UFO propulsion, metric engineering, and horizon physics

[Thomas R Morrison]

We keep hijacking various threads to discuss advanced concepts in theoretical physics which, I feel, have a direct bearing on the immensely significant question of UFO propulsion. So I thought it would be better to dedicate a thread to these ideas where we can debate them all in one place. And stop annoying the rest of the board members in the process

First let me briefly set the context for this discussion by briefly describing the concept of gravitational field propulsion. Put simply, theorists have discovered that if a body of positive/ordinary gravitating matter is placed next to a body of negatively gravitating matter, the two will self-accelerate indefinitely in the direction of the positive matter. It sounds crazy, but the math works out in both Newtonian physics and general relativity.

For decades this seemed like a purely speculative thought model because we’ve never observed a form of matter that possesses negative inertia, and it would appear that such a thing doesn’t exist. However, in recent years a reputable physics professor who specializes in general relativity has proposed a way around this problem – using the pressures terms in Einstein’s stress-energy tensor to make a bubble composed of positive matter exhibit the properties of negative inertial mass and a negative (repulsive) gravitational field. So it appears that the game is afoot.

And here are the characteristics that are predicted for a gravitational field propulsion system: silent hovering, dramatic accelerations with no on-board g-forces (because all matter within the gravitational field gradient is accelerated uniformly), possible faster-than-light velocities (this field propulsion concept is the one theoretically viable loophole around the limit of light speed), no emissions, and no intrinsic energy expenditure (once the system is active, it doesn’t take any energy to accelerate the device, other than whatever efficiency losses are inherent in its operation).

If that sounds like a hand-in-glove fit for the performance characteristics most commonly reported by ufo witnesses, then we’re in complete agreement.

Now I think it’s extremely unlikely that we’ll see any kind of successful gravitational field propulsion experiment within our lifetimes. In fact it would appear that such an advancement is many hundreds or even thousands of years ahead of us, if we continue to advance technologically. But it does appear to be an inevitable achievement, because the trajectory of the concept from an “impossibility” to a “curious speculative model” to “a possibly viable theoretical model” and so forth, seems very clearly to be moving in the direction of an eventual technological realization of this concept. And ufos appear to be evidence that many other civilizations have already achieved it.

I’ll start by replying to a recent post by marduk, which appeared in this thread:

First For starters, the equivalence of inertial and gravitational mass is experimentally established to within 10^-13 (one part in ten trillion), the current limit of experimental precision.

Totally agree! They happen to be equivalent, but I have yet to see a compelling reason that they are. It is an interesting question.

Yes it is. In fact, the question “what is the origin of inertial mass” is a highly controversial and unsettled question in physics – we just published an episode of Physics Frontiers about it:
Physics Frontiers - The Origin of Inertia

I tend to favor the theoretical explanation presented by Dennis Sciama in 1953 (in his PhD thesis under Paul Dirac), which describes inertial mass as the gravitational interaction of all of the matter in the universe (aka Mach’s principle) because this model explains both the origin of inertia and the equivalence of inertial and gravitational mass with a single postulate. And it uses the clear and uncontroversial mathematics of gravitoelectromagnetism to arrive at an encouraging ballpark numerical estimate.

But different theoreticians subscribe to different models for inertia, and they’re all absolutely convinced that their explanation is the correct one – so it’s wise to be circumspect about it.

Likewise, the stress-energy tensor is as valid as the metric predictions of GR (they're mathematically equivalent), so it's well proven at this point. Every conceivable form of hammer has been taken to GR, and it always prevails. There’s no doubt that it’s correct for modeling all of the effects that we’ve discussed here. When it's superseded by an even more general theory someday (a grand unified theory, presumably), we already know that any future developments won’t obviate its mathematical validity, just as we know that Newtonian mechanics holds true within the nonrelativistic regime. If GR isn't accurate at some level, then we know that it'll only deviate in extremely strong gravity regimes such as neutron stars and black holes, because no deviations from prediction have emerged in all of the regimes that we have been able to test to extremely high precision (which is basically everything short of neutron stars and black holes). If you study it, you’ll find that the better you understand it, the more you’ll agree with me on this.

My argument is not one from belief in or against the stress-energy tensor. It's on how you can influence the tensor to achieve a desired outcome.

But I think those two statements are incompatible. Because the stress-energy tensor provides a wide range of variables that modulate the mass, and therefore the gravitational field, of a body or system. Take the pressure components of the stress-energy tensor for example. GR tells us that a body under high positive pressure (compression) has more mass and a stronger gravitational field than a body under low pressure. This has been indirectly confirmed through astrophysical observations, iirc. Likewise, a body under tension (negative pressure), such as a stretched rubber band, has lower mass and therefore a weaker gravitational field than a body without tension. These are uncontroversial features of the stress-energy tensor, so you can either believe it, or not. But if you accept general relativity, then the variability of mass is a given, and there are many different ways to achieve it.

And there’s no hand-waving in those papers [Paranjape’s papers about negative mass solutions in GR] – they’re solid. They’re derived directly from general relativity – there’s no new theory in there. It’s akin to deriving the concept of a suspension bridge using Newtonian physics – you now it’ll work before you build it because you know that Newtonian mechanics works for structural engineering (except in this case, you’re engineering the spacetime metric instead of steel and concrete). And they were published in the most respected peer-reviewed physics journal on the planet, Physical Review. It’s been three years since those papers came out, and I haven’t seen a single challenge to them in the academic literature (typically it takes less than a year for somebody to find an error that slips past the review panel). And there are no contrivances either – this is fundamental physics, not wild speculation. So it’s safe to say that they’re as credible as general relativity itself, because they were derived directly from the general theory of relativity. And to date, every prediction derived from general relativity has eventually been proven correct - gravitational waves being the latest confirmed prediction among many.

Line one of the paper you reference that I responded to goes as follows:

“Negative matter is a hypothetical form of matter who's active-gravitational, passive-gravitational, inertial, and rest masses are opposite to normal, positive matter.”

That is pretty much the definition of hand waiving.

You're quoting from Robert L. Forward's 1990 paper "Negative Matter Propulsion," which predated the recent discovery in Paranjape's 2014 paper that a negative mass effect can be created with positive matter by exploiting the pressure terms in the stress-energy tensor. Honestly I was a little annoyed when I discovered that paper because I was going to write one about the exact same idea.

Of course, a valid and peer-reviewed theoretical derivation is still not the same as demonstrating the validity of his calculations with a physical experiment in the lab. But it’s a major advancement in the theoretical physics of metric engineering, and affirms the prospect of one day engineering a working gravitational field propulsion system.

Also, tension isn’t a special state of matter: you use it every time that you use a rubber band.

I’m glad to see that you appreciate my enthusiasm. It’s just a shame that you can’t share it.

I want it to be true. I want this to be an engineering problem and not a scientific one.

The problem is that everybody I talks to says that it's not and even the Alcubierre drive probably only works as a thought experiment.

I understand that. I’m just pointing out that Paranjape’s work moves the concept from a mere gedanken experiment, one step forward toward some kind of realizable physical experiment, because two key obstacles have now been removed from the equation; 1.) the positive energy theorem, and 2.) the requirement for exotic matter. Those were the two primary objections that had previously relinquished warp field propulsion to the realm of “amusing but unphysical ideas.”

