The Trouble with Many Worlds - <AUTHOR> http://blog.rongarret.info/2019/07/the-trouble-with-many-worlds.html <comment><USER2> The many-worlds interpretation is a good way to reason about quantum mechanics (certainly better than giving some special status to the experimenter), but it's meaningless to ask whether those other worlds really exist or not, not just because it's un-falsifiable, but also because if one defines "existence" to include alternate worlds, then every possible state of the world exists. If everything exists, then it's no longer a useful property to talk about.

One can replace many-worlds with an idea similar to relativity: you can only make statements about the universe from the perspective of a particle within that universe. Things entangled with that particle are "real", and one can make statements about them, things not entangled with that particle are not real.

When dealing with composite observers like ourselves, it's possible for a particle to be entangled with only part of the observer. Since entanglement propagates quickly, this is only a temporary inconvenience, but there are certainly some metaphysical questions to answer about that interim state.

<comment><USER3> >it's meaningless to ask whether those other worlds really exist or not

Dunno - if you think of something like the two slit experiment whether the worlds where the particle goes through slit one or where it goes through slit two exist or not seems to have experimental results as they produce an interference pattern.

You can also ask about more complicated situations and whether the other worlds exist may not be meaningless if they have an effect on event probabilities in ours, if only a small one.

<comment><USER2> In the many worlds interpretation, as soon as a world has "split"/"the wave of differentiation has hit"/"particles have been entangled"/"whatever terminology you want to use" from the observer, it has _zero_ impact on any future results, not just a small impact. Until that split happens, we're just talking about our own world. It's never possible to observe any evidence for more than one world, that follows from the way we define what a "world" is.

Many-worlds does not try to explain why particles have a wave function, it only tries to explain the source of the apparent randomness in the way that wave function collapses, whilst removing the need for experimenters to be in some way "special" and immune from quantum effects.

<comment><USER4> Is that really true? In principle, if many worlds is the case then you could have a super machine enact a powerful unitary transformation which transforms the state of the observer such that there is interference between the two copies of the observer.

</comment></comment></comment></comment><comment><USER5> Something that never made sense to me is why people think of Quantum Mechanics (the non-relativistic classical one) as fundamental. While some of its principles certainly are, clearly QFT (quantum field theory) is fundamental. From the perspective of quantum field theory there really is no observer just different field that couple to each other. Something like a measurement can in principle be described by a complicated interaction of fields (think of shining light at a double slit). The big mistery is I would rather say why the path-integral formulation of QFT (of which the principle of least action is the classical limit) agrees so well with reality.

<comment><USER6> There are a couple of reasons (you alluded to them when you said some of the principles of QM are indeed as fundamental as QFT):

\- My favorite one is that in terms of computational complexity, the QM and QFT are equivalent. A computational machine based on the rules of QM can simulate QFT efficiently.

\- How does QFT describe the following situation: you have a particle created at location x that then propagates and passes through a double slit setup where you might selectively close one of the slits at any time (i.e. you measure the particle's location). Any challenges of interpretation present in QM are still present in the QFT formalism (but mathematically, both do predict the evolution of the system correctly).

\- While my QFT experience is limited, I have the impression that the tools for dealing withixed states it has are less developed than the ones in QM. Given that due to the previous reasons QFT does not give much new insight to the topic of measurements, it is reasonable to stick to the simpler (but equivalent in our parameter regime) theory of QM and it's more sophisticated mixed-state toolkit.

<comment><USER5> \- Regarding your first point, I'm pretty sure this is untrue without further qualifications (which I understand that you don't mention because this a forum and not a scientific setting). In any case any such mapping would most likely be NP hard (assuming your quantum computer has q-bits that can only interact according to some graph, I would expect this to reduce to a graph isomorphism problem).

\- You would deal with that by writing down a path integral (see for example Feynman's PhD thesis) (btw. particle creation is not possible in non- relativistic QM). The tricky thing is that of course "closing the slit" is a very tricky thing to model in a path integral, but the situations "slit closed" and "slit open" are rather straightforward. In any case even without any computation what is clear from the path integral perspective is that nothing mysterious is going on: You are supposed to sum over all possible histories of the particle passing through the slit and hitting the screen, weighted by e^iS. If there is some temporal variability in the position of the slit, this just results in a huge complication in the integral to be carried out (if you model closing the slit by a time dependent potential let's say). The path integral is fundamentally a very good way of thinking about this, because it generalises to much more complicated settings (gauge theory etc.), whereas there really is nothing fundamental about measuring, you just happen to drastically and in a temporally complicated way change the background your quantum fields are propagating in.

