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I am approaching this from a layman’s perspective and curious about what those more expert in the field have to say about my understanding of Superfluid vacuum theory and the holographic principle and my corresponding question.

Recent studies (I believe these were mathematical modeling studies rather than experiments) have suggested that superfluids; specifically liquid helium, exhibit similar holographic characteristics as blackholes. That is that their entropy/informational content is proportional to their surface area rather than their volume. Similarly the universe has been calculated to have this holographic nature; that it’s informational content corresponds to its scale in 2 dimensions rather than 3.

My understanding of superfluids are that they form at extremely low temperatures; close to absolute zero. That once formed such superfluids (droplets of them propelled by pilot waves on their surface) can exhibit properties seen in wave particle duality and quantum tunneling. That superfluids expand or spread to equilibrium regardless of gravity similar to the way in which the universe is seemingly accelerating in expansion towards a “cold death”. Aspects such as these have been referenced to suggest the universe or reality itself is at a fundamental level a superfluid. (Superfluid vacuum theory)

My question is whether such a superfluid model of reality is suggestive of the possibility that space time itself undergoes “phase changes” and therefore may not always have behaved the way that it does now. I note the temperature of the universe is very close to absolute zero but it has been cooling since the “Big Bang”. Could it be that the Big Bang itself was infact some form of phase change whereby our laws of physics and reality itself essentially condensed into existence as a zero viscosity holographic superfluid the surface of which all information is represented on? Would this then suggest that the universe may have existed prior to the Big Bang but simply in a very different form (one where quantum mechanics would not have functioned as it does now)?

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First, the bad news.

  • "Superfluid vacuum theory", despite having its own wikipedia page, is not a common or standard term in physics. Ultimately it seems to refer only to the theory espoused in a thoroughly obscure paper from 2009, one which proposed that the origin of mass is something other than the Higgs mechanism (the Higgs boson was observed three years later) and which predicts deviations from special relativity at high energies (no such deviations have been observed, even at the very highest energies).

  • I am not aware of any sense in which laboratory superfluids, whether liquid helium or otherwise, satisfy the holographic principle.

  • You mention superfluid droplets "propelled by pilot waves on their surface" that exhibit quantum properties.

    The pilot wave is an idea from the beginning of quantum mechanics, according to which particles are guided by waves. In recent years, Brady and Anderson got some press by asserting that experiments in which droplets are guided by waves, show that quantum mechanics might be explained in this way. But it has been known for many decades that a truly quantum pilot wave (as in Bohm's formulation of quantum mechanics), that guides more than one particle, cannot correspond to a single wave in three-dimensional space. So Brady and Anderson are necessarily on the wrong track.

    Meanwhile, superfluids and their properties are actually a consequence of quantum mechanics. Aiming to explain quantum mechanics as a result of superfluids is circular, unless one has an independent non-quantum account of what a superfluid is.

  • It's hard to see how the accelerating expansion of the universe corresponds to any behavior of a superfluid. Superfluids don't expand forever and they don't speed up as they do so. (Unless the idea is that the accelerating expansion is holographically dual to, maybe, some kind of Bose condensation??)

So there are a lot of ingredients to your understanding that don't add up. I would be curious to know if you got all of this from one place, or if you have assembled it yourself from a variety of sources. Either way, there is a lot of hype and misinformation out there, and you are hardly to be blamed for falling for it.

Meanwhile - superfluids are real (and dark matter might be a superfluid); the quantum vacuum contains, not superfluids, but various other "condensates"; quantum black holes are generally expected to have an entropy and a temperature; and there are many mathematical examples in which a dimension of space "emerges" from quantum entanglement.

So there are many phenomena and theories which are in the direction of what interests you, but which are better attested or more robust.

Concerning your actual question(s)... Given that emergence of macroscopic space-time "from quantum mechanics" is a serious topic now, it is absolutely possible that the big bang was just a phase transition out of some other quantum regime. But I can't think of any really good work which gets into the specifics of that. There are lots of relatively amateur papers, in which e.g. one has quantum algebraic expressions, and then one considers a "large N" limit, and this limit is said to resemble ordinary space-time. And there are more sophisticated papers (mostly I mean, papers by string theorists) in which similar but more advanced exercises are carried out, but it's still hard to find the physical meaning behind the mathematics.

With respect to your actual proposal - "some form of phase change whereby our laws of physics and reality itself essentially condensed into existence as a zero viscosity holographic superfluid the surface of which all information is represented on" - I have trouble seeing how the concept of a "viscous superfluid" has meaning independent of space-time.

Especially since holography generally involves the emergence of an extra dimension, it sounds as if you are starting with more than zero dimensions of space, and then an extra dimension is emerging. There is an old proposal called "dS/CFT", one version of which says that our universe evolving in time is holographically dual to a timeless space of just three dimensions. Maybe there's a version of dS/CFT in which the timeless dual is a "viscous superfluid" at the end of time, but, I'd want to see the mathematical argument for that. :-)

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  • $\begingroup$ Thank you for the comprehensive response. I admit to building an impression by way of second hand information rather than a primary understanding of the physics and mathematics. However, the behavior I refer to whereby superfluid bears the same 2d holographic nature as a black hole (I understand this as a sort of event horizon for the atoms which constitute the superfluid) was reported here: scientifist.com/superfluid-helium-behaves-like-a-black-hole. The result of a mathematical simulation as I understood it. Potentially part of the hype you refer to though. :) $\endgroup$ – user43685 Aug 13 '18 at 10:05
  • $\begingroup$ I finally read the article. They refer to the entropy of the entanglement across a boundary, as being proportional to the area of the boundary, in a superfluid. According to the review article arxiv.org/abs/0808.3773 entanglement entropy scales like this in the ground state of many other quantum systems, but not all... There may or may not be a relationship to why the black hole entropy would scale in the same way. Black hole thermodynamics is derived from macroscopic reasoning, and there are rival theories regarding the black hole microstructure responsible for it. $\endgroup$ – Mitchell Porter Sep 2 '18 at 12:30

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