It’s not the end of the road – not by a long shot. But it is a beginning.

That can be advantageous in the treacherous world of ufology, but when it comes to understanding theoretical physics, it’s a major liability. Because you tend to dismiss all of it, even the rock solid stuff. You’re not going to believe that anything is possible until somebody proves it experimentally, which honestly makes these kinds of discussions exasperating, because you’re impervious to everything including peer-reviewed academic findings directly derived from the most successful physics theory in human history. It’s just a personal temperament thing, I suppose. I have the opposite kind of temperament: I’m enthralled with landmark theoretical breakthroughs because I can see their significance and the inevitably of their future developments and applications. This reminds me of the days when physicists first calculated that we could send a man to the Moon: some people guffawed at the "paper proof" that it could be done, while others bristled with enthusiasm. It's up to you to choose which one you want to be - so choose wisely, my brother.

I'm an empiricist. If you want to prove it, demonstrate it exists in reality. Build it and I'll cheer for you in the hopes that it works.

But I won't believe you until it actually does work.

Don’t I know it, lol. Indeed – this is the eternal conflict between temperaments on opposite ends of the spectrum: the theorists and the materialists.

It seems obvious to me that the progress from a speculative theoretical notion to an applied technology, is comprised of a series of discrete incremental steps – so I get excited as each step is checked off on the way to physically realizing a revolutionary breakthrough.

You, perhaps rightly, see no tangible benefit or even definitive “proof” until the final step has been achieved.

I suppose we’ll never see the merits in our differing viewpoints, because we’re simply wired differently.

Yes we have many steps to take before we can effectively engineer with applied general relativity. Trust me – I’m keenly aware of that, and I brainstorm about those steps relentlessly. But it’s already inevitable. I recently saw a paper proposing a currently achievable experiment to create a gravitational field in the laboratory using a pair of large superconductive magnets and a Michelson interferometer to detect the gravity generated by its electromagnetic field. So experimental general relativity is about to step through the door.

Ya, I saw that too, and I'm hopeful someone does the experimental verification of that.

This is an excellent example of our differing perspectives. Because from my point of view, while I’d love to see this experiment performed (a technologically generated gravitational field measured in the laboratory), its success is a mathematical certainty – so it’s not really interesting to me. The proposal is as valid as the blueprints for the Large Hadron Colider; there's no real doubt that it would work. But unlike the LHC, it can’t teach us anything useful, so it seems kinda pointless to build it.

I suppose that from your perspective though, it would provide proof of the validity of the electromagnetic stress-energy tensor. But that's not even an issue of debate, so it seems kinda pointless to perform that experiment, although it would be cool. I’m more interested in exploring the exciting new territories that we haven’t condensed into an achievable physical experiment yet, because that’s where the real pay dirt is waiting.

I'm actually on your side with this; however like much in this whole field, caution and skepticism is needed from people within it to be healthy.

And "You just don't understand it" may be an argument that works with others - like the argument my father in law gave me about converting to his religion - but it doesn't work with me.

And I know enough about math and science that I'll need a better argument than that, too.

But I’ve already given you all of the math and science required to properly assess the validity of GR and the stress-energy tensor – it was in this paper that I cited previously:

“The Confrontation between General Relativity and Experiment,” Clifford M. Will, 2014
https://arxiv.org/pdf/1403.7377.pdf

So I can only conclude, after providing this evidence and yet still facing opposition about it, that you either didn’t read it or you didn’t understand it. And frankly I assume that you just didn’t bother to read it, because I’m confident that you could understand it if you bothered to look (the key experimental and observational analyses are in Sections III and IV, iirc).

It’s just frustrating that you seem to prefer to maintain your present skepticism, rather than make the effort necessary to dispel it with regard to the validity of GR and the stress-energy tensor - which is the basis of my position on all of this stuff.

A real scientist’s answer to the question of why real scientists don’t care about these incredible UFO videos:

“You can’t plan for it.”

Why most scientists don't care about these incredible UFO videos

Oh, brother – the term “real scientists” is as pretentious as it is subjective. Lots of “real” scientists are very interested in this subject, and the intriguing but clearly inclusive videos that we’ve seen recently. He even says so in that interview:

“Caleb Scharf: "I think it's very, very difficult as a scientist to look at something like this and say anything except, you know, it's intriguing.”

But taken in context with the hundreds or perhaps thousands of compelling anomalous reports that we’ve already seen over the last 70 years, there’s ample cause for more than a passing curiosity. Any “real scientist” who’s aware of this larger body of evidence would understand that it merits a proper scientific investigation.

And frankly it’s bizarre that any astrophysicist would be stymied by “you can’t plan for it.” They don’t know when or where a pair of black holes will collide either, or when or where the next gamma ray burst will occur – and yet they collect precise data on those kinds of events all the time.

So of course you can plan for the study of unexplained aerial devices in our own atmosphere. We could use Earth-facing detectors on orbital satellites, for example, to collect data on sighting events reported by pilots and other eyewitnesses and radar operators. We could gather gun camera footage and other scientific data from equipment aboard military jet interceptors (the DoD did this back in the 50s, iirc, but they never released the data for scientific analysis). We could deploy terrestrial observatories in hotspot areas, like Christopher O’Brien’s San Luis Valley Camera/Observatory project.

There are all kind of ways that we could prepare to observe the anomalous events that occur randomly in our airspace – it’s ridiculous to say otherwise. This isn’t 15th-Century feudal Europe; this is the 21st Century where anything that can be physically observed can be physically and scientifically studied with all kinds of sophisticated instrumentation: repeatability in a laboratory environment is no longer a bulwark against scientific progress.

 

[marduk]

Longer response coming, but I still don’t see a way to directly alter the stress energy tensor - or any metric style mechanism - using anything but vast amounts of energy.

Nature tends to do this using energy in the form of mass. We could do the same.

It’s just really inconvenient to use another earth to nullify earths gravity by forming a local la grange point near the surface.

I guess you could label that an engineering problem, but it’s a big one.

 

[marduk]

If that sounds like a hand-in-glove fit for the performance characteristics most commonly reported by ufo witnesses, then we’re in complete agreement.

The thing is, it doesn't sound like it to me.

If it's using a local gravitational source to hold it up, what's holding that gravity source up? Whatever it is, it's still in the Earth's gravity well.

What happens when a bird flies over it? What happens when things are under it?

The object I saw as a child was huge, and flew at treetop level over a forest. None of the trees even moved. Leaves didn't come up, we didn't see or feel anything. This thing was the size of a city block. Anything that held it up should have effected two kids less than 150 feet away from it.

If it expands space/time under it to give it a kind of buoyancy, why doesn't it split the molecules of stuff that's under it? If space itself is expanding, the space between the atoms should be expanding, too. It should be ripping stuff apart. Explosively. I've never heard of that.

 

[marduk]

You're quoting from Robert L. Forward's 1990 paper "Negative Matter Propulsion," which predated the recent discovery in Paranjape's 2014 paper that a negative mass effect can be created with positive matter by exploiting the pressure terms in the stress-energy tensor. Honestly I was a little annoyed when I discovered that paper because I was going to write one about the exact same idea.

