Another theory on FTL travel

[Thedus]

OK, bear in mind I am not a physicist, so this theory will have some holes. ...feel free to point them out.

 

There are a few agreed upon "rules" for FTL travel that need to be dealt with in order for it to occur: an object cannot have mass, and if said object does have mass the mass must remain constant at all times. Through the theory of Special Relativity FTL travel cannot be achieved because if a ship is able to sustain infinite thrust and increase in acceleration the closer the ship gets to light speed the slower it will travel due to the fact that Newton's second(?) law is no longer applicable at such speeds: the faster the ship is going the more mass it would seem to acquire. This goes against the need for constant mass. And since infinite thrust is impossible due to the need for a fuel to generate the thrust then even if the ship could overcome the conversion of energy to mass it would still never reach light speed due to constant changes in mass brought on by fuel consumption and interaction with Aether. ...It occurs to me that the closer to light speed the ship gets it would probably be expending increasingly less fuel and generating increasingly lessened thrust as well.

 

Through this theory time also appears to dialate for the individuals within the ship the closer the ship gets to light speed - in an ideal scenario this would want to be avoided so that the astronauts onboard could maintain an even frame of reference for travel time, actual date and times based on Earth (most likely GMT) for the purposes of mission logs, it may also aid in navigation and course plotting.

 

To overcome the time differential we could look to the use of a Alcubierre metric to generate the necessary spatial wave form to "carry" the ship from point A to point B. The flat space at the core of the wave would allow time to remain constant with the time in the flat space outside of the wave. This would also eliminate the mass issues noted above. However leaving the Alcubierre metric could be problematic once it has started - much like stopping a tidal wave once it as begun to form. In theory the ship would need to cross through the wave to exit the metric... Which could potentially cause temporal shifts onboard the ship between the flat space within the wave and the flat space outside.

 

In a previous thread WebFeet suggested the use of an Aether bubble. The bubble would deflect Aether while maintaining a constant environment inside. As the ship travels all excess Aether that the bubble comes into contact with is deflected thereby eliminating any potential changes in mass in the ship brought on by increasing interaction with Aether as well as the expentature of fuel.

 

Now here's where my own theory comes in: What if we combine WebFeet's idea with the Alcubierre drive? Instead of creating a spatial wave for the ship to ride on what if the ship was sustained inside a wave bubble? Instead of a static Aether bubble we would have a dynamic Aether bubble whose surface was covered by a controlled directional ripple.

 

The ripples would originate at the exact front of the craft and move backward - eventually terminating at the posterior end of the bubble. The intensity of the ripples would dictate the speed at which the bubble, and the ship inside travel through space. For example a mild ripple may be equal to light speed, an increase to a specific rate would equal LS+1 and so on, thereby allowing travel times to vary according to predetermined factors such as cargo: If medical supplies were desperately needed at an outpost at Epsilon Reticuli they could conceivably be sent at an increased speed... Such as LS+3.

 

Such a means of FTL propulsion would also allow for navigation without the need of chemical or air burst rockets. A gradual change in the ripple origination point would alter the direction the ship was traveling in. If the Ripples originated a 0*x0* the ship would travel straight, if this origination point was shifted to 5* x -5* the ship would move the starboard with a downward angle. This change in origination would have to occur very slowly - otherwise the ripples could intersect as they move back over the bubble causing a disturbance in the bubble surface which could ultimately break the Aether bubble's "surface tension." The result would be the ship dropping out of light speed. The same principle could be applied to increased ripple size for accelerated travel: just as on water the more intense the ripples the more likely there is to be a disturbance in the surface tension which could ultimately cause the bubble to collapse.

 

What I haven't been able to theorize is what would generate the Aether bubble and how the ripples could be generated.

[maddog]

OK, bear in mind I am not a physicist, so this theory will have some holes. ...feel free to point them out.

 

I believe you. I am not going to go item by as there is much to respond to, just

highlights.

 

There are a few agreed upon "rules" for FTL travel that need to be dealt with in order for it to occur: an object cannot have mass, and if said object does have mass the mass must remain constant at all times. ... And since infinite thrust is impossible due to the need for a fuel to generate the thrust then even if the ship could overcome the conversion of energy to mass it would still never reach light speed due to constant changes in mass brought on by fuel consumption and interaction with Aether. ...It occurs to me that the closer to light speed the ship gets it would probably be expending increasingly less fuel and generating increasingly lessened thrust as well.