\- On the contrary, basically QFT is the only way to deal with mixed states in a principled way. For scattering you typically start out with the assumption that things are in pure states at t=-infty and t=+infty, but in between the whole point of introducing quantum fields is to keep track of how things are spatially (plus gauge degrees of freedom etc.) "mixed". To be more specific QM is just a D=1,0 QFT, with 1 time dimension and (zero-dimensional) points as spatial dimensions. A mixed state rho is nothing more than a general quantum field on these discrete points.

<comment><USER6> On point 1: I did not get your argument about NP hardness and equivalence to graph isomorphism. On the contrary, algorithms for efficiently simulating non- trivial QFTs on a non-relativistic quantum computers exist: [https://arxiv.org/abs/1111.3633](https://arxiv.org/abs/1111.3633)

Point 2: If "there is nothing fundamental about measuring" in the QFT case, I do not see what is so special about the QM case (you just take a partial trace over the "environment"). I (admittedly with humility as I am not as well versed in QFT) really do not see how your answer is any different from this (and I do not see how the path integral gives you anything new __for this particular problem __, albeit being a beautiful formalism).

Point 3: QM has developed a lot of tools to deal with Marcovian and Non- marcovian non-unitary dynamics (the whole zoo of master equations available in it). Of course QFT can deal with density matrices if QM already can do that, but the sophistication of the toolkit used for that purpose in QM seems yet unsurpassed to me. And to your last point about creation of particles: Second quantization is already available in non-relativistic QM, so there is nothing weird about an a^dagger*b Hamiltonian in QM (I use it all the time for cavity- qubit interactions) - so, yes, you can not deal with the creation of arbitrary particles in QM, but you can still easily work with some restricted modes of a field, without involving QFT.

<comment><USER5> Regarding point 1: I should say that I'm not an expert in Quantum Computing, but reading the referenced paper leaves me unconvinced that such an algorithm exists in general. In the paper they show that they can simulate phi^4 efficiently and with arbitrary small discretisation error. My point regarding the graph isomorphism in this case is as follows: In order to carry out the discretisation, they employ a d-dimensional lattice and additionally introduce a discrete number of Q-bits per lattice site. Then they require to be able to evolve the state according to some time dependent hamiltonian (with interactions adiabatically switched on and off). All proposed realistic quantum computers only allow for a limited operator set of primitive operations, dictated by the physical geometry of the implementation (1d lattice of atoms in a trap etc.). My point was that more likely than not you will always be able to come up with theories for which a mapping respecting these physical constraints is hard (you won't easily be able to simulate a 3d lattice with multiple q-bits per lattice site on a 2-d lattice of q-bits). Also the article has to restrict itself to the case of massive particles and as you know lattice simulation of fermions is also a problem.

Point 2 & 3: You are right of course, ultimately this is a question of what techniques are useful. My comment was mostly aimed at the situation where people start to discuss the philosophy of QM. There I find that QFT clarifies the situation more than any philosophical elaboration on "measurement" and things like that do.

</comment></comment></comment></comment></comment><comment><USER7> I find this article rather hand-wavy. I mean, we have a very good understanding of the measurement process in quantum mechanics through experiments performed e.g. by Haroche's and Siddiqi's groups, which demonstrate that quantum measurements are continuous, deterministic processes. Irreversibility and the transition of a quantum state to a "classical" state can be explained very well using entanglement and decoherence, which originate from the coupling of the measured system with a very large, external quantum system. With this approach, no magical wave-function collapse or breaking of time reversal symmetry is required to explain the observed collapse of quantum oscillations after measurement.

The interpretations of quantum mechanics that rely on wave-function collapse need to provide a plausible mechanism for how the irreversibility within the measurement process comes about, as a collapsed wave function is no longer time-reversible (i.e. if we would flip the sign of the Hamiltonian we would not be able to go back to a previous state as the wave function was irreversibly changed during the measurement) and I haven't seen any physically plausible attempt at this so far. So personally I still favor the many-worlds hypothesis, if only because it doesn't require invoking a so-far unknown process that destroys reversibility during quantum evolution.

