Physics and time travel

[Hazard]

This thread is a fork from this thread:
http://achrongame.com/forums/viewtopic.php?f=23&t=1191&start=10#p10617

Discontinuous jumps faster than light are allowed by special relativity. Even particles traveling at FTL speeds (tachyons) are allowed. It's just crossing the lightspeed barrier by acceleration that's not allowed.

Not exactly, at least according to what I'm familiar with. If you have any form of information traveling FTL, then you've violated causality, as you've gone beyond the light cone. Even with wormholes, you have continuous spacetime that doesn't allow communication beyond the light cone; it's just that the light cone may now have an odd shape and overlap in unusual ways.

Tachyons are currently only hypothesized, and even if they exist, couldn't be used to carry information.

Secondly, the laws of thermodynamics aren't laws. They're just stochastic rules of thumb. Indeed, the fluctuation theorem gives us a few cases where global entropy decreases instead of increases.

[ulr=http://www.achrongame.com/forums/viewtopic.php?f=25&t=1243#p10761]Resource analysis[/url]

I realize that. But, time travel gives you a way to "sort" matter by entropy, so you can get situations where it's not a local temporary deviation, nor even a martingale process. Say you perform some localized exchange-based sort algorithm (e.g., bublesort) of matter using your chronoporter across time. Now you've ordered the state of some closed area of the universe from high entropy to low entropy. In doing so, you could extract energy out of it to fuel the sorting (depending on chronoportation costs), and it becomes a strong positive feedback loop.

If you were to run this universe infinitely many times with different random seeds, you'd still end up with the same result. That's why it'd be a violation.

Also, 'smooth translation' doesn't work: not unless you yank the entire universe back along the same axis.

Doesn't it work if you assume special relativity isn't perfectly accurate? Could you have a time dilation discontinuity shaped like the function 1/x, where beyond some boundary (where x = 0), time runs in reverse for that space? (much like you can have time dilations within a gravity field, though I remember reading something recently that this may not be as consistent as previously thought)

modedit Shalkka:
Here are pointers to sections on some of the central points of the topic

Pretopic
What real life physics rules hold/are violated in the Achron universe?

Chapter 1
*Conservation of angular momentum
*Conservation of causality
*Conservation of consistency

Resource Analysis

Chapter 2
*Computability class of universe
*Achron is being developed so long that it can attune itself to these kind of distinctions

Chapter 3
*Layperson tries to/understands conservation of angular momentum

derail into reading habits

mini chapter 4
*Einstein-Cartan theory
*Brane cosmology

Chapter 5
*Relation of chronoportation and teleportation in "realistic" theories
*nice diagram
*Does math obfuscate, how do the technicalities relate to the discussion? (debated)
*Space time contains operations such as rotation and relativity of frames, time gets a special treatment and thus is categorically separate (debated)
*Chapter 6 stuff

Chapter 6
*Location of big bang
*No going past from big bang like no going north from north pole

Chapter 7
*Reality of time
*time is illusion/made up concept to structure reality
*time is real, directionality is made up
*time is
*semantic short-hands
*Time as a property of space-time, emergence

Chapter 8
*Thinking without time
*What it takes to prove "no time" or "time"
*Management of belief systems, accepting views you do not understand

Chapter 9
*Discussion management
*Management of beliefs systems, using newbies to avoid indoctrination

[Kron]

Akh, I'd just like to state that I screwed up some of physics in the last thread. If there's a break in translational symmetry, it violates the law of conservation of linear momentum.

Teleportation and chronoportation still only violate conservation of angular momentum.

And now for you regularly scheduled physics dose:

This thread is a fork from this thread:
http://achrongame.com/forums/viewtopic.php?f=23&t=1191&start=10#p10617

Huzzah! More physics!

Not exactly, at least according to what I'm familiar with. If you have any form of information traveling FTL, then you've violated causality, as you've gone beyond the light cone. Even with wormholes, you have continuous spacetime that doesn't allow communication beyond the light cone; it's just that the light cone may now have an odd shape and overlap in unusual ways.

Why yes, it does violate causality.

... But what's interesting is that causality never pops up anywhere within the laws of physics. It's just a common sense notion we've been carrying with us. Certain kinds of quantum mechanical experiments make the entire concept look pretty leery altogether.

Frankly, I think causality will go the way of 'absolute simultaneity'. That is, out the window.

Tachyons are currently only hypothesized, and even if they exist, couldn't be used to carry information.