Of course, a valid and peer-reviewed theoretical derivation is still not the same as demonstrating the validity of his calculations with a physical experiment in the lab. But it’s a major advancement in the theoretical physics of metric engineering, and affirms the prospect of one day engineering a working gravitational field propulsion system.

I only used that paper because you referenced it as evidence, and then said it wasn't hand waiving.

As an advancement though, I totally agree. As a framework for future experimental shenanigans, it's interesting.

 

[marduk]

I understand that. I’m just pointing out that Paranjape’s work moves the concept from a mere gedanken experiment, one step forward toward some kind of realizable physical experiment, because two key obstacles have now been removed from the equation; 1.) the positive energy theorem, and 2.) the requirement for exotic matter. Those were the two primary objections that had previously relinquished warp field propulsion to the realm of “amusing but unphysical ideas.”

It’s not the end of the road – not by a long shot. But it is a beginning.

How has the need for exotic matter been removed again? I remember you mentioning that, but I forget.

 

[marduk]

Don’t I know it, lol. Indeed – this is the eternal conflict between temperaments on opposite ends of the spectrum: the theorists and the materialists.

It seems obvious to me that the progress from a speculative theoretical notion to an applied technology, is comprised of a series of discrete incremental steps – so I get excited as each step is checked off on the way to physically realizing a revolutionary breakthrough.

You, perhaps rightly, see no tangible benefit or even definitive “proof” until the final step has been achieved.

I suppose we’ll never see the merits in our differing viewpoints, because we’re simply wired differently.

Lol, you're Sheldon and I'm Leonard.

At least I got the hot chick.

 

[marduk]

But I’ve already given you all of the math and science required to properly assess the validity of GR and the stress-energy tensor – it was in this paper that I cited previously:

“The Confrontation between General Relativity and Experiment,” Clifford M. Will, 2014
https://arxiv.org/pdf/1403.7377.pdf

So I can only conclude, after providing this evidence and yet still facing opposition about it, that you either didn’t read it or you didn’t understand it. And frankly I assume that you just didn’t bother to read it, because I’m confident that you could understand it if you bothered to look (the key experimental and observational analyses are in Sections III and IV, iirc).

It’s just frustrating that you seem to prefer to maintain your present skepticism, rather than make the effort necessary to dispel it with regard to the validity of GR and the stress-energy tensor - which is the basis of my position on all of this stuff.

Lol, what I'm trying to say is that the problem of altering the stress-energy tensor is equivalent to the problem of altering space-time. It's not that I don't understand the theory, it's that I don't understand the application.

You need a helluva lotta mass/energy to do it. It's not that it can't be done, it's that it's really inconvenient to do so. Like Kardashev type II or III civilization amounts of energy availability.

Even the wildest current hopes of the Albecurrie drive (I hate trying to spell it) is something like the total conversion of a few tons of matter to energy to make it work. That's still something like the total human energetic output since the dawn of civilization kind of energy... for one starship to use and direct.

Remember whatshisname with the 'give me a hammer and a stopwatch and I can break anything with resonance' comment? Works great in theory, doesn't work at all in the real world.

 

[marduk]

body of negatively gravitating matter

How do you make it?

How do you account for it not being seen in the observable universe so far?

How do we know it's not just a theoretical concept?

 

[Thomas R Morrison]

Longer response coming, but I still don’t see a way to directly alter the stress energy tensor - or any metric style mechanism - using anything but vast amounts of energy.

Energy is only one of the 16 terms in the stress-energy tensor. So there are lots of other ways to modulate mass - we've already discussed pressure as one method. And the electromagnetic stress-energy tensor is expressed in units of pressure as well, so we know that electromagnetic fields can produce an equivalent form of positive and negative pressure, purely electrodynamically. One method, that I described in that other thread, became evident when I was studying the background about the bismuth/magnesium materials that have been mentioned in this context: a photonic metamaterial can have a negative refractive index at certain frequencies, so exposing a sample like that to the right frequency of photons can produce a negative Poynting vector and a negative Maxwell stress tensor, both of which would reduce the mass of the sample. That's what the electromagnetic stress-energy tensor says. But yes, it would take a lot of energy to produce a measurable mass reduction.

But we've already got lasers with petawatt (10^15 Watts) power levels, so we're already in the ballpark, technologically.

Nature tends to do this using energy in the form of mass. We could do the same.

It’s just really inconvenient to use another earth to nullify earths gravity by forming a local la grange point near the surface.

I guess you could label that an engineering problem, but it’s a big one.

General relativity is very interesting, once you dig into it. For example, in many ways the energy density is even more influential on spacetime curvature than bulk mass. But the energy densities available to us technologically are limited to a tiny spectrum of low densities, compared to other realms like nuclear matter. However, in some respects we've made significant headway in that area - for example, the quark-gluon plasmas that we're creating at the LHC are over 100 times as dense as neutronium. That may not be helpful to us at the moment, since those events are so fleeting. But there's nothing really stopping us from making progress in that direction, perhaps creating trillions of such collisions per second, and eventually doing so with a scaled down version of the LHC that operates with the same beam energy. As we surpass the magnetic field densities available with modern superconductive magnets, one day, perhaps centuries hence, we should be able to scale the LHC down to the size of an automobile.

But yes these are big problems. Like I said, I think we're looking at large timescales before we can effectively engineer with general relativity. My primary interest is solving the problem at an applicable theoretical level, so we can have a blueprint for building such a device once our technology catches up to that level of physics. Because that would be the light at the end of the tunnel for terrestrial confinement, which would be very exciting for future generations to pursue. And, I think that once we have an unambiguous vision for the production of a gravitational field propulsion system, then people will be far more accepting of the reality that we're being visited by advanced civilizations that have already achieved it.

We may stumble upon an unanticipated short-cut to realizing this kind of technology, however. This audacious little paper by Jack Sarfatti recently caught my eye - he had the unorthodox notion of dramatically manipulating the speed of light within a metamaterial to potentially radically alter the requisite energy scales for manipulating the spacetime metric (the scaling constant for the stress-energy tensor is G/c^4 so slowing the speed of light down to a few dozen meters per second could, in concept anyway, completely change the game). I wouldn't bet my lunch money that it would actually work (nature is rarely so accommodating), but what the hell - it's worth a try:

Is Low Power Warp Drive Possible? Breaking the Space-Time Stiffness Barrier

And here's the other point I'd like to make about this - the existence of ufos seems to indicate that the energy scales that we're currently calculating for achieving these effects, are off by at least dozens of orders of magnitude. Because if they weren't, then the first ufo crash would vaporize the Earth. Or equivalently, a ufo powering down on the surface of the planet wouldn't rest on the surface - it would fall straight through to the other side and keep perforating the Earth like Swiss cheese, because the energy densities that we think are required for this propulsion principle would have to be far denser than neutronium. These arguments aren't proof of this line of thought, but I do find them compelling - it does appear that the field propulsion principle that these objects are using (albeit a form of gravitational field propulsion, or perhaps some indistinguishable effect achieved via an unknown method of manipulating of the quantum potential) require far less energy than we currently calculate. And that's a very encouraging sign, imo.