<comment><USER8> What do you mean by measurements being deterministic? In Haroche's cavity-QED experiments the outcome of each individual measurement is fundamentally random and cannot be predicted. Quantum mechanics (regardless of which interpretation one choses) only gives a probability distribution for the outcome of many measurements.

<comment><USER7> Quantum measurements are not discontinuous, instantaneous processes but rather determined by the continous evolution of the joint Hamiltonian comprising the system being measured and the measurement system. You can perform partial measurements of a quantum state and even exert feedback on the quantum system to keep it at a given state (so-called quantum feedback). The outcome of a given measurement is only random because we are part of the measurement system and become entangled with it, which in combination with decoherence - due to the near-infinite number of degrees of freedom in the measurement system - leads to our experience of "quantum jumps". All of this can be explained with the Schrödinger equation alone, without the need to invoke the principle of wave-function collapse.

I don't like theories that require such a wave-function collapse mechanism in order to get rid off all the extra "worlds" because they would require a physically plausible mechanism that governs this collapse and the breaking of time-reversal symmetry that it creates. It is also hard to think about a scaling mechanism that would govern the wave-function collapse: If we imagine that we will one day be able to build large quantum computers with many millions or even billions of quantum bits we will be able to couple e.g. a single qubit to the computer and perform a pseudo-random (but entirely deterministic) range of operations on the other qubits. Should we assume that at some point the wavefunction of the single qubit that is coupled to the many other qubits will collapse? In that case we should not be able to reverse the qubit to its initial state by reversing all operations performed on the other qubits. At which scale should this happen then? If we could eventually scale up the quantum computer to comprise a near infinite amount of qubits in such a way that it's able to run a simulation of a toy universe with a conscious observer in it, would that be enough to induce wave-function collapse (even if we can still reverse the deterministic gate sequence at any time)? In such a case, for each qubit state there would also be a version of the observer, each seeing a different "collapsed" wave-function of the qubit. However, we could still reverse the gate sequence of the computer at some point and bring it back to its original state, uncollapsing the wavefunction of the qubit in the process. Now, we would of course also reverse the state of the observer(s) to their/its initial one. The question is, can we restore the state of the single qubit to an uncollapsed quantum state while keeping the state of the observers untouched? And if we could do it, what would it mean for the observer(s), will we collapse their wave function in the process? Given infinitely precise control over our quantum computer we should actually be able to do it since the evolution of the quantum system is still deterministic. The more interesting question is if this reversal of the single qubit state will automatically lead to a collapse of the two observer(s) back to a single one as well (here I'm not sure but this should be calculable).

In any case the conscious observer in our quantum computer would have no way (as far as I can think of) to determine whether it lives in a many-worlds quantum universe or one where wave functions collapse. We, on the other hand, would know that its a many-worlds quantum universe because we just execute a reversible, deterministic gate-sequence on the computer.

Sorry for rambling, my point is that it's a very metaphysical and (mostly) irrelevant question for most physicists, and it's unlikely that we will really come up with a way of deciding this question as we are part of the system that we are trying to investigate. Answering the questions for a quantum world that we simulate in a powerful computer might be possible, but it won't tell us much about our own universe. I personally just prefer the many-worlds hypothesis since it seems more elegant and simple and does not require coming up with a new mechanism for destroying time-reversal symmetric in quantum mechanics.

<comment><USER9> > All of this can be explained with the Schrödinger equation alone, without > the need to invoke the principle of wave-function collapse.

But you need to invoke the principle of "we are part of the measurement system and become entangled with it, which in combination with decoherence leads to our experience of "quantum jumps"" which is not that much easier to understand and you still have to introduce the Born rule somehow if you want to predict probabilities.

The questions in your comment may be good questions, but the MWI doesn't really answer them either.

</comment></comment></comment></comment><comment><USER10> As someone who's read a lot of work on the philosophy of quantum mechanics, I want to say that this piece is VERY well written. (And I wasn't the person who posted it to HN.)

<comment><AUTHOR> Thank you! (I'm the author and the poster.)

<comment><USER11> My apologies if I get this wrong. Is this stating that the many possibilities are all coexisting and that our brain is acting as a filter to provide a view of possibilities that we define as ourselves?