 

Through this theory time also appears to dialate for the individuals within the ship the closer the ship gets to light speed - in an ideal scenario this would want to be avoided so that the astronauts onboard could maintain an even frame of reference for travel time, actual date and times based on Earth (most likely GMT) for the purposes of mission logs, it may also aid in navigation and course plotting.

 

To overcome the time differential we could look to the use of a Alcubierre metric to generate the necessary spatial wave form to "carry" the ship from point A to point B. ...

 

In a previous thread WebFeet suggested the use of an Aether bubble. ...

 

..

 

What I haven't been able to theorize is what would generate the Aether bubble and how the ripples could be generated.

 

A series of incorrect/misleading/incomprensible statements:

 

1. [Paraphrased]FTL ... an object cannot have mass

Incorrect: Any such object/particle were it to exist would have imaginary mass. This

does not make sense in a real world. Admittedly I haven't studied Roger Penroses

Twister Theory as yet (want to). From what I do understand dimensions (spatial ones)

are extended into complex numbers which can allow for imaginary values. Still what

does that mean.

 

2. You're a century of. Einstein got rid of the need for "Aether" in SR. :rant:

 

3. "...It occurs to me that the closer to light speed the ship gets it would probably be expending increasingly less fuel and generating increasingly lessened thrust as well."

DUH?: Add this one to growing list of silly quotes. "If we go faster we need less" ???

 

4. "...time also appears to dialate for the individuals within the ship."

In who's reference. Not theirs! If someone were magically able to watch their faces

the whole time in their travels. They would notice the dialation of time. How would

you go about avoid such?

 

5. Call me ignorant. What is an "Alcubierre metric" ?

 

6. How do you go about creating an "Aether bubble when Aeter doesn't

exist ? I guess you answered this question in that you don't know (yet?) !

 

Excuse me for asking, do you like live near an indian reservation. Just wondering because

I have heard that there Peyote is mighty rightous and I thought maybe you had taken a

few buttons when you came up with this.

 

I have to go now. However, after I give it some thought I will come and post here the

notion about Tachyons (said to be a class of theoretical particles that are FTL in nature).

I am not saying such particles exist or not. Conventional wisdom and the current Standard

Model says they don't. Let me state in a new post.

 

Please help me out and if you have details on my question 5 and 6 (those are the only ones

I want to know more about). Call me adventerous. :hihi:

 

Maddog

[maddog]

Thedus,

 

Ok, now that I am home and time to think...

 

Tachyon: Ignoring whether such particles can exist for the moment; such particles would

be considered going Faster Than Light (herein called FTL) -- (always). Doing so prevents

anomalies in SR and divergences (infinity). Their mass value is only considered to be

imaginary when the frame of reference of the observer is moving slower than light. You

can see that yourself if you use Einstein's SR dilation equation and allow the observed

particle to v > c. Thus in this way the mass of the particle, the time reference of the

particle as viewed from a real observer would be imaginary. However, the energy is

still real in both frames. There is a difference. As the Tachyon particle slows down,

dilation occurs as if it was real and speeding (below c). As it speeds up likewise the

particle loses energy and goes even faster. Since the mass of such a Tachyon approachs

0 as speed increases, this implies there is no actual rest mass for Tachyon either.

 

If you don't allow either types of particles to communicate

(FTL => Tachyon, STL => Tardyon)

you in essence do not violate Einstein's SR Theory directly. This would still play havoc

with the notions of causality and why you don't hear discussion of such particles as a

class or type.

 

However, there was one Physicist I found while I was in college (and article) on

 

"The classical theory of Tachyons", by R. Recami, 1976 in the Italian journal

Nuovo Il Cimento (I forget which vol). Since then I have seen him write articles from

time to time.

 

With the explosion of material from 1984 on Superstring theory, I have been hearing of

'Ghosts' and why they are 'bad' for causal relationships. I am curious if these weren't

considered the same. It was because of Ghosts creeping back that the 26 dimension

theories were pretty much abandoned.

