# Best Shot at FTL?

1. Jun 30, 2012

### MattRob

Hello,
So, I'm writing sci-fi and I'm "doing my homework" to make this thing a pleasant read to those in the know, and my own standards demand I make this as possible as... Possible.

So what's the best shot at an FTL-capable vessel, that's practical in a century? (i.e, not wormholes or Alcubierre drive which require astronomical amounts of energy and/or mass)

First I was looking at a paper by H. David Froning describing rotation into higher dimensional space by use of (to the best of my memory) "conditioned electromagnetic radiation coupled with the forces behind mass and inertia", which would polarize the vacuum around the spacecraft (I believe it meant by effecting virtual particles?) as to increase vacuum permeability/decrease resistance to acceleration and increase the local speed of light in the polarized space.

I believe this linked page describes it.

The only issue was the original paper stated it required enormous amounts of energy. Exactly what kind of amounts of energy would be good to know...

Heim theory is another idea I've been looking at. I've read the wiki page, and it doesn't look good for Heim theory right now, but perhaps something that could make a comeback this century. What would FTL travel according to Heim Theory entail?

2. Jun 30, 2012

### phinds

I think the quest for FTL is an example of what the military call "pissing up a rope". YOU end up wet, with no effect on the rest of the universe.

I understand you want to make it as real as possible, but it just isn't.

3. Jun 30, 2012

### julian

Funnily, years ago, I came across a small article on like page 13 of my local newspaper about how some scientist at Swansea university had proved that if negative matter existed then you could warp spacetime and make faster the light travel. I think maybe Hawking himself mentioned this result in this thing he did where he tried to give some kind of 'plausable' explanantion for the 'physics' of Star-Treck......but dont quote me as is a distant memory. But this would be something to look into.

Last edited: Jun 30, 2012
4. Jun 30, 2012

### MattRob

I'm pretty sure that's an Alcubierre drive.

5. Jul 1, 2012

### Dickfore

Well, tachyons (particles that travel faster than light) have to have imaginary mass, i.e. $m^2 < 0$. To see this, start with the square of the 4-momentum:
$$P^{\mu} P_{\mu} = \left(\frac{E}{c} \right)^2 - p^2 = (m c)^2$$
and use Hamilton's equation of motion:
$$\mathbf{v} = \frac{\partial E}{\partial \mathbf{p}}$$
to get the velocity of the particle.

Differentiate w.r.t. p the first equation implicitly to get:
$$\frac{2}{c^2} E \mathbf{v} - 2 \mathbf{p} = 0 \Rightarrow \mathbf{v} = \frac{c^2 \mathbf{p}}{E}$$
Therefore, to get $v > c$, we must have $p > E/c$, which means the 4-momentum is a spacelike 4-vector, and its square is negative. This justifies my initial claim.

One place where I have seen imaginary (rest) mass (or negative mass squared) is in spontaneous symmetry breaking, such as the Higgs mechanism. Namely, the bare mass squared of the Higgs boson in the Standard model has a negative sign, making the Higgs boson a tachyon.

EDIT:
You may be interested in Superfluid vacuum as an interesting possibility.

Last edited: Jul 1, 2012
6. Jul 1, 2012

### Hurkyl

Staff Emeritus
You're going to have to resort to, well, a fiction. I'm pretty sure the best shot of getting FTL within 100 years is some sort of unanticipated breakthrough, be it some physical theory we currently have no expectation of existing, discovery and reverse engineering of an alien FTL drive that operates under unknown principles, or the completely surprising discovery of a natural (and stable!) anomaly in space-time that allows travel along certain routes to be shorter than otherwise anticipated.

7. Jul 1, 2012

### sbrothy

It seems the OP is talking about "showing" and "visualizing", which makes me believe he/she intents this as a film of some sort. The problem with FTL in animated stories is that in books, you might handwave it with a hefty amount of technobabble but barring that - it's uphill. In a movie it's still just gonna look like a big shiny portal og a gleaming phallic vehicle. :)

Atomic Rockets.

I think it is a must for anyone thinking about writing anything set in space. (Or for anyone who just plan of having every sci-fi story ruined which tvtropes.org will help you with just fine. :D

8. Jul 1, 2012

### MattRob

Hmm. So what about the possibility of H. David Froning's higher dimensional rotation? I found an overview to the paper; http://proceedings.aip.org/resource/2/apcpcs/699/1/1168_1?isAuthorized=no [Broken]
Is that good science?

And what of Heim theory? http://en.wikipedia.org/wiki/Heim_theory
According to the snippet here: http://en.wikipedia.org/wiki/Faster-than-light#Heim_theory
Heim theory allows higher dimensional rotation by magnetic fields. This looks exactly like H. David Froning's proposition!

So what would that entail? I remember in the full paper, Froning described that using a conditioned electromagnetic field, coupled with the forces behind gravity and inertia, would polarize the vacuum around the spacecraft, rotating it into higher dimensional space, causing:
1. Decrease vacuum resistance to acceleration
2. Increased local speed of light, relative to bodies not in polarized space

So when the spacecraft passed light speed relative to non-polarized objects, it would vanish, then as it de-polarized, it would re-appear traveling slower than light near it's destination.

So what about interstellar micrometeorites, and atomic gas?

Would a Bussard ramjet work equipped with this, or would the interstellar gas "vanish" from the spacecraft's perspective?

Or perhaps because the area around the spacecraft is polarized, then micrometeorites and interstellar gas would enter the polarized region, vanishing from nonpolarized space, and "appearing" to the spacecraft, almost identically to how it would behave when entering the region of space around an Alcubierre drive, except instead of being caused by distortion of space, it's caused by polarization. Is this correct?

And what sort of energy would it take to do this? Say, how much energy per cubic meter per degree of rotation in higher dimensional space?...

Hard questions, I'm hoping there's someone that knows, or at least knows how to find out.

Imaginary masses in reality -that's a hard thing to intuitively understand, lol. But IIRC, mass comes as a result of waves in the Higgs field? But if Higgs are Tachyons then does that imply FTL travel is somehow possible? I'm not sure how you'd get real mass to do that, though.

Superfluid vacuum was interesting, though I think I got just a loose grasp. But from what I got, strictly speaking the Lorentz tranformations aren't exactly correct? I still don't see exactly how this would allow an FTL spacecraft, though H. David Froning's description of an FTL drive did include a superfluid vacuum.

I'd only do that as an absolute last resort... Although physics is sure to be different in 100 years, I still want to investigate any possibility with currently understood and/or speculative physics.

Nah, it's a written book. I've been to both those places (and why would you link me that horrible site? http://xkcd.com/609/ lol, jk, it's great), and they're great sites, but I've seen a few experts on these forums and I was wondering what input they had to add. I'll look at their FTL pages, though.

And anyways, a good author knows many times more about the milieu of his fiction than what's on the pages ;)

Last edited by a moderator: May 6, 2017
9. Jul 1, 2012

### DennisN

I definitely second that.

Thanks for the mention of Superfluid vacuum, Dickfore, I found that quite interesting (in general, not because of any FTL), don't think I've heard of it before!

In Science Fiction I personally prefer brief and "fuzzy" descriptions of new technology, rather than extensive technobabble; to me the explanations often become more weird than the technology itself, making the science even less believable. Somewhat like various interpretations of quantum mechanics ! (sorry, couldn't resist that one). I personally like how it's done in the movie Contact, and also how it's done in the original Star Wars; it's just "hyperdrive", push the button and go. But that's my opinion, of course.

10. Jul 1, 2012

### Staff: Mentor

It's total gibberish. I wouldn't let that stand in the way of a good story, but it's still gibberish.

Last edited by a moderator: May 6, 2017
11. Jul 3, 2012

### CWatters

Perhaps in 100 years we will have found a way to control the inflation of space (Well he did say it's fiction). So you point your machine in the direction you want to go, and it it "deflates" a narrow corridor of space bringing your destination "nearer". You turn it off and travel to your destination at less than light speed. Then you point your machine back they way you came and press the inflate button again. Simples.

12. Jul 3, 2012

### Decimator

The best option is to figure out exactly what you want the FTL drive to do, then have it do exactly that and nothing else. You should not give details on its function, since any such details would be nonsense anyway. If you want your ships to move ten light years per hour, then they move ten light years per hour. If you want them to hop from oort cloud to oort cloud, then that's what they do.

Another question to ask yourself is if the story you intend to write actually requires FTL travel. Our solar system is a pretty interesting place!

13. Jul 3, 2012

### Dickfore

Last edited by a moderator: Sep 25, 2014
14. Jul 3, 2012

### rbj

Matt, do you know or have an understanding of special relativity? call it "Alcubierre drive" or "Heim theory" or something else, do you understand why, if c is constant for all inertial frames of reference, that it is impossible to be in a frame of reference at a speed equal to or exceeding c from the POV of any other frame of reference?

just because you see it in Star Trek or Star Wars doesn't mean that it will ever exist, no matter how technologically developed we get.

for Sci-Fi, i thought that the "hyperspace" notion (Star Wars) required less "suspended disbelief" outa me than "warp drive" (Star Trek).

