Thursday, April 18, 2019

Physics of Everday Life

Based on Scott's review, I read through Stephen Pinker's Enlightenment Now. I can't top Scott's exposition of the book, but it is pretty incredible how far humanity has gone when you step back to look at the big picture.

One line intrigued me, one that Pinker credits to a book called The Big Picture by Sean Carroll
The laws of physics underlying everyday life (that is excluding extreme values of energy and gravitation like black holes, dark matter and the Big Bang) are completely known.
Hasn't this statement almost always been true, in the sense that the leading minds would make this claim at many times in history. The ancient Greeks probably believed they understood physics that underlies everyday life. So did physicists after Newton. Life back then not today. My everyday life involves using a GPS device that requires understanding relativistic effects and computer chips that needed other scientific advances.

Is it possible we could do more in everyday life if we knew more physics? I'd certainly use a teleporter in everyday life.

And is the statement even true today? We all use public key cryptography, even to read this blog. It's not completely clear if we understand the physics enough to know how or if large-scale quantum computers capable of breaking those systems can be built.

Everday life is relative.


  1. For balance, one should add though that Pinker's book (similarly to his previous one, and unlike his earlier books) is quite ridiculous. This review sums up the problems quite well:

  2. When I read this striking statement in Carroll's book, I took him to be making a strong claim that everyday-life physics was Done in a sense that had not been true in previous centuries. Specifically, that it was not possible in a non-exotic realm (like on Earth outside of supercolliders) to do experiments that showed puzzling discrepancies with predictions of the Standard Model.

    Of course, it all depends on where you draw the boundaries of both "physics" and "predictions". I think that by "physics" Carroll assumes fundamental physics, which wouldn't imply the ability to efficient predict the behavior of a lot of condensed-matter physics and complex systems. We can't use the Standard Model to predict either hurricanes or earthquakes, but I think most physicists would expect that improvements in our ability to predict those is not going to need any "new physics" (implicitly, fundamental physics).

    Personally, I would put questions about our ability to build large-scale quantum computers either into "engineering" or into some category that also includes earthquakes and hurricanes.

    If "physics" were to include making predictions about how efficiently it was possible to make predictions, then it would include all of Theoretical Computer Science, and of course would not quite be Done yet.

  3. The last paragraph from the preface of Wittgenstein's 'Tractatus' may be enlightening here: "On the other hand the truth of the thoughts that are here communicated seems to me unassailable and definitive. I therefore believe myself to have found, on all essential points, the final solution of the problems. And if I am not mistaken in this belief, then the second thing in which the value of this work consists is that it shows how little is achieved when these problems are solved."

  4. Early vs Late Wittgenstein  "I therefore believe myself to have found, on all essential points, the final solution of the problems [of philosophy]" … notwithstanding this early conviction, in later life Wittgenstein completely changed his mind! :)

    Pinker vs post-Pinker Enlightenment  Recommended is Saree Makdisi's undergraduate textbook Reading William Blake (Cambridge University Press, 2015). In a nutshell, works like Makdisi's stand in contrast with Pinker's works, as the later Wittgenstein contrasts with the earlier Wittgenstein.

    Quantum Supremacy versus the ECT  Week-by-week, new rounds of arXiv publications are showing students ever-more-plainly — aren't they? — that Quantum Supremacy stands in relation to the Efficient Church-Turing Thesis (ECT) broadly as the early Wittgenstein stands in relation to the later Wittgenstein.

    In a nutshell, the early Wittgenstein philosophy, and rationalistic Enlightenment, and quantum computation too, all three are grounded in logically beautiful models of reality — models that upon examination don't realistically reflect the dynamical reality of hot neural minds, empathic cognition, and lossy electrodynamics.

  5. There's also the story of the young Max Planck after graduation from the Maximilians gymnasium school in 1874, looking for a subject to study: music, the classics, or physics. "The Munich physics professor Philipp von Jolly advised Planck against going into physics, saying, >in this field, almost everything is already discovered, and all that remains is to fill a few holes.<" Substitute Carroll for von Jolly and hope that our future Max Plancks are not led astray from "everyday physics" and its implications by taking his quote too seriously.

  6. The laws of computing underlying everyday life (that is excluding P vs NP and the like) are completely known.

  7. More on Carroll's thesis that the physics underlying everyday life is completely known: