UFO propulsion, metric engineering, and horizon physics

[DROBNJAK]

I clearly stated in the second reference we are talking about "effective mass", not real mass. But the first reference seem to be the real "negative mass".

Anyhow, they both behave as in the theory, which is at least a good small step. And they both can be created with meta-materials.

 

[Thomas R Morrison]

That's the whole point. It's an analogy, meaning analogous to acceleration, just like curved space is an analogy. Absolutely. You come across as exceedingly bright, that's why this is such a curiosity. I see where the disconnect is with you, but I can't seem to figure out how to bridge it. Ironic that you should mention the Greeks because they are the ones that came up the theorems for Euclidean geometry which can be worked out entirely conceptually. That is a proclamation, not an explanation that addresses the logic used in the thought experiments. It's a figure of speech, like writing from an omniscient point of view. It doesn't literally make the author God. It is a point of view. We're not debating the value of the math. I'm not sure why I can't get that across to you. That's the most interesting part to me. Maybe someone else will come along who also sees both sides of this and do a better job of explaining.

In the meantime, you have a mind for visualization ( I assume because of your sculpture work ), so how it is that you can't imagine a simple cubic volume of space inside of which objects are placed and see that formulas can be mapped onto those objects in a way that causes them to behave exactly like they are predicted to behave in the real world, without having to distort any of the space, and in addition to that, you could draw a straight line between any two objects in that space. You should be able to plainly see that no curved space is necessary to create a system that does everything the math you're referring to predicts. Therefore there is no reason to think real life space is curved either. Stuff just behaves as if it is curved due to the forces that are imparted on them by nature.

If you don't have the capacity to visualize such a system, that would explain a lot. Not everyone does: Why some people can't see pictures in their imagination

I don’t want to debate the validity of GR or the philosophy of science in this thread, because I want to focus on gravitation and metric engineering and UFO propulsion here. But if you’ll repost this over here I’ll respond to it:
Time, Time Travel, and Closed Timelike Curves

Inflation isn’t antigravity, I think.

Gravity bends space time. Inflation expands it.

You could have inflation in a curved region of space time, and it would just expand the curve.

Antigravity should flatten space time.

From the Wikipedia link you shared:

“To say that space expands exponentially means that two inertial observers are moving farther apart with accelerating velocity.”
Inflation (cosmology) - Wikipedia

I can see how the terminology can be confusing, so I’ll clarify further:

Positive/ordinary gravitation is described as a positive spacetime curvature, and it pulls matter together. So at a cosmological scale, if the curvature were positive, then the universe would be collapsing, or in other words, shrinking, because the spaces between material bodies everywhere would be getting smaller.

Negative gravitation, aka antigravity, is described as a negative spacetime curvature – it makes material bodies recede from one another. So on a cosmological scale, if the universe had a negative spacetime curvature, then the spaces between all material bodies would be expanding.

Our universe has both. At small scales like planets and stars and galaxies and galaxy clusters, the sum of these two positive and negative gravitational fields is positive, because the positive gravity associated with the positive matter is much larger than the cosmological constant (which is a negative gravitational field pervading the whole cosmos uniformly – it’s isotropic to the limits of our observational precision). At very large scales the positive gravitational fields of the matter within a given volume of space become smaller than the negative gravitational field inherent in that volume of spacetime (the mysterious source of this negative gravitational field is called “dark energy”), so the universe as a whole is expanding at an accelerating rate.

Just like it expanded at an accelerated rate in the first instants after the Big Bang, only much more slowly in the present era.

The only viable models that can explain either the inflationary epoch of the early universe, or the cosmological acceleration of the present era, or both, are gravitational theories – because positive and negative gravitational fields explain the behavior of matter in both cases (the other forces of nature like electromagnetism or the nuclear strong force or the weak force can’t produce the dynamics of either cosmic inflation or dark energy).

So one of the most active areas in theoretical physics today is the development of modified versions of general relativity. There’s a comprehensive review of the various strategies for modifying general relativity in this section of this excellent review paper:

“Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models,"
Section II. Modified gravity unifying the early-time inflation with late-time acceleration
Physics Reviews, Nojiri and Odintsov, 2011

There are eight classes of modified gravitational theories that are being developed right now to explain Big Bang inflationary cosmology and the cosmological acceleration of the present era using repulsive gravitational aka antigravitational mechanisms. And there are no cogent theories that can model cosmological behavior without both positive and negative gravitational fields.

Make of that what you will. But it seems very clear to me, and to every theoretical physicist working on this subject today, that gravity and antigravity are inextricably woven into the fabric of our universe, and always have been. They just don’t use the term “antigravity” because it’s been so stigmatized that using that word can destroy your career.

And "Cosmic inflation is driven by a "temporary cosmological constant" so the total energy of the Universe grows with the volume of the Universe, too." is just flat out wrong.

No, it’s not. So far, the leading explanatory contender for cosmic inflation are f(R) theories of gravity, which modify the action in general relativity in the most extreme regimes: at extremely high curvatures (the inflationary era) and at very low curvatures (the modern cosmological era). The simplest way to express the inflationary mechanism is by calling it a “temporary cosmological constant” because that’s what it looks like phenomenologically. But to be technically accurate he’d have to get into the specific intrinsic features of the eight different classes of mechanisms proposed to create that effect, which would be incredibly tedious and totally incomprehensible to the average reader looking for an answer to the question posed.

Guth described the inflationary universe as the "ultimate free lunch":[109][110] new universes, similar to our own, are continually produced in a vast inflating background. Gravitational interactions, in this case, circumvent (but do not violate) the first law of thermodynamics (energy conservation) and the second law of thermodynamics(entropy and the arrow of time problem).

Inflation (cosmology) - Wikipedia

Sure, you can technically get away with saying that gravitational interactions don’t violate the conservation of energy, but rather “circumvent” it. Because technically energy itself is ill-defined in general relativity – there’s always at least one funky method for defining a reference frame (often accelerating reference frames) where energy is conserved.