Yeah, I gotta agree with you on this one. Tachyons don't let you send information.

I realize that. But, time travel gives you a way to "sort" matter by entropy, so you can get situations where it's not a local temporary deviation, nor even a martingale process. Say you perform some localized exchange-based sort algorithm (e.g., bublesort) of matter using your chronoporter across time. Now you've ordered the state of some closed area of the universe from high entropy to low entropy. In doing so, you could extract energy out of it to fuel the sorting (depending on chronoportation costs), and it becomes a strong positive feedback loop.

Well, you're just describing a Szilard Engine.

I also completely agree with you: which is why I think chronoporters will require energy to run. There's probably a micro-fusion reactor in its base or something.

Doesn't it work if you assume special relativity isn't perfectly accurate? Could you have a time dilation discontinuity shaped like the function 1/x, where beyond some boundary, time runs in reverse for that space? (much like you can have time dilations within a gravity field, though I remember reading something recently that this may not be as consistent as previously thought)

Unfortunately not: Noether's Theorem is completely unrelated to relativity. It's a lot more fundamental than relativity or QM too... I'm not sure you can really try and screw with this one like you can screw with thermodynamics.

Here's an excerpt from the conserved current wikipedia page:

Examples of canonical conjugate quantities are:

• Time and energy - the continuous translational symmetry of time implies the conservation of energy.
• Space and momentum - the continuous translational symmetry of space implies the conservation of momentum
• Space and angular momentum - the continuous rotational symmetry of space implies the conservation of angular momentum
• Wave function phase and electric charge - the continuous phase angle symmetry of the wave function implies the conservation of electric charge

You don't really want to start really screwing with temporal symmetry. Energy conservation is probably the most important one on the list.

[Kron]

The 'orbital teleport insertion' from the Demo Campaign intrigued me. So here's...

A Tactical Analysis on the use of Obital Teleportation in Troop Deployment
... or: How I learnt to stop worrying and love Wolfram Alpha

There are two parameters to take into consideration when considering teleportation across gravity wells:

• Conservation of linear momentum
• Conservation of energy

Conservation of angular momentum is a lost case.

The second one is relatively easy to deal with, to be honest: energy is a scalar quantity that's extremely liquid. No-one blinks at the concept of piping energy around in electric cables, building energy-generating devices like nuclear reactors, storing energy in capacitors and batteries... we've got this one covered (in principle).

Linear momentum is a tricksy one though. It's a vector; making it very hard to store. It also doesn't tend to pop up in tactical teleportation planetside, since it's easy to simply transfer momentum along with the object being teleported.

This is not the case in long-range teleportation though. For example, if you teleported to the opposite side of the world, you would have a subjective velocity of twice the Earth's equatorial velocity in relation to the ground! You'd pop up at ground height moving at 930 m/s due west, and promptly become an explosive smear across the ground (releasing a level of energy equivalent to approximately half your mass in TNT).


When considering orbital insertion, it cannot be stressed how important it is to not turn your soldiers into living bombs. Extraction will probably be even worse: destroying your ship from the inside-out too. We shall therefore focus on simple ways to minimize subjective velocity between your troops and the ground.

It's really hard to have spaceships dodging and weaving and accelerating and decelerating constantly. Thinking of them as gigantic fighter jets will give you the mistaken impression that they can easily accelerate to a suitable speed for troop deployment and then return to a parking orbit somewhere safe above the planet.
If you want to try something like this, then the Tsiolkovsky equation would like to have a word with you. Conserving delta-V is crucial, and it flying around like you're a jet pilot is going to get your ship stranded in free fall very quickly.

Gentlemen, I introduce to you the newly christened Telesynchronous Orbit:
Orbital distance = (Mass of planet * Gravitational Constant) / (Planetary ground speed)^2
Basically, I just plugged the planetary ground speed into the orbital speed / distance equation. Simple! Ingenious even!

... Except that if you try plugging in the Earth's equatorial speed, you get 1.145 million miles. That's 6.15 lightseconds. That's so far away you're only debatably in orbit!
The problem is this: planets rotate really frackin' slowly. Orbital speeds tend to be really really fast. Getting them to coincide is a lesson in frustration.

Solution: I actually haven't worked it out yet! To be continued...

[Kron]

Part 2

I tried working out more complex orbital patterns that would allow a spacecraft to make a low-velocity flyby of the planet. None of them worked; it pretty simply comes down to the law of conservation of energy. (Kinetic Energy of starcraft) > (Gravitational Potential Energy of starcraft) if you want to be able to escape a gravity well. If you can't, you'll just collide into the planet.

