Fundamentally – What do I know?

Fundamentally – What do I know?

Black holes ain’t so black, and science ain’t so different from the humanities. Singularities have horizons crammed with information. Nothing objective is more fundamental than the information available.

This is a summary of recent work ostensibly on quantum gravity and the role of humans more generally in the science of reality. It also draws on some common fluid-dynamics metaphors and as suggested in the title, a reliance on fundamental information. The update here is in the light of the 2018 “How The Light Gets In” festival at Hay-on-Wye.

Big-data, algorithms, AI, fake-news, post-truth, post-humanism, you name it; from the wider humanities dimension of information patterns, I’ve already summarised what I heard in that general #HTLGI18 write-up. We’re all post-post-modernists now. From the the new physics perspective I’m hanging it off the work of Erik Verlinde but let’s be clear, the scope is the whole already suggested:

We’re talking
Physics and Humanity
Information and Analogy

A key feature of Erik Verlinde’s work – in fundamental physics – is that his new theory of gravity would appear to remove the need for the existence of Dark Matter whilst providing a rational explanation for Dark Energy. That would involve unpicking a great deal of post-Einstein work subsequently tested by real observation so, as they say, extraordinary claims require extraordinary evidence. Despite evolving, publishing and presenting versions of his work for over a decade, Verlinde and his colleagues are still working their way through satisfying the scientific community with fleshing out the detail, backing it up with the maths and establishing testable effects that will enable empirical verification. The jury is out. It could go either way. Situation normal.

So far so good. I’m an engineer/technologist not a scientist and couldn’t handle the relevant maths anyway, so I’m adding nothing to that. I might of course be the crank – a gentleman of a certain age, obviously – with a garden shed or two, where I’ve invented my own theory of everything.

I have a theory about dinosaurs,
and this this my theory.

They are very thin at one end,
very fat in the middle,
and thin again at the other.

Firstly, I’ve invented nothing, I’m simply reporting what I see and read with my own eyes. Secondly, there can be no grand-unified scientific theory-of-everything. I come to bury that idea. All I’m am asking is that more multi-disciplinary experts, in science and the humanities, take the ideas of others seriously in collaborative dialogue rather than discipline-specific politically-motivated critical analysis. Truth over tribe.

What I see, you can see too.

What I see are parallels in content and common analogies shared between other new theories of fundamental physics, theories already competing for hearts and minds in the scientific community as well as in popular science writing. In order to be considered “true” any one of these newer theories needs to be accepted by that community as, basically, an improvement on the existing. Whichever theories “win” or even if only minor modifications to the existing emerges, it seems highly likely that some of the common explanatory aspects will also emerge as “true”.

These common features are at two levels. At the level of fundamental postulations concerning the role of information underlying physics and at the human scale. The human-scale real-word physics analogies we can see with our own eyes. Erik uses versions of this slide:

That’s a cosmic galaxy, an atmospheric cyclone and a marine whirlpool.

Three different but
visually similar
natural phenomena.

Is the
underlying physics
also similar?

Neither Erik nor I are the first to point out these phenomena share visible features. No-one can fail to notice the impression of a vortex in turbulent fluid-flow – ether be gone! Those who work with the engineering mechanics – I hesitate to say science – of actual fluid-flow (say Navier-Stokes equations of compressible flow) have had to deal with one theoretical problem shared with fundamental physicists.

Singularities.

Singularities arise in the theory but cannot be handled directly without infinities that “fuck up” the maths. We have to integrate around their virtual existence in order to account for their real effects. In steady state or laminar conditions there are no vortices. In turbulent fluid the changing patterns of flow are modelled as the superposition of many imagined vortices even when no physical vortex emerges. When a vortex does emerge we also get a strange calm at the centre, the eye of the storm, the dry column of air drawn down your drain hole – a quite different flow-regime locally. The real effects are everywhere – aircraft wing-tips, standing waves on the surface of fast flowing rivers, the hum of the wind in cables- even where no real stable vortex emerges visibly. There is a horizon – a step-change, a phase-shift – between the original and emergent flows. Something happens here that doesn’t happen there.

At the centre of every vortex, real or imagined, is a singularity. And, between that singularity and the rest of the world is an horizon.

The same is true of physics dealing with black-holes, whether quantum-scale or super-massive, big-bang or big-crunch, real or imagined. Physics had its “shut up and calculate” moment in Copenhagen. We engineers had it with our Navier-Stokes equations. Maths that works despite the flaws at the fundamental level, provided you stay clear of the problem itself, the right side of the horizon.

As I say, all this has been pointed out by many others. Navier-Stokes in the context of fundamental physics shows up in many a Google search.

Clearly – in some way –
the underlying physics is similar.

The question is therefore – in what way?

As a string-theorist before developing his latest theory of gravitation, Erik is effectively in competition with non-string theories of gravity. He’s quoted as rejecting Quantum Loop Gravity (QLG). Yet both he and Carlo Rovelli, for example a proponent of QLG, share some maybe non-obvious features of these analogies. In QLG the “loops” involve integration around the planck-scale / quantum-level singularities. They and others also share a corollary feature of this. A singularity is a point with a horizon.

In looking at what can be known about the physical world, we notice very quickly the complementarity of information and entropy. That’s a question of how many data-points does it take to “know” or fully describe any given physical state or arrangement in space-time?

Carlo and Erik, and let’s now add David Deutsch, share a fundamental information view of physics. In fact there is a whole but quite separate metaphysical rebuild of physics going on under the Integrated Information Theory (IIT) banner. Talk about extraordinary evidence needed. Again Google is your friend. Information that needs to be integrated before you can see anything like a whole. A whole partitioned by horizons.