Similarly you can say that the Alcubierre metric circumvents the conservation of momentum and the speed of light, because locally, that’s true. But that doesn’t change the fact that you moved from Point A to point B faster than the speed of light without expending any energy to do it.

Kinda defeats the whole point of conservation laws when they can be “circumvented” in practice like that, y’know what I mean? But in any case, technically, the only constraint on energy in general relativity is that in a closed universe E = 0. But it isn't closed, it's open. And even if it were closed, that tells you nothing about specific systems within it, or exactly how the energy sums to zero. So as the universe continues to accelerate faster and faster every second, all that relativists can do is throw their hands up and say “well it probably all works out somehow, perhaps we’ll figure it out someday.”

 

[marduk]

I don’t want to debate the validity of GR or the philosophy of science in this thread, because I want to focus on gravitation and metric engineering and UFO propulsion here. But if you’ll repost this over here I’ll respond to it:
Time, Time Travel, and Closed Timelike Curves


From the Wikipedia link you shared:

“To say that space expands exponentially means that two inertial observers are moving farther apart with accelerating velocity.”
Inflation (cosmology) - Wikipedia

I can see how the terminology can be confusing, so I’ll clarify further:

Positive/ordinary gravitation is described as a positive spacetime curvature, and it pulls matter together. So at a cosmological scale, if the curvature were positive, then the universe would be collapsing, or in other words, shrinking, because the spaces between material bodies everywhere would be getting smaller.

Negative gravitation, aka antigravity, is described as a negative spacetime curvature – it makes material bodies recede from one another. So on a cosmological scale, if the universe had a negative spacetime curvature, then the spaces between all material bodies would be expanding.

I think we're kind of saying the same thing.

Imagine a ball on a trampoline. Gravity is the bend in the trampoline's surface. Expansion would be making the trampoline itself bigger by stretching it out.

Antigravity would be taking the bend out of the trampoline's surface. But that isn't what expansion does.

I think that's an important distinction, because if the expansion is isotropic along the entire surface of the trampoline, the gravity well could get deeper or wider - which isn't antigravity. It's just gravity.

Expansion might look like antigravity at cosmic scales - where spacetime is flat, but on local scales were spacetime is curved isn't antigravity at all.

 

[Thomas R Morrison]

I think we're kind of saying the same thing.

Imagine a ball on a trampoline. Gravity is the bend in the trampoline's surface. Expansion would be making the trampoline itself bigger by stretching it out.

Antigravity would be taking the bend out of the trampoline's surface. But that isn't what expansion does.

I think that's an important distinction, because if the expansion is isotropic along the entire surface of the trampoline, the gravity well could get deeper or wider - which isn't antigravity. It's just gravity.

Expansion might look like antigravity at cosmic scales - where spacetime is flat, but on local scales were spacetime is curved isn't antigravity at all.

No this is wrong. If you view the trampoline as spacetime, then positive gravity is the curvature created by the ball resting in the center. So when you place other balls around it, the space between them will shrink as they all fall together in the middle. That's what they're calling "contracting spacetime." It's a stupid way of saying it, because the trampoline isn't actually getting smaller - only the distances between the balls get smaller. But since the relative distances between the balls are our only way to measure space, you could also say that the space itself is getting smaller.

Antigravity would be lifting up the center of the trampoline, and watching balls on either side of the bulge fall away from one another. That dynamic explains cosmic inflation and the cosmological constant. The only difference is the magnitude of vertical curvature.

The universe overall appears to be flat because the locally positive gravitational fields around matter, are balanced out by the negative gravitation curvature between the galaxy clusters. So if you add all of the positive gravitational curvatures to all of the negative gravitational curvatures between the galaxy clusters, the sum is zero.

The thing I don't like about the terminology is this: gravitational charge and electrical charge are perfectly analogous in the weak-field limit (although the interaction sign is flipped). And when we say "electrical charge" that can be either positive or negative. Similarly, when we say "gravity" or "gravitational field," that should also be either positive or negative. But instead when we say "gravity" we mean "positive gravity." And then we have to come up with a new term "antigravity" to talk about the negative pole of gravitation. But the gravitational field is both, just like the electrical field is both. And it always has been - GR doesn't prefer one over the other, and the universe wouldn't even exist without negative gravitation. But we've built our own ridiculous prejudice against the idea of a negative gravitational charge into our language - so even today, with negative gravitation manifest right in front of us with cosmological acceleration and the inflationary era, people still have a knee-jerk reaction that there's something wrong with the idea. Bloody hell.

 

[DROBNJAK]

It's like giving someone a truckload of apples and assuming that there's so many ways they can be arranged, that sooner or later they'll figure out a way to arrange them so that all turn into oranges. It will never happen.

It will happen. That's the freedom that mathematics gives you.

With obvious disclaimer that I am not knowledgeable enough, with maths one can easily go far beyond tangible world of "common sense". Neither humble transistor, nor not so humble atom bomb would exist without freedom of insight that maths gives us. One can easily imagine a meta-material that will combine EM radiation and ordinary matter in such a way that we produce an "effective negative mass", in a sense that both @Thomas R Morrison, with his negative refraction index, and Martin Tajmar had been talking about.

As far as UFO lore is concerned, there are very strong data trends that suggest that aliens have an easy access to meta-materials, like we have to steel or aluminum. For example, implants that were taken out of abductees had been confirmed to be made from carbon nano-tubes arranged into 3D structures, like 3D electronic circuits.

In my personal UFO research I don't really want to commit to any particular direction, because there are many good trails. But, suffice to say, it was UFO data trends that led me to General Relativity, not the other way around.

 

[Realm]

I clearly stated in the second reference we are talking about "effective mass", not real mass. But the first reference seem to be the real "negative mass".

They are both about "effective mass", as can be seen in the first bullet of your screenshot already.

Actual negative mass is just a hypothetical idea at the moment and has never been observed. No matter how Thomas tries to embellish the story, for obvious reasons, it's quite clear that the vast majority of experts regard its existence highly unlikely, and even if it existed, it may not actually work for space travel.

