49 réponses à ce sujet

[Reorte]

Screwing up physics with your handwave to get FTL is an aspect of ME (and a lot of science fiction) that doesn't bother me, since it's pretty much necessary to set up the universe. Finding a consistent, practical way of doing it would mean you've managed to invent a real, working FTL drive, and that would no doubt be rather more significant than any works of fiction you'd made.

[ImaginaryMatter]

Screwing up physics with your handwave to get FTL is an aspect of ME (and a lot of science fiction) that doesn't bother me, since it's pretty much necessary to set up the universe. Finding a consistent, practical way of doing it would mean you've managed to invent a real, working FTL drive, and that would no doubt be rather more significant than any works of fiction you'd made.

 

It doesn't bother me either. I'm just putting forward an alternate universe theory because alternate universes are neat.

[JasonShepard]

The problem with using just E = mc^2 is that the equation only applies to the center of momentum frame (in Relativity every thing is relative... except for the speed of light). Otherwise we need to use the full equation:

 

E = [(mc^2)^2 + (pc)^2]^(1/2) = KE + mc^2

 

Where m is rest mass, KE is kinetic energy, and p is momentum. I'm not an expert at Relativity but I think calculating that the speed of light changes within the center of momentum frame is a misuse of the conservation of energy. Rest mass energy is simply one form of energy, presumably when the mass of an object is decreased due to the mass effect the rest mass energy is decreased and the energy in the equation is made up elsewhere (like the object moving faster, thus having more KE).

 

 

Of course. But the zero momentum frame (ZMF) is just as valid as any other frame. And within the ZMF, the equation simplifies down to E = mc^2. The extra stuff applies to how things change when you move out of the ZMF - but it doesn't make results from the ZMF any less valid.

 

If m changes in a closed system, something has to give within E=mc^2. Either you have an energy change (e.g. detonating an atomic bomb converts m into E) or you have a change in c (considered impossible by real world modern physics). However, if you're going to have FTL within a universe, it's clear that c is NOT a universal constant (otherwise you have time travel). ME has FTL without time travel. Therefore c is not constant in the MEU.

 

And... yes, conservation of energy does appear to be violated by some other stuff that you can do with mass effect. Particularly mass accelerator weapons. This is mostly because the mass effect breaks modern physics, and because Bioware's writing team is not a team of Physics graduates (which is probably a good thing - speaking as a physics graduate!).

 

But if you want an in-universe explanation for mass accelerators - the best I can give is that energy is actually being conserved somehow and a better understanding of the laws of physics in the MEU would explain how. Unfortunately, those laws don't exist because it's fiction. Bioware never explained how eezo can create a field that lowers the local value of mass. I'm sorry, but that's what it does come down to, eventually: The MEU isn't the real world. Something like the mass effect *might* be possible in the real world, but it would require a major rewrite of most of modern science. Which means applying modern physics to it doesn't work. Which means it works because the writing team says it does (and a few similarities to modern physics helps with the believability that this is a future version of physics).

[ImaginaryMatter]

Of course. But the zero momentum frame (ZMF) is just as valid as any other frame. And within the ZMF, the equation simplifies down to E = mc^2. The extra stuff applies to how things change when you move out of the ZMF - but it doesn't make results from the ZMF any less valid.

 

If m changes in a closed system, something has to give within E=mc^2. Either you have an energy change (e.g. detonating an atomic bomb converts m into E) or you have a change in c (considered impossible by real world modern physics). However, if you're going to have FTL within a universe, it's clear that c is NOT a universal constant (otherwise you have time travel). ME has FTL without time travel. Therefore c is not constant in the MEU.

 

And... yes, conservation of energy does appear to be violated by some other stuff that you can do with mass effect. Particularly mass accelerator weapons. This is mostly because the mass effect breaks modern physics, and because Bioware's writing team is not a team of Physics graduates (which is probably a good thing - speaking as a physics graduate!).

