In self sovereign identity systems based on verifiable claims, attributes are attested through signed claims on digital identifiers that the user control (e.g. a public key). Blockchains here are the most effective mean to implement claim revocation: if someone who produced a claim wants to revoke it, he writes that on a blockchain.
One thing that comes to mind is reversible computing. (https://en.wikipedia.org/wiki/Reversible_computing). When computation is irreversible (as is the case for all our current information elaboration systems and substrates), it is bounded below in the energy that dissipates. The bound is quantified by the Landauer principle, and has to do with the entropy involved in "forgetting" the previous states. If a computation process is reversible, it doesn't incur in such limit. One can maybe imagine time crystals concocted to carry out useful computation, spending no energy in the process.
Tommaso Toffoli [1] invented the reversible Toffoli Gate [2].
Norman Margolus [3] invented the Margolus Neighborhood [4], which is useful for rotationally symmetrical cellular automata rules [5] like billiard ball cellular automata [6] [7].
Toffoli and Margolus also explored other energy conserving cellular automata like spin glasses [8], which are disordered magnets that store energy in the bonds between atoms.
Edward Fredkin [9] invented reversible second order cellular automata [10], which look back two steps in time, and are useful for simulating the Ising model of ferromagnetism.
Then again, maybe Otis Eugene "Gene" Ray, the "wisest man on earth", caused this article to quantum tunnel through time from April 1 1997 [11] [12].
To play with the following code that implements a spin glass, go here:
http://donhopkins.com/home/CAM6/
then click the square in the upper left, click "Rules", pick the rule "von Neumann Spins Only", and draw in the cells by dragging around with the left button. JavaScript sure cooks these days!
// ruleFunction_VonNeumann_spinsOnly computes the Spins Only rule
// for VonNeumann neighborhood lookup table.
//
// Cellular Automata Machines, p. 190, section 17.3, Spins Only.
//
// This models a spin glass, which is a matrix of atoms with
// magnetic spins (up or down).
//
// https://en.wikipedia.org/wiki/Spin_glass
//
// A spin glass is a disordered magnet with frustrated
// interactions, augmented by stochastic positions of the spins,
// where conflicting interactions, namely both ferromagnetic and
// also antiferromagnetic bonds, are randomly distributed with
// comparable frequency. The term "glass" comes from an analogy
// between the magnetic disorder in a spin glass and the
// positional disorder of a conventional, chemical glass, e.g.,
// a window glass.
//
// Spin glasses display many metastable structures, leading to a
// plenitude of time scales which are difficult to explore
// experimentally or in simulations.
//
function ruleFunction_VonNeumann_spinsOnly(ruleDict, state) {
// This makes a checkerboard pattern that alternates every
// step, so we can apply the rule to every other cell every
// other step. That way we know our four neighbors will not be
// changing at the same time we are changing.
var activeSite =
(state.horiz ^ state.phaseTime) == state.vert;
// Count how many of our four neighbors are set.
var sum4 =
state.n0 +
state.w0 + state.e0 +
state.s0;
// When it is our turn to run in this cell (at every other
// step), then we flip our value if exactly two of our
// neighbors are up, and two are down. Since energy is stored
// in two adjacent cells with different spins, we can flip our
// value without changing the energy of the system, because
// the perimeter between up and down cells remains the same.
var result =
(activeSite
? [
state.c0,
state.c0,
state.c0 ^ 1,
state.c0,
state.c0
][sum4]
: state.c0);
return result;
}
I was only getting started! There are so many much more interesting cellular automata than Life, which is so overrated. As Marvin the Paranoid Android says, "Life? Don't talk to me about life! Loathe it or ignore it. You can't like it."
The classic book on the subject is "Cellular Automata Machines: A New Environment for Modeling" [1]
This article has a lot of great references: "When–and how–can a cellular automaton be rewritten as a lattice gas?" [2].
And Fredkin's "Digital Mechanics: An Informational Process Based on Reversible Universal Cellular Automata" [3] is also a classic paper about the subject.
Fredkin, Toffoli, Margolus and others have done a lot of interesting research into reversible computation, which has many practical and theological [4] applications, and will some day be very useful at the Restaurant at the End of the Universe [5].