Tajmar makes it clear how Zeilinger obtained just negative effective mass here:

Some recent experiments have indicated that test particles under appropriate conditions can behave as having negative effective inertial masses. Zeilinger and his team obtained neutrons with a positive or a negative effective mass.[2, 3, 4] Transient negative effective masses were also recently reported for electrons in n-doped GaAs under very high electric fields and short time-scales on the order of a few hundred femto-seconds.[5]

http://www.ifi.unicamp.br/~assis/J-Advanced-Phys-V4-p77-82(2015).pdf

Anyhow, they both behave as in the theory, which is at least a good small step. And they both can be created with meta-materials.

Those don't really make actual negative masses any more likely, as is already evident from the news articles about those findings, including that you linked from NewScientist:

This effect could be useful in a diametric drive, a speculative “engine” in which negative and positive mass interact to accelerate forever. NASA explored using the effect in the 1990s in a bid to make a diametric drive for better spacecraft propulsion. But there was a very big fly in the ointment: quantum mechanics states that matter cannot have a negative mass. Even antimatter, made of particles with the opposite charge and spin to their normal matter counterparts, has positive mass.

“Writing a negative mass in quantum field theory doesn’t make any difference,” says Archil Kobakhidze at the University of Sydney, Australia. The equations involve terms that are always squares of mass, so any negative mass will become positive anyway. “It has no observable meaning.”

Light can break Newton’s third law – by cheating

‘The existence of mechanical objects with a negative mass in free space violates so many of the fundamental laws of physics that it can be excluded with great certainty,’ says Prof. Dr. Ulf Peschel, professor of Experimental Physics at FAU. But only in free space: the limitations do not apply to human-made systems that are subject to their very own laws. The researchers led by Prof. Peschel used this fact to realise the optical equivalent of the diametric drive.
...
Even if spacecraft propulsion with negative mass will remain a pipe dream in the end, this science fiction-style idea from Marc G. Millis made it into reality after over 15 years and some detours.

https://www.fau.eu/2013/10/22/news/research/the-negative-mass-effect/

The team refers to their device as an optical diametric drive, a very tenuous but still instructive comparison that refers to a hypothetical engine tech that could get humans to the stars. A diametric drive is basically an anti-gravity system that uses a block of material with negative mass to create a negative gravitational field that would endlessly repel an object with actual mass (a spaceship). If that sounds like utter fantasy, that’s because it is; the concept of negative gravity has no meaning in quantum physics, which works using mass-squared equations that make all negative mass parameters into positive ones. The idea of moving through space thanks to a block of material with a never-ending propulsive ability calls to mind the perpetual motion machines of days gone by.

But could those old attempts have simply been too literal with their terminology? Though nothing remotely like an anti-gravity material has yet been found, light can have a negative effective mass if manipulated just right — and that’s what this team’s device is designed to do.
...
The team suggests that their work could lead to everything from faster communications to more powerful computers, but those are likely almost as far out as interstellar anti-gravity drives.
...
This study shows that even seemingly meaningless concepts can have real implications in modern physics; quantum physics may be a loopy mess of seemingly impossible concepts, but acting as if those concepts are true lets you put a man on the Moon and connect the world through global communications. This study implies that while negative mass might not actually exist, the concept itself could still let us find ways around previously impassable barriers.

Researchers break Newton's third law - with lasers - ExtremeTech

 

[Thomas R Morrison]

One can easily imagine a meta-material that will combine EM radiation and ordinary matter in such a way that we produce an "effective negative mass", in a sense that both @Thomas R Morrison, with his negative refraction index, and Martin Tajmar had been talking about.

I wouldn’t say “easily” – the T00 term in the stress-energy tensor represents a huge magnitude of positive energy. Generating sufficient physical and/or electromagnetic tension to surpass that number is a horrific problem. If something along the lines of Sarfatti’s idea won’t work out, then we’re looking at centuries or even millennia before we can expect to engineer at those energy scales.

I haven’t watched that Tajmar lecture yet – though I’ve read a number of his papers. But yes we’re talking about “negative effective mass.” The key distinction with the recent experiments though, is that those though experiments involve negative effective mass inside of a bulk material (we’ve seen negative effective mass with some particles in solid materials, and now we’ve seen it in macroscopic regions within a quantum fluid).

What we’ve been talking about previously is negative effective mass within the context of spacetime itself. Manipulating the stress-energy tensor, Paranjape has shown that we can make a body of matter that has a positive rest mass exhibit a net effective mass in free space: both negative inertia and a negative gravitational field. That’s precisely what we need to make a gravitational field propulsion system work, and now we know that it can be done without exotic matter – at least in theory. Which is a huge step in the right direction.

And since the positive energy theorem doesn’t apply to our accelerating de Sitter universe, we may be able to achieve the same effect with metamaterials, by exploiting the property of negative refractive index within the context of the electromagnetic stress-energy tensor.

I tend to think that we’ll probably have to exploit a number of terms in both the stress-energy tensor and the EM stress-energy tensor, all at once, if we’re going to have any hope of achieving a net negative effective mass in an experimental setup. Because it’s probably going to be much easier to exploit several terms using a combination of principles, than it would be to exploit any single component of the matrix to exceed the rest-mass energy of a physical sample.

 

[marduk]

No, it’s not. So far, the leading explanatory contender for cosmic inflation are f(R) theories of gravity, which modify the action in general relativity in the most extreme regimes: at extremely high curvatures (the inflationary era) and at very low curvatures (the modern cosmological era). The simplest way to express the inflationary mechanism is by calling it a “temporary cosmological constant” because that’s what it looks like phenomenologically. But to be technically accurate he’d have to get into the specific intrinsic features of the eight different classes of mechanisms proposed to create that effect, which would be incredibly tedious and totally incomprehensible to the average reader looking for an answer to the question posed.


Sure, you can technically get away with saying that gravitational interactions don’t violate the conservation of energy, but rather “circumvent” it. Because technically energy itself is ill-defined in general relativity – there’s always at least one funky method for defining a reference frame (often accelerating reference frames) where energy is conserved.