 

But if you want an in-universe explanation for mass accelerators - the best I can give is that energy is actually being conserved somehow and a better understanding of the laws of physics in the MEU would explain how. Unfortunately, those laws don't exist because it's fiction. Bioware never explained how eezo can create a field that lowers the local value of mass. I'm sorry, but that's what it does come down to, eventually: The MEU isn't the real world. Something like the mass effect *might* be possible in the real world, but it would require a major rewrite of most of modern science. Which means applying modern physics to it doesn't work. Which means it works because the writing team says it does (and a few similarities to modern physics helps with the believability that this is a future version of physics).

 

That was my point though (sort of), that all of this takes place in an alternate universe with a different set of rules. Like EDI said a place where 1 + 1 equals 3, although more subtle.

[JasonShepard]

It doesn't bother me either. I'm just putting forward an alternate universe theory because alternate universes are neat.

 

I agree. Heck, I basically believe in alternate universes. You can take the stance that each playthrough of Mass Effect is an alternative universe. And, lets face it, our laws of physics probably don't include something like eezo, so if you want it to exist somewhere, you HAVE to resort to alternative universes.

 

Unfortunately, the basic version of the multiverse (that anytime something can happen, both things happen) is inherently untestable. To test it, you'd need to somehow break through from one universe to another - and the multiverse theory has nothing to say on whether that's even possible. If it isn't possible (the simpler, and therefore preferable theory), you can't prove anything with the theory - making it, sadly, a useless theory.

 

(The quantum mechanics multiverse interpretation implies that some overlap occurs on an atomic scale, but we've got no way of scaling that up to human scale. You'd need a 'perfect box' - no leakage of ANYTHING in or out, heat, radiation, sound - to pull off something similar to Schrodinger's Cat in the real world. And that's not quite impossible, but it's close enough as makes no difference.)

[TopTrog]

Interesting discussion :-). I have a question - is it stated anywhere in the codex or other material from Bioware that the Mass Effect will reduce mass only to zero or a positive number ?

 

I had always assumed that the Bioware writers got their inspiration for Element Zero by the concept of "exotic matter" with negative energy density / mass. If negative mass = negative inertia, this would in principle allow FTL travel in a way consistent with the laws of physics as currently checked vs. observation ("Alcubierre Drive"), with no different physics or multiverse required in principle. It surely has all sorts of problems, but has not yet been conclusively ruled out - which makes it a nice touch compared to most other SciFi stuff.

[JasonShepard]

Interesting discussion :-). I have a question - is it stated anywhere in the codex or other material from Bioware that the Mass Effect will reduce mass only to zero or a positive number ?

 

I had always assumed that the Bioware writers got their inspiration for Element Zero by the concept of "exotic matter" with negative energy density / mass. If negative mass = negative inertia, this would in principle allow FTL travel in a way consistent with the laws of physics as currently checked vs. observation ("Alcubierre Drive"), with no different physics or multiverse required in principle. It surely has all sorts of problems, but has not yet been conclusively ruled out - which makes it a nice touch compared to most other SciFi stuff.

 

Ah. Star Trek's warp drive (Or at least, what Star Trek writers adopted as their explanation for warp drive.) Yes, assuming Element Zero can take similar properties to exotic matter - ie net negative mass - you could craft an Alcubierre drive.

 

Unfortunately, I don't believe that the Codex directly states an answer.

[shodiswe]

Maybe the Leviathans had fitted the Citadel with one of those drives... During your assault on the Cerberus Base the whole citadel is immediately moved to Earth. Noone saw it being moved, apparently..

Lets say the next mass effect is set post the Reaperwar then maybe you will be flying around with the Citadel and making contact with new species that arn't connected through the relay network. The other 99% of the milkyway.

It would fit well with the Mass Effect: Contact title.

Kind of Like Star Control 2 and 3. You got that huge ancient alien ship that helps you travel the galaxy and bring your fleet with you. (The fleet part was a Star Control thing)

[TopTrog]

Ah. Star Trek's warp drive (Or at least, what Star Trek writers adopted as their explanation for warp drive.) Yes, assuming Element Zero can take similar properties to exotic matter - ie net negative mass - you could craft an Alcubierre drive.

 

Unfortunately, I don't believe that the Codex directly states an answer.

Thank you - so that would still be a possible backstory, then :-).