The thing is, it doesn't sound like it to me.

If it's using a local gravitational source to hold it up, what's holding that gravity source up? Whatever it is, it's still in the Earth's gravity well.

Arg. I do wish you'd read the papers that I provide - it would save me a lot of effort.

The beauty of this propulsion principle is that the field source has zero net mass - the positive gravitational mass is equivalent to the negative mass. And, when the system is operational, the craft floats in its own dipolar gravitational field gradient. So it literally "falls up" whether it's in deep space, or near the surface of the Earth. That's what's so amazing about this principle - it's a clever workaround that circumnavigates several of our most sacred notions of physics, such as the conservation of momentum and the conservation of energy. It doesn't actually violate these laws - but it sure as hell appears to do so, until you work out the physics at the general relativistic level - which in this case are wildly counterintutive (and frankly awesome).

What happens when a bird flies over it? What happens when things are under it?

We can't be certain, because we haven't been able to determine the field distribution yet - it could be confined to the craft itself; we don't know. But a naive model would suggest that the craft would have a positive gravitational field above, and a negative gravitational field below. And it would fall off by the inverse cube law, because it's a dipole field. So a bird flying right over the top of such a device as it's hovering in place, would probably feel about 2 g's of acceleration downward toward the craft, as it's attracted to the positive gravitational field on top. Similarly, a bird flying directly below the hovering craft would be repelled by the negative gravitational field on the bottom, and experience roughly 2 g's of acceleration (1g caused by the Earth, and 1g caused by the craft) - after being momentarily pushed away, it would be far enough from the craft that the field wouldn't be noticeable anymore.

While undergoing accelerations in flight, however, the field effects would be significantly greater.

The object I saw as a child was huge, and flew at treetop level over a forest. None of the trees even moved. Leaves didn't come up, we didn't see or feel anything. This thing was the size of a city block. Anything that held it up should have effected two kids less than 150 feet away from it.

Not necessarily. It would depend on a few factors. Consider a neodymium magnet and a piece of iron - the force field is very powerful in close proximity (many g's of acceleration) but quickly becomes undetectable just a few inches away. That's an inverse cube law effect. Now consider that a hovering craft only requires a 1g field gradient. You probably wouldn't be able to even feel it unless you got within about one axial length defined by the distance between the two gravitational poles generating the lift. So if the craft were 100ft thick and the poles were at the very top and bottom, then you probably wouldn't even notice that you'd become slightly heavier as it passed directly overhead unless it was less than 100ft above you. I'm just spit-balling ballpark estimates here, but you get the idea. But of course it's not inconceivable that the field is confined to the space within the craft. Weirdly, the metric distortion only needs to act through the center of mass in order to work - the Alcubierre metric works like that actually: you could stand right under the thing and not even feel anything. But that seems like a very exotic metric to me - there are much easier ways to design a metric propulsion system than confining all of the field energy into a thin shell like that. I think he just modeled it as a shell because it makes the math less complicated to analyze.

If it expands space/time under it to give it a kind of buoyancy, why doesn't it split the molecules of stuff that's under it? If space itself is expanding, the space between the atoms should be expanding, too. It should be ripping stuff apart. Explosively. I've never heard of that.

The real action is actually between the gravitational poles - what happens beyond them is irrelevant to the propulsion effect. It just seems counterintuitive because we're so used to pushing against stuff - reaction propulsion.

And you're envisioning really extreme field gradients. All you need to hover is a 1g gradient across the craft. So let's say that your craft is hovering directing on top of the ground, and the field radiates naturally without any containment. In that case, the force only adds about 1g downward upon the ground. An ant right beneath it would weigh as much as two ants. It's really not that dramatic when you think about it.

How do you make it?

Paranjape showed that a bubble of positive matter under sufficient surface tension (like a soap bubble) can, if the magnitude of the tension is high enough, have negative inertial mass and generate a negative gravitational field. Nobody's published a method for producing that level of tension with a specific form of matter, but he showed that it's not prohibited by the general theory of relativity within the context of our accelerating universe. That's significant progress from where we were before - trying to figure out how to make high negative energy density states...though some interesting work in quantum theory points to that possibility - here's one paper about it:

Propellantless Propulsion with Negative Matter Generated by Electric Charges, Tajmar, 2013

How do you account for it not being seen in the observable universe so far?

Lots of physically realizable conditions don't occur naturally. Negative refraction metamaterials are one obvious example. But really the same could be said of any kind of modern technology - nature doesn't just come up with iPhones either.

How do we know it's not just a theoretical concept?

Oh it is a theoretical concept. It's in a similar position as quantum entanglement back in 1935 - the theory says that it's possible, but we haven't got the faintest idea how to prove it experimentally yet. Or perhaps gravitational waves would be a better example. Oliver Heaviside predicted them back in the late 19th century (that guy's genius was stunning), and Einstein understood that they were a feature of general relativity - but he ran the calculation and concluded that they were so weak that actually detecting them would be essentially impossible; he couldn't foresee human technology validating that prediction. Just a century later they made headline news. Einstein hadn't anticipated the advent of laser interferometry.

I think pretty much everything that's ever been predicted by general relativity and quantum field theory has been verified either directly or indirectly at this point. I don't expect that this new prediction of net negative mass solutions of the stress-energy tensor will be any different - it's well within the applicable parameters of the mathematics. The only place where general relativity breaks down theoretically is at the singularity, and we're confident that the quantum theory of gravity (once we have it) will handily resolve that specific problem.

 

[marduk]

Energy is only one of the 16 terms in the stress-energy tensor. So there are lots of other ways to modulate mass - we've already discussed pressure as one method. And the electromagnetic stress-energy tensor is expressed in units of pressure as well, so we know that electromagnetic fields can produce an equivalent form of positive and negative pressure, purely electrodynamically. One method, that I described in that other thread, became evident when I was studying the background about the bismuth/magnesium materials that have been mentioned in this context: a photonic metamaterial can have a negative refractive index at certain frequencies, so exposing a sample like that to the right frequency of photons can produce a negative Poynting vector and a negative Maxwell stress tensor, both of which would reduce the mass of the sample. That's what the electromagnetic stress-energy tensor says. But yes, it would take a lot of energy to produce a measurable mass reduction.

I'm going off these 16 terms: Stress–energy tensor - Wikipedia

All of those terms are some variant of 'energy' right? In the abstract sense that it takes energy to produce?

 

[DROBNJAK]

@Thomas R Morrison you mentioned somewhere that one can circumnavigate a perimeter of visible universe in 80 years only his spaceship held on a constant acceleration. Do you have a reference for that?

 

[marduk]

We may stumble upon an unanticipated short-cut to realizing this kind of technology, however. This audacious little paper by Jack Sarfatti recently caught my eye - he had the unorthodox notion of dramatically manipulating the speed of light within a metamaterial to potentially radically alter the requisite energy scales for manipulating the spacetime metric (the scaling constant for the stress-energy tensor is G/c^4 so slowing the speed of light down to a few dozen meters per second could, in concept anyway, completely change the game). I wouldn't bet my lunch money that it would actually work (nature is rarely so accommodating), but what the hell - it's worth a try:

Sure, it's worth a shot, but it's this kind of stuff that drives me bonkers when I read articles that scream 'warp drive possible!'