Similarly you can say that the Alcubierre metric circumvents the conservation of momentum and the speed of light, because locally, that’s true. But that doesn’t change the fact that you moved from Point A to point B faster than the speed of light without expending any energy to do it.

Kinda defeats the whole point of conservation laws when they can be “circumvented” in practice like that, y’know what I mean? But in any case, technically, the only constraint on energy in general relativity is that E = 0. In other words, the net energy of the entire cosmos is zero. But that tells you nothing about specific systems within it, or exactly how the energy sums to zero. So as the universe continues to accelerate faster and faster every second, all that relativists can do is throw their hands up and say “well it probably all works out somehow, perhaps we’ll figure it out someday.”

No this is wrong. If you view the trampoline as spacetime, then positive gravity is the curvature created by the ball resting in the center. So when you place other balls around it, the space between them will shrink as they all fall together in the middle. That's what they're calling "contracting spacetime." It's a stupid way of saying it, because the trampoline isn't actually getting smaller - only the distances between the balls get smaller. But since the relative distances between the balls are our only way to measure space, you could also say that the space itself is getting smaller.

Antigravity would be lifting up the center of the trampoline, and watching balls on either side of the bulge fall away from one another. That dynamic explains cosmic inflation and the cosmological constant. The only difference is the magnitude of vertical curvature.

The universe overall appears to be flat because the locally positive gravitational fields around matter, are balanced out by the negative gravitation curvature between the galaxy clusters. So if you add all of the positive gravitational curvatures to all of the negative gravitational curvatures between the galaxy clusters, the sum is zero.

The thing I don't like about the terminology is this: gravitational charge and electrical charge are perfectly analogous in the weak-field limit (although the interaction sign is flipped). And when we say "electrical charge" that can be either positive or negative. Similarly, when we say "gravity" or "gravitational field," that should also be either positive or negative. But instead when we say "gravity" we mean "positive gravity." And then we have to come up with a new term "antigravity" to talk about the negative pole of gravitation. But the gravitational field is both, just like the electrical field is both. And it always has been - GR doesn't prefer one over the other, and the universe wouldn't even exist without negative gravitation. But we've built our own ridiculous prejudice against the idea of a negative gravitational charge into our language - so even today, with negative gravitation manifest right in front of us with cosmological acceleration and the inflationary era, people still have a knee-jerk reaction that there's something wrong with the idea. Bloody hell.

Again, I think we’re getting hung up on terminologies.

I like this description: https://www.quora.com/How-accurate-is-it-to-label-dark-energy-as-anti-gravity

“What dark energy really does is that it causes space to repel itself. So dark energy is anti-gravity but only for space itself.”

 

[DROBNJAK]

@Thomas R Morrison What does theory say? If warp drive is happening inside a shell of the craft (like maybe meta-material), does that mean that inside of the craft, like crew compartment, doesn't feel the acceleration?

 

[Thomas R Morrison]

Again, I think we’re getting hung up on terminologies.

I like this description: https://www.quora.com/How-accurate-is-it-to-label-dark-energy-as-anti-gravity

“What dark energy really does is that it causes space to repel itself. So dark energy is anti-gravity but only for space itself.”

I'm sorry but that's ridiculous, "it causes space to repel itself." Gravity is an acceleration field, period. Positive gravitation accelerates matter toward the source; negative gravitation accelerates matter away from the source. The gravity field associated with dark energy isn't special or magical - it's simply the opposite polarity of an ordinary gravitational field. In fact the only thing that we actually know about dark energy is that it manifests a negative gravitational field - everything else is speculation. Like all gravitational fields, the negative gravitational field of dark energy couples to matter, and the late-time integrated Sachs-Wolfe effect proves that it couples to photons as well, and it probably couples to dark matter too. The mental gymnastics that some physicists will resort to in order to avoid the idea of antigravity are absolutely unbelievable. He even admits that the basis for his objection to antigravity isn't based on physics - it's based on his cultural prejudice that an antigravitational device is impossible:

"The problem is that the word 'anti-gravity' invokes a vision of a vehicle floating above the ground (as seen in many science fiction movies). Dark energy will not allow the development of anti-gravity floating vehicles."

No, sir: that's only a "problem" if you're convinced that gravitational field propulsion is theoretically impossible, and that UFOs don't exist. Dark energy probably won't help us build such a device, but it proves that negative gravitation exists, so it's theoretically possible to perhaps one day build such a device.

The cosmological acceleration is no more "space repelling itself" than gravity is "space attracting itself." There is a gravitational self-interaction, but it's minuscule. The density of dark energy is so tiny that we were only recently capable of observing its gravitational coupling to matter at all – the gravitational self-interaction of dark energy would be many orders of magnitude weaker than that. Consider the case of the Earth - the gravitational self-interaction is around 1/40,000,000,000th of the magnitude of the Earth's gravitational field. The Earth's average density is around 5.5 g/cm³, but the density of dark energy is only about 7 × 10^−30 g/cm3 (if that model is even correct: modified gravity theories are also a viable explanation) - the second-order effect of gravitational self-interaction is insignificant at these densities.

Spacetime doesn't actually expand or contract, it's simply curved either positively or negatively. You can only say that it expands or contracts because your reference points are simultaneously in inertial frames, and moving. That's what the general theory of relativity states. I have no idea wtf theory he's talking about where "space repels itself."

@Thomas R Morrison What does theory say? If warp drive is happening inside a shell of the craft (like maybe meta-material), does that mean that inside of the craft, like crew compartment, doesn't feel the acceleration?

As long as there's a more or less uniform gravitational field gradient across the volume of the craft, then they won't feel the accelerations. It doesn't really matter whether the gravitational dipole is generated by components at the top and bottom of the craft, or if the poles are generated within the hull itself, as long as the fields span the interior - which would happen naturally because we know of no way to confine a gravitational field within a volume of matter (although I wouldn't be completely surprised if someday we discovered a gravitational equivalent of the Meissner effect).