[AlanC9]

I had always assumed that the Bioware writers got their inspiration for Element Zero by the concept of "exotic matter" with negative energy density / mass. If negative mass = negative inertia, this would in principle allow FTL travel in a way consistent with the laws of physics as currently checked vs. observation ("Alcubierre Drive"), with no different physics or multiverse required in principle. It surely has all sorts of problems, but has not yet been conclusively ruled out - which makes it a nice touch compared to most other SciFi stuff.

Sort of a hybrid of that concept and E.E. "Doc" Smith's Bergenholm Drive, from the Lensman series. That drive reduced the mass of the ship and everything in it to zero. Note that Smith doesn't just handwave the lightspeed limit away, he lampshades it. One of his characters actually says that inertialess travel should still limit you to lightspeed in the home reference frame. Turns out it just doesn't.

[AlanC9]

Actually, ME probably gets the concept from Frederik Pohl. The Heechee FTL drive first seen in Gateway turns out to work by mass-cancellation. I think Pohl's the likely transmission vector because that series' plot is essentially Mass Effect as written by a pacifist. Or rather, Mass Effect with the Dark Energy plot. Humans find alien ruins in Sol system, including working FTL ships. As humans explore the galaxy they find no trace of the alien culture, which simply vanished without a trace while we were still hominids. Turns out that all over the galaxy any advanced civilizations have been either exterminated or reduced to barbarism by unknown forces. Meanwhile, something is apparently altering physical constants of the universe in such a way as to make it hostile to organic life.....

[TopTrog]

Actually, ME probably gets the concept from Frederik Pohl. The Heechee FTL drive first seen in Gateway turns out to work by mass-cancellation. I think Pohl's the likely transmission vector because that series' plot is essentially Mass Effect as written by a pacifist. Or rather, Mass Effect with the Dark Energy plot. Humans find alien ruins in Sol system, including working FTL ships. As humans explore the galaxy they find no trace of the alien culture, which simply vanished without a trace while we were still hominids. Turns out that all over the galaxy any advanced civilizations have been either exterminated or reduced to barbarism my unknown forces. Meanwhile, something is apparently altering physical constants of the universe in such a way as to make it hostile to organic life.....

That sounds interesting, thank you :-). I´ll give Pohl and Smith a look.

[sH0tgUn jUliA]

I know there's a gateway to an alternate universe in a region between the third fairway and the sixth fairway at a golf course I play at. If you hit your ball in there, even though the grass is mowed you will never find it. It is like the black hole that exists in dryers that swallows socks and teleports them into another dimension.

[shodiswe]

Actually, ME probably gets the concept from Frederik Pohl. The Heechee FTL drive first seen in Gateway turns out to work by mass-cancellation. I think Pohl's the likely transmission vector because that series' plot is essentially Mass Effect as written by a pacifist. Or rather, Mass Effect with the Dark Energy plot. Humans find alien ruins in Sol system, including working FTL ships. As humans explore the galaxy they find no trace of the alien culture, which simply vanished without a trace while we were still hominids. Turns out that all over the galaxy any advanced civilizations have been either exterminated or reduced to barbarism by unknown forces. Meanwhile, something is apparently altering physical constants of the universe in such a way as to make it hostile to organic life.....

I played Gateway and Gateway 2 homeworld I think it was called years back. Quite enjoyable.

My character finaly found the Heechee in Gateway 2 I havn't read the books though.

[shodiswe]

Sounds like they are thinking about doing some kind of Gateway TV series aswell.

http://io9.com/frede...seri-1541426616

[SwobyJ]

[78stonewobble]

I think it simply reduces the mass to a non-zero positive. Even if it did reduce the mass to zero though, under Relativity it would travel exactly at the speed of light, no faster no slower -- so you still run into the same problem of traveling faster than light. FTL is a bit tricky with Relativity, possibly impossible. You would either have to have imaginary mass, use wormholes, or have something like an Alcubierre drive (which warps space around it); there's more but that's what I can think of at the top of my head.

 

As you say even reducing the mass of something with element zero would not guarantee faster than light in our universe. 

 

However in mass effect the civilisations can also increase gravity (somehow). Otherwise we would not be able to walk around on the normandy or spacestations. 