 

I know this doesn't really talk much about your theory (which I didn't really understand),

it is a valid discusion on FTL (particles) at least (not space ships). :hihi:

 

Maddog

[hefner]

The inability of spacecraft to achieve, in less than 4 Earth years, displacement to a place 4 light-years distant from Earth.. has nothing whatsoever to do with mass increase necessitating infinite fuel consumption. That notion is in widespread gossip, but there is no truth to it. High speeds are no impediment to thrust at all! That's because there's no such thing as "high speeds", only high relative speeds. How fast you appear to be moving, by the reckoning of some arbitrary onlooker, cannot change anything intrinsic to your craft; think about that! How many different arbitrary onlookers can you count, hmm? each one on a different relative trajectory? Which one of those onlookers' viewpoints will be arbitrarily chosen as the deciding factor in screwing up your life!? :hihi:

[hefner]

...So I like to look at it this way: yes, it would require an ever more disproportionate expenditure of fuel to add speed, as you approach the limit c, but not because you are getting heavier! Light moves at about one foot per nanosecond, or 12 IPN. Let's say you accelerate from Earth until you're moving away at 10 IPN. You can then apply your rocket engine thrusters according to the normal Newtonian calculations, and easily achieve an additional 1.0 IPN. But because of clock and ruler distortions, that additional 1 IPN in your frame, constitutes only an additional 0.28 IPN as far as Earthbound folks are concerned. See? the steep climb has nothing to do with mass change.

[geko]

I was actually thinking about means of travelling the other night whilst lying awake in bed and i came to the conclusion that the speed of light is pretty slow. Sure, to mars or even pluto or something this speed would be pretty novell, but it's hardly a viable option for extensive space travel - millennia of travel and you're still in the milky-way?! pff

 

Also, this is not to mention getting to and travelling at that speed is very expensive on resources. What do the laws indicate? Something like it would take an infinte amount of energy to get there (this amount no being available) and then this much energy would give the propelled object and infinte amount of mass (this amount not being possible). Something like that im sure.

 

So anyway, from this we can deduct i believe that trying to harness the speed of light as a means of travel is pointless.

 

This then leads me to try and think of other means of travel apart from linear (<-i think is the right word to use), and i come to... no idea. I suppose the idea of worm holes and such is the first idea that comes to mind - but this idea is just as wacky at our level of understanding isnt it?

 

So i was thinking, are we forever stuck in our own solar-system? I like to think that one day humans will have colonised space (our galaxy at least) and that we harness the energy of the suns etc., with some kind of array to power our needs. But how to get there? How do we get to these other suns to use and planets to colonize? This would be a very exciting discovery.

[paultrr]

The Alcubierre metric refered to was that utilized by Doctor Alcubierre when he devised an interesting mathamatically example out of GR to something proposed from time to time by science fiction(ie Warp Drive). The metric is simple a normal GR metric which involved using gravity to move some point ahead of a craft closer to the craft and at the same time move a point behind the craft further away from the craft(requiring negative energy) while all the time the craft remains in a non-accelerated frame of reference.

 

As for what is termed superluminal paths or FTL paths there is also the idea proposed by Fernando Loup a bit back in which using a path through hyperspace from multidimensional theory might solve travel times to the stars. The problem faced by that alternative idea can be summed up as follows:

 

The Geometry of Space-time in Special Relativity with hyperspace added in

 

SR uses a 'flat' 4 dimensional Minkowski space, usually referred to as space-time. This space, however, is very similar to the standard 3 dimensional Euclidean space, and fortunately by that fact, very easy to work with.

 

The differential of distance(ds) in cartesian 3D space is defined as: ds^2 = dx_1^2 + dx_2^2 + dx_3^2 where (dx_1,dx_2,dx_3) are the differentials of the three spatial dimensions. In the geometry of special relativity, a fourth dimension, time, is added, with units of c, so that the equation for the differential of distance becomes: ds^2 = dx_1^2 + dx_2^2 + dx_3^2 - c^2 dt^2 In many situations it may be convenient to treat time as imaginary (e.g. it may simplify equations), in which case t in the above equation is replaced by i.t', and the metric becomes

 

ds^2 = dx_1^2 + dx_2^2 + dx_3^2 + c^2(dt')^2 If we reduce the spatial dimensions to 2, so that we can represent the physics in a 3-D space, ds^2 = dx_1^2 + dx_2^2 - c^2 dt^2 We see that the null geodesics lie along a dual-cone: defined by the equation

 

ds^2 = 0 = dx_1^2 + dx_2^2 - c^2 dt^2 , or

 

dx_1^2 + dx_2^2 = c^2 dt^2 Which is the equation of a circle with r=c*dt.