 

[DROBNJAK]

Even if lots of EM energy is needed to be pumped into meta-material, we know that ionized air created by UFO's electric field can stall petrol engines from up to 2,000ft (700m) as Dr. Mark Rodeger's research had shown. You have more on this subject in the link in my signature.

Taking into the account that electric field falls with inverse square of distance, that's lots of electrical energy on the craft's surface. This really blends nicely with idea that UFOs are doping their own hulls with EM waves.

Extract of 447 car engine stallings between 1909-1981, from MUFON's database of 40,000 UFO cases,

- - - - - - - - - - - - - - - - - - - - - - - - - - - - -​

I know that I exausted everybody with photos and diagrams, but just one more, pls ;-)

Question is, what about plasma? Plasma is easier to make and manage than meta-materials, and UFOs in various stages of flight are always shrowded in plasma. Is it conceiable to create a thin warp drive bubble in plasma? Maybe some form of plasma management is able to create "effective negative mass"?

 

[DROBNJAK]

Yeah, it just came to me that resonance is a method of storing energy.

Storing unlimited amounts of energy in that "negative effective mass" meta-material would be really easy. Resonance is essentially energy storage mechanism and it is particularly easily done with waves. Waves can occupy the same space and they will easily add up on top of each other. Higher the frequency faster more energy can be stored. So if we are talking about GHz or THz EM waves, resonance can easily store energy equivalent of star's output. Its more of a problem making a material that would not melt.

 

[marduk]

I’m totally not agreeing here, man.

 

[DROBNJAK]

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.

Possibly I took it quite too far. Here is how this guy explained time crystals. you have atoms experiencing effect before the cause and running ahead of themselves. But time crystals go back and forth, while positive & negative mass move in straight line.

or jump to 1:49

 

[Thomas R Morrison]

I’m totally not agreeing here, man.

That’s fine, because it would probably take about three months of 12-hour conversations every day to lay the groundwork for a proper discussion about this. But maybe if I plant the seed of my viewpoint here, then after a few years of reading papers about general relativity and cosmology you’ll sit back and go “ohh…okay, that actually makes sense.” Because the prevailing view of all this stuff is so deeply rooted now that it's virtually impossible to see it differently - everyone is married to the expanding spacetime idea these days. But let's see why that is.

The reason people say that spacetime is expanding at cosmological scales is because of the way that the Friedmann–Lemaître–Robertson–Walker (FLRW) metric is formulated. The FLRW metric defines something called a “comoving coordinate system,” where the “comoving distance” between galaxy clusters is fixed/unchanging. So if you start with that coordinate system, then you have to define the changing spatial separation between galaxy clusters using a different term which they call the “proper distance,” which as we know is constantly increasing between galaxy clusters. And the rate of this increasing distance is called the “scale factor.” Therefore, since the “comoving distance” is defined to be constant, while the observed “proper distance” is increasing, astrophysicists say that the spacetime between them is expanding. And using that coordinate system, that’s a perfectly legitimate way of looking at it.

But let’s back up for a minute, because we’ve skipped over the fundamental physics at the heart of all of this. The real issue here is the problem of defining a coordinate system in general relativity, because it’s nothing like the nice neat coordinate system that we humans tend to envision our world with, Euclidean geometry, where forces generate motion against a flat static geometrical background. Instead, we find ourselves in a cosmos where the geometry of spacetime is curved (or at least appears to be curved, so Usual Suspect won't bristle at me ; ) - where gravitation isn’t a force at all, but rather the result of this curved geometry, which we can envision as curving both “up” and “down” for illustrative purposes. Within the galaxies, we have positive gravitational curvature, which we visualize as a dip downward. And in the vast distances between galaxy clusters, where the “dark energy” effect becomes dominant, we have negative gravitation, which we can visualize as a very slight hill lifted upward.

Regardless of which form of gravitational field that your galaxy is subjected to, either positive or negative, your galaxy remains in “free fall” – which GR calls “an inertial reference frame” (a reference frame that feels no forces acting upon it). Just as a rock dropped from a mountain is in free fall (neglecting atmospheric friction) and therefore feels no force acting upon it, the same is true of the galaxies undergoing positive or negative gravitational acceleration. In other words, locally, the galaxies are “at rest” in their own reference frames. And this is why the FRLW metric chose to define a “comoving coordinate system” - if all the galaxy clusters are locally at rest, then a coordinate system that defines their positions as a constant reference frame, is really the only way to define a global cosmological reference frame: there’s nothing else to reference, other than the galaxy clusters themselves.

You have to admit though, that it’s kinda weird to choose a coordinate system that’s physically expanding, and define that as a "rest frame.” And that’s how astronomers arrived at the idea that spacetime is expanding. Because if you start with the idea that the galaxy clusters are at rest and then define your unit of distance on that, when they’re clearly all flying apart from each other, then all you can say to explain it is by claiming that the spacetime between the galaxy clusters is expanding.

But general relativity itself is coordinate invariant – GR doesn’t define a cosmological coordinate system - it works for any self-consistent and well-defined coordinate system that you choose to use. So we can look at all of this quite differently, and I feel more intuitively in accord with its own formulation – which is simply geometrical.

Consider a simple example: two stars falling together via their gravitational interaction. Each star is in free fall: they don’t feel any gravity pulling them together, and yet they’re moving closer at an ever faster rate. From each star’s own point of reference – just as the FLRW metric defined each galaxy cluster as a point of reference – we can say that they’re at rest, even though they’re moving together at an accelerating rate. Applying the same kind of coordinate system that the FLRW metric employs, we can say with perfect validity that the spacetime between the two stars is shrinking.

But is it actually shrinking, or is this “shrinking spacetime” simply a product of our choice of coordinate system? It’s relative, I suppose. From my point of view, I think it’s stupid to favor the view that spacetime is shrinking between those two stars, because the general theory of relativity can explain it far more simply: the two stars are merely following the geometry of spacetime curvature – the gravitational field – that exists between them. The spacetime between them isn’t shrinking; the stars are simply falling closer together.