 

My humble, of the top of my head, headcannon is that they actually do use some form of Alcubierre or warp drives. 

 

They've further reduced the mass necessary for the warping of space and can use eezo to offset the effect of the remainder of the necessary mass. 

[78stonewobble]

If m changes in a closed system, something has to give within E=mc^2. Either you have an energy change (e.g. detonating an atomic bomb converts m into E) or you have a change in c (considered impossible by real world modern physics). However, if you're going to have FTL within a universe, it's clear that c is NOT a universal constant (otherwise you have time travel). ME has FTL without time travel. Therefore c is not constant in the MEU.

 

Out of curiosity here... 

 

If we suppose that C is a universal constant in the ME universe as well. 

 

How would the construction of a FTL capable ship lead to any paradoxes, which are the main argument against time travel? 

 

I mean, it can travel to another star system and back, before light does, but it wouldn't arrive before it was constructed. 

 

Couldn't you argue that it only allows you to travel into the future, just like travelling at relativistic speeds would (which can allready be considered timetravelling), but "slower", in the sense that the only difference between FTL and relativistic travel is that to get somewhere spacially, less time will have passed for an outside observer. 

 

PS: Sorry if it's a stupid question. I'm not a physics graduate, but kudos for taking that up. That nets you my bad ass sign of approval. I wish I could have gone that way, but I'm just too stupid at math.

[JasonShepard]

Out of curiosity here... 

 

If we suppose that C is a universal constant in the ME universe as well. 

 

How would the construction of a FTL capable ship lead to any paradoxes, which are the main argument against time travel? 

 

I mean, it can travel to another star system and back, before light does, but it wouldn't arrive before it was constructed. 

 

Couldn't you argue that it only allows you to travel into the future, just like travelling at relativistic speeds would (which can allready be considered timetravelling), but "slower", in the sense that the only difference between FTL and relativistic travel is that to get somewhere spacially, less time will have passed for an outside observer. 

 

PS: Sorry if it's a stupid question. I'm not a physics graduate, but kudos for taking that up. That nets you my bad ass sign of approval. I wish I could have gone that way, but I'm just too stupid at math.

 

Okay... Lets see what the easiest way to tackle this particular problem is... (While at the same time trying to stay on the mass effect topic.)

 

One physics lesson coming up, but with minimum maths:

 

***

 

The problem with c being constant is that it's constant for everyone. Imagine that you are standing on the Citadel and you fire a photon into space. The photon travels away from you at lightspeed. At the exact same moment, I leave the station in the Normandy, travelling in the same direction at just less than the speed of light (compared to you).

 

You will see the Normandy and the photon (if you can somehow 'see' a single photon) travelling at roughly the same speed, but with the photon steadily extending a lead (since it's going only slightly faster).

 

But here's the mind-bendy bit. What do I see? I look at the photon... and compared to me, it's still travelling at c. So I see it shoot ahead of me at, well, lightspeed.

 

These two perspectives, while different, are consistent. By consistent, I mean that if we both looked at a chain of dominos falling, we'd still see the dominos falling in the same order (ie causality isn't broken). However, it does mean that my perception of time and space needs to be warped compared to yours (and vice-versa).

 

And that's why Relativity includes stuff like time-dilation and length-contraction.

 

***

 

However, you asked why Relativity forbids us from going FTL.

 

First, lets consider travelling at lightspeed. So, at the same moment that I leave the Citadel in the Normandy and you fire a photon into space, lets say that the Destiny Ascension also decides to get in on this race. It also leaves the Citadel, travelling in the same direction, and travelling at lightspeed.

 

From your perspective, the Destiny Ascension and the photon are neck-and-neck, neither extending a lead on the other since they're travelling at the same speed. I would have a similar perspective (but with some disagreement over how fast they were travelling away from me).

 

But now let's put someone onto the Destiny Ascension. Lets say Garrus has hijacked it (you know he would if he could). Garrus looks out the window at the photon...

...and sees it travelling at lightspeed away from him.

