater than the speed of light.

I think that's the way I understand it but when you get to this level of physics things can be quite bizarre.

Very interesting indeed. The heart beat of God and the blood flow from one side to other and the black hole as heart of God. Good thinking.

I will like to add here that black energy and dark matter are not some patch of spill over oil on floor but also dynamic structures full of activities and interactive even though we may not be able to find now how and some good thinking can tell just that.

Keep thinking and you are more alive and kicking than dead brains.

If black holes are collapse of space and time then there is lot more to think about it. I am somewhat not sure about the size of black hole in terms of stored energy or mass. Is it more than a Galaxy? How do you find it out? Pull force and matter chewing mechanism? What a hungry thing it is?

I don't know much about black hole, but I do have some questions. 1) How does the Black Hole close?? They must or else the everything that come close to it will be suck into the black hole, and eventually, the whole galaxy will be in the black hole, would it?? 2) When an object is sucked into the black hole, where do they go?? Does the black hole have infinite size and nothing ever goes out?? Or do they get thrown out the "other side"?? If they do go out the other side, does the object accelerate to the point of the speed of light?? Just wondering.

MIdniteFighter

Black holes don't "close". And yes, everything that comes close to one (out to an "event horizon") does indeed get "sucked in". But remember the law for the range of gravitational force. It might be possible, eventually (billions of years), for a massive black hole at the center of a galaxy to eat the whole galaxy, but I'd question that. Recall that a typical galaxy may be 100,000 light years in radius, That's pretty big! For a black hole's gravity to extend that far... The proof would seem to be that most observable galaxies do contain massive black holes at their core, but the galaxies and their billions of stars have existed for many billions of years. An "object", per se, doesn't get sucked into a black hole. The attractive and disruptive forces are so strong that any material body is broken down into its component atoms long before it actually enters a black hole. There is a familiar scenario where a person crosses the event horizin, and his/her body gets strung out like unraveling yarn from a sweater, the feet being accelerated faster than the body, the body faster than the head. What exists inside a black hole is apparently unknown. By comparison, tiny neutron stars, perhaps a mile or two in diameter, but which contain a mass nearly as large as a star, the matter is so crushed that the atomic electrons are forced into the protons, creating a body composed almost entirely of neutrons. The density of such a body would be thousands of tons in a few cubic centimeters. Most of us cannot comprehend "matter" in these states. Perhaps the black hole itself is pure energy. It's certainly not matter as we understand matter. Black holes have finite size. How can we understand the mass of 10,000,000 stars being collapsed into a point (a singularity) in space? I would think that matter being accelerated into a black hole would achieve a speed which is a significant portion of the speed of light. The friction between atoms and particles being sucked into the black hole causes sufficient heat to cause the emitted radiation to be at X-ray wavelengths, but only until the matter passes beyond the event horizon. Then the matter essentially leaves our Universe, because we cannot see it, altho we know it is still there, due to the effects of its gravitation field. The matter now exits in a form that we don't understand, altho a sea of quarks has been proposed. Think of the repulsive forces that keep quarks imprisoned inside atomic particles, and they can never escape. Multiply that energy by 10 to the 1,000,000 power. That's a black hole.

Cardio07 -

You've obviously done some deep thinking & thorough reading!

One interesting point. You mention a familiar scenario:

"body gets strung out like unraveling yarn from a sweater"

This "noodling out" effect is due to tidal forces. As I understand the math, tidal forces are greater when the black hole is smaller. With a really huge black hole, like our own "Monster in the Middle", one could conceivably drift across the event horizon without any such effect! (Hey, Jorrie, are you out there? Is this correct?)

Navigating the accretion disk would still be a harrowing trip, though.

Hi AstroNut, sorry I missed this one's early phases and now it's a lot to wade through!