And we can model cosmological behavior in exactly the same way, using the clear geometrical language of general relativity, without employing the comoving coordinate system of the FLRW metric. And in doing so, we can more clearly see the role of dark energy (or more precisely, the role of the negative gravitational field that we associate with dark energy) in cosmological evolution.

So let’s go back to our galaxy clusters separated, say, across a vast cosmic void. We’ll choose two galaxy clusters on opposite sides for simplicity.

The positive gravitational field surrounding each individual galaxy cluster produces an acceleration toward the other, but at the huge cosmic scale of distance between them, the negative gravitational field (which we can envision as a hill between the two clusters that’s highest at the center of the cosmic void) is greater than the positive gravitational field between them. So the two clusters free-fall away from one another as naturally as two balls on opposite sides of a hill roll away from one another. The spacetime between them isn’t expanding – the distance between the two clusters is simply increasing. And as all of the galaxy clusters at the periphery of this great cosmic void fall away from the center of the void, the positive gravitational acceleration between them gets even smaller. And since the distance between each galaxy cluster and the center of the cosmic void is 1 radius (the distance to the center of negative gravity), whereas the distance between galaxy clusters on opposite sides of the void is 2r (the distance between the centers of positive gravity), then by the inverse square law the galaxy clusters will increasingly accelerate away from the center of the cosmic void, and therefore each other. Which is what we observe.

By simply choosing a different, and local, coordinate system (in this case centered on the middle of the cosmic void in-between the galaxy clusters that we just considered), we’ve replaced the concept of expanding spacetime with the much simpler concepts of general relativity that we apply to every other gravitational system that we observe, from the planetary, to the stellar, to the galactic, and ultimately to the galaxy-cluster scales.

This is a perfectly valid way of looking at it: spatial separation is simply increasing driven by negative gravitation…rather than spacetime itself expanding. Both choices of coordinate system result in the same observations. But by focusing on the relative motion of observable galaxy clusters undergoing gravitational acceleration, instead of transforming it away with an accelerating coordinate system, we’ve eliminated the assumption that an unobservable empty volume of spacetime is increasing in size.

So that’s how I look at it. And that’s why I don’t have to resort to bizarre ideas like “spacetime repelling itself,” which suggests that you can push against a volume of nothing, and which overturns a century of general relativity that tells us that gravitation is not a force at all but rather a purely geometric phenomenon.

Possibly I took it quite too far. Here is how this guy explained time crystals. you have atoms experiencing effect before the cause and running ahead of themselves. But time crystals go back and forth, while positive & negative mass move in straight line.

Yep - time crystals are simply quantum oscillators, sorta like a spring-mass system. They're not related to negative mass, afaik.

 

[Realm]

Since metamaterial seems to have become a buzzword with almost mythical status, especially in connection to anti-gravity, for some reason, I think it's time to try to separate facts from fiction.

Take a solid block of transparent glass as an example of "normal" matter. When you shine light though it, it refracts a bit on the edges but mostly passes straight through. Most metamaterials are like being able to fill that block with tiny mirrors, causing the light to act in surprising ways. Since visible light is just part of electromagnetic spectrum, such materials can be designed similarly for other wavelengths, like radio- and microwaves, or DeLonge's favorit, terahertz radiation. Some, like acoustic metamaterials, work similarly with other types of waves.

Even though there are also gravitational waves, they are quite a bit different deal, and just think what sort of devices it needs to just detect them from the most violent events in the universe. While there are some speculative ideas like gravitational wave mirrors, actual metamaterials we have don't have anything to do with those or gravity in general. So where are the origins of such claims in the pseudo-scientific circles? One part of the story might be that similarly to all those "negative effective masses", metamaterials have also been used to emulate various phenomena as if it was the real deal, which some may have mixed up once again:

Electromagnetic metamaterials are capable of emulating many exotic space-time geometries, such as black holes, rotating cosmic strings, and the big bang singularity. Here we present a metamaterial-based model of the Alcubierre warp drive, and study its limitations due to available range of material parameters. It appears that the material parameter range introduces strong limitations on the achievable “warp speed”, so that ordinary magnetoelectric materials cannot be used. On the other hand, newly developed “perfect” bi-anisotropic non-reciprocal magnetoelectric metamaterials should be capable of emulating the physics of warp drive gradually accelerating up to 1/4c.

https://arxiv.org/ftp/arxiv/papers/1009/1009.5663.pdf

Let's take one more look at that layered magnesium and bismuth that Linda Moulton Howe, Hal Puthoff and Tom DeGullible have been playing with. There's no sensible reason to assume something like that has anything to do with anti-gravity or negative mass. The story had hoax written all over it from the get-go and it has never had any evidence of anything of any significance. Yet it lived to this day, picked up terahertz radiation and metamaterials as new buzzwords as they became fashionable, and ended up as "if you hit it with enough terahertz it will float" version, as if that had ever happened.

Those new buzzwords came through pseudoscientist Puthoff, who recommended further testing to LMH as was discussed before:

So he indicated those bismuth layers should pass terahertz radiation through freely, but quick googling I did back then didn't reveal why semimetal bismuth would work like that. Further confusion followed from one study where bismuth was used as walls of a waveguide (with empty space in between where the wave actually propagated), and how Thomas seemed to think that it would rather pass through those magnesium parts, which as I said back then, didn't make much sense, as a good conductor would just block it efficiently:

I presume that he means to say that subwavelength THz radiation could migrate along the magnesium in-between the bismuth layers, because magnesium's a good conductor but bismuth isn't.

That lack of understanding didn't hinder his fanboyism though:

I'm just surprised and intrigued to find what appears to be a viable theoretical concept for mass reduction using layered metals - that hadn't occurred to me, so I have to give points to Hal Puthoff for coming up with it. I just started considering metamaterials for metric engineering recently, but I hadn't yet realized that thin metal layers could provide a theoretically valid approach to achieving the required effects, so I'm impressed that he's a step ahead of me on this. He may be the right kind of mind to crack this problem after all, working with expert specialists along the way of course.

