Superluminal warp drive possible?
Recently a friend shared a link to an article about NASA’s plans for a superluminal warp drive powered ship (see https://jalopnik.com/the-painful-truth-about-nasas-warp-drive-spaceship-from-1590330763). Of course, intrigued by the physics, I’ve considered the question myself. Is it reasonable? But wait think about this, I found myself asking…
If superluminal waves could be possible shouldn’t we see evidence in the natural universe? After all gravitational waves are now being detected with instrumentation that is sensitive enough to not only detect these from an originating cosmological event but also ruling out that an errant signal weren’t produced from things like the vibrations of cars in heavy traffic during rush hour on any given day, or seismic activity or anything else coming from earth that might perturb the signal bearing mirrors used in inferring the gravitational wave in the first place. In other words, as anything else building a sensitive enough instrument is enough of a challenge, but also like candlelight that loses luminosity over distance, gravitational waves propagate in relation to inverse square law losing signal strength accordingly over the vastness of space.
But even if amplitude of such waves (that is, how much disturbance we actually see) diminishes over distance, the frequency attribute of these signals remain the same. That is, we sense that the gravitational wave is a luminal event, and not superluminal event.
So this begs the question: if superluminal distortions of space time are possible? Is it possible that we might sense them in our natural universe? And what events might produce these? And how in the first place would you generate a superluminal wave? Of course, if binary star systems or black holes can muster luminal velocities but not superluminal(faster than light), what in the natural universe can do this?
I thought about superluminal expansion of the universe (see https://physics.stackexchange.com/questions/316883/universe-expansion-sub-luminal-velocity-elements) And it is a compelling question. Of course, it seems the very conditions of our early universe may have provided prerequisite conditions. But seemingly the all the energy stored in our universe that would lead to so many billions upon billions upon billions (as they would say) of stars would have to be a spectacular amount of mass-energy!
Thus, you might imagine where I am going with this. It seems like you’d need some unique physical conditions to take place to produce a superluminal space time distortion. At least the assumption, is that if its possible and we have evidence…well it seems we have evidence that superluminal propagation is true, but that its origins go to not commonplace events happening with any regular frequency, or that this is owing to synthetic events followed by something far more exotic in producing this.
Yes we could try to replicate the conditions found in binary star systems and potentially generate space time distortions, but these would likely be luminal transmissions, I’d imagine? Seem reasonable?
Of course, I am inferring that scale of mass and energy bear relation to propagation of space time fabric distortion say by gravitational waves and then linked to other cosmological events such as expansion of the universe. It seems any correspondence here suggests that faster than light communication must be extremely rare…or certainly given to much small scales of distance in travelling owing to inverse square laws and the amount of energy supplied in producing such waves making them not as likely traversing great distances and more likely to have faded into indiscernible cosmological white noise.
On the bright side for superluminal communication, there is a bit of a mystery as to why the features of the universe shares some homogeneous distributions (that is, where parts of the universe are seemingly beyond the ability of communicating with one another in terms of luminal exchange), it seems inexplicably inferred something strange (and nearly superluminal ) may be going on, so this maybe there is more hope than realized!
At present our civilization struggles with housing stellar equivalent energy systems, however. Thus imagine housing quite dense masses capable of producing significant warping of space time…if you remember as a kid hearing that a teaspoon of a neutron star falls right through earth. The truth of the matter is that such high density and likely exotic matter, the sort capable of causing space time distortions by scale where it does matter, isn’t something that is so easily stored. You propose what you think is the strongest of a given vault system, and not so fast, that matter has ripped or melted its way right through your containment system. You need enough matter at least in providing a distortion to the space time field around your vessel, so at least, its not nearly on the scale of the size of a star, but in a way….hmm…you are thinking about this and the distortion that earth poses to any vessel orbiting. Yes, earth with all of its matter is warping space time enough so to accelerate bodies orbiting at 9.8 m/s² . And this is just for the amount of matter that comprises a planetary body such as Earth…and now we are approaching the task of creating a superluminal wave…maybe that starts well into subluminal ranges and is itself accelerating to superluminal ranges so as to accelerate a human body safely far less than 9 g (a general threshold described as incapacitating and beyond deadly).
The problem is all in the containment system, and how to create ripples in space time that aren’t merely luminal ones but superluminal ones and presumably do this in a way that is safely done for human space flight. You are thinking superpositions of waves maybe, and it seems this must be no easy task. So you imagine creating fields of waves that through positive superposition must culminate in waves at a given focal point behind and destructive interference in front of the ship…you had a fixed point that generated a superluminal wave, you might have considered it generated from a relatively stationary point, and so maybe receiving nodes and wave station generating nodes were positioned along the route that the vessel was entirely at the mercy of for path guidance alongside de accelerating forces. It makes little sense to try and expend so much energy to accelerate a body that is in principle the generator of such waves and likely as stationary immobile relative to the ship as could be had of a man and the largest mountain that he attempted moving by his own hands. The waves are generated by something, remember, exotic and distinct relative ordinary matter. Far denser than anything found on Earth and likely quite hot. You fiddle with complex management systems that attempt to control this “ionized” hot plasma or whatever it is that is as tedious in controlling as a pin balanced perfectly at the head of a razor’s edge fulcrum or magnified million fold …no make that a billion, no a trillion…how large?
This couldn’t be something so easily managed could it? Arotating gyro does the trick as easily as water solves an invasion? The truth of the matter is that we are still working on harnessing and containing the energy mass equivalent way scaled down version of a single relatively modest sized star.
The thing is that you’d have to be using scaled events somehow, someway that go beyond even what larger scale black holes can accomplish in generating ordinary luminal gravitation ripples, and that is the inherent problem with generating a wave that must require likely quite a bit of energy…I mean the sort of energy that is quite likely excessive to one star and many stars as well as the densest stars imaginable! This is beyond world ending energy, could it be galaxy ending sized energy? :)
I run wild with notion only pointing out what we naturally know likely occurs and thus have something to model from as opposed to entirely theoretical that is likely a tenuous as holding the throat of a wormhole for any length of time to make feasible the size of a human sized space vessel to pass through…the truth of the matter is that type of matter is likely synthesized and there is likely nothing natural about it to provide adequate modeling.
Though consider the origins of superluminal gravitational waves under specialized circumstances (see https://arxiv.org/abs/1406.2609f)…but this dates back to 10^-43 seconds after the big expansion. At this time owing that gravity were squeezed into much smaller spaces than that found today, a form of quantum refraction were occurring…so it seems a model could potentially exist here…but it is also in an unfamiliar universe to that which we have today which is a whole other problem!
