The Gates were created by the TITANS when they left, so they can be anywhere in Earth you would like it to be. It actually could be quite interesting for a player group to go exploring through one such Gate and end up in a barren land, inhabitable world ravaged by nuclear winter... only to find out it is Earth some time after that.

Charlton Heston, eat your heart out. "You maniacs! You blew it all up!" There is a mention (maybe in a sidebar?) of one of the contested gates being nuked and then reforming from the ashes. This suggests at some kind of femtotech or other sorts of Aurther C. Clark magical handwavium. This being so, I wouldnt put it past a pandora gate to waddle around a little on its own, if it was in danger of being subducted into an active fault. or even if they were put in place by the bracewell probes (a non-canonical interpretation that i think is fine to play with) there is nothing that says they couldnt have been erected AFTER the exurgent virus was triggered. hence, they only popped up post-fall. But regardless of all that, whats wrong with putting them under the ocean? sleeve into some octomorphs and get to work! They found one under the ice of an outer planet, it couldnt be that hard to pinpoint one undersea on earth. especially if you popped some gatecrasher through one of the other gates, and he shows up on earth. wouldnt that be a supprise, now?

nothing wrong with that. it could have been in all those places. might move around a bit, either of its own volition or controlled by whoever placed it there. heck, you could say that the gates -- like some sort of monoliths -- ARE the bracewell probes. they could have been there since the solar system formed, and they could totally be consious in their own right. or they could tap into some sort of higher transcendent consiousness. if were going all existential on this, maybe they dont move people through space at all. maybe they open into pocket dimensions of their own imagining, sometimes reflecting reality and sometimes not. i mean, if you can transport mater instantly over arbitrary distances, what cant you do? i wouldnt cross "willing new realities into existance" off the list of possibilities -- and certainly not subliminally influencing the growth of a species. Inteligent Design, indeed.

Perhaps the gates have different age versions, and can have old or new versions. Ancient ones, spread eons ago, new ones thats recently constructed. Premise; Extinct Aliens had a gate system , Despite extinct , their gates was still kept under guard by alien defense systems. The Pandora gates devices at sites might instead be a a positioning beacon with a activate button. scenario1 Unaware of this some unlucky genius in our solar system, using the same phenomena - built a gate or a positioning beacon. When that earth version activated, it naturally connected to the compatible alien Pandora gate system & all hell broke loose. scenario2 Some unlucky genius explorer found a ancient alien artifact probe. the ancient probes likely reported the discovery of us. Somewhere something responding to the alien probes discovery, it activated nearby ancient gates (perhaps the squealing probe itself). Wave2. And all hell broke loose. [b]Destroying a gate[/b] Perhaps they isn't reforming, It just seems that way. Instead a new one is sent in (reconnecting the transit system) . Some technology at undisclosed location, makes wormholes traversable & can force wormhole to open up into specific areas.

something I've been wondering too, is there a P-gate on Echo IV, or just on Echo V, and Gatecrashers travelled by ship between Echo V and Echo IV that brings that image of the Valkyrie flying over the Unobtanium mine before landing on Hell's Gate's pad at the beginning of Avatar.

From what I've understood, the objects going through the get don't move at all, they're just at one points, then at both at the same time, and finally at one point again, as the space was fold around them long enough to transport them. how big really is a Pandora Gate, actually?

I know that line, but what did the authors mean? a whole convoy of several wagons, or a single wagon? How do you picture the surounding of the gates? I picture a huge industrial complexe built around it, behind a tightly guarded perimeter, with offices, factories, laboratories, hospitals...and hotels. Since I'm certain there must be a waiting queue for departing G-crashers, visiting executive and the loved ones of the Crashers who are either leaving or arriving, and those waiting for an ego-cast or a ship transfer... I'm not sure what you mean by the relativy problems.

a fret train in the mid to late 22nd century might be bigger than the one we know today. for all we know the fret train then could be as big as the Big O's train, and as large as a Nimitz class carrier ship!

nezumi.hebereke wrote:

The point is though, the Einstein-Rosen bridges collapse before anything goes through. That's important. Admittedly, I'm not exactly a physicist, though. Atomic Rocket talks a bit more about causality (although doesn't address our precise concern as well as I'd like): http://www.projectrho.com/rocket/rocket3v.html#causality Or more detail, here: http://www.physicsguy.com/ftl/html/FTL_part4.html#chap:unsolvableparadoxes "It is important to note that the real crux of this problem does not come from the form of the FTL travel used, but from the relationship between the two, ordinary frames of reference for observers (O and Op) who never themselves travel FTL" (and specifically addressed in section 9.3, folding space). So yes, you CAN get from A to B faster than light can get from A to B, but doing so messes with causality. This could make for a VERY fun EP adventure, albeit, one that would make the GM's head explode. (And for the record, I have tried it - but it was with one player, who I knew VERY well, and with a certain degree of railroading.)

