If you can supply a solution for
these problems, then that would help a great deal to know what the "known parameters of empirical reality" are.
It’s perfectly reasonable to point out that there are still plenty of unresolved questions in physics – those are my favorite topics actually. But it’s silly to imply that “because we don’t know everything, then we don’t know anything.”
We know enough about physics to require that a hypothesis conform to the demonstrable characteristics of empirical reality. We know that when you knock a cup of coffee off your desk, it’s going to hit the floor - not disappear into an invisible dimension before landing in the apartment next door, for example. If there were additional large spatial dimensions, that kind of thing would happen all the time. In fact, the number of legs you need to stabilize a bar stool depends on the number of spatial dimensions of your reality: in a 4-dimensional space, a stool with three legs would fall over. And there would be no stable planetary orbits either:
Q: What would life be like in higher dimensions?
And the use of the term “extra-dimensional” commonly employed in this context isn’t simply imprecise, like “do you mean ‘Wednesday’ in my time zone, or yours?” Nobody has yet provided any discernible model of what they mean by “extra-dimensional,” and how it would be consistent with well-established and well-understood observations. It hasn’t even achieved the status of an “idea” yet, because nobody can even clearly define what they mean by it. So this isn’t just semantics – the term “extra-dimensional hypothesis” is truly devoid of any rational meaning. Saying “ufo’s come from abracadabra” has exactly the same significance: none.
Theoretical physicists have been analyzing the mathematical properties of additional dimensions for nearly a century. Ever since Einstein defined time as a component of the 4-dimensional spacetime manifold, theorists have been investigating the consequences of even more dimensions than four. So we already know the characteristics of realities with additional dimensions. It is possible that extra dimensions exist curled up into knots smaller than the size of an atom. And physicists are actively looking for indications of their existence. But they’ve found no sign of their existence, and there’s no place to hide aliens inside them because they have to be subatomic in scale, or we would’ve noticed them already.
But even this diagram of the particle zoo does not include the possibility of SUSY, or a description of the vacuum where these particles exist.
Supersymmetry is a pretty idea, but physicists have been trying to detect a SUSY particle for decades, and we’ve still seen zilch. Lots of pretty theories fail in the lab.
Supersymmetry’s absence at LHC puzzles physicists
And vacuum fluctuations are a key feature of quantum field theory, which is the bedrock of the standard model, and pre-dates it by decades. Every particle of the standard model is expressed as both a field of minimum energy (its vacuum fluctuation), and as that field’s excitation state (the particle itself). So vacuum fluctuations aren’t treated as separate entities on that chart - rather, they’re implied by each and every particle on it.
I am not a physicist, but to me, the vacuum, with its vast seething sea of virtual particles, and real particles, appears to present a lot of yet-unanswered questions. The "vacuum catastrophe" is one. Though perhaps you have a convincing solution for the discrepancy of what, about a hundred orders of magnitude?
You’re mixing apples and oranges here: the vacuum catastrophe has nothing to do with higher dimensional physics.
But yes, there is a clever yet largely unsung model by CERN theoretical physicist Dragan Hajdukovic that appears to resolve the vacuum catastrophe very elegantly. Hajdukovic has explored the cosmological consequences if antimatter (and therefore the antimatter aspect of virtual particle pairs) possesses a negative gravitational charge in the same manner that antimatter possesses an opposite electrical charge to matter. In that case, a vacuum free of matter possesses no net cosmological constant, but a vacuum populated with matter becomes gravitationally polarized by the matter, yielding a cosmologically short-range effect precisely akin to the dark matter phenomenon, and a long-range effect on the correct order of magnitude to explain the acceleration attributed to dark energy. If he’s right, then in additional to explaining dark matter and dark energy with a single postulate, the vacuum catastrophe vanishes because we’ve been working on an incorrect assumption about the gravitational charge of antimatter, and therefore vacuum fluctuations. We’ll have to see how the gravitational experiments with antimatter go at the ALPHA, GBAR, and AEgIS collaborations at CERN, to know if Hajdukovic is on the right track. Right now we still don’t know if antimatter falls up or down in the Earth’s gravity field.