 

I need to nail this home for everything else to follow, so forgive me reiterating the logic: The point of c (lightspeed) being a constant is that if anyone measures the speed of a photon, they will always consider it to be travelling at lightspeed compared to them. Lightspeed is a constant - and so, no matter what you are doing, photons are travelling at 1,000,000,000km/h compared to you. (No matter what you are doing, photons are doing it faster!)

 

Therefore Garrus cannot see the photon sitting just outside the window, travelling at the same speed as him. That would be equivalent to seeing it stationary, moving at 0km/h. He has to see it moving at 1,000,000,000km/h, just like everyone else.

 

So Garrus sees the photon moving away from him at lightspeed... and everyone else sees the photon travelling alongside the Destiny Ascension. These two perspectives are not consistent. You can't make zero distance into large distance by warping distance (or time). That would be equivalent to making something out of nothing, and runs us into infinities and divisions by zero. We've hit a paradox. That means this situation is impossible - Garrus cannot be travelling at lightspeed.

 

And since, to travel faster than light, there would have to be a moment (as you increased the speed of your ship) where you travelled at lightspeed, we've just ruled out FTL as well.

 

***

 

That's not enough for you, is it? "What if we invented a spaceship that jumped to the speed, rather than accelerating up to it? What happened to the time-travel you mentioned earlier?"

 

Okay. Let's not ask how she got it to that speed, but now lets have Liara flying the Shadow Broker's ship at FTL away from the Citadel. She'll be ahead of the photon (since she is travelling faster-than-light...). So she walks to the back of the ship and looks back at the photon.

 

This is going to get very mind-bendy, so lets tackle it step by step.

 

• You are standing on the Citadel. You see the photon heading towards the Shadow Broker's ship at lightspeed. You and Liara have to agree, not only on the speed of the photon, but also on its direction.
   
• So Liara has to see the photon heading towards her at lightspeed. So from her perspective, the photon is gaining on her, closing the distance.
   
• However... from your perspective, the Shadow Broker's ship is travelling faster-than-light, and is getting further away from the photon.
   
• With each passing second, Liara sees the photon getting closer. With each passing second, you see Liara getting away from the photon. See where I'm going with this?
   
• Liara's perception of time is reversed compared to yours. Anything happening on the Shadow Broker's ship is happening in reverse as far as the rest of the (slower than light) universe is concerned. There's the time travel.

***

 

FTL causes other problems, such as making it possible to fire a bullet FTL that ricochets and kills the person who fired it before they pulled the trigger. But explaining that particular series of events is tricky without introducing reference frames and messing around with space-time diagrams. Since I've explained how one version of time travel occurs, I trust that you'll believe me when I say that there are, inevitably, other examples.

 

Since the mass effect universe makes no reference to any time travel happening, the only conclusion is that the speed of light is not a constant in the mass effect universe. That's okay. It's perfectly possible that lightspeed isn't constant in our universe either - just that it's been constant in every experiment we've ever run, including those experiments that involve relativity. But then, we've never had a chance to run an experiment that included eezo...

 

And that concludes today's no-maths Mass Effect physics lesson. I hope you enjoyed it

[78stonewobble]

@JasonShepard:  Thank you for the explanation of why relativity forbids FTL travel with mass effect squadmate sock puppets for those of us, who needed it on that level. *lol* I love it. Single greatest post I've ever read here.  

 

 

Yeah, the whole reference frame thing is mindboggling and counter intuitive at times, even the little I've read up on it. 

 

 

What I'm still somewhat unclear on is, how this would play out in a alcubierre drive scenario, where the ship locally stays far slower than lightspeed and I assume the mindboggling comes from the photons passage through the warped space/time around the ship. 

 

 

What you are referring to in the last part is called Closed Time-like Curves right? Novikov's self-consistency principle does seem like logical explanation, if they ever appeared to be possible. 

 

It seems impossible, that nature should allow you to kill yourself, with a shot, before you fire the shot, that ricochets back in time, that kills you. Could you call it: "Effect prevents cause." 

 

Whereas it doesn't seem quite as impossible, for you to get hit by a shot, that makes you fire your shot, that ricochets back in time, that hits you. Which we could call "effect=cause". 

 

A little bonus question, if you're ever up for answering. Doesn't some quantum mechanical phenomena appear like effect happening before cause?

