Frequently Asked Questions

- Answering Criticisms
- Technical Questions
- Wormholes
- Explaining the Setting
- FTL in OA
- Generic Questions
- Why are certain things excluded?

Wormholes are a cornerstone of the OAUP scenario, in that an interconnected set of interstellar civilizations like that we've depicted would be impossible without them. It is also one of the scenario's more controversial features. The following is a list of commonly asked questions.

Before proceeding onto the FAQs themselves we recommend you first read Wormholes - A Layman's Guide. If you require a more in-depth look at the information provided by the Layman's Guide, please refer to these parent articles: Wormhole Engineering in Orion's Arm: An Overview and Traversable Lorentzian Wormholes: An Overview.

References:

Before proceeding onto the FAQs themselves we recommend you first read Wormholes - A Layman's Guide. If you require a more in-depth look at the information provided by the Layman's Guide, please refer to these parent articles: Wormhole Engineering in Orion's Arm: An Overview and Traversable Lorentzian Wormholes: An Overview.

References:

- Foam-like structure of the Universe - A. Kirillov and D. Turaev
- How to make a traversable wormhole from a Schwarzschild black hole - S. Hayward and H. Koyama
- Fate of the first traversable wormhole: black-hole collapse or inflationary expansion - H. Shinkai and S. Hayward
- Density Fluctuations in the Oscillatory Phase of Nonclassical Inflaton in FRW Universe - K.K.Venkataratnam1 and P.K. Suresh

Exotic matter, being made of bosonic fields, has no problem happily coexisting with you or any other material object occupying an overlapping volume in spacetime. In practical wormholes, the negative stress-energy tensor fields are confined to a region of the wormhole called the Caustic, which is a very thin (micrometers or thinner) region of spacetime.

Wormholes are distinguished by their topological character. An astrophysical black hole has one "mouth" (also known as the event horizon). A theoretical black hole has two "mouths", the black hole end and the white hole end, as does a wormhole.

One cannot perform topology change. A wormhole with two mouths cannot be converted into one with 1, 3, or more mouths.

In addition to their topology, objects in general relativity are described by their metric which is, roughly, the shape of spacetime including all matter and curvature as described by gravitation fields.

The metric of the mouth of a given wormhole requires a minimum distance from other objects with an equivalent magnitude metric (e.g. star, planet, etc.) This is called "asymptotic flatness". If the asymptotic flatness condition is violated, the wormhole metric stops behaving like a wormhole, and the wormhole collapses. This collapse has been shown to involve either:

One cannot perform topology change. A wormhole with two mouths cannot be converted into one with 1, 3, or more mouths.

In addition to their topology, objects in general relativity are described by their metric which is, roughly, the shape of spacetime including all matter and curvature as described by gravitation fields.

The metric of the mouth of a given wormhole requires a minimum distance from other objects with an equivalent magnitude metric (e.g. star, planet, etc.) This is called "asymptotic flatness". If the asymptotic flatness condition is violated, the wormhole metric stops behaving like a wormhole, and the wormhole collapses. This collapse has been shown to involve either:

- Conversion of 70% of the wormhole "mass" into energy, with the remaining 30% becoming a black hole (BOOM!)
- Exponential expansion of the wormhole into a baby universe at "right angles" with our current universe

First, some disambiguation.

Exotic matter was the term used in Morris and Thorne's 1988 paper on wormholes to describe mass/energy with a negative stress-energy tensor. Later refinements codified this as mass/energy that violates the Averaged Null-Energy Condition (ANEC), which is described in detail on page 6 of reference [1].

Exotic matter can also refer to such strange states of matter as charmonium, pentaquarks, magmatter, Q-balls, and their ilk.

With respect to wormholes, exotic matter means mass/energy that violates ANEC. The term "negative stress-energy tensor fields" is more technically accurate and precise, and less likely to be confused with the other forms of exotic matter. It also seems to be a term only a physicist would use. ;-)

Exotic matter was the term used in Morris and Thorne's 1988 paper on wormholes to describe mass/energy with a negative stress-energy tensor. Later refinements codified this as mass/energy that violates the Averaged Null-Energy Condition (ANEC), which is described in detail on page 6 of reference [1].

Exotic matter can also refer to such strange states of matter as charmonium, pentaquarks, magmatter, Q-balls, and their ilk.