Warren Ellis pointed out that human culture is a work-around. Popper already said all life is problem solving. Deutsch brings the idea that this is fundamentally what humans do into his quantum information view. Human intelligence is the Universal Constructor? of evolving solutions to new problems. It’s why given a fundamental information view, human thought and intelligence really are significant to the physics of the cosmos. All three – Verlinde, Rovelli and Deutsch – allude to this.

If information is the fundamental component, then everything else – particles, forces – are emergent. Even laws of physics – recognisable / repeatable / predictable patterns in space-time are emergent objects. So is anything we can assert about the truth, properties or qualities of these. Objective epistemologically and real enough, but not fundamental or absolute physically.

Physics becomes the epistemological question of what can we know about the world.

Are there any fundamental limits to what can be known? By humans or anyone else. Take a phenomenon like entanglement – how something known here affects something (not yet) known there, without any communication between here and there – the whole “observer effect”. These are not just weird quantum anomalies yet to be explained. They are evidence that knowledge is fundamental. Information is about arrangements of / patterns in the data-points. Knowing the pattern, knowing any one bit of information does indeed immediately tell you something about any other bit in the pattern. Any pattern.

Just two more points about how much can be known.

• How small can a data point get? How many data points, how many possible arrangements, how much information can there be in the world?
• How far can a known pattern extend beyond our here and now in spacetime? Does the idea of knowledge of the whole make any sense?

Taking the second first, all I am going to say is that our physics is our knowledge. Even the best model(s) of physical reality may only ever be valid locally (spatially and temporally) from a human sense-making, anthropic perspective. We should not be surprised if galactic sale models and theories don’t apply at the quantum level, even if quantum information underlies them both at different places in the universe at different times. We may even find there are very real horizons between these zones and eras of applicability. Horizons across which nothing makes sense without a reboot. Apart from this meta-model of knowledge dependence, how could we hope for any unifying physical model?

As to the other point, what is a quantum of information? How many data-points could we get on the head of a pin? Is this anything other than the qubit of quantum computing?

Let’s start with giving ourselves a problem, after all they’re what we’re good at. Let’s assume data-points can be infinitely small and therefore infinitely closely packed – say in triangles / tetrahedra, whatever that means – in the dimensions of space-time . We’ve just bought ourselves an awful lot of mathematical singularities!

As soon as anything is happening – any pattern exists in space and/or time, space-time – there must be at least one space-time dimension that is larger than zero or there is no meaningful pattern. The potential singularities involved in our model of real world behaviour must have a non-zero horizon around which we can integrate. No pattern, no information. Zero information, zero scale. Something analogous to the Planck-scale, let’s call that the quantum information scale. The smallest singularity-containing black-hole large enough to contain a single bit.

This has a very interesting corollary for any horizon, pointed out by Erik already. It could almost become the definition of a black-hole – or anything else with an event horizon. The horizon is the surface at which all the information (ie everything) falling into it or projected onto it from “our” side is crammed together at this Planck-scale. It can’t get any smaller without losing (knowledge of) information. It is the limit to knowledge, anyone’s knowledge.

None of the above is science, there is certainly no maths or proof and even the philosophical thinking proceeds by analogy without dialectic rigour. What you see is what you get.

This is primarily my take on the work Erik Verlinde, Carlo Rovelli and David Deutsch with many earlier references to others omitted. As well as these modern, living physicists, there are even pre-Mach / pre-Einstein sources of the fundamental information & infinitesimally small data-points view. Like any enlightened scientist Verlinde acknowledges that these questions of limits to knowledge and boundaries to the cosmos are all pre-Socratic of course.

There was a sense at HTLGI18, reflected in Julian Baggini’s notes as much as my own, and even made quite explicit in the introduction by Hilary Lawson, that despite the apparent post-truth doom and gloom, we really do seem to have passed an event horizon. Fresh air, where the quest for absolutes in The Truth and The Good no longer seems to be the kind of thing worth coming to blows over, not even dialectically.

We’re all post-post-modernists now. Even physicists can agree.

Singularities have horizons crammed with information.
Nothing objective is more fundamental than the information available.

Black holes ain’t so black, and
Science ain’t so different from the humanities.

Let’s collaborate on unpicking what is useful to all of us.

=====

[Stub – still in draft – but with existing links you can follow meantime.]

[To be added: links to original sources and previously on Psybertron.]

[Post Note: OK, so I’m a pattern-seeking-human, bear with me:

This is the key figure from the new paper. https://t.co/mIvVLzhhMQ See how the new results agree with the earlier results. Note the pale grey line indicating that this area is ruled out by other experiments (assuming the standard explanation). 5/6 pic.twitter.com/YzRsMRGC2G

Sabine Hossenfelder (@skdh) May 31, 2018

What do I see? I see a laminar-flow regime bottom right, the “standard model” and a transition (horizon) to multiple turbulent flow regimes top left.]

[Post Note: Is this science beheading a philosopher, or is it a scientist sticking his neck out and peering across a horizon?

It was Max Born said, whilst managing all those geniuses assembled at Copenhagen, that “theoretical physics is actual metaphysics“. (The link behind the picture is actually a bunch of more sophisticated atheist philosophers upbraiding the likes of new-atheist Larry Krauss. In fact Larry was a participant by video-conference at the HTLGI before last, where he was ploughing his dissing-philosophy furrow.) Hat tip @AnitaLeirfall.]