Actually, Wheeler and Fuller stated that [i]natural[/i] Einstein-Rosen bridges collapse too quickly (I was incorrect in my quote... Einstein never stated that wormholes collapse so quickly). Thorne and Morris did, however, theorize that it might be possible to create and sustain artificial Thorne-Morris wormholes through the use of a spherical shell of exotic matter. Considering the spherical shape of the Pandora gates, this might be what the developers were going at. (What is it with scientists naming shit after themselves? Why can't we just come up with new words for new things? It'll get really confusing if every single new thing that comes about has somebody's last name in it.)

For thousands years, it was "scientifically" demonstrated that man can't fligh. But lo and behold, in early 20th Century, some brothers on the East Coast of the US actually made it and flew. Now millions people a year fligh across the world. Those who created the Gates are thousands, if not millions years more advanced than we are. Though the physics exist, they have found ways to go around it, just like our airplane wings can sustain fligh by their curves. It's used to try and find the cause behind the Pandora Gates, we don't have the scope for it, we have the effects: we reach planets far far away (hi, Shrek!) and a whole new slate of ressources. Let's not look a gifted horse in his mouth.

nezumi.hebereke wrote:

But that doesn't matter. Even if you can create a stable wormhole, as soon as you transmit any information through it, you violate causality. No information = no people either. This is precisely why Wheeler and Fuller stated the bridges collapse - to prevent stuff being sent through and making a headache for everyone else. This is the exact same idea behind quantum entanglement not permitting FTL communication - that nothing is actually 'traveling' is irrelevant. The information gets from A to B before light can get from A to B, violating frames of reference, putting effects before cause, dogs marrying cats, black is white. It is possible the Pandora gates link to other Universes (or other quantum branes or whatever). That would be totally cool. As for scientist names... As long as we keep getting cool names like Casimir, I'm cool with it.

How does it violate causality? The space within a wormhole is still a part of spacetime in the same exact way as normal spacetime is... it's just artificial and temporary. Besides, it's not the same idea behind quantum entanglement not permitting FTL communication... that has a completely different problem related to brownian motion.

Arenamontanus wrote:

The causality problem comes about if there is *any* way of going from A to B (or sending a signal there) faster than a light signal travelling in the normal manner would.

It should be noted that this is true for the entanglement FTL stuff in EP too. If I can tell my Extropia stockbroker to sell Cognite stock through FTL and he FTLs me back an acknowledgement, then some observers (moving relative to me) will see the opposite sequence. Now, did I selfishly reveal their latest PR disaster because I was told by my broker that I would give a sell order, or did I honestly give a sell order after I had just revealed their PR disaster? Note that self-consistency doesn't prevent this kind of confusion, it just says that there is no way to get a paradox out of it. Everything just fits together. This is why I have no problem with allowing entanglement communications in my game, despite that they seem to break real quantum mechanics (there are a bunch of no-signalling theorems showing why you cannot send information FTL with entanglement and they have experimental support, and you can even apparently derive quantum mechanics from the ban on FTL (pdf) ). However, the real question is why transhumanity doesn't use this for hyperturing computation: if you can send information FTL/back in time, you can build absurdly powerful computers (pdf). Of course, in EP this might be a Bad Idea. Which is of course mathematically equivalent to a good plot McGuffin.

nezumi.hebereke wrote:

So if someone is trying to do something which would cause a paradox... what happens? If he manages to create a portal back in time and tries to shoot himself, what's the result?

Something will naturally happen that prevents the paradox. As he leaves the time portal he gets run over by a passing truck. The gun jams. He shoots the wrong guy. The police grabs him before he can kill. Or he changes his mind. I would guess the event would be more likely to be a minimal one than a big one. Quantum mechanics allows things like heads spontaneously teleporting away from the body or random quantum field fluctuations blowing up stuff, but coincidences conspiring are probably (not sure if anybody has done the math on this) more likely.

Arenamontanus wrote:

The causality problem comes about if there is *any* way of going from A to B (or sending a signal there) faster than a light signal travelling in the normal manner would. Wormholes locally respect causality, every small region of space-time around and in them is well-behaved, but the global effect is a short-cut.

Exactly. Wormholes don't [i]technically[/i] cause an object to travel faster than light. It creates a new pathway by which a object can travel slower than light and arrive there faster than light traveling by standard pathways. It'd be like if I created a machine that shot a beam of light at a mirror positioned 1 AU away, which then came back and tagged a small sensor; the light beam will take 16-20 minutes to get from point A to point B, but I can probably walk from one to the other in a couple seconds. In this case, the light is traveling a straight path, but through bending spacetime I can create a pathway that is shorter than that straight path... light traveling through that pathway is still going to arrive far quicker than me.