15. Jul 3, 2012

### Nabeshin

Do you understand that the speed of light restriction is only local in character? Within the alcubierre drive, nothing locally exceeds c, however global motion faster than c is possible.

16. Jul 3, 2012

### Gordianus

Many Sci-Fi authors wrote wonderful stories just by assuming FTL was available. No explanations were given. Period.
Isaac Asimov advised on using this method. Do you think positronic brains are feasible? I don't care, his novels were so good...

17. Jul 4, 2012

### MattRob

I think some details would be kinda neat. I think I'll just go with something along the lines of H. David Froning's proposal, as Nugatory wrote;

Since the true heart of any physics is mathematics, and I won't be spilling equations all over the text, that really doesn't make much of a difference. I won't go out of the way to explain it, but I do need to know how it works for the sake of consistency and coherence. It'll be one of those things that don't make it into the text but the author knows ;)

As for our solar system, unless somehow we've not noticed an Earth-like world lush with complex alien life, then I'll have to go interstellar :P Though I do agree, I think people skip over our own solar system too much when it's not called for. Number one mistake sci-fi authors make is forgetting how big space is. Really I think it's far beyond the comprehension of any human being, and probably the people who know best are the Apollo astronauts. Just one of those things you can't really intellectually comprehend; you have to see it with your eyes to fully comprehend it.

And that's just a short "hop skip and a jump" to Luna. Really nothing compared to interstellar, or even interplanetary travel. Watching the Earth shrink into a tiny little point of light over a few weeks, or even days, as you zip away will probably be one of the most... Humbling? Awe-inspiring? Whatever, one of the most amazing sights in history.

Well, I've heard the "handwave it" suggestion a few times, but this is the most convincing I've seen it written, by far, when you bring Asimov into it.

Even magic sometimes needs a sort of consistency and working, though. And seeing as this isn't magic, it'll need to have some consistent explanation. Like I wrote just now, I think I'll go with something like the Conditioned ElectroMagnetic radiation polarizing the vacuum around the spacecraft, so I have something consistent and original to work with in my notes and in my mind, but it'll hardly touch the text beyond what's absolutely necessary.

My first and foremost objective is to come up with something original, and I think that fits the bill :)

18. Jul 4, 2012

### Vorde

The easiest thing is just to come up with some source of negative energy. We know that with negative energy some forms of time travel of feasible. Of course in real life there isn't any negative energy, but thats were fiction comes in handy.

19. Jul 4, 2012

### Ryan_m_b

Staff Emeritus
A few comments that I hope help; firstly if you haven't seen it already atomic rockets is a great resource for budding SF authors IMO (EDIT: Just saw that you have earlier up thread). It contains many pages on the various troupes of SF with advice and comments that can help you weave ideas into a story as well as containing a lot of side information to point out the effects of the causes (plot devices) e.g. if you're going to allow faster than light travel you either have to throw out causality or relativity or include some form of CPC (Larry Niven invoked the plot device that any attempt at time travel removed the reason for the journey and thus it never happens). This is also a good resource for addressing causality and other effects of FTL communication or travel. You don't have to address it of course but some readers may question it and the best SF is generally regarded as that which fully examines the effects of the plot devices and story premises. Finally on that specific topic you don't have to have FTL to make space opera as Al Reynold's Revelation Space demonstrated with its gigantic, near-light-speed travelling ships.

My second general piece of advice would be to pay considerable thought to the ecological considerations of your book. If you're going to have space habitats or ships you are going to need the technology to make closed ecosystems: environments that contain sustainable food webs capable of maintning a healthy human population. If you can't do this then either all ships and habitats will need resupply from Earth or you'll have to include further technologies that allow for resources to be scavanged in space or on other moons/planets that can be processed into nutrients for the environment. I know this sounds like a small thing but it has huge effects because if you can do it then there is no need to leave the solar system (simply build a station in space or a tented/domed settlement on a moon/planet) and if you can't do it then leaving the solar system wont solve anything. Reason being if there is an alien world out there with a biosphere it is either going to be so different as to be inhospitable; can't eat the food, can't grow crops on land with alien soil biota etc or if it is similar enough it's going to kill everyone via some immune response be it superantigenic or just simple infection from a pathogen we have no immunity for. Even if that weren't the case introducing terrestrial life to alien environments is going to have a huge effect as all cases of invasive species do. Funnily enough we had another SF author here recently who touched on this topic so rather than typing out further suggestions I'll quote my response to them;

Last edited: Jul 4, 2012
20. Jul 5, 2012

### Decimator

What's the basic premise of the story? That'll influence what you want to use for FTL.