However, what is required for practical low power warp drive is not propagating radiation, but a new kind of metamaterial, filled with very low frequency off-mass-shell non-propagating near field virtual photons that are Bose-Einstein condensed into macro-quantum coherent Glauber states of sharp phase and uncertain number. It may be possible to generate them from the aforementioned strong EM field nonlinearities. Ideally, for example, the Fourier transforms of the material responses for the electric permittivity alone that is strongly negative for low frequencies as close to static as possible. Imagine such a longitudinally polarized non-propagating quasi-static near electric field in the hypothetical meta-material containing the virtual photon coherent Bose-Einstein condensate sandwiched between two parallel oppositely charged conducting plates Ð a new kind of electrical capacitor

This is like watching 'The Core' - a movie that I actually love - but still makes me groan when they hand waive the material 'unobtanium' that makes the whole movie work.

 

[DROBNJAK]

First let me briefly set the context for this discussion by briefly describing the concept of gravitational field propulsion. Put simply, theorists have discovered that if a body of positive/ordinary gravitating matter is placed next to a body of negatively gravitating matter, the two will self-accelerate indefinitely in the direction of the positive matter. It sounds crazy, but the math works out in both Newtonian physics and general relativity.

I've seen some references that such behavior was confirmed in a lab, but on non-gravitational systems. Apparently, some engineers in Germany had done it his chasing with photons and second case, Frank Wilcheck's entangled time crystals behave like that. Sort of, same equations, different physical phenomena.

“The Confrontation between General Relativity and Experiment,” Clifford M. Will, 2014
https://arxiv.org/pdf/1403.7377.pdf

So I can only conclude, after providing this evidence and yet still facing opposition about it, that you either didn’t read it or you didn’t understand it. And frankly I assume that you just didn’t bother to read it, because I’m confident that you could understand it if you bothered to look (the key experimental and observational analyses are in Sections III and IV, iirc).

I read that paper. That's widely known stuff, at least in physics circles. Astrophysicist had been working for years analyzing data from neutron stars, black holes etc. GR gets much closer to observation than just plain Newton's stuff. GR rules supreme.

But taken in context with the hundreds or perhaps thousands of compelling anomalous reports that we’ve already seen over the last 70 years, there’s ample cause for more than a passing curiosity. Any “real scientist” who’s aware of this larger body of evidence would understand that it merits a proper scientific investigation.

Exactly. I've heard it so many times: "Show me the proof!?". Like people expect aliens to lend in somebody's back-garden, take selfies with a witness and sign an affidavit.

Statistical proof is proof none the less than hard physical proof. Medicines don't work on all the people, some medical treatments, like chemotherapy, only have 40% success rate but they are still in use. Advertising only works 2%-10%, but still businesses depend on it for their existence. Whole of quantum mechanics depends on statistical proof. What the hack, hard proof is only one type of the proof.

US and French governments had done extensive UFO studies. In US case 21% of cases were found to be anomalous. In French study 25% of cases were found to be unexplained. These were cases where witnesses were close enough to be 100% sure that they were not looking into something ordinary. There was Soviet study as well and Soviet prime-minister Andropov initiated creation of Institute-21 (?) near Moscow that employed about 20 specialists.

There are two pillars of UFO forensics. First pillar is strong statistical trends in data, like EM fields, inundations in soil, RGB lights, plasma etc. Second pillar are physical effects that comply with modern science, but general public is mostly unfamiliar with them. For example inductive heating of car bodies, like in Zanfretta case.

- - - - - - - - - - -
UFOs display lots of GR effects, like time dilation (but without space dilation) which is very strange because GR actually doesn't allow this. Even Jaque Valle mentions these effects.

It is quite obvious that technologically we are very far from metric engineering. That's why it would be most interesting to actually make a summary of all UFO physical effect and than compare them with GR, without worrying about engineering.

- - - - - - - - - - -
@Thomas R Morrison it would be quite nice if you can put together a reading list, with a short preface for each item, on GR metric engineering, so we can join it to the list technical UFO papers. Although list must be quite final because forum software only allows editing for few days.

 

[marduk]

Hey wait a minute.

If the rig can lift itself without using the amount of energy it would take to do so using reaction propulsion or any normal means...

That means you could create a perpetual motion free energy device. You lift it by using N energy, then drop it and get N+X energy in return.

Where N = the metric propulsion system and X = kinetic energy of letting it drop.

Which violates the laws of thermodynamics, no?

 

[Thomas R Morrison]

I'm going off these 16 terms: Stress–energy tensor - Wikipedia

All of those terms are some variant of 'energy' right? In the abstract sense that it takes energy to produce?

Hm. I never thought about it that way, because “energy” has a very specific definition in physics, but sure I suppose you could look at it that way. It’s probably not a good idea to think about it that way though, because then you run into situations like using positive energy to stretch a rubber band, but that gives you a negative pressure term instead of a positive one. And your units won’t work out when you try to calculate with the different terms in the stress-energy tensor because each group of terms has different time and space dimensions.

@Thomas R Morrison you mentioned somewhere that one can circumnavigate a perimeter of visible universe in 80 years only his spaceship held on a constant acceleration. Do you have a reference for that?

It’s a fairly common example of special relativistic time dilation (at 1g the traveler can circumnavigate the observable universe in under a single lifetime, but of course many billions of years would pass for the external universe), so I’m sure there are many references to it out there, but here’s one:

“Indeed, a constant 1g acceleration would permit humans to circumnavigate the known Universe (with a radius of some 15 billion light years) in under a subjective lifetime. A more likely use of this effect would be to enable humans to travel to nearby stars without spending their entire lives aboard the ship. However, any such use of this effect would require an entirely new method of propulsion.”
Time dilation

Sure, it's worth a shot, but it's this kind of stuff that drives me bonkers when I read articles that scream 'warp drive possible!'

You and me both – it’s a shame that science journalism falls prey to clickbait articles just like everything else, but that’s why I focus on legitimate research articles published in reputable journals, instead of pop science sites like gizmodo etc.

However, what is required for practical low power warp drive is not propagating radiation, but a new kind of metamaterial, filled with very low frequency off-mass-shell non-propagating near field virtual photons that are Bose-Einstein condensed into macro-quantum coherent Glauber states of sharp phase and uncertain number. It may be possible to generate them from the aforementioned strong EM field nonlinearities. Ideally, for example, the Fourier transforms of the material responses for the electric permittivity alone that is strongly negative for low frequencies as close to static as possible. Imagine such a longitudinally polarized non-propagating quasi-static near electric field in the hypothetical meta-material containing the virtual photon coherent Bose-Einstein condensate sandwiched between two parallel oppositely charged conducting plates Ð a new kind of electrical capacitor

This is like watching 'The Core' - a movie that I actually love - but still makes me groan when they hand waive the material 'unobtanium' that makes the whole movie work.

Haha – yeah it sorta sounds like that, but he just seems to enjoy making his speculations as technically precise, and as incomprehensible for the reader, as humanly possible.