...

And then I hit upon something new. Something which was unbelievably obvious in retrospect; we can keep ships running in decaying orbits.

It comes down to the ease of teleportation, really. If you have a spacecraft sitting completely stationary above a planet, it will accelerate into the planet and crash.
But what if it teleports to the other side of the planet right before it hits atmosphere? Well, it'll carry its linear momentum with it and decelerate back to its starting altitude... at which point it will accelerate back into the planet again.

There is an art, it says, or rather, a knack to flying. The knack lies in learning how to throw yourself at the ground and miss.

Rinse, repeat: We have a new class of teleport-stabilized orbits based on missing the ground.

We can easily park a spacecraft in one of these. It will then be capable of inserting and extracting forces from/to two diametrically opposing points on the planet when it reaches either of its apsides.

[Shalkka]

Is conservation of angular momentum a "strong" law? I for example found this mention on wikipedia:

In modern (late 20th century) theoretical physics, angular momentum is described using a different formalism. Under this formalism, angular momentum is the 2-form Noether charge associated with rotational invariance (As a result, angular momentum is not conserved for general curved spacetimes, unless it happens to be asymptotically rotationally invariant).

Coulnd't it be then that chronoporting might be properly legal? And if it must be conserved wouldn't counteracting the imbalance as cost to chronoport make it allright? For example gravitomagnetic effects make an orbiter rotate if the thing orbited rotates and if you wanted to keep your vessel perfectly unrotated you would have to slightly spin your craft.

[Hazard]

... But what's interesting is that causality never pops up anywhere within the laws of physics. It's just a common sense notion we've been carrying with us. Certain kinds of quantum mechanical experiments make the entire concept look pretty leery altogether.

Frankly, I think causality will go the way of 'absolute simultaneity'. That is, out the window.

Interesting - throwing out causality altogether is something relatively new to me. On the one hand, you have Hawking's infamous "chronology protection conjecture" that does imply causality (granted, it's only a conjecture). On the other hand, how much causality do you throw out? Do you consider two attracting charges undergoing acceleration from their force causality that can be broken? Or do you think causality is only a weak statistical law like the 2nd law of thermodynamics as we were discussing before?

On a side related note, I've never been comfortable with the Copenhagen interpretation of quantum mechanics, and more objective ontologies, such as Penrose's interpretation, have always sat better with me.

Well, you're just describing a Szilard Engine.

The key difference is that in my case, Maxwell's demon isn't filtering particles through a gate, it's actually sending them back (or forward) in time.

...Noether's Theorem ... You don't really want to start really screwing with temporal symmetry. Energy conservation is probably the most important one on the list.

But by chronoporting things, you've already thrown conservation of energy (in a closed system) out the window, unless you consider the closed system to mean the entire timeline. Even then, you might be able to come up with a way where you can create more potential energy if you chronoport something to just the right spot at the right point in time.

It's really hard to have spaceships dodging and weaving and accelerating and decelerating constantly. Thinking of them as gigantic fighter jets will give you the mistaken impression....

Don't worry - we don't make the common mistake of thinking of space ships as fighter jets .

Gentlemen, I introduce to you the newly christened Telesynchronous Orbit:... Except that if you try plugging in the Earth's equatorial speed, you get 1.145 million miles. That's 6.15 lightseconds. That's so far away you're only debatably in orbit!

But what if it teleports to the other side of the planet right before it hits atmosphere?

Awesome! The 145 million miles part is a bit far. However, we're violating angular momentum already, so what does it matter (j/k). More seriously, if you're already placing something in a brand new inertial frame, potentially outside of the light cone, why does it need to maintain its relative momentum (between the inertial frames) when changing inertial frames?

Is conservation of angular momentum a "strong" law?

Well, as long as the universe is invariant under rotation, then I believe it is a strong law under Noether's theorem. So unless some quantum-level derivative of the Michelson–Morley experiment shows otherwise, then it's a strong law. If positions in space are quantized, does that mean that directions are as well? If so, then perhaps it is only strong in approximation when assuming the huge number of discrete states are continuous. Kron, your thoughts here?

[Kron]

Coulnd't it be then that chronoporting might be properly legal? And if it must be conserved wouldn't counteracting the imbalance as cost to chronoport make it allright? For example gravitomagnetic effects make an orbiter rotate if the thing orbited rotates and if you wanted to keep your vessel perfectly unrotated you would have to slightly spin your craft.

Not that easy. I've worked this stuff out before, and here's my basic finding: conserve center of mass.

It's the simplest way of describing it. We can't simply spin an object and fix the angular momentum imbalance of teleporting an object a certain distance. We can try and teleport objects in the opposite direction to balance things out though.

So here's a way of fixing the conservation imbalance in teleporters and chronoporters: during that 'charge-up phase' before they shift the units, they actual 'port large quantities of air in the very opposite direction (a much further distance to compensate, because air is light and tanks are heavy)!

Interesting - throwing out causality altogether is something relatively new to me.

Wow, I'm surprised. I expected the designer of Achron to have a somewhat... lax view on causality... ^^

On the one hand, you have Hawking's infamous "chronology protection conjecture" that does imply causality (granted, it's only a conjecture). On the other hand, how much causality do you throw out? Do you consider two attracting charges undergoing acceleration from their force causality that can be broken? Or do you think causality is only a weak statistical law like the 2nd law of thermodynamics as we were discussing before?

I don't believe in Hawking's 'chronology protection conjecture', but I do believe in the Novikov Self-Consistency Principle. This is mostly because it has math backing it.

To summarize the NSCP: time travel is possible, but time paradoxes aren't. Achron throws the NSCP out of the window though, so let's pay it lip-service at best.

As for my perspective on causality, I don't think it's a 'weak statistical law'... I don't think it's a law at all. There is no mathematical formulation behind causality whatsoever: it's just a consequence of our human common sense notions about time. Simultaneity is another example of a common sense notion that has no real basis in physics.

On a side related note, I've never been comfortable with the Copenhagen interpretation of quantum mechanics, and more objective ontologies, such as Penrose's interpretation, have always sat better with me.

I'm an MWI-er. The Copenhagen Interpretation makes me twitch too.

The key difference is that in my case, Maxwell's demon isn't filtering particles through a gate, it's actually sending them back (or forward) in time.

But by chronoporting things, you've already thrown conservation of energy (in a closed system) out the window, unless you consider the closed system to mean the entire timeline. Even then, you might be able to come up with a way where you can create more potential energy if you chronoport something to just the right spot at the right point in time.

The important lesson that I wanted to draw from the Szilard Engine is "If your machine looks like it creates energy from nothing, it will spend energy in performing its actions". The Szilard Engine actually proved that there is a minimum energy cost involved with discovering information about a system!

So, chronoporters and teleporters are likely to spend energy in the process of throwing objects across time or across gravity wells. They're likely to spend more energy than they can recover from the action, thanks to the basic "Guys, we can't reach 100% efficiency" principle from mechanics and engineering.

Awesome! The 145 million miles part is a bit far. However, we're violating angular momentum already, so what does it matter ;-) (j/k). More seriously, if you're already placing something in a brand new inertial frame, potentially outside of the light cone, why does it need to maintain its relative momentum (between the inertial frames) when changing inertial frames?

Conservation of linear momentum. Even if we jump around past our light cones or into the past, we simply still have to obey conservation laws. They're a lot more fundamental than relativity and QM as far as I can tell.

Is conservation of angular momentum a "strong" law?

Well, as long as the universe is invariant under rotation, then I believe it is a strong law under Noether's theorem. So unless some quantum-level derivative of the Michelson–Morley experiment shows otherwise, then it's a strong law. If positions in space are quantized, does that mean that directions are as well? If so, then perhaps it is only strong in approximation when assuming the huge number of discrete states are continuous. Kron, your thoughts here?

It's a "strong" law, yes (it isn't statistical or anything).

Also, I am pretty sure that positions in space and directions are not quantized. Only conserved quantities are quantized (momentum, energy, etc.).

[Hazard]

Wow, I'm surprised. I expected the designer of Achron to have a somewhat... lax view on causality... ^^

I should clarify: it's more that I'm less familiar with violating causality in modern physics with respect to information (i.e., entanglement doesn't communicate information). I'd further clarify that I tend to be a probabalistic determinist (causality may only be held by statistical properties), and even if the determinism is only local (as it is in Achron) or in a meta sense (if time is thought of as a constrained dimension, you could have another level of meta time with other constraints that governs causality, breaking it in the "lesser" time dimension). I do tend to have many surreal thoughts, but I've always thought of breaking causality as more of a hypothetical than an actual.

