What Warps Space? | Finding Answers About Intersteller Travel

[j6p]

Ok let me see if I can frame this question correctly.
I know that mass warps space but what I'm trying to find out is if anything else can warp space? I'm trying to figure out how a worm hole can form or how warp travel can be achieved. I watched the Peter Jennings show last night and as I was ROFLMAO, all of a sudden Dr. Kaku came on and I sat straight up and began to listen. When he explained worm holes and warping space I began to think about this interstellar travel thing a bit more seriously but then it hit me, matter warps space. After thinking along these lines for about 15 seconds I realized that there has to be something else that causes worm holes and the warping of space.
So that is what's behind my question: What warps space?

 

[juju]

Hi,

To form wormholes you supposedly need some form of material called "exotic matter". This is necessary to hold open the mouth of the wormhole.

There has also been some theoretical work done on the idea of magnetic wormholes.

juju

 

[Mentat]

Ok let me see if I can frame this question correctly.
I know that mass warps space but what I'm trying to find out is if anything else can warp space? I'm trying to figure out how a worm hole can form or how warp travel can be achieved. I watched the Peter Jennings show last night and as I was ROFLMAO, all of a sudden Dr. Kaku came on and I sat straight up and began to listen. When he explained worm holes and warping space I began to think about this interstellar travel thing a bit more seriously but then it hit me, matter warps space. After thinking along these lines for about 15 seconds I realized that there has to be something else that causes worm holes and the warping of space.
So that is what's behind my question: What warps space?

The warping of space is a geometric consequence of the presence of matter. The more dense that matter, the greater the "warping effect".

The "womholes" I'm familiar with are not just made from bent space, but also require a black hole on one "side" and a white hole on the other "side". A "white hole" is the opposite of a black hole, and it would take matter with "negative mass" (whatever that might mean physically) to "bulge" space out as necessary for white holes to exist.

Basically, the idea of a wormhole requires a series of assumptions that we have no good reason to make (except, perhaps, to harness a positive outcome technologically).

 

[j6p]

Thank you juju and Mentat

 

[Tensor]

I don't know what the present thinking on this is, but AFAIC matter warps space because matter IS space -- just a special way of arranging it.

But don't ask me what space itself is.
;>

 

[selfAdjoint]

Energy and momentum warp spacetime. Matter is some of that, but light is some more (light has no mass, but even so, it has momentum and energy). Gravity waves would be some more yet.

 

[sd01g]

what is space?

Unfortunetly no one knows what SPACE really is. It seems to me that all anyone can meaningfully say about space is that it is required for Real Things to move around in. NO space--NO movement. If one can produce real movement without using space, I would like to know the process.

Large masses like the sun do not really warp space, they just curve the trajectory of things that move in their gravitational field.

If space is nothing, then it certainly cannot be warped. If is something, then what is it? Saying that space can be warped make it sound like we know what we are talking about. Less is known about what space really is than what GRAVITY really is which is not very much.

I am sure that there are many who disagree with the above. I would like to know your opionions.

 

[juju]

Hi,

I don't think that space is just emptiness. it cannot be. It has properties.

I think space is a dynamic energy/momentum/spin field with certain structure and symmetries.

The presence of matter with its own energy/momentum/spin field characteristics reorganizes the structures and symmetries of the fields of space to produce the forces that we perceive as operating there. In this way the original nature of space is "warped" but only in reference to the operation of the restructured fields.

juju

 

[sd01g]

Hi,

I don't think that space is just emptiness. it cannot be. It has properties.

I think space is a dynamic energy/momentum/spin field with certain structure and symmetries.

The presence of matter with its own energy/momentum/spin field characteristics reorganizes the structures and symmetries of the fields of space to produce the forces that we perceive as operating there. In this way the original nature of space is "warped" but only in reference to the operation of the restructured fields.

juju

Thanks juju: A very interesting definition of Space. I was wondering if your Space in homogeneous with no gaps in the field? If there are gaps in the field, what would these gaps be called? Also, did your Space exist prior to the Big Bang and was it a causative agent in the BB? Finally, is your Space bounded by anything?