With respect to wormholes, exotic matter means mass/energy that violates ANEC. The term "negative stress-energy tensor fields" is more technically accurate and precise, and less likely to be confused with the other forms of exotic matter. It also seems to be a term only a physicist would use. ;-)

There are actually at least three forms of negative-stress energy tensor fields:

- Quantum Fluctuations: Quantum fluctuations occur in classical quantum field theory in scalar fields describing photons and neutrinos. Such fields are governed by the Quantum Inequalities first formulated by Ford and Roman, and can be classically observed in the Casimir effect (although practical wormhole construction is impossible using Casimir fields). Such fields form the extraction kernel of a Weylforge.
- Inflation: The inflationary scalar field which caused expansion of the current Universe. One of the unanswered mysteries remains the status of the "Landscape", the enormous phase space of M-theory compactification parameters. A local minimum of the Landscape is responsible for our current Universe.
- Phantom Energy: The accelerated expansion of the Universe may be attributed to the approximately 70% of mass-energy known as dark energy, or quintessence in some Cosmological models. Candidates for dark energy include ghost scalar fields [2] and axions [3], and phantom energy traversable wormholes have been shown to exist [4] that are capable of accreting dark energy and expanding sufficiently fast to overtake the accelerated expansion of the Universe.

If you mean how far apart can the mouths be moved and the wormhole still work, the distance is infinite. So you could, in principle, have a wormhole connecting opposite ends of the universe. You just have to carry one end there by linelayer, with a maximum speed of 74% the speed of light. If you mean, how far apart can the wormhole mouths appear when popping up in the quantum foam and potentially being expanded, then you are limited to the area within the Weylforge - a few thousandths of a meter.

See connecting wormholes.

Linelayers aren't capable of self-replication at the destination system because wormholes can only be created in a weylforge, which are large, immobile structures and remain at the originating system. One half of each new wormhole pair would have pass through the gate carried by the first ship and given to each daughter vessel, but this would cause the destruction of the wormholes.

No. If it were possible to create planar wormholes, one could construct a polyhedral wormhole structure with many gates (though technically each pair of surfaces is a single wormhole, the structure then incorporates multiple wormholes). Non-spherical wormholes also have the advantage of relatively benign asymptotic flatness requirements, such that placing them within close proximity shouldn't cause stability problems. Unfortunately, non-spherical wormholes have nearly intractable engineering requirements. There is no way to minimize the amounts of negative stress energy required, and the amounts of "exotic matter" scale quadratically with linear gateway size. For example, a simple one-meter facet requires 10E-3 solar masses of negative energy density. Also, the corners are completely unstable, and cannot be constructed using the known array of topological artifacts (monopoles, strings, and branes). The best solution uses "negative energy cosmic strings", but these require a stiffness property not possessed by the usual (physical) Nambu-Goto/Polyakov strings.

Naturally occurring wormholes typically appear and vanish with their mouths separated by distances comparable to the Planck scale. However, during the cosmological inflation epoch, some wormhole mouths could become separated by very large distances. As the temperature of the Universe dropped, some of these relic wormholes could have had their topological properties frozen into the large scale structure of spacetime (much like bubbles of air in ice).

Planck-scale wormholes appear and disappear due to the frothy nature of spacetime itself, not due to the Heisenberg Uncertainty Principle (as is the case with virtual particles). Thus, widely separately relic Planck-scale wormholes would be stable (due to conservation of topology), and could be present in the universe today. As previously mentioned, some current (2007) theories posit this as an element of dark matter.

Planck-scale wormholes appear and disappear due to the frothy nature of spacetime itself, not due to the Heisenberg Uncertainty Principle (as is the case with virtual particles). Thus, widely separately relic Planck-scale wormholes would be stable (due to conservation of topology), and could be present in the universe today. As previously mentioned, some current (2007) theories posit this as an element of dark matter.

Due to Lorentz contraction, the motion of a wormhole cannot exceed 0.74c without the wormhole failing.

The Morris-Thorne-Kuhfittig wormholes used in Orion's Arm are spherically symmetric. Assuming you could find a means to rotate the wormhole, inducing relativistic rotations is equivalent to introducing a perturbation in the wormhole metric. A time-dependent perturbation of as little as 1% of the wormhole "mass" can cause wormhole collapse, with the effects as described above.

Visser collapse only becomes an issue when you either move WH mouths around at relativistic speeds such that you get time dilation between mouths, or if you set up a network of WH such that you can create a time machine.

Moving WH mouths around a solar system at non-relativistic speeds to set up a network should not cause a problem. There might be a tiny amount of time dilation between gates, but it would be so small that the gates would have to be very close to each other to induce Visser collapse.

Moving WH mouths around a solar system at non-relativistic speeds to set up a network should not cause a problem. There might be a tiny amount of time dilation between gates, but it would be so small that the gates would have to be very close to each other to induce Visser collapse.