But it’s not a “far out” idea at all, actually. His central idea is actually very simple. He’s just saying: “if you regard the c terms (the speed of light terms) in the Einstein field equation as variables, rather than the conventional interpretation where c is defined as the speed of light in vacuum, then you may be able to dramatically manipulate the spacetime curvature within a material that has a very slow speed for the propagation of light (which we’ve seen experimentally with Bose-Einstein condensates).”

On one hand that seems like a total Hail Mary, but on the other hand there’s some compelling work that describes vacuum polarization (a well-established concept in QED) as the underlying basis for the metric deformations of GR. And I don’t rule that stuff out because GR doesn’t tell us anything about the coupling mechanism between the stress-energy-momentum and spacetime – GR is a purely quantitative theory. So there must be an underlying quantum mechanism behind GR, and alterations in the physical properties of the quantum vacuum, like the dielectric permittivity, seems like a reasonable place to look for the coupling mechanism. We’re so used to thinking of spacetime as purely dimensional constructs that it’s easy to forget that it’s actually a field with specific physical properties. And there may be more direct and efficient ways to interact with that field than simply concentrating mass-energy in a given volume.

Consider this: for centuries the only thing we know about magnetism, was that loadstones attracted iron. So if you wanted to make a stronger magnetic field, then all you could do is gather up more loadstone. And if you did a calculation to find out how much loadstone would be required to, say, lift a rail car – you’d find that you’d need some crazy amount of loadstone equivalent to the size of the Moon or something. And people would’ve laughed at you for thinking that you could lift a rail car with a magnetic field. But then we figured out electromagnetism, and now we can life a rail car with an electromagnet the size of your couch. It’s likely that the same kind of thing will happen with gravity once we understand the underlying physics of it.

Anyway, in your quote above Sarfatti proposes a method to trap a large a magnitude of energy within the metamaterial, while exploiting the negative terms within the EM stress-energy tensor that are available in photonic metamaterials, to produce the negative curvature required for warp field propulsion.

I don’t see anything physically unattainable in there – it should be possible to design a metamaterial with the basic requisite properties that he’s describing. But I don’t know much about quantum optics and metamaterials engineering, so I don’t know how difficult it would be to actually design and manufacture, and there may be other ways to get the energy levels that he’s talking about without having to get into off-mass-shell virtual particles and all of that business.

I've seen some references that such behavior was confirmed in a lab, but on non-gravitational systems. Apparently, some engineers in Germany had done it his chasing with photons and second case, Frank Wilcheck's entangled time crystals behave like that. Sort of, same equations, different physical phenomena.

Hmm…I haven’t seen anything like that. Only recently have we seen negative effective mass in a quantum fluid, but I haven’t seen them couple it to positive matter to produce a linear acceleration yet. If you happen upon a link sometime I’d like to read it. We just published a Physics Frontiers episode about time crystals, and they’re just quantum harmonic oscillators, as far as I can see.

I read that paper. That's widely known stuff, at least in physics circles. Astrophysicist had been working for years analyzing data from neutron stars, black holes etc. GR gets much closer to observation than just plain Newton's stuff. GR rules supreme.

Yeah that’s why I cited it – it’s the most comprehensive and authoritative (and routinely updated) review paper on the experimental and theoretical developments regarding GR and the parameters for alterative theories of gravity, that I’m aware of anyway.

It is astounding that a theory that was published over a century ago still fits all of the observational data to the limits of modern precision, across the whole spectrum of pertinent experimental and astronomical phenomena. When you see it all scrutinized in one place, it really makes a powerful argument for the validity of the mathematics, and makes it easy to understand why the phenomena that don’t fit – dark energy and dark matter – are mostly likely produced by something other than a flaw in GR itself. Though I do wonder sometimes if one or both of those phenomena could be features of GR somehow, which we just haven’t understood properly yet. That’s just idle speculation, but when papers like Jack Wisdom’s “Swimming in Spacetime: Motion by Cyclic Changes in Body Shape” come out and reveal yet another fascinating prediction of the theory, I wonder what else we might find in there someday.

I Exactly. I've heard it so many times: "Show me the proof!?". Like people expect aliens to lend in somebody's back-garden, take selfies with a witness and sign an affidavit.

It is frustrating, and reveals more about the intelligence of the “skeptic” than it reveals about the physical status of the phenomenon.

Because it doesn’t take much thought to realize that the reasonably accessible data to establish some level of “proof” is far different than the readily acceptable standard of” proof,” which is ultimately a highly subjective and often arbitrary term to begin with. There was a time when people cited the prevalence of snakes around logs as “proof” that snakes spontaneously arose from rotting wood. And when somebody like Neil deGrasse Tyson sets the bar at “I’ll believe in aliens when I can have dinner with one,” I find his level of scientific acumen to be on par with that of a wailing infant. It’s not a reasonable standard. Because if we were to visit a planet inhabited by stupid and dangerous primates whose primary occupation was mass murder on national scales, the last thing we’d do is land in front of their parliament building and request a dinner party to become acquainted. Instead we’d probably spy on them, perhaps study them in carefully controlled covert bag-and-tag operations, and evade their aircraft whenever they got a little too close for comfort. Which is exactly what we seem to be observing.

UFOs display lots of GR effects, like time dilation (but without space dilation) which is very strange because GR actually doesn't allow this.

I’m intrigued by this as well, but it’s unclear to me if this actually entails new physics, or if there are methods for manipulating time that are permitted within GR, which we just haven’t figured out yet. I would love to see a proposal for manipulating time without curving space as well, but I’ve never run across one. [There is one that I can think of, but it's very specific: if you were within a sufficiently dense sphere, space would remain flat within it, but the gravitational potential energy would slow time down - so that would be an excellent time machine for travel into the future.]

@Thomas R Morrison it would be quite nice if you can put together a reading list, with a short preface for each item, on GR metric engineering, so we can join it to the list technical UFO papers. Although list must be quite final because forum software only allows editing for few days.

It’s such a nascent field of inquiry at this point…I don’t know how many useful papers I could add to such a collection. I mean, there are tons of papers about what you could do with a metric engineering technology, but I’ve only seen a handful of interesting approaches to actually working with it experimentally, and I’ve already shared those in this thread because I find them so fascinating and pertinent to our discussion. The two Paranjape papers were the first to propose a theoretical approach to generating a net negative mass without relying on the existence of exotic matter. And that Sarfatti paper is the only one I’ve seen that proposes a method that could be within the reach of modern technology. Everything else that I’ve seen is even more speculative. So it could be years before we have a collection of credible papers that propose experimentally viable approaches to this subject.

Hey wait a minute.

If the rig can lift itself without using the amount of energy it would take to do so using reaction propulsion or any means...

That means you could create a perpetual motion free energy device. You lift it by using N energy, then drop it and get N+X energy in return.

Where N = the metric propulsion system and X = kinetic energy of letting it drop.

Which violates the laws of thermodynamics, no?

Yes and no.

The laws of thermodynamics only apply to local/inertial reference frames. So in special relativity, energy is conserved. But with GR when you work across accelerating reference frames, the conservation of energy, as we understand it classically, falls apart. Which is why so many people associate metric engineering with free energy.