 

I seem to remember reading it vaguely. 

[Kabooooom]

Actually, you can get it to fit. Consider E=mc^2. If m is lowered by the mass effect, but energy is conserved, E has to stay the same. This forces the local speed of light to take on a larger value - allowing for FTL compared to other places. As far as local space time is concerned, you are still slower than the speed of light.

Of course, I have no idea what this would do to your space-time path on a diagram...

WRT Einstein's name not being used much - in some ways, it was nice to see exposure for other important scientists. Big E was very important, but for many people he's the only scientist they know the name of. Kepler, Herschel, Hawking all made important contributions. Furthermore, Einstein had an Alliance Carrier named after him - which are the biggest ships that the Alliance wields (tied with dreadnoughts, but also unique to humanity).

You are the only person besides myself who I have seen propose this explanation for how the mechanics of the mass effect actually work. I enjoyed reading your posts, especially since you are apparently a physics grad.

[TheOneTrueBioticGod]

But wouldn't the ship really be *effectively* be a photon, since it as no mass? 

I was under the assumption that FTL was possible because eezo can manipulate dark energy to the point where an object has volume, but no mass.
Which does lead to a paradox, as one cannot divide by zero. 

Of course, this gets even more confusing, as we don't know how a object without mass(which doesn't exist, as far as we know) would react to the application of thrust. Mathematically, it would once again be a paradox, but in practice, shouldn't it imply infinite acceleration? 

My head hurts. 

 

[JasonShepard]

@JasonShepard:  Thank you for the explanation of why relativity forbids FTL travel with mass effect squadmate sock puppets for those of us, who needed it on that level. *lol* I love it. Single greatest post I've ever read here.

 

 

Yeah, the whole reference frame thing is mindboggling and counter intuitive at times, even the little I've read up on it. 

 

 

What I'm still somewhat unclear on is, how this would play out in a alcubierre drive scenario, where the ship locally stays far slower than lightspeed and I assume the mindboggling comes from the photons passage through the warped space/time around the ship. 

 

 

What you are referring to in the last part is called Closed Time-like Curves right? Novikov's self-consistency principle does seem like logical explanation, if they ever appeared to be possible. 

 

It seems impossible, that nature should allow you to kill yourself, with a shot, before you fire the shot, that ricochets back in time, that kills you. Could you call it: "Effect prevents cause." 

 

Whereas it doesn't seem quite as impossible, for you to get hit by a shot, that makes you fire your shot, that ricochets back in time, that hits you. Which we could call "effect=cause". 

 

A little bonus question, if you're ever up for answering. Doesn't some quantum mechanical phenomena appear like effect happening before cause?

 

I seem to remember reading it vaguely. 

 

Glad you liked it. I'll let you in on a little secret - most scientists use sock-puppets when thinking stuff through Admittedly, their sock-puppets are more likely to be 'Person A' and 'Event B' rather than 'Garrus' and 'The Normandy leaves the Citadel', but it boils down to the same thing.

 

I don't know how an alcubierre drive would work. However, anything travelling faster than light can make a closed time-like curve for itself (yes, that is the correct wording ), regardless of how it's going FTL. While an alcubierre drive isn't technically going faster than light (it's essentially making space flow around it rather than moving through space), I believe it would still run into some potential time-travel problems.

 

Yes, "effect=cause" seems more probable than "effect prevents cause", but both would require a major rewrite of how causality works. Even if you shoot a bullet that hits you, causing you to shoot the bullet... there's no *initial* cause. And that's a problem.

 

And... Ah. Quantum Mechanics. Allow me to put it this way - as mind-bendy as Relativity is, Quantum Mechanics is far worse. I can handle Relativity (mostly). I still can't wrap my head around Quantum. However, you are correct that QM has some fairly strange stuff happening in very short time periods - for example, it appears to be able to borrow energy from a vacuum so long as it returns it a split second later. I don't know of anything like "effect precedes cause" however.

 

***

 

You are the only person besides myself who I have seen propose this explanation for how the mechanics of the mass effect actually work. I enjoyed reading your posts, especially since you are apparently a physics grad.

