Been aware of a couple of tweets from Sabine at BackReaction on the topic of continuity over scales in physics, starting with a post by Krauss in Nautilus, and culminating today with another Nautilus link to a Max Tegmark piece that Sabine “wishes she could find something to disagree with” and this from FQXi on Quantum Cybernetics. As Sabine suggested in response to the first, so much more one could say if we had the time. Somewhere in there Frank Wilczek gets a reference too. So far this week I’ve just skimmed over these, but needed to read so I could comment.
Before I do, the meme coming back to me is Peter Rowlands observation on the topic of a theory everything, that abandoning the idea of physics having a coherent story to tell, was to make physics itself meaningless. Certainly a physics made of mathematical laws relating the objects of physics can never cut it. Information is more fundamental than a mathematical physics that accepts its fragmentation.
For me the real issue is the weirdness of causation itself, and it follows from Hofstadter’s strange loops, that at different scales different (why) causes and effects are in play, but they are all manifestations of an underlying reality, a coherent (how) story of the workings. This the common accusations of reductionism and determinism, that some high level behaviours are simply the sum total or net effect of many smaller causes and effects. Dennett warns against this greedy reductionism.
So what does Krauss have to say?
We know of no theory that both
makes contact with the empirical world,
and is absolutely and always true.
True. And that’s the reason the demand for “evidence” can become a fetish, if evidence is presumed to be objectively empirical. We know the world rationally through many forms of evidence or experience, not all of which can be objectively empirical.
So, what is going on?
Is a universal theory a legitimate goal,
or will scientific truth always be scale-dependent?
And here the fetish is that “scientific truth” is some primary or universal truth. Physics – fundamental science – is about how things work, not about “truth”. Is it possible Krauss has learned the value of philosophy?
The closer you get to the electron,
the more deeply you are penetrating inside
the “cloud” of virtual particles that are surrounding the electron.
Thereby preserving a preference for a particle model. The “cloud” of virtual particles in inverted commas is a hopeful sign. Further quoting Feynman:
“theory is simply a way to sweep difficulties […] under the rug.”
Feynman’s concerns were, in a sense, misplaced.
The problem was not with the theory,
but with trying to push the theory …
Well it is the problem – theories are only models, not reality. All models – theories – are created for a purpose (a local subjective reason). So, clearly it’s not likely to work out of that context. Unger and Smolin (and others) have already suggested that maths and physical laws change over time (and hence space). Like everything else, they evolve. What is universal is not “a” physics, but a meta-physics, with meta-laws and processes. The field of possibility exists, the particles are simply our objectified things. Waves and forces happen, but they’re only things when we objectify them for our subjective purposes, our working model. Krauss concludes:
Which road is the real road to reality is up for grabs. If we knew the correct path to discovery, it wouldn’t be discovery. Perhaps my own predilection is just based on a misplaced hope of continued job security for physicists! But I also like the possibility that there will forever be mysteries to solve. Because life without mystery can get very boring, at any scale.
Refreshingly honest admission of personal interest as a physicist. It’s wishful thinking to see reality as a physical model. The road of physics can never lead to reality, just better (more useful) physics. Of course, he couldn’t be that honest when given the opportunity of debating with a philosopher or two.
Tegmark on the other hand – given his title, I cannot imagine how he avoids a Dennett and Hofstadter GEB / EGB reference!
The bird surveys the landscape of reality from high “above,” akin to a physicist studying the mathematical structure of spacetime as described by the equations of physics. The frog, on the other hand, lives inside the landscape surveyed by the bird.
The delusion of physicists that they are working towards some god’s eye view of reality in a nutshell. Living in the landscape is reality. Reminded of William James observing the squirrel going “around” the tree in Tegmark’s next analogy, the moon orbiting the earth. I had to stop reading Tegmark at this point:
That our universe is approximately described by mathematics means that some but not all of its properties are mathematical. That it is mathematical means that all of its properties are mathematical; that it has no properties at all except mathematical ones. If I’m right and this is true, then it’s good news for physics …. It also implies that our reality is vastly larger than we thought, containing a diverse collection of universes obeying all mathematically possible laws of physics.
“That it is” is merely an assertion. No science to see here, folks. Lines, volumes and patterns woven through space-time are not new metaphors. Quoting a non-physicist friend Tegmark reports:
If someone says
“I can’t believe I’m just a heap of atoms!’’
I object to the use of the word “just”.
Good. Me too. Reality isn’t “just” a collection of things. History (the braid) matters, for one thing. Just seeing higher levels as assemblies of the lower is the greedy reductionism Dennett warns against.
On the Adesso and Girolami piece on Quantum Cybernetics in FQXi – some good stuff. Ashby, Wiener, “requisite variety” and a lot more, though not sure I came away understanding what they mean by their catchphrase. But OBVIOUSLY, given my agenda, Cybernetics is reality; how the real world’s working are governed. The objects of maths and physics are artefacts, phenomena, species we give names to in order to manipulate their information (through Cybernetics), but not fundamental reality.
In fact the summary in the headline says it:
Quantum Cybernetics – the quest for a meta-theory of quantum control that could one day explain physical systems, certain biological phenomena—and maybe even politics.
Not sure about “quantum control” but it’s certainly a meta-theory we’re in need of. [Ah, and “control” simply as a translation of “governance” (cybernetics)?]