I do believe in the Novikov Self-Consistency Principle

That one has never sat well with me. How do you make a system that only allows fixed points without guaranteeing that the entire domain is a basin of attraction without any unstable fixed points? I don't think that's possible given the nature of time travel - you can easily do things that would result in unstable fixed points (e.g., going back and killing your grandfather). To say that the universe would prevent such states seems that the universe would have infinite computing power, as to compute the path to avoid all such states seems to be at least far into NP-hard complexity, but probably much worse; you could probably set up an arbitrarily complex situation where the universe where the universe would need to resolve an undecidable problem in order to prevent violating Novikov's self-consistency principle. It just doesn't seem natural to me.

I'm an MWI-er.

(MWI = multiple worlds interpretation for those unfamiliar with the term.)

The branching factor of MWI seems too large for me - too much information to maintain to be practical in our universe.

There is no mathematical formulation behind causality whatsoever: it's just a consequence of our human common sense notions about time. Simultaneity is another example of a common sense notion that has no real basis in physics.

I suppose we need to better define causality then before proceeding, because it seems to me like we're talking about different things.

The working definition that I am using is basically that a states at one point in time leads (at least probabilistically) to another state at a later point in time. For example, all else equal, two attracting charges would move closer to one another. Basically, I'm thinking about it like this: causality means that an inertial frame can be described completely (in a probabilistic sense) by some initial state (which may be probabilistic as well), some interaction with its neighboring inertial frames (which also can be probabilistic), as a function of time. Let's start there. Would you agree with this definition, and if not, what would you change? Then, which part of the definition do you not believe holds in our universe?

For example, the impossibility of simultaneity in this case might say that time is further a function of the state of the inertial frame (which can be renormalized). - I'm not 100% sure on this as I don't have time to think this through all the way at the moment.

The important lesson that I wanted to draw from the Szilard Engine is "If your machine looks like it creates energy from nothing, it will spend energy in performing its actions". The Szilard Engine actually proved that there is a minimum energy cost involved with discovering information about a system!

So, chronoporters and teleporters are likely to spend energy in the process of throwing objects across time or across gravity wells. They're likely to spend more energy than they can recover from the action, thanks to the basic "Guys, we can't reach 100% efficiency" principle from mechanics and engineering.

I still think that you can use time travel as a positive feedback loop and keep amassing energy, the same way you can increase information in an ontological paradox.

Also, I am pretty sure that positions in space and directions are not quantized. Only conserved quantities are quantized (momentum, energy, etc.).

Some (most?) of the loop quantum gravity theories quantize space to some degree. So we don't know for sure yet.

[Kron]

I do believe in the Novikov Self-Consistency Principle

That one has never sat well with me. How do you make a system that only allows fixed points without guaranteeing that the entire domain is a basin of attraction without any unstable fixed points? I don't think that's possible given the nature of time travel - you can easily do things that would result in unstable fixed points (e.g., going back and killing your grandfather). To say that the universe would prevent such states seems that the universe would have infinite computing power, as to compute the path to avoid all such states seems to be at least far into NP-hard complexity, but probably much worse; you could probably set up an arbitrarily complex situation where the universe where the universe would need to resolve an undecidable problem in order to prevent violating Novikov's self-consistency principle. It just doesn't seem natural to me.

What doesn't feel natural to me is that the timeline will take a certain number of oscillations to fix itself... and those oscillations will take time.

I actually do imagine the universe as using a strange-attractor style system (the attractor existing within the universe's quantum mechanical configuration space) to resolve temporal paradoxes. But from the perspective of anyone in the universe, it's instantaneous. "Oh snap our time machine blew a gasket because apparently if we used it we'd end up creating a time paradox" etc. etc.

The branching factor of MWI seems too large for me - too much information to maintain to be practical in our universe. ;-)

Occam's Razor (or Solomonoff Induction if you want to be more precise) only discourages complex rules for universal interactions, not large quantities of entities. Would you consider the atomic theory of chemistry to be 'too much informaiton to maintain to be practical in our universe'? There are a lot of atoms out there, y'know. ^^

I suppose we need to better define causality then before proceeding, because it seems to me like we're talking about different things.

The working definition that I am using is basically that a states at one point in time leads (at least probabilistically) to another state at a later point in time. For example, all else equal, two attracting charges would move closer to one another. Basically, I'm thinking about it like this: causality means that an inertial frame can be described completely (in a probabilistic sense) by some initial state (which may be probabilistic as well), some interaction with its neighboring inertial frames (which also can be probabilistic), as a function of time. Let's start there. Would you agree with this definition, and if not, what would you change? Then, which part of the definition do you not believe holds in our universe?

Ah. I'm talking about this. You seem to be talking about the principle of locality.

In which case, you actually bring up an interesting consideration. As far as I can tell, the principle of locality is sound... and yet teleportation or time travel without wormholes would violate it. I suppose we can try handwaving away portation as planck-duration wormholes? Hmmm....

I still think that you can use time travel as a positive feedback loop and keep amassing energy, the same way you can increase information in an ontological paradox.

I'm not seeing the positive energy feedback loop, to be honest. CTCs probably have potential energies associated with them (like activation levels for molecules), so you'd have to spend progressively more energy to spawn bigger and bigger complete temporal feedback loops.

We see temporal feedback loops in the Zero Point Energy field, and I'm pretty sure that's how they work. I should really do some more research into the Casimir Effect...

Some (most?) of the loop quantum gravity theories quantize space to some degree. So we don't know for sure yet.

I'm skeptical of LQG theories. I shall treat them as complex hypothesis until they amass any evidence. '^^

[Kron]

And now, more walls of text from Kron! Yayyyy!

On Achron Resources
... or: We require more Vesperene Gas.

My phenomenal powers of observation have lead me to deduce that Achron has 4 resources, which each serve some standard functions.

• L-Crystal: Gold.
• Q-Plasma: Lumber.
• Reserves: Population.
• Power: Unknown but... probably Power. ;)

My phenomenal powers of hard science knowledge have lead me to an epic quest: Come up with better names for L-Crystal and Q-Plasma. They sound like placeholders, to be honest... and Q-Plasma is basically technobabble. I abhor technobabble!

So, I have the following goals:

• The new names must be basically embedded within hard science, and their applications must flow from their hard science properties.
• The new names should have neat abbrevations. "L", "Q"... clearly there is a love for singular capital letters. I shall try to uphold this!
• The resources should help explain why three interstellar civilizations are mining it on the battlefield. Seriously, it's usually easier to mine behind your frontlines and simply project manufactured forces into your enemies. I can accept the humans doing this (because they've been cut off from reinforcements), but the other two races? Salvaging from human supply crates? A bit strange...

The last point has an interesting solution: if we make the resources extremely powerful and hard to manufacture forms of matter... then its conceivable that everyone's primary sources for the stuff are the Remnant System. The RS is filled with remnants of dead alien civilizations (or something, I don't remember); they could have presumably left behind a lot of really cool salvageable matter!

And so, I have decided that better names are... *drumroll*

• L-Crystal --> M-Matter:
  Monopolium is a term for matter made of magnetic monopoles. These are topological defects: bugs in the universe's sourcecode.
  I'd describe what they're capable off, but I wouldn't do it justice. Here's a fantastic summary of its capabilities, that I greatly recommend you read.
  To those who hate my walls of text and just want me to give them soundbites...
  
  • Monopolium makes railgun construction easier than banging rocks together to make fire.
  • Monopolium in concentrations naturally detonates normal-matter atomic nuclei, allowing you to construct some of the most wonderfully efficient total-conversion nuclear drives possible... that run on air.
  • Monopolium in large quantities lets you build armor so tough, it can survive in the heart of a sun. It can also help you build armor so reflective, it can reflect supernova radiation.
  Monopolium can be be embedded within normal matter to make it easy to transport. This is called "magmatter". Or as I now christen it... "M-Matter".
• Q-Plasma --> X-Matter:
  Anyone who's done even cursory examinations of things like wormholes or the Alcubierre Warp Metric have probably heard of "Exotic Matter". Also known as 'negative energy' or 'exotic energy', Exotic Matter is yet another topological defect... rather than an electromagnetic defect though, it's closer to a gravitational one.
  
  Exotic matter is technically any kind of mass that violates an 'energy condition'. But the one that most people know of as 'exotic matter' is the stuff that specifically violates the Averaged Null Energy Condition. Why, you ask? Because this basically lets you screw around with spacetime. ANEC-violating Exotic Matter is the bread and butter of any kind of spacetime engineering project.
  
  This is kinda why I want to be in Achron: the game is all about spacetime manipulation. Now to be perfectly honest, Q-Plasma seems to be used to purchase units that have nothing whatsoever to do with spacetime engineering... but the acronym really sold me: X-Matter.