So, since I am speculating, I propose calling the Standard Model particle zoo together with the vacuum the "realm of physics."
Don’t forget about general relativity – together, quantum field theory and GR describe nearly every feature of empirical reality to astonishing precision.
And that’s the challenge for the term “extra-dimensional” – if someone can define what that term means without violating
the facts that we know to be true via the mountains of evidence supporting those two theories, then we could elevate it to the status of a hypothesis.
Nothing new there. My speculative, orders of magnitude smaller, more energetic substance that supports our "realm of physics" I will tentatively call the "realm of hyper-physics."
Since I am speculating, then I propose that just as our "realm of physics" supports conscious entities, so my proposed "realm of hyper-physics" supports conscious entities as well. And since the "hyper-physics realm" supports the structures of the "physics realm" then any conscious hyper-physical entities might very well be able to interact with us in our physical realm, and do things that to us are impossible.
I like this idea – it’s really weird and novel, and it reminds me of the most exotic and bewildering experience of my life. Back in college when I was incredibly reckless, I forced the veins in my head to bulge out like in the movie
Scanners, just to freak out my friends for laughs. But I pushed it too far and passed out at our lunch table (that really
did freak them out, haha) – and on my “out” I saw this intricate and rapidly evolving geometric pattern in my mind’s eye, as if my consciousness were plunging down to a point, and it seemed like witnessing the invisible structure of subatomic reality up close and personal. Or perhaps I was observing the fabric of consciousness itself; it’s hard to say. But I sensed that I wasn’t alone there – like there was some form of intelligence in this totally unrecognizable field of complex but beautiful and highly geometrically ordered structure reminiscent of fractal patterns, but in motion. Ever since then I’ve wondered if there are uncharted vistas of an interior reality that might be populated with entities comprised of the non-physical substance of thought, ideas, and possibly inspiration. I can’t imagine how the realm of consciousness could intersect with physical reality though, except perhaps indirectly by influencing our thoughts, and thereby our actions, in this physical 4D reality.
But that’s an altogether different realm than empirical reality - there are good reasons to object to the notion of complex ordered processes at the physical sub-Planck scale. That’s a domain where we need a quantum theory of gravitation, because quantum field theory and general relativity are both in play at that scale, and we just don’t have a grand unified theory yet. I have been keeping an eye on the astronomical efforts to detect any granularity of spacetime, and so far they seem to disprove the notion of quantized spacetime at the Planck scale:
https://phys.org/news/2012-08-spacetime-smoother-brew-knew.html
There is a very real possibility of physics underlying quantum field theory, though. Lately I’ve been fascinated with a theory that claims to supersede quantum field theory, called stochastic electrodynamics (SED). The neat thing about SED is that it chucks the abstraction of the uncertainty relation by postulating instead a Lorentz-invariant background field of real photons, which introduces an increasing magnitude of random “noise” to our measurements at progressively smaller scales. It’s one of the many tragedies of historical circumstance that SED receives hardly any attention in the academic literature, because if it’s a correct interpretation then the technological ramifications could radically transform human civilization.
Okay. All speculation. But so are various warp drives and worm holes that are harnessed for the propulsion of ET craft.
See, that’s wrong. “Speculation” is defined as “the forming of a theory or conjecture without firm evidence.”
Warp drives and wormholes, on the other hand, are rigorously defined theoretical and mathematical constructs entirely consistent with the general theory of relativity, which is supported by very firm evidence in many regimes. GR tells us exactly how to produce these effects by concentrating energy fields of a specific magnitude in a specific geometry. If warp drives and wormholes aren't possible, then they’re not possible for reasons beyond the scope of Einstein’s theory of gravitation (which, to date, has never made an unsuccessful prediction). So they’re far above the realm of speculation; they’re actually theoretical predictions of general relativity that simply appear to be well beyond our technological capability to create. The linchpin problem with both of these concepts turns out to be the same factor: negative energy regions of extremely high density. General relativity permits this kind of negative energy condition, and quantum field theory also permits regions of negative energy, as we’ve seen with the Casimir effect and “squeezed light” states, but we still have no idea how to produce negative energy regions at the densities required to yield observable gravitational effects.