 

If we extend this to three spatial dimensions, the null geodesics are continuous concentric spheres, with radius = distance = c*(+ or -)time.

 

ds^2 = 0 = dx_1^2 + dx_2^2 + dx_3^2 - c^2 dt^2 dx_1^2 + dx_2^2 + dx_3^2 = c^2 dt^2 This null dual-cone represents the "line of sight" of a point in space. That is, when we look at the stars and say "The light from that star which I am receiving is X years old.", we are looking down this line of sight: a null geodesic. We are looking at an event d = sqrt{x_1^2+x_2^2+x_3^2} meters away and d/c seconds in the past. For this reason the null dual cone is also known as the 'light cone'. (The point in the lower left of the picture below represents the star, the origin represents the observer, and the line represents the null geodesic "line of sight".) The cone in the -t region is the information that the point is 'receiving', while the cone in the +t section is the information that the point is 'sending'.

 

The biggest difference with adding in extra dimensional hyperspace is that the cone spreads out and shortens in height for the hyperspace frame almost becoming an instanton where far larger distances are encompassed in relation to our normal space-time frame. However, when you try and compare events from one frame to another with the limits our frame imposes you find that while event rates in hyperspace yield a superluminal path that path in relation to our frame moves into the future. Thus, while for anyone using such a superluminal path(see Fernando Loup’s works on Cern) their journey will appear to be faster than light in our normal space-time they have simply journeyed into our far future. What has happened is the null geodesics which are continuous concentric spheres, with radius = distance = c*(+ or -)time, has in the hyperspace frame, our normal concentric sphere a vastly shrunken version. Yet, in our frame of reference the hyperspace sphere may be many spheres removed from our own.

 

When a careful comparison of frame to frame is done one finds that unless one cares to limit this future time travel through hyperspace to C or less paths that such travel does not actually get around some of the current problems we face when it comes to traveling to the stars. However, interesting enough, such dual frames do not only offer solutions to how entanglement might work, they do offer a possible solution to creating metrics simular to the one proposed by Alcubierre. I say simular to his simply because that original metric has many problems when it comes to trying to make such a physical reality. One such example is the large amount of exotic energy required which violates quantum energy conditions for our space-time.

 

The main problem with almost all of the theoretical original ideas on FTL travel is if one trys to construct such fields one is required by the velocity of such fields to construct the field faster than the path itself allows. Fernando's hyperspace idea does allow such in a fashion simply because the path is one into the future lightcone in relation to our space-time. But, one would still have to solve the other problems like creation of negative energy in the first place as well as how to cross over into hyperspace in the first place.

 

Do not get me wrong here. There are possible solutions to all these problems out there. For one the amount of exotic energy required can be lowered in theory. But, all of these ideas are based upon being able to engineer in a way we simply do not have the ability to do at this time. What few bother to realize is most of this off the wall thinking has added to our understanding of nature itself on many fronts. At one time it was almost taboo to suggest there could be any theoretical way around the speed of light. Now there are even mainline researchers out there sugessting that C itself may not always have been a constant. Thinking about such has actual value and is a worthy path of research. For one, if we ever do want to actually travel to the stars we will need to find a way to either reach C or exceed it. Current propulsion methods simply will not work for star travel when it comes to travel time, supplies, fuel, etc.

[paultrr]

I too hope that one day we will find a way to explore the universe and to move out acorss it. For one, this planet and this solar system has a limited life span. Granted, from what we know in theory so may this universe. But, as a Father I would like to think that my children's children would have a future which is why on one level I have spent the better part of the last couple of decades thinking along such lines and the focus of a lot of the articles I have done in the past few years has been on the subject of space craft propulsion from a theoretical stand point. A lot of us reasearching such do so for many reasons. Some grew up on Star Trek, Star Wars, Babylon Five, and simply would like to see something of that kind of future. Some aspire to being the one who develops such an idea and getting recognized as a real world equal to Zephran Cochran from ST fame. Some simply like the challenge such research offers. But most of us all share that background hope and wish for the survival of the human species.

 

However, if earth history is any example making it to the stars is only part of what we face when it comes to survival. For one, I doub't that if life exists out there all of it will welcome us with open arms ala Star Trek. If I was going to suggest any version of SF was closer to the real future that awaits us it would be that shows like Babylon Five where we face friends and foes alike is closer to reality. Evolution is about survival and growth.

[Tormod]

Thanks, paultrr, very enlightening posts.