You're right about the bigger the black hole, the friendlier its event horizon becomes. This is because your size (or your ship's size) is small compared to the event horizon's circumference. Present knowledge (classical relativity and quantum gravity) still predicts problems for an astronaut nearing the center, singularity or not! Spacetime curvature and thus tidal forces will probably become extreme there…

As far as the accretion disk problems are concerned, I suppose one can try to navigate from 'above/below' that disk, near the polar regions of the hole, trying to avoid the jets of particles and radiation that theoretically 'spew out' there.

Regards, Jorrie

Whoa!!

I'm scheduled to give a talk on Black Holes this summer. Looks like I'll have a lot of new research to cover before then!

There are a lot of very good books on the subject, and I'm sure on line also. It's easy to get bogged down in theoretical physics and math, so my 2 cents worth would be to keep it light and try to keep the subject matter at an average level, rather than to talk at the novice or PhD level. There is so much for associated subject matter, from quantum theory to gravitational fields, theories of time, to the structure of matter, the structure of "space" in the Universe, star masses, the H-R diagram and stellar life cycles, and so on. I can give you a few names for books if you need them, but I don't claim to have but a small fraction of the available literature. Astronomy and Cosmology has long been one of my long hobby ventures. I taught advanced chem courses at U Mass for 30 years, but my professional work is in medical polymers and devices. Just a brief table of masses, as a projected slide, from some massive thing we all know of, to the mass of the Earth, the Sun, massive stars and then massive black holes is eye opening. I have been on the outside of our space program for many years, having graduated from the Redstone Arsenal missile and rocket school many years ago (Dr. Wherner von Braun) and work at White Sands PG. Best wishes for your talk! It's a great sublect!!

Has anyone ever seen a "black hole" from the other side. How do we know that it isn't a 2 dimensional hole into another universe?

Has anyone ever seen a "black hole" from the other side. How do we know that it isn't a 2 dimensional hole into another universe?

First of all according to the physics that we have at the moment we never will be able to see a black hole from the other side of the event horizon. The matter that gets sucked in cant be going anywhere because the gravity that this matter creates that drives the black hole. It the matter went somewhere else the black hole would not have any increase in gravitational strength with the addition of the matter. The other thing is that it is the gravity that makes a black hole a black hole so if the matter that causes the gravity ends up in another universe then the black hole wouldn't be a black hole any more.

Heres what I think. Nothing travels faster then light, not even gravity. Once the escape velocity of a black hole equals the speed of light, the event horizon cuts it's own gravity off from the rest of the universe. What happens inside? Well, the conditions of our early universe seem to resemble the conditions I would expect to find in a newly formed black hole so, perhaps, at the moment a star becomes a black hole, a new "big bang" is created inside of it. Every black hole in our visible universe may contain it's own 'microverse' just as our visible universe itself may be a microverse contained within a black hole in a greater universe. Prahaps then, the "big rip" of our microverse merely discribes the natural disipation of the black hole we're all living in.

I believe you are thinking of "gravity" as a flow of discrete particles or photon-like particles, re gravity not being able to pass back thru an event horizon. If that were so, how are black holes ingesting new matter and stars due to the gravitational force of the black hole?Try to think of a gravitational effect as the warping of space-time. There most likely isn't any discrete particles or radiation associated with gravitational forces. Think of the propagation of gravitational flux as a wave-like disturbance in space-time. There are a number of research teams now trying to detect gravitational waves, or the disturbance of space-time. The most likely candidate for rather intense gravitational waves would be the collision of two black holes, and the resulting gravitational waves formed in space-time. One avenue of reading might be Earth's moon slowing moving away from Earth, and the resultant loss of energy for the Earth, causing a minute slow-down in the rotation of the Earth. There are a lot of theories re are the galaxies moving generally apart from each other, are they moving apart faster now than a billion years before? If so, is the force (effects) of gravity changing? Is there a repulsive force (dark natter or dark energy) countering gravity? Lots of good, thought provoking reading out there!