But before we go any further, I should mention that the term N = 0 in your equation: once a gravitational field propulsion system is charged, it doesn’t take any expenditure of energy to accelerate (beyond whatever incidental efficiency losses are inherent in the control system). Such a craft can either hover or accelerate or decelerate by simply redistributing the energy in various ways. This seems like “magic” from the POV of Newtonian mechanics, but it’s perfectly feasible within the context of GR.

Let’s look at two cases. First let’s consider gravitational field propulsion itself – the Alcubierre drive is a simple example. The craft remains stationary with respect to its local flat spacetime, as the metric is distorted around the craft to produce motion. So with respect to its own reference frame, the craft itself never gains any energy or momentum. And with respect to an external/Eulerian observer, the positive mass of the craft has positive kinetic energy, but the negative mass of the craft has an equal magnitude of negative kinetic energy, so they cancel out. All well and good there.

Now imagine that you could tie one end of a long rope around a distant galaxy that’s accelerating away from us driven by the metric expansion of spacetime, and wind the other end around a spool attached to a motor on Earth. The motor will turn and generate electrical energy. This shouldn’t be too surprising – after all, we know that galaxy clusters are accelerating away from us on cosmological scales, so by the naïve/classical definition of energy, the universe is gaining energy every moment. So energy isn’t conserved in general relativity – in fact, in many cases it’s impossible to even clearly define it. People often talk about how quantum theory defies our notions of classical physical reality, but GR does too.

Energy Is Not Conserved, Sean Carroll, 2010

 

[Realm]

But it does appear to be an inevitable achievement, because the trajectory of the concept from an “impossibility” to a “curious speculative model” to “a possibly viable theoretical model” and so forth, seems very clearly to be moving in the direction of an eventual technological realization of this concept. And ufos appear to be evidence that many other civilizations have already achieved it.

You have repeatedly stated you try to avoid jumping to conclusions while discussing issues where the conclusions actually look quite inevitable, yet now that they really don't, you cut corners like that.

There are plenty of speculative topics like time travel, wormholes and white holes, where opinions have varied and shifted over time. If you look at for example the Wikipedia pages of those, all of them state in the introduction already how they are consistent with GR. It's basically just a prerequisite for taking theoretical possibilities seriously. Whether they can actually physically exist depends on the details and information we don't yet have. Anti-gravity hardly makes an exception in that.

Put simply, theorists have discovered that if a body of positive/ordinary gravitating matter is placed next to a body of negatively gravitating matter, the two will self-accelerate indefinitely in the direction of the positive matter. It sounds crazy, but the math works out in both Newtonian physics and general relativity.

Which was one of those findings that was actually interpreted as a negative in terms of plausibility:

Hence Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive-mass object,[5] an effect called "runaway motion" by Bonnor who disregarded its physical existence, stating:

“ I regard the runaway (or self-accelerating) motion […] so preposterous that I prefer to rule it out by supposing that inertial mass is all positive or all negative.
...
So once this runaway phenomenon has been revealed, the scientific community considered negative mass could not exist in the universe.

Negative mass - Wikipedia

Anti-gravity/negative mass doesn't seem to have that many voices of strong support, but rather a small number of researchers, who seem to give it higher probability than most. As we have already discussed, Paranjape if one of them, and to me his research looks more like resuscitating a troubled theoretical possibility. And even he talks about it as a possibility and primarily in the context of early universe, rest being even more iffy:

We have considered negative mass bubbles in an inflating universe. We find bubbles that are non-singular and satisfy the dominant energy configuration. They could exist in the early universe with important consequences for cosmology. The present accelerating phase is also possibly asymptotically de Sitter.

An Error Occurred Setting Your User Cookie

In the realm of speculation, the possibility of creating negative-mass bubbles in the laboratory could have incredible applications for energy production, warp-drive transportation, and armaments.

http://physicstoday.scitation.org/do/10.1063/PT.6.3.20170524a/full/

This news article about that study also reminds how it's just a possibility of something that's considered quite unlikely, and how it's definitely not a proof of physical existence:

Matter with negative mass, a seeming impossibility, could actually have existed in the early universe, a new study shows.

A novel solution to Einstein’s equations for gravity permits the existence of negative mass in a rapidly expanding universe like our own, physicists Manu Paranjape and Saoussen Mbarek of the University of Montreal report November 14 in Physical Review D.

Although the research doesn’t prove that such exotic particles once floated around the cosmos, it suggests that negative mass could have played a major role in the epoch called inflation, when the universe ballooned in size just after the Big Bang.

Negative mass might not defy Einstein

What's more, not everyone accepts that as negative mass solution at all. Sabine Hossenfelder is another reputable theoretical physicist and here's what she said about that research at the time:

However, it is somewhat misleading to call the solution that they find a negative mass solution. The cosmological constant makes a contribution to the effective mass term in what you can plausibly interpret as the gravitational potential. Taken together both, the effective mass in the potential is positive in the region where this solution applies. The local mass (density) is also positive by assumption. (You see this most easily by looking at fig 1 in the paper.)

Selling this as a negative mass solution is like one of these ads that say you’ll save 10$ if you spend at least $100 – in the end your expenses are always positive. The negative mass in their solution corresponds to the supposed savings that you make. You never really get to see them. What really matters are the total expenses. And these are always positive. There are thus no negative mass particles in this scenario whatsoever. Further, the cosmological constant is necessary for these solutions to exist, so you cannot employ them to replace the cosmological constant.

It also must be added that showing the existence of a certain solution to Einstein’s field equations is one thing, showing that they have a reasonable chance to actually be realized in Nature is an entirely different thing. For this you have to come up with a mechanism to create them and you also have to show that they are stable. Neither point is addressed in the paper.
...
In summary, I think it’s an interesting work, but so far it’s an entirely theoretical construct and its relevance for the description of cosmological dynamics is entirely unclear. There are no negative mass particles in this paper in any sensible interpretation of this term.

Backreaction: Negative Mass in General Relativity?

So for all that I have seen, anti-gravity/negative mass is still just a speculative possibility and Paranjape hasn't really progressed it onwards from that stage but rather prevented it from slipping backwards.

 

[Realm]

If the rig can lift itself without using the amount of energy it would take to do so using reaction propulsion or any normal means...

That means you could create a perpetual motion free energy device. You lift it by using N energy, then drop it and get N+X energy in return.

Obviously it works as follows:
The positive and negative masses of a hovering craft are perfectly balanced and cancel each other, resulting zero weight. Upwards/downwards movement needs to alter that balance. How do you do it? Obviously by picking up and dropping ballast. That's what explains all the abductions. It also explains cattle mutilations as unfortunate side-effect of needing to fine-tune inconveniently large ballast. Handling of the ballast requires energy, so it's not a perpetual motion free energy device.