 

[j6p]

I envision space being a vacuum

I heard that a vacuum is loaded with something like virtual particles. If so then these little packets of potential energy would fill in the gaps.
So the way I picture the grand scheme of things is: a vacuum (that would be space) expanding at a rapid rate, probably at or better than the speed of light. As that vacuum expands, some of these virtual packets of potential energy don't get back together quick enough to annihilate and matter comes into existence. As for what is causing this vacuum to expand or better yet, what is pulling at it...I haven't a clue but if there is something out there it would be pretty hard to find. I guess one reason would be because it's expanding the vacuum at a rate as fast or faster than light and we're inside that expanding vacuum. It should take more energy than we can muster in order to get to the outer boundary of our habitat.
I've come to this way of thinking as a result of the discovery that the universe is expanding at a faster rate rather than slowing down.
I looked at things around me and realized that once a projectile is separated from the force that repels it, it begins to slow down so I figure that if there were a big bang that caused the creation of the universe then we should have began to slow down, after the bang, but we aren't. That leaves me with the notion that there is another force causing this expansion, something beyond our sensor range.

 

[juju]

Thanks juju: A very interesting definition of Space. I was wondering if your Space in homogeneous with no gaps in the field? If there are gaps in the field, what would these gaps be called? Also, did your Space exist prior to the Big Bang and was it a causative agent in the BB? Finally, is your Space bounded by anything?

I would consider that the space is a continuous field in that it has a structure and symmetry at each point.

I believe it existed prior to the BB. I think the BB was an explosive action in just a small part of space.

It seems to have been part of the initial cause of the BB in a similar way to inflation and dark energy.

I don't know about the boundedness, but there appears to be more pointers to the idea of an unbound space. However, one cannot be sure.

juju

 

[Huckleberry]

Shouldn't it also be considered that the warping of space can create energy? I imagine a one dimensional universe where nothing can happen because there are no forces. If that dimension is bent then suddenly a force is created, but a bent one-dimensional universe is no longer completely one-dimensional. It would have two-dimensional properties that would manifest as the resultant force.

If that arc was bent completely around into a circle it would still be one-dimensional. In order for the circle to be completely two-dimensional it would need surface area and would have to take almost no distance (I'm not sure that infinity exists within the universe) on the one dimensional line. Thus a two-dimensional universe would be incredibly small compared to a one-dimensional universe.

The same holds true for bending a 2D universe to a 3D and a 3D to a 4D. Each bending of these dimensions results in a different force. These forces are the four forces, Gravity, Magnetism, and the weak and strong Nuclear forces. Probably not in that order though. I imagine heat/cold is the bending of the first dimension, magnetism of the second, gravity of the third, and the other nuclear force for the last. I could go into detail about why I believe those forces rely on those dimensions, but space and time do not permit.. :)

So really although we perceive the universe in 3D I believe it is actually a small part of a much larger universe that we cannot perceive. I believe that as our mass/energy ratio changes we perceive the dimensions differently. In other words as we increase or decrease our velocity we may see things that where not there before and not see things that were. For example, the dark matter that surrounds our galaxy may, in my opinion, just be ordinary matter that happens to be moving faster than the speed of light in comparison to ourselves. It's not hard to believe if you consider that our solar system is moving at about 500million miles an hour around the galaxy. We also revolve around the sun and rotate on our axis and they all add velocity. Even Gravity is an acceleration that must be included. I wonder how quickly the borders of our visible galaxy are moving?

What was the question again?
Huck

 

[Sempiternity]

I'm wondering, has anyone read Black Holes & Time Warps by theoretical physicist, Kip Thorne?

In the glossary at the end, Kip Thorne defines "spacetime curvature" as:

The property of spacetime that causes freely falling particles that are initially moving along parallel world lines to subsequently move together or apart. Spacetime curvature and tidal gravity are different names for the same thing.

Black Holes & Time Warps defines "spacetime" as:

The four-dimensional "fabric" that results when space and time are unified.

...while "tidal gravity" is defined as:

Gravitational accelerations that squeeze objects along some directions and stretch them along others. Tidal gravity produced by the Moon and Sun is responsible for the tides of the Earth's oceans.

The Elegant Universe defines "spacetime" as:

A union of space and time originally emerging from special relativity. Can be viewed as the "fabric" out of which the universe is fashioned; it constitutes the dynamical arena within which the events of the universe take place.

When you think of space and time and their respective definitions, you can understand that these two concepts are extraneous, where neither really mean anything "real" or "tangible." They are concepts used by scientists for measurements in experiments and conceptual thought. It's more convenient to think of the "spacetime continuum" as proposed by Einstein's general relativity than to ponder for long hours over the definition of what this really might mean. With this in mind, people can move forward and derive various theorems using mathematical formulae and experiments, to gain a better idea as to how nature and "reality" really work. This is why the most common analogy of the geometric curvature of space is of a type of mass that bends and curves a type of sheet (example, a suspended rubber membrane warped by the weight of a bowling ball in its center).