Wormholes are usually prevented from moving at relativistic velocities by linear instabilities due to length contraction. Empire time doesn't exist, for more details see the Time and History in Orion's Arm FAQ.

Using wormholes for power distribution: Go to your nearest O- and B-type stars. Enclose them in Dyson spheres lined with energy collectors. Bring along a wormhole mouth. Send the energy back through the Nexus. Now you're a Type 2.5 Civilization!

Even easier: use a grazer (a wormhole with an asymmetric "mass" distribution between mouths) to deconstruct the stars into a handy plasma stream which you then pass through a monopole field, magmatter screen, or Q-ball field to totally convert the star masses directly into energy.

Even easier: use a grazer (a wormhole with an asymmetric "mass" distribution between mouths) to deconstruct the stars into a handy plasma stream which you then pass through a monopole field, magmatter screen, or Q-ball field to totally convert the star masses directly into energy.

There are a variety of sources used to create wormholes.

- At the Planck scale, spacetime undergoes quantum fluctuations, as pointed out by Wheeler, who coined the term "spacetime foam" (Wheeler also invented the term "black hole" and "wormhole"). The fluctuations of the spacetime foam create non-simply connected manifolds, also known as wormholes. In fact, current (late 2007) thinking [1] postulates relic leftover wormhole networks "frozen" after the Universe inflated and cooled as a possible Dark Matter candidate.
- A type of black hole (see below) can be converted into a wormhole using phantom radiation. Orion's Arm calls these Hayward-Koyama wormholes. [2]
- Versions of M/string/Randall-Sundrum theory contain wormhole solutions.

See the Exotic Matter FAQ.

The Morris-Thorne-Kuhfittig wormholes described in the "Wormhole Engineering in Orion's Arm: An Overview" use exotic matter from scalar quantum field fluctuations, i.e. negligible amounts that are already available. This is fortunate, because large amounts of exotic matter are difficult to obtain.

Hayward wormholes require enormous amounts of exotic matter in the form of phantom radiation, and for that reason are much more difficult to construct (as well as being less "mass efficient").

Hayward wormholes require enormous amounts of exotic matter in the form of phantom radiation, and for that reason are much more difficult to construct (as well as being less "mass efficient").

Yes, although as the creator's toposophic level rises so does the efficiency of wormhole construction. For example a third singularity intelligence could create a 100km radius wormhole using 1.369e35 kg of matter (almost 70,000 stars like the sun), while a sixth singularity intellect would only require 1.369e26 kg (roughly 23 earths). In addition to the efficient use of mass, the third singularity intellect can only expand a wormhole at about 1/120th the speed of a sixth singularity intellect.

With respect to wormholes, we are like DaVinci -- we have the knowledge to design and construct wormholes. We just lack the tools and materials at present.

In this case, as soon as we're able to manipulate black holes and stellar-sized masses, as well as generate inflaton fields [4] (which requires 10^13-19 GeV particle accelerators), we'll be able to construct wormholes.

It's the whole tooling thing that puts wormholes up at S3.

With respect to wormholes, we are like DaVinci -- we have the knowledge to design and construct wormholes. We just lack the tools and materials at present.

In this case, as soon as we're able to manipulate black holes and stellar-sized masses, as well as generate inflaton fields [4] (which requires 10^13-19 GeV particle accelerators), we'll be able to construct wormholes.

It's the whole tooling thing that puts wormholes up at S3.

Yes, the same properties as any other object such as mass, spin, and charge. Typically, mass is better described by the metric, as wormhole mass is more difficult to quantify in the same way as stellar mass, there being several operating definitions such as Bondi mass or ADM mass. (I have typically put quotations around the term mass to allude to these issues). Spin is normally zero, because wormholes aren't created from astrophysical processes (and so don't acquire angular momentum); charge is an undesirable property.

A wormhole is essentially a black hole with a skin or caustic of "exotic matter" where the event horizon of a black hole would be.

A wormhole is essentially a black hole with a skin or caustic of "exotic matter" where the event horizon of a black hole would be.

Wormholes are dynamically unstable; a fluctuation equivalent to as little as 1% of the wormhole "mass" can cause collapse. Thus, the larger the wormhole, the more stable it is. However, wormhole failure modes are non-linear and chaotic, and given the extremely large energy releases and other bad effects, all wormholes are stabilized as a matter of course.

See the Layman's Guide to Wormholes.

Yes and no. Any mass large enough to impart a spin on the wormhole would defy the asymptotic flat space requirements and cause the wormhole to fail spectacularly.