 

[DROBNJAK]

We may stumble upon an unanticipated short-cut to realizing this kind of technology, however. This audacious little paper by Jack Sarfatti recently caught my eye - he had the unorthodox notion of dramatically manipulating the speed of light within a metamaterial to potentially radically alter the requisite energy scales for manipulating the spacetime metric (the scaling constant for the stress-energy tensor is G/c^4 so slowing the speed of light down to a few dozen meters per second could, in concept anyway, completely change the game). I wouldn't bet my lunch money that it would actually work (nature is rarely so accommodating), but what the hell - it's worth a try:

Is Low Power Warp Drive Possible? Breaking the Space-Time Stiffness Barrier

That's very nice approach. Instead of creating Alcubiere's warp drive in open ended empty space, which would require astronomical amounts of energy, author suggests creating warp drive inside thickness of the spacecraft's meta-material hull. One can easily imagine a situation where properties of regions of a hull can be quickly changed to make craft to change flight direction. Maybe, something like this:


Carlos Diaz, Mexico, Nov 1991

Video was analyzed by MUFON's regional director for Maryland Dr Bruce MacCabee, who worked as optical engineer for US Navy and found to be authentic.

Meta-materials really sound like UFO stuff. There were some reports about unnatural toughness of the UFO hulls, where there were attempts to cut through the 'metal' with hydrogen torches without success. Even cannon shells fired from close proximity didn't manage more than to dent them.

And here's the other point I'd like to make about this - the existence of ufos seems to indicate that the energy scales that we're currently calculating for achieving these effects, are off by at least dozens of orders of magnitude. Because if they weren't, then the first ufo crash would vaporize the Earth. Or equivalently, a ufo powering down on the surface of the planet wouldn't rest on the surface - it would fall straight through to the other side and keep perforating the Earth like Swiss cheese, because the energy densities that we think are required for this propulsion principle would have to be far denser than neutronium. These arguments aren't proof of this line of thought, but I do find them compelling - it does appear that the field propulsion principle that these objects are using (albeit a form of gravitational field propulsion, or perhaps some indistinguishable effect achieved via an unknown method of manipulating of the quantum potential) require far less energy than we currently calculate. And that's a very encouraging sign, imo.

Exactly, I brought up this exact point before in this forum. UFOs crashes reported so far do not result in much bigger explosions than large aircraft. During the Roswell crash a loud bang was never reported, although whole craft disintegrated.



Actually there was a MUFON case #74,282, in US north-west, close to the border with Canada, where an electrical engineer was present with two hunting friends. Engineer had ample expertise in electric power transmission. From the size of the UFO's hull and the color and the thickness of the surrounding plasma he was able to estimate that the energy required to produce that plasma was about 78..80MW. That's equivalent to 16.2 electrical locomotives. Or, cold war NERVA Phoebus mini-nuclear reactor would produce 1,100 MW / 78 MW = 14.0 more power output than what that UFO spent on its plasma. NERVA Phoebus could had supplied power for both G fields and plasma.


NERVA Kiwi & Phoebus Mini Nuclear Reactors with physicist
Robert Hanrahan standing there for scale.

 

[Thomas R Morrison]

@Usual Suspect - Here's where we left off in the Time Travel thread - I'll respond here since it's relevant to this thread as well:

As already stated. I don't have any problem with the idea of thinking of space as curved for the purpose of making accurate calculations for the way things work. But that situation only means that the things that are measured in space behave as if space is curved, not that space itself is actually curved, and to reiterate the salient example. Let's assume the amount of gravitational lensing is calculated using this curved space method, and do a thought experiment. To do this we don't need to include all the variables such as how everything is moving in space and the time it takes light to get here from there, because those aren't relevant to the point being made.

In this thought experiment we can simply draw out a situation where we have light from a source passing near a massive object that results in the rays appearing to bend when they get near the object. However simply because light rays from a source bend around a massive object doesn't mean the actual position of the source has changed. Therefore we are now faced with two situations. There is an actual position and an apparent position of the source, and logically only one of them is the actual position in space.

Logically, to determine the actual position of the light source in space, we can simply calculate the amount of lensing adjust the angle accordingly, and then draw a straight line through space from the point of observation to the actual position of the source. Consequently being able to draw a straight line through space to the actual position of the source means there's no actual space curvature. To emphasize this point. Hypothetically if some sort of instant point to point beaming were possible, we could plot the position of the source adjusted for the lensing and all the other variables and transport directly there in a straight line.

This situation has to be true because otherwise, the apparent position and the actual position would have to be identical ( but we know they're not ). So to reiterate. What is really happening is not that space is actually curved, but that a method of calculation is being used to describe how light rays passing near a massive object behave. That method says, "Let's think of space as if it's curved." However we know it's not because we can adjust for the effect of the lensing and plot a straight line through space to the actual destination. Consequently taking that extra step and saying, "Space really is curved." is not justifiable. It's also not a moot point because knowing the actual position and the apparent position of a destination are important real world considerations.

This isn’t actually a logical argument – you’re saying: “ let’s take our observation that light follows a curved trajectory around a gravitating body, and then subtract that curved trajectory from the equation, so we can draw a straight line between the two points.” That doesn’t prove anything: that works whether you explain the curved trajectory as curved spacetime, or if you explain the curved trajectory as a force acting between the light and the material body. But the curved spacetime model (general relativity) predicted the correct magnitude of curvature, whereas the Newtonian explanation of a force acting between the light and the gravitating body only predicts ½ of the observed curvature. So that was the first compelling evidence for Einstein’s metric curvature theory of gravitation.

But it turns out that it’s perfectly valid to explain gravitation as a strictly quantum phenomenon acting within a flat spacetime after all – this is what quantum gravity is all about. There’s an excellent old paper about this from 1975, but incredibly, I can find no free copies of it online, which I find infuriating. Withholding essential scientific knowledge from the general public for 43 years should be illegal – science belongs to everyone. Here’s the citation anyway, in case you or a friend can get you a free copy of this paper through an online university archive:

Classical general relativity derived from quantum gravity, D. G. Boulware and S. Deser, 1975 - ScienceDirect

In a nutshell, this situation is exactly like classical electrodynamics vs. quantum electrodynamics. You can either take the classical view that entails electric and magnetic fields, and all of that math works out fine until you get down to very small spatial scales and very low energies. But in those latter situations you need quantum electrodynamics, which replaces the notion of fields with the notion of virtual particle exchanges, to get the right answers (and of course at larger scales and energies both theories predict the same, or rather indistinguishable, results).

We expect the same thing to happen with gravity. There’s only one small problem: nobody’s come up with viable theory of quantum gravity yet. And theoretical physicists have been working on it, hard, for several decades.

So you have a choice: you can either work with general relativity because it provides all of the correct answers (and will certainly continue to provide the correct answers at all non-quantum scales and energies regardless of future developments, just as classical electrodynamics does), or you can assume that sooner or later somebody will work out the correct theory of quantum gravity, comfortable in the faith that someday we’ll abandon general relativity in favor of a quantum theory of gravity that operates within the context of a flat Minkowski spacetime. Either choice is a valid one, but the first choice gives you a precise mathematical and conceptual edifice to work with today. So I favor that choice, and I’ll switch horses if and when quantum gravity works out.

 

[marduk]

Ok, so in theory, I could lift a few kilo tons of water into the air, then let it fall down a tube and turn a generator.

Part of that energy would be used to lift the water again, and the rest would be free.

It would run forever, and provide a surplus of free energy. And waste heat. An infinite amount of both.

I totally don’t buy it.