Ultimately most of the outstanding problems in physics today come down to one thing: we’re still missing the Holy Grail of theoretical physics - a grand unified theory that formally unites quantum field theory with gravitation, and hopefully dark matter and dark energy as well. Once we have that, then one of two things will probably happen: either we’ll rule out warp drives and wormholes because some new rule will become evident which forbids them, or we’ll suddenly realize that they’re much easier to create than we had imagined. Gauging from past scientific advancements, I tend to assume that the grand unified field theory will introduce many more possibilities than it dismisses.
Appreciating the debate on the nature of dimensions. Kudos to William and going right to the limits of empirical reality. I do have a physics degree, emphasis in astronomy, in particular stellar structures and evolution. I find that I will inevitably run into the same two brick walls of epistemology. As far as we can tell, the human apparatus is designed to perceive and operate in the four dimensions of spacetime. The empiricists would say that's because that's all there is. The rationalists would point out the anthropomorphic bias and the logical fallacy of the 'part' attempting to have perfect knowledge of the 'whole'.
Welcome aboard, Nyet Nikovo. I’m glad that you enjoy this kind of discussion: all of the most interesting discussions happen here on the fringes.
I don’t see “the part trying to have perfect knowledge of the whole” here – we don’t need perfect knowledge of anything to mathematically analyze the ramifications of a higher-dimensional reality, and compare them to our observations. This process shows us that extra dimensions would have to be either A.) subatomic in scale or B.) limited by a specific gauge symmetry to reproduce the 4D reality that we observe; otherwise we would’ve easily noticed their effects because the laws of physics would operate very differently than we observe.
Second, Kant rightly pointed out that there is no way to separate out the influence of human perceiving apparatus on that which is being perceived. EEGs of subjects on LSD have shown that according to brain activity - they really are smelling the music and hearing the paint. The cortex switchboard operator is just out to lunch. So yes, we can break out our Calabi-Yau manifolds, branes, and strings. But until we have a non-human observer who can and is willing to confirm, it's all mathematical speculation.
The extra dimensions of string and brane theories are definitely mathematical speculation. In fact I’m reluctant to even call them theories, because they’re actually vast classes of theories, which all make different (and usually untestable) predictions. And whenever a string theorist
does make a testable prediction, which invariably fails, they just say “oh well, that rules out a few thousand variations of string theory - but there are millions more where that came from!” Yikes. I prefer the old-school guideline: if it’s not falsifiable, then it’s not a scientific theory.
And I don’t see why a non-human observer would be in a better position to describe our reality than we are: mankind hasn’t been limited by our senses since the advent of the optical telescope – we can detect almost anything with instruments nowadays, and we can model extremely counterintuitive phenomena mathematically, as we've seen again and again with quantum field theory. So I have great faith in the human capacity to transcend the limitations of our monkey brains and limited senses, to discern the most exotic and abstract characteristics of physical reality.
That being said, experiments involving non-locality, quantum entanglement, and supraluminal information transfer are pointing to some fascinating possibilities. Nothing like a good brain twist over a cold beer on a hot day.
A little nitpick here: quantum entanglement doesn’t involve superluminal information transfer. Entangled particles change states simultaneously when one or the other is measured, but since there’s no way to influence the state before it’s measured, information can’t be communicated via entanglement.
It's amazing that quantum field theory predicted entanglement. The de Broglie-Bohm pilot wave theory appears to be even more interesting in some respects – restoring causality and continuity to quantum phenomena is deeply appealing. I’ve been wondering if there’s some way to influence the quantum potential that determines the particle trajectories in that model: if we could interact with the quantum potential itself, then we might be able to produce an effect like warp field propulsion, without having to employ gravitational fields.