Arenamontanus wrote:

Now, causality is overrated. Modern physics can deal fine with things like events in the future affecting the past (from a quantum mechanics perspective time symmetry is the natural state), but price is to accept other weirdness. Personally I think the Novikov self-consistency principle is the solution: http://en.wikipedia.org/wiki/Novikov_self-consistency_principle Time travel and FTL (if they can happen) cannot produce paradoxes or inconsistent states because such situations get zero probability amplitude due to wave function interference. This works out very nicely in simple test models, and it is much neater than the Visser wormhole back-reaction (things blow up due to virtual particle flows when you try to make a time machine out of your wormholes) or the Hawking chronology protection conjecture (there has to be an event horizon stopping you because otherwise things would be... indecent :-) ) The little downside is that many people (i.e. players) absolutely refuse to think they are unable to create inconsistent pasts and will really tax your GMing abilities by trying.

So far in EP, there are no situations that actually call for real FTL technology. Even QE communications, while allowing for data to get from point A to point B faster than light can, does not actually transmit data faster than light. Rather, it seems to allow the controlled severing of particle entanglement in such a way that data exists on both ends of the same time, likely caused by the way that the entangled particles are severed. I suppose you can draw analogies to data being transmitted by pulling strings taut at both ends and then sending messages by releasing the string at either end. The release of the string can be perceived almost instantly at either end... and likely far faster with entangled particles since the "string" holding them together isn't a physical object. Information isn't so much transmitted as it is deduced from simultaneous events.

Arenamontanus wrote:

Scientists very rarely name anything after themselves. That kind of egomania is frowned upon and ridiculed severely. But people tend to name cool things after the discoverer (or more commonly, the wrong discoverer).

Either way, it seems a bit foolish to me. Our language would have functioned like crap if we would have had similar naming conventions outside of the field of science.

nezumi.hebereke wrote:

(Thank you. Decivre is awfully smart, so if he pushes me past a certain point, my only answer is 'because I read it on a web page, okay?!?' Yes, I'm actually planning to go to the library today and pick up some physics books. See what you've made me do??)

Thank you for the compliment. If it makes you feel better, I often use internet research to keep up on discussions outside of my fields of expertise. As a someone in the field of computer science, I have good knowledge on the past, present and future of computer technology... and my work in computer simulation programming has allowed me to dip into a number of other fields with a decent degree of "jack-of-all-trades" technology. Outside of this, however, my knowledge is limited and I require supplementation generally through online research. Hell, this forum was the first time I had ever dealt with physics in a fluidless environment (vacuum). Despite what some might think, there is nothing wrong with using the internet to make a statement: it shows that you're doing your research. I am glad you've gotten interest in learning physics, though. I won't apologize for that. :D

nezumi.hebereke wrote:

So if someone is trying to do something which would cause a paradox... what happens? If he manages to create a portal back in time and tries to shoot himself, what's the result?

Not quite. So far as anyone knows, time travel is absolutely impossible; an object traveling faster than light theoretically travels backward in time, but it is impossible to exceed the speed of light. Think of it like dividing by 0... you just can't do it. M-theory (string theory) certainly opens up some possibilities that might make time travel possible in some ways, however.

Arenamontanus wrote:

Yes. And this is why I try to avoid FTL or time travel in my games. I hate railroading.

So long as you make time travel non-paradoxical, and use FTL travel that skirts around laws of relativity (such as jump gates and entanglement technology), there's no inherent problem. Oftentimes, I recommend the use of parallel universes, or make it so that time-traveling objects are no longer innately tied to their "past", and time travel essentially consists of destruction and recreation of an object at a previous point in spacetime. The "newly created object" is an independent thing, and won't magically disappears if it destroys a "past" version of itself. This also means that any alterations to the universe as it is suppose to happen effectively define it as a new universe.

even if there are gates on both, it seems very difficult to make gates dial predicatably and reliably. exo colonies seem to be constantly at risk of being cutoff and isolated, at the whims of a barely understood and potentially malevolant pandora gate. hence, i would guess that they built a ship on the other side of the gate (most likely with a combination of nanohives and imported engineering tools) with local or imported materials, and flew.

Arenamontanus wrote:

nezumi.hebereke wrote:

i.e. - it's now a requirement for GMs to railroad? Like, the laws of physics compel me to drop cows on PCs?

Yes. And this is why I try to avoid FTL or time travel in my games. I hate railroading.

Alternately, you can just go "fuck causality" and then have the PCs [url=http://www.mspaintadventures.com/?s=6&p=003763]come across their own corpses[/url] when contemplating time travel. Come to think of it, a decent adventure might be had if Firewall were to hear about the beta of a AR/VR game that was coming out, which they had computed would require a hyper-turing server running somewhere to possess the functionality it was described as having. The PCs are assigned to investigate.

now that movie picked my interrest Another good place would be in Irak where the old Babylon existed or Persia. That holy city with weird time/space occurences. Now wouldn't that be a nice twist, a "prince-of-persia"-meet-Outlander- ish adventure where a group of PC have to stop Exsurgent vectors to cross the gate not through space but through time? total change of scenary for the players, who wouldn't have expected an Arabian Nights game in place of their sci-fi/horror.