QM models gravity as a field generated by mass. That was the view I was coming from. If the gravity of a star is generated by it's mass, then it's event horizon should block it's gravity once it equals c. GR models gravity as a curvature of four dimensional space-time. A four-dimensional curve can be translated into a three dimensional flow. Not a flow of particles but a flow of the inertial frames in which particles exist. In this case, the mechanism of gravitation is different but the effect of an event horizon becoming eqaul to c would be the same. The event horizon would act as a light cone seperating the interior of a black hole from everything around it. As long as a star continues to suck up the matter around it, then it's event horizon isn't equal to c and it hasn't become a true black hole.

in reading all the threads related to gravity, i have a proposal / question: would not the total gravitational forces of the universe be constant if the amount of matter is also constant? and that these gravitational threads just move as matter clumps or in the case of black holes, intensifies due to the gravitational thread count as the mass grows? and that gravity has no speed, but only constant force curving along with space time?..Jorrie, some help on this one..

Hi dberts, you wrote: "would not the total gravitational forces of the universe be constant if the amount of matter is also constant?"

It's not clear what you mean by "total gravitational forces of the universe", because the force vectors summed over a volume has no physical meaning, AFAIK.

Please also explain what you men by "gravitational threads". I'm not familiar with the term. I can attempt an answer only if I understand what you mean.

What I can say is that we do not know what the mass of the universe is and will probably never know - we only know the mass density in the regions that we can observe.

Regards, Jorrie

hi jorrie...my apologies. but to follow up. my use of the term thread was just a way saying the attraction lines or force between two bodies..and as the mass grows, the gravitational forces grow with them. i was trying to ask about a relationship, that seems to me, constant in the universe. if we could assume for a moment, that the total mass is some known finite number, would not the gravitational forces also be a constant? agree if summing the vectors would equal zero, but maybe that is not the way to measure this. as we can measure the attractive forces between two mass objects, couldn't we go on from there to measure it all if assigning a value to the total mass of the universe?

sorry for confusion, but while this subject is certainly not my field of expertise, it is something i like to think about due to the complexity.

Hi dberts, you asked: "if we could assume for a moment, that the total mass [of the universe] is some known finite number, would not the gravitational forces also be a constant? "

The only way I can see this to make any sense is if the universe was finite and you would be able to get 'outside of the universe' and measure its gravitational pull on you, yes, then it would be constant.

But still, this does not make sense - we cannot go 'outside of the universe'! If we think about a finite, yet unbounded universe, normally pictured like the surface of a sphere, then there is no nett gravitational pull on any specific point. Just like there is an equal amount of Earth's surface to your west than to your east, it all cancels out.

I hope this helps, because this goes into quite intricate cosmology - you may want to visit my website Relativity 4 Engineers and read the cosmology part of it.

Regards, Jorrie

Those are good points and valid questions. I would also add to the discussion: What about the gravity waves produced when two (or more) black holes collide or merge in space-time? Are these "gravity waves" created with the loss of mass? What happens to the "total" gravity quantity in the closed Universe when a nearly infinate number of stellar bodies throw off gigantic amounts of energy during their life time, and especially during a Nova, SuperNova or HyperNova events? Would not the conversion of significant amounts of matter (re gravity) be lost in the "closed system" from this transformation of matter into energy? Jorrie, this is getting into deeper theory and we are on the edge of pure speculation!

Hi Cardio07, you asked: "Are these "gravity waves" created with the loss of mass?"

You must remember that mass and energy are really the same thing. Gravitational waves carry energy from a pair of black holes (or neutron stars) that 'collide', or rather spirals into each other. That energy is however not lost, it still exists in the universe afterwards.

Also remember that all forms of energy produces "gravity", even light and gravitational waves do. In fact a 'static' gravitational field also produces gravity in the sense that the gravitational field is stronger than what Newton predicted.

Bottom line: when you convert mass into energy, nothing is lost!