 

I'm not sure if I came up with the E=mc^2 mass effect solution myself, or if I read it somewhere. So it's possible that I took it from one of your posts in the past, if you posted it in BSN. I don't recall. It does, however, match with the Codex saying that the speed of light is locally increased by the mass effect, so I suspect someone at Bioware also figured it out.

 

***

 

But wouldn't the ship really be *effectively* be a photon, since it as no mass? 

I was under the assumption that FTL was possible because eezo can manipulate dark energy to the point where an object has volume, but no mass.
Which does lead to a paradox, as one cannot divide by zero. 

Of course, this gets even more confusing, as we don't know how a object without mass(which doesn't exist, as far as we know) would react to the application of thrust. Mathematically, it would once again be a paradox, but in practice, shouldn't it imply infinite acceleration? 

My head hurts. 

 

Exactly. We don't know how physics behaves when you introduce eezo to the equation. Lightspeed being a constant just tells us that we can't have a reference frame travelling at the speed of light - it doesn't make sense to our understanding of the universe. Then again, neither does the idea of reducing something's mass without actually taking anything away from it...

[78stonewobble]

 

Glad you liked it. I'll let you in on a little secret - most scientists use sock-puppets when thinking stuff through Admittedly, their sock-puppets are more likely to be 'Person A' and 'Event B' rather than 'Garrus' and 'The Normandy leaves the Citadel', but it boils down to the same thing.

 

I don't know how an alcubierre drive would work. However, anything travelling faster than light can make a closed time-like curve for itself (yes, that is the correct wording ), regardless of how it's going FTL. While an alcubierre drive isn't technically going faster than light (it's essentially making space flow around it rather than moving through space), I believe it would still run into some potential time-travel problems.

 

Yes, "effect=cause" seems more probable than "effect prevents cause", but both would require a major rewrite of how causality works. Even if you shoot a bullet that hits you, causing you to shoot the bullet... there's no *initial* cause. And that's a problem.

 

And... Ah. Quantum Mechanics. Allow me to put it this way - as mind-bendy as Relativity is, Quantum Mechanics is far worse. I can handle Relativity (mostly). I still can't wrap my head around Quantum. However, you are correct that QM has some fairly strange stuff happening in very short time periods - for example, it appears to be able to borrow energy from a vacuum so long as it returns it a split second later. I don't know of anything like "effect precedes cause" however.

 

Well, perhaps actual sockpuppets would improve the lectures.

 

After my post I read up a little again on the Alcubierre drive and he does say that any method to travel faster than light can in principle be used to travel back in time. So yeah, that too would run into potential timetravel problems. 

 

The only "solution" I could think off, for our little bullet scenario, would be that it would have to be acceptable that a bullet can materialise semi randomly out of nowhere, hit you and force you to fire a bullet which then disappears. A sort of macroscopic quantum fluctuation? 

 

Would make it hard to know when to duck though... 

 

But what do I know... *lol* ... 

 

I'm still trying to wrap my head around just a basic understanding of relativity. 

 

From what I read though, to more completely rule out any FTL, we would need a "full theory of quantum gravity"... So we can dream a little while longer.

[Kabooooom]

But wouldn't the ship really be *effectively* be a photon, since it as no mass?

I was under the assumption that FTL was possible because eezo can manipulate dark energy to the point where an object has volume, but no mass.
Which does lead to a paradox, as one cannot divide by zero.

Of course, this gets even more confusing, as we don't know how a object without mass(which doesn't exist, as far as we know) would react to the application of thrust. Mathematically, it would once again be a paradox, but in practice, shouldn't it imply infinite acceleration?

My head hurts.

Well, under normal FTL, the ship isn't entirely massless. By JasonShepard's and my point of view, the mass is just incredibly reduced, and the speed of light within the mass effect field is consequently incredibly raised.

The only situation in which there is a truly massless corridor of space is between two relays. And it is uncertain if the ship itself is massless as well. If so, it wouldn't fit with this explanation. However, if the ship wasn't truly massless but the mass was present but negligible, then the increase in the speed of light would approach a limit at infinity as the mass continued to decrease. This makes sense, as the travel between relays is shown to be nearly instantaneous.