Claiming there's no difference between prediction and understanding reminds me to what philosophers of science call "instrumentalism": theories are only to be judged by how well they work in predicting facts. But imagine a world in which Newton, instead of formulating the law of universal gravitation and the laws of motion, built a complex machine that, given the relative positions of a set of planets, could work out their subsequent trajectories, with astonishing precision. Nobody would be able to explain why it works in any "deeper" way. Would that world be undistinguishable by ours? If anything, would have Einstein had the same chances of devising general relativity? And Schwarzschild of deriving from it that black holes should exist? Doesn't the fact that we care whether black holes exist, despite how little they admittedly influence the set of mundane phenomena we observe everyday, imply that this world is distinguishably different from that with the accurate, hypothetical Newton black box?
> But imagine a world in which Newton ... built a complex machine that, given the relative positions of a set of planets, could work out their subsequent trajectories..
Thanks for the reply, I see what you're saying. Just to get metaphysical though, can't one argue that that's essentially what Newton did? Granted the machine he made was mathematically elegant, and the study of its components has been fruitful, but nonetheless it's the nature of physics that one never knows whether a formalism is really describing what's going on, or whether it might someday be superseded. Can we not imagine, say, a future where the art of warping spacetime is so well-understood that Newton's theories about a gravitational "force" are seen as just a bit of predictive machinery - useful for making approximations, but bearing no connection to the "truth" underneath?
I guess that that's what happened, and what's happening everyday... Newton action at a distance wasn't convincing enough, so others sought other, "deeper" explanations, among which most notable is of course general relativity. (And it's probably noteworthy that, from an "instrumental" point of view, its benefits were initially marginal...) The difference to me is between saying "the explanatory power of this current theory can (and will eventually) be outdone" and "being able to explain is a dimension of no importance in a scientific theory". Maybe that is Chomsky's concern, even though this instrumentalist attitude is far from new or unknown (think of Copenhagen (lack of) interpretation of quantum mechanics, and its (in)famous motto: "Shut up and calculate"!) If you are interested in this line of reasoning, I found David Deutsch ("The beginning of infinity") and Karl Popper ("Conjectures and Refutations") two passionate (and opinionated) voices!
Thanks for the recommendations. Admittedly I'm just being perverse in applying this to fundamental physical laws but the distinction feels very important in areas like linguistics (where researchers' ideas of "truth" tend not to be expressible in calculus).
That is, I picture an exchange where a deep-learning researcher says "our clustering algorithms found that languages A & B share characteristic C", and a linguistics professor replies "Aha, but the underlying truth is that A & B belong to the X class of languages, and X-like languages always have C". Intuitively the latter version somehow feels more robust, but in practice they're basically equivalent, and the first version arguably carries less baggage.
And since human nature limits the size of group that can work together, the only way I can imagine for larger groups to avoid tree structure would be to have no structure: to have each group actually be independent, and to work together the way components of a market economy do.
That might be worth exploring. I suspect there are already some highly partitionable businesses that lean this way. But
I don't know any technology companies that have done it.
Also, the guy who founded VISA has spent his later years putting forward ideas on how build large organizations that still maintain the anarchic qualities which allow independance from too much central control.
I also thought of Valve when reading that sentence. Being anarchic is a compelling idea. There are some conditions to be met though. You would need highly autonomous people who have good grab of the big picture to drive the group forward.
Highlight: "With these monosynths you can get inhumanly fast (or slow) complex pulses that phase, bounce off each other and interlock in ways that no human ensemble could ever achieve, while retaining the live performance element in all the other areas".
To me, the example of one of the most thrilling potentialities of computers and informatics.
"The Beginning of Infinity", from David Deutsch, in which evolution, Popper epistemology and theory of computation blend into a world view fruitful of thrilling perspectives for humanity. To me, as mind blowing as anything can ever be.
I think your link is the perfect answer to the problem highlighted in the post (which is, incidentally, a problem I was facing myself, so thank you!). There's also an Haskell implementation of priority search queues: http://hackage.haskell.org/package/PSQueue-1.1/docs/Data-PSQ...