And you can’t just “dream up” exotic metamaterials properties that represent components of the electromagnetic stress-energy tensor which permit mass reduction. Frankly it’s impressive that Puthoff did the research and found the metamaterials studies that relate to this composite structure, and that he understood its potential significance within the context of GR. Sure, he was looking for any features of this material that could be anomalous – that was his task. The fact that he succeeded in seeing a viable prospect for something anomalous is a credit to his scientific acumen, not an indictment of his methodology.

It’s not like he was given something like the sole of a tennis shoe, and then rigged some crazy hypothesis to imbue it with an exotic physical property via some bogus pseudoscience theory. He found a credible anomalous possibility within well-established physics. That kicks ass. Because even if his idea doesn’t apply to the sample that he studied, it’s a fascinating avenue to explore theoretically and perhaps even experimentally. I hope and expect that they'll do that.

Well, I tried googling again, and found that in reality pseudo-scientist Puthoff simply managed to find papers that were published some 7 years before, that essentially described the exact same situation. So his "impressive" accomplishment was just basically repeating what Viktor Podolskiy et al. wrote on using bismuth with metal walls as a waveguide for Teraherz radiation with those exact wavelengths:

The proposed system is schematically shown in Fig. 1. It is represented by a planar (capacitor-type) waveguide with metal walls and anisotropic core. The dielectric constant of the core material is assumed to be uniaxial, with anisotropy axis perpendicular to the waveguide walls.
...
the realization of the non-magnetic left-handed materials requires a strongly anisotropic dielectric response. In this section we propose to use a material with effective electron mass anisotropy as one of the realizations of this non-magnetic LHM system. Note that while no natural material having simultaneously negative ǫ and µ have been found so far, the materials with strongly anisotropic effective mass do exist – such as e.g. monocrystalline bismuth.
...
Another exciting property of left-handed system based on bismuth film is the extremely low material loss. In fact, the losses in Bi are so small that already in 1960s, bismuth mono-crystalline systems could yield the carrier mean free path at liquid helium temperatures on the order of millimeters

https://arxiv.org/pdf/physics/0505024.pdf
https://arxiv.org/pdf/physics/0405077.pdf
Non-magnetic System with Negative Index of Refraction for Terahertz Application - IEEE Conference Publication

So it's that specific crystalline structure (which was known, produced and used already in the 60s) that allows it to propagate those waves freely in specific direction, and that structure probably is the same as that "atomic alignment" LMH and others have been talking about. I'm guessing Puthoff made just a vague reference to "physics literature" instead of proper ones to those papers as they would have already revealed how none of this has anything to do with mass loss or anti-gravity.

There's also nothing magical in terahertz waveguides. They were more like a stepping stone towards the more interesting but challenging domain of visible light:

The materials with negative refractive index [1] (also known as left-handed media, LHM) have attracted a great deal of attention during recent years [2, 3, 4, 5, 6, 7, 8, 9, 10, 11]. However, despite numerous efforts to bring LHMs to optical or even THz domain [12, 13, 14], all modern realizations of these fascinating systems are limited to GHz waveguides[7, 9, 15, 16].

A few years later, Podolskiy et al. published somewhat similar advances to prevent loss of light, which was a significant breakthrough:

Photonic metamaterials are engineered composite materials with unique electromagnetic properties, and have attracted significant research interest in recent years due to their potential to create “negative index” materials that bend light the opposite way of anything found in the natural world. But their performance has been significantly limited by the absorption of light by metals that are part of their composition - metal might absorb much more than 50 percent of the light shined on it, and drastically reduce the performance of devices based on these materials.

The solution to this problem, researchers discovered, is to offset this lost light by adding an optical “gain” to a dielectric adjacent to the metal. The new publication outlines how to successfully do that, and demonstrates the ability to completely compensate for lost light. It had been theorized that this might be possible, the researchers said, but it had never before been done, and the theories themselves were the subject of much scientific debate.

https://phys.org/news/2008-12-breakthrough-metamaterial-optics.html

So basically, if that piece of material would work the way Puthoff suggested, it would just pass that radiation through like Podolskiy explained years before. That's it. And I doubt it has the quality to do even that.

So what about this then:

Because I think he's right to seriously consider the substantial physical ramifications if the theory of stochastic electrodynamics is in fact the underlying physics for quantum field theory, and in this response to LMH, he explains that they found no unusual properties with her sample - but he raises an interesting untested possibility that such thin layers of these metals could act as a waveguide for terahertz waves, and exhibit a negative refractive index. And a negative refractive index invokes a little-known possibility with regard to generating a negative Poynting vector, and a negative Maxwell stress tensor at a boundary, which would produce a series of negative terms in the electromagnetic stress-energy tensor - and this would indeed produce a drop in inertial mass (though it would take a very high level of energy propagating in this manner to produce a measurable effect, and I can't see how that would be possible without melting the sample long before any change in mass could be detected)

It seems to be basically technobabble that confuses fundamentals. Maxwell stress tensor for example is part of the electromagnetic stress-energy tensor which in turn is part of the total stress-energy tensor, as is that mass. Hitting that piece of scrap with vast amounts of one type of energy is mass reduction basically only in the same sense as attaching a rocket to it. That's even if it worked like that, and it doesn't.

Here's one fitting reminder from one answer to a related question:

This is the most important paragraph of this answer: Work in "anti-gravity" is a crackpot minefield. You will find huge chunks of well thought out, well presented, elaborate, legitimate sounding science that are complete rubbish. The signal-to-noise ratio is infinitesimal and teasing out real science from the Roswell/UFO bits is very hard. Keep your skeptics eye and tin foil hat firmly in place at all times.

https://www.quora.com/Is-it-possible-to-build-a-gravity-mirror-using-modern-metamaterials

 

[DROBNJAK]

Problem is because @marduk insists on being stuck in engineering mindset: nuts, bolts and screwdrivers. But topic of this thread is "near horizon" speculative physics.

It's true that if you have nuts and bolts handy you can make something simply by trial and error, even without knowing theory. For example, Romans made fantastic cupolas on public buildings, that stood up for centuries, without knowing equations for stresses in spherical membranes. Even the guys who made first aeroplanes didn't know much about Bernuli's principle.