Regards, Jorrie

Jorrie, I think we are referring to different systems. I am thinking of "isolated" systems, wherein, for example, a star goes Nova, etc. That star has planetary bodies orbiting it. Suppose that star loses 50 % of it's mass as radiated particles (atoms, etc) and radiation. Would not that loss of mass of the former star significantly affect the orbits of the planetary bodies surrounding it, due to loss of mass at the center of the system, and therefore the loss of gravity holding the planetary bodies "in place"? To be even more confusing, how does one reconcile the "gravitational component" of light (radiation) with the use of laser beams as an applied force, and "Solar sails" that might propel a space ship thru space, using the "pushing" power of radiation? I agree that "mass" and "energy" are interchangable, but it is difficult for me to comprehend how garvity would be conserved if a very massive body were to be completely converted into energy. That energy would almost surely be totally dispersed into the Universe, whereas the former massive body has a discrete gravitation field that is localized at it's center of mass. One can "see" the gravity of a massive body, producung a gravitational field, but how does on calculate the gravitational constant, etc of dispersed energy? I guess I'm looking at matter and energy in a completely different way than you are. My understanding is obviously limited!

Hi Cardio07, sorry for the belated reply; been a bit busy lately, almost a 'retired engineer', but not quite!

You wrote: "Suppose that star loses 50 % of it's mass as radiated particles (atoms, etc) and radiation. Would not that loss of mass of the former star significantly affect the orbits of the planetary bodies surrounding it, due to loss of mass at the center of the system, and therefore the loss of gravity holding the planetary bodies "in place"? "

Sure, a nova or supernova destroys the local equilibrium completely. The mass/energy ejected does go into the larger scale 'local space', so there is no problem with conservation of mass/energy.

You also wrote: "...but how does on[e] calculate the gravitational constant, etc of dispersed energy? "

Dispersed energy and dispersed mass are essentially the same thing. And the gravitational constant (G) has nothing to do with how much mass there is! AFAIK, it is a constant for all of the universe...

"I guess I'm looking at matter and energy in a completely different way than you are. My understanding is obviously limited!"

We are all limited in understanding, but it helps to study the basics. I like to think that for the more technical (as opposed to more 'scientific') person, my website (Relativity 4 Engineers) and eBook goes a long way towards clarifying the basics.

Regards, Jorrie

Dear Jorrie

It is nice feeling to see you put a lot of efforts to explain with lots of clarity. My feelings are different as I am dreamer and not very scientific. My worries are poetic.

I get worried by looking at the existence of the universe. I find no reason for its existence. But somehow it exists and I do exist. If there were no Physics laws, I will not exist. So, why there were Physics laws at first place? Are the laws also in the form of set of laws. If you take one then all others are from a set of laws and you have no entry into another? Or are there gates, of overlapping laws that allow migration from one set of laws into another? Can I be transported into another laws and then what happens to myself which was constructed from one set of laws?

I am also worried about formation of Physics laws associated with matter. Why these laws are there at all? Are these laws governing the universe or universe governing the law? Some time I feel these laws are there and universe fits into it and then I start worrying that laws without anything has no meaning so must not exist. Does each matter also carry a law with it? Then what makes laws of one matter to interact with laws of other matter? As we see that laws are almost common for all similar looking matter or that are with similar laws, we know as same type matter. What makes laws of Physics? Are these in some way linked to the kind of matter we have in our universe and may differ from the matter otherwise different from it. Laws of multiple universes (one that is affected by the laws and one that is not affected by the laws known to us) may coexist in same universe and each may have their own laws to govern their existence. How much complexity existence beyond our universe and its laws is something I start worrying now is an outcome of the existence of our universe itself. If this does not exist then nothing else exists, if this is there than anything else also is possible and there is nothing to say that is not possible. Possibility extends in mind and that one reason we all search for unknown all the time and we also find something out there in nothing (of past knowledge). Those trying hard to build a whole structure and bridges out of imagination with small reflections here and there as proof of their being on the track is like blind-man's understanding of the world. I appreciate it as whatever is the way to look at? This is the only hope we all have.