Black holes are thought to be an extreme point of general relativity in which mass/energy densities warp spacetime in such a way that the escape velocity (the velocity needed to escape from the object mass) becomes greater than that of the speed of light. They are thought to be created by massive stars greater than 1.4 solar masses that have expended all possibilities of further nuclear reactions and that have a greater gravitational attraction than can be sufficiently countered through electron or neutron degeneracy. The star then collapses upon itself. An "apparent/event horizon" is created at the point where escape is no longer possible from the surface of the star. The mass of the star continues to implode to a high-density point due to excessive amounts of mass and gravity. Some physicists then think that it then creates what is known as the "singularity."

Kip Thorne describes a singularity as:

A region of spacetime where spacetime curvature becomes so strong that the general relativistic laws break down and the laws of quantum gravity take over. If one tries to describe a singularity using general relativity alone, one finds (incorrectly) that tidal gravity and spacetime curvature are infinitely strong there. Quantum gravity probably replaces these infinities by quantum foam.

In The Elegant Universe, by string theorist, Brian Greene, Greene continues the notion of a black hole by giving a postulate that two ends of a black hole could "glue" together through "topology-changing transitions." In the proposed senario, the very "end" of a black hole (i.e., the point at which spacetime is most warped in a black hole; singularity) would "tear" the fabric of spacetime. (This is an unusual thought to ponder. What I usually do is consider all of spacetime to be some sort of floating membrane of dimensions in a realm of unreality, that is, hyperspace. If anyone has ever read Flatterland by Ian Stewart, it may be more understandable. Afterall, Force is an illusion--a by-product of warped space-time ~ Michio Kaku) Ordinarily, this "tear" would suck everything into it because it is essentially a hole through spacetime in "hyperspace" that needs to be filled. Greene continues on by stating that this universal doom is bypassed by a three-brane superstring forming a barrier around the tear that protects the universe from this hazard. In some cases, the two ends of a black hole may tear the fabric of spacetime, then re-glue with each other through "topology-changing transitions" to form a new wormhole. This may be how they are created in the first place, that the end of a black hole (where a singularity is located) may puncture spacetime and re-glue. Kip Thorne calls this the "classical strategy" for creating a wormhole (referring to classical mechanics and relativity). *(For more information about this, please check out The Elegant Universe by Brian Greene, Chapters 11 and 13.)

In the book Black Holes & Time Warps, by theorist, Kip Thorne, Thorne also gives an explanation of the "classical strategy" for creating a wormhole: the "tear-and-sew" method.

In a classical strategy, our infinitely advanced civilization would try to warp and twist space on macroscopic scales (normal, human scales) so as to make a wormhole where previously none existed. It seems fairly obvious that, in order for such a strategy to succeed, one must tear two holes in space and sew them together.

In Chapter 14, Kip Thorne goes on to explain how he was introduced into the area of wormholes and the invistigation spurred by his friend, Carl Sagan. He describes his search for a "traversable wormhole," one that would be suitable for interstellar space travel (for use in Contact, by Carl Sagan), since the tunnels known before him were either highly unstable or unreasonable. He eventually came up with the solution to what he was looking for: exotic matter.

First, the only way to hold the wormhole open is to thread the wormhole with some sort of material that pushes the wormhole's walls apart, gravitationally. I shall call such material exotic because, as we shall see, it is quite different from any material that any human has ever yet met.

Second, I discovered that, just as the required exotic material must push the wormhole's walls outward, so also, whenever a beam of light passes through the material, the material will gravitationally push outward on the beam's light rays, prying them apart from each other. In other words, the exotic material will behave like a "defocusing lense"; it will gravitationally defocus the light beam. See Box 14.1.

Third, I learned from the Einstein field equation that, in order to gravitationally defocus light beams and gravitationally push the wormhole's walls apart, the exotic material threading the wormhole must have a negative average energy density, as see by a light beam traveling through it. This requires a bit of explination. Recall that gravity (spacetime curvature) is produced by mass (Box 2.6) and that mass and energy are equivalent (Box 5.2, where the equivalence is embodied in Einstein's fameous equation E = Mc^2). This means that gravity can be thought of as produced by energy. Now, take the energy density of the material inside the wormhole (its energy per cubic centimeter), as measured by a light beam--that is, as measured by someone who travels through the wormhole at (nearly) the speed of light--and average that density along the light beam's trajectory. The resulting averaged energy density must be negative in order for the material to be able to defocus the light beam and hold the wormhole open--that is, in order for the wormhole's material to be "exotic."