But trial and error has its limitations. You can't build Hadron Coliders by trial and error. And more modern technology is, more you depend on successful theory and maths. Here, General Relativity is that successful theory. So successful that it will stand unquestioned for at least another century.

On the end of the day it all goes back to the math. Even physics is secondary to math. Only problem is one has to has right model and that is what physicists are wrangling about.

@marduk no offense, but you are simply missing the opportunity to expand your horizons beyond nuts & bolts.

 

[Randall]

I just realized that this is actually The UFO Pseudoscientific Technobabble Thread ... lol. Listen, the whole problem is simple. Just get a couple of ZPMs and connect them in reverse phase to an array of flux capacitors, inject a little antimatter into the warp coil, and fasten your seatbelts!

 

[Thomas R Morrison]

I just realized that this is actually The UFO Pseudoscientific Technobabble Thread

If you listen to Realm he'll have you believe that there are no mysteries in the universe, nothing remains undiscovered, and every effort underway to expand the leading edge of theoretical development with an eye toward future applications, is nothing more than hopelessly misled pseudoscientific technobabble. That seems to be his sole purpose in life. And he's pretty good at it - if I didn't know that he was talking out of his ass half the time, I'd fall for it too.

But the truth is, he overreaches constantly in his obsessive efforts to disparage any and all avenues toward real scientific progress. For example, he has no understanding of general relativity or the stress-energy tensor, because if he did, he'd understand that mass is a variable in GR, and it's well-accepted that pressure (mechanical and electromagnetic and nuclear and gravitaitonal) alters the mass of a body: positive pressure increases mass, negative pressure (tension) decreases mass. Every time a chemical bond forms, or atomic nuclei fuse, or a gravitating body captures another body, the net mass of the particles/bodies involved in the reaction drops because of this simple underlying fundamental physical principle - so anyone who argues against it is only betraying their own ignorance of physics. He doesn't understand that we're not talking about new physics here, we're simply talking about new ways to utilize existing physical principles, because he doesn't understand physics at all. This subject has nothing to do with Podolskiy's research on waveguides (where he's not even considering any potential applications with the electromagnetic stress-energy tensor), or Podletnov's bogus "gravity shielding" (aka "gravity mirror") claim that appears in his incredibly lame Quora citation (just look at the author of that quote - Quora is even less reliable than Wikipedia because anyone can post anything there, and they're often wrong and/or highly biased), and this has absolutely nothing to do with the reaction force that he mistakenly conflated with the mass reduction permitted by general relativity, in his dumb and inappropriate rocket analogy.

He simply doesn't know the difference between science and pseudoscience, so he dismisses everything that he doesn't understand as pseudoscience, and then cites unrelated false claims or irrelevant information in a flailing effort to discredit potentially legitimate and interesting strategies for future research.

I don't have time for that crap - I could waste my entire life responding to each and every effed up foible in his ill-spirited posts on this forum. So I generally don't bother with it. In fact I was reading articles in reputable physics journals about negative energy fluxes in photonic metamaterials when I saw that he'd gotten to you, and felt obligated to step in on your behalf. Because there's a lot to be excited about coming down the pike, and you won't see it coming if you buy into his relentlessly negativist blithering BS.

Scientific progress is a difficult and messy business, and the last thing that anyone needs is some passive aggressive OCD internet heckler who's out to convince the world that the mainstream academic community has already ruled out every interesting new possibility, and that everyone striving to expand the boundaries of human technological capability are just crackpots and asshats.

F that noise. It's easy to argue that anything that hasn't been achieved yet in the lab is impossible. It takes zero scientific acumen to argue that position - any idiot can look stuff up on Wikipedia and see what's already been accomplished, and vapidly declare that anything which hasn't been achieved yet must be impossible. But it takes years of deep study and real scientific insight to see the possibilities that haven't appeared in all of the academic textbooks yet. But all of the stuff that's in those textbooks today was accomplished by the kind of people who dared to see new possibilities and took personal and professional risks to manifest them in reality.

Those are the real heroes.

But people like Realm will never achieve anything new because they defeat themselves (and anyone else who listens to them) before they even get started. Progress takes courage and hard-won comprehension, not some pathological obsession with denouncing everything and everyone striving to reach higher on behalf of humankind. The internet is overrun with people like that, who think that Wikipedia or frickin' Quora makes them an effing expert on everything, and I'm sick to death of it.

And btw:

Problem is because @marduk insists on being stuck in engineering mindset: nuts, bolts and screwdrivers. But topic of this thread is "near horizon" speculative physics.

There's nothing wrong with the engineering mindset - we'd get nowhere without it. As I see it, marduk does an excellent job in the adversarial role that's really at the heart of the scientific process.

He makes me work for it - like the Scully to my Mulder, lol. Frankly that kind of skepticism often helps me clarify my own thinking. I owe him a debt of gratitude for that.

 

[Randall]

There's nothing wrong with the engineering mindset - we'd get nowhere without it. As I see it, marduk does an excellent job in the adversarial role that's really at the heart of the scientific process. He makes me work for it - like the Scully to my Mulder, lol. Frankly that kind of skepticism often helps me clarify my own thinking. I owe him a debt of gratitude for that.

I'm mostly just messin' . I've said more than once that maybe it won't be NASA that comes up with the answer, but some guy, perhaps not unlike yourself who's gotten to tinkering in his garage. Still, once in a while it doesn't hurt to hit the reset button and remind ourselves that we're ( speaking for myself here at the very least ) not astrophysicists or aerospace engineers, or theoretical physicists. We're just pop-science geeks who want to think we're doing something special. So occasionally it doesn't hurt to pop our heads out of the ketchup bottle and have a laugh at ourselves. If we don't put ourselves in our place once in a while, someone else will. Might as well beat 'em to the punch.

But bottom line: Creative minds inspire other creative minds and who knows what sort of ripples will come out of this thread? Personally I think it's one of the best in the forum .