In the center of a black hole, where mass is equal in all directions around this point, there must exist a region of zero gravity, where gravitational forces cancel each other out.Same for a star.There would be intense pressure in these places, but no gravity, per se.The mass of a black hole cannot leave this universe,because the gravity remains, unless of course,gravity as we know it is only the tip of the iceberg, sticking into our dimension from other dimensions.Perhaps this could explain the relative weakness of gravity compared to other forces: it is spread out across many dimensions, and we are only observing part of it's true nature.Latest theories embrace 11 dimensions, and Membrane collisions that produced the "Big Bang".

Guest wrote: "In the center of a black hole, where mass is equal in all directions around this point, there must exist a region of zero gravity, where gravitational forces cancel each other out.Same for a star."

I do not think one can say that for a BH. The singularity is not describable by mathematics and quantum effects must take over, where it's all in probabilities, I think - but not my forte.

Extra dimensions? Yes, the solution may well lurk somewhere in there...

Regards, Jorrie

hi jorrie....to me , it seems illogical that another dimension would exist outside of the dimensions defined in this universe. how could a dimension exist outside of infinity? or pass through or appear in it?

There's a very nice web site - I think I found it thru a CR4 entry - called Thetenthdimension.com, which walks one thru the possible 10 dimensions. Don't try to visualize them all in our 3 D space-time!! But check it out.

thanks cardio07....i will take a look.

jorrie...i must have been wearing my design engineering hat and did not consider that alternative...thanks.

Hi dberts, you asked: "to me , it seems illogical that another dimension would exist outside of the dimensions defined in this universe".

What scientists call 'dimensions' can mean a lot of things. Even our familiar 4-dimensional space-time is just a convention of sorts, because time is not the same thing as a spatial dimension. It is however a required parameter to fix the coordinates of an event in space-time (place and time).

Suppose you also want to record the nature (or type) of event. Easy, just add another parameter called 'type' and we have a 5-dimensional event. Scientists do the same sort of thing to record very fundamental parameters associated with space and time.

Regards, Jorrie

PS: Cardio07 gives yet another 'perspective' on dimensions in post #48...

I might also add, Jorrie, for discussion participants, that time is also a variable in our Universe. Time is affected by acceleration and gravity flux in various areas in the Universe. We tend to be very cavalier in our treatment of time as well as the various dimensions!

A black hole that we are likely to encounter, outside of the theoretical, is likely to have 2 event horizons, concentric and separated by spacetime.

One event horizon is created by the mass of the hole, the other is created by the spin, thus a "ring singularity" is formed.

There are 2 other types of possible black holes, but one involves an electrically charged (Reisner-Nordstrum) black hole, and if they ever formed, they would quickly neutralize themselves by attracting opposites charges to them, and the other is a static black hole, with no spin.It is not likely that we will encounter a black hole with no spin.

The static black hole would have a single point singularity, no matter the angle of your approach it, once inside the event horizon, you are doomed to encounter the singularity.

It is theoretically possible, however, if one could properly plan and execute a trip between and thru the 2 event horizons of a spinning black hole, to exit into another place,and/or time. As long as you did not approach from the "equator" of the event horizon, escape would be possible.Not easy, but possible.

There is much debate about where you will end up.You could end up in an anti-gravity universe, or a universe just like ours...or perhaps our own universe, but a different time and place .The destination would depend on the angles of entry, and exit of each ring singularity.Certain angles would result in a one-way trip, with no possible way to return.

All of these aspects of black holes are covered much more eloquently than I can even attempt here, in a book by William J Kaufman, titled "Black Holes and Warped Spacetime".(C)1979.I highly recommend it.It is no longer in print, but is available on line.

Hi HiTekRedNek, you wrote: "There is much debate about where you will end up.You could end up in an anti-gravity universe, or a universe just like ours...or perhaps our own universe, but a different time and place."

True, and there's also also much debate on whether or not that "wormhole" can remain open long enough for something to shoot through, because it is thought to be very unstable...

Another great popular book on black holes and wormholes is Kip Thorne's "Black holes and time warps".

Regards, Jorrie