...Then, in 1974, came a great surprise: Hawking inferred as a by-product of his discovery of black-hole evaporation (Chapter 12) that vacuum fluctuations near a hole's horizon are exotic: They have negative average energy density as seen by outgoing light beams near the hole's horizon.

...We also know that, if an infinitely advanced civilization somehow acquires a wormhole, then the only way to hold the wormhole open (so it can be used for interstellar travel) is by threading it with exotic material. We know that cacuum fluctuations of the electromagnetic field are a promising form of exotic material: They can be exotic (have a negative average energy density as measured by a light beam) in curved spacetime undera wide variety of circumstances. However, we do not yet know whether they can be exotic inside a wormhole and thereby hold the wormhole open.

I hope this helps you in some way to understanding what "spacetime" really is and how wormholes are created. There are other theories of the matter (such as the one given by Mentat concerning a hypothetical "white hole"), so this issue may not be resolved any time soon, making most of this simply pieces of a hypothesis and philosophy (much like string theory itself, for now).

---------------------
References

Thorne, Kip. Black Holes & Time Warps: Einstein's Outrageous Legacy. New York: W. W. Norton & Company, Ltd., 1994.

Greene, Brian. The Elegant Universe. New York: W. W. Norton & Company, Ltd., 1999.

 

[sd01g]

spacetime?

In Brian Greene's book 'The Fabric of the Cosmos', he states on page 485:

'Throughout this book we have periodically alluded to the ultramicroscopic constituents of spacetime, but although we've given indirect argument for their existence we've yet to say anything about what these constituents might be. And for good reason. We really have no idea what they are.'

Could it be that when we combine a concept like SPACE-which we are not sure what it is, with a concept like TIME-which we are not sure what it is, we should produce a concept that we really do not know what it is?

When we start with these concepts-which we are not really sure what they are-and combine them with some really elegant math which must be true because it is so elegant, it is no wonder we end up with things like M-theory-which we really do not understand, parallel universes-which we really do not understand and INFLATION-which we do not really understand-to explain the Big Bang Theory-which we think we almost understand.

 

[Integral]

Could someone please explain to me what the relationship between this thread and the book Visions is?

Please PM me the connection, If you convince me I will unlock it.

 

[selfAdjoint]

Visions is about dreams of the technological future. Whether he included wormhole engineere=ing in that book or not, it belongs in the technological dream-future, no? Recent work by Visser et al. shows you can't really finesse the negative enrgy requirement, which about kills the idea for me, but others have different standards. I enjoy the thread.

 

[Integral]

I guess my point here is that this discussion of the physics behind the structures would be more appropriate in the cosmology forum. I would like to see more discussion on the implications and possible uses of the structures as this is the general theme of Visions.

 

[juju]

I think one of the implications of space as I see it, is that we ought to be able to engineer an EM wormhole using scaler/vector/spin potentials rather than a gravitational wormhole using exotic matter. Some gravitational modulation might be necessary but exotic matter would not.

juju

 

[selfAdjoint]

I think one of the implications of space as I see it, is that we ought to be able to engineer an EM wormhole using scaler/vector/spin potentials rather than a gravitational wormhole using exotic matter. Some gravitational modulation might be necessary but exotic matter would not.

juju

It has been proved within general relativity that a wormhole must violate the weak energy condition. It can only exist and do this with the assistance of negative energy, and Matt Visser and a colleague recently showed that you can't just HAVE negative enrgy, it is constantly decaying from contact with ordinary matter so you have to be constantly renewing it.

As you, or any of us views space doesn't cut any mustard unless we can come up with a coherent theory that in addition to doing what we like, does everything that general relativity has been successful at.

 

[hey.like]

Why it is the time

Why it is not the time, the reasonable is that is not to measure ease.
The time with space no zero dimension area!

 

[hey.like]

Near the mass ,the space and time deviate

Near some worm hole, the time is permission to deviation or fluctuate as it is very near the field resource.
When the time deviate the outside system, the wormhole is convex with negative time, but its action will be concave.