<comment><AUTHOR> That depends on what you mean by "this". If by "this" you mean MWI (the Multiple Worlds Interpretation of quantum mechanics) then:

> Is this stating that the many possibilities are all coexisting

Yes.

> and that our brain is acting as a filter to provide a view of possibilities > that we define as ourselves?

No, your brain is not "acting as a filter". There are multiple "your brains" all "coexisting" in multiple universes (which MWI-ers call "the multiverse"), none of which can ever communicate with each other.

</comment></comment></comment></comment><comment><USER12> Your objections seem to me to arise straightforwardly from a disconnect over the definition of "you". Taking DW's position, and your axiom of unique self, I can resolve the issue by saying something like:

Knowing that you can never be certain which branch you will end up in, bet on the outcome that maximizes the liklihood that you will end up in a branch you favor. Your bet, of course, will follow the form of the Born rule.

<comment><USER13> Please explain the disconnect. In MW, there are many future "you" (or "I"), all of which will exist. The fact that they do not share information with each other doesn't change the fact that they are all you (or I). There isn't a single branch you "end up" in, you are in all of them.

<comment><USER12> Your choice of the future here is arbitrary - we could just as easily say that there are many past and present "you" in the multiverse. This assumes a definition closer to DD/DW's than the author's.

The author seems to assert that his experience of self is incongruous with this definition of your identity. As a historical fact, "you've" always either chosen chocolate or vanilla, not both. The other branches aren't in fact you, any longer.

</comment></comment></comment><comment><USER14> Armchair physicist here, and yet:

> The probabilistic predictions of quantum theory are conventionally obtained > from a special probabilistic axiom. But that is unnecessary because all the > practical consequences of such predictions follow from the remaining, non- > probabilistic, axioms of quantum theory, together with the non-probabilistic > part of classical decision theory.

Well this seems crazy! We can drop the Born rule axiom, because you (a game theorist) will make the same decisions whether the universe is deterministic or probabilistic?

The difference is crucial, right? A PRNG requires hidden state: exfiltrate the state and predict all future results. But there is no room in the wavefunction + Schrödinger equation for such state: you either augment it (Bohmian mechanics) or accept the essential probabilistic nature.

Probabilistic predictions cannot be obtained from deterministic axioms, just like PRNGs cannot produce true randomness.

How does Deutsch resolve this?

<comment><AUTHOR> Deutsch is a many-worlder so he would say there is nothing to resolve because there is no randomness. Everything in the time-evolution of the multiverse is deterministic.

<comment><USER15> Could I ask a question? As you are clearly someone with a deep knowledge QM.

Why is Bohmian mechanics so frequently dismissed? It's such a straight forward premise - there is an actually physical guiding wave and everything else falls out "normally". Instead pages are written about MWI and hypothetical agents optimizing their overall decision in universes they'll never see. And undefinable concepts of trillions of universes splitting simultaneously. And I'm not trying to be snarky at all, as I feel what you wrote above is one of the best presentations od the topic I've seen.

To be perfectly frank QM is starting to scare me about physics. To a layman which I am, Bohmian mechanics is so simple and straightforward it's almost "obviously right". The macroscopic analogy of Farady waves is almost a nail in the coffin (to a layman). Allow for non-locality of guiding waves, just like ripples on a lake and everything else is deterministic and matches all scientific observations. Events have probability for the same reason the weather has probability: because we can't measure with the sensitivity required to account for the complexity of the system and the difference in initial conditions.

And yet, I've never seen any write up against Bohmian. I've never seen anyone with deep knowledge on the subject discuss why Bohmian isn't the best interpretation. It's just dismissed as an "also-ran". What scares me is 20 years from now something will emerge making it clear that Bohmian is the "correct" interpretation. And then the question in my mind will be, "what took it so long to even be seriously considered?". It would be proof to me that physicis is being shifted from investigating and following up on the best explanation for data to instead becoming "lawyers" trying to find data to support their favorite pre-decided argument (ie their favorite QM interpretation).

Now all of that said, there is a reason why laymen don't make meaningful contributions to a field. Their are deeper complexities that make their intuitions wrong. But why are these flaws in Bohmian never discussed?

Would you mind taking even a few sentences to write up "what's wrong with Bohmian" that would make the infinitely more complex MWI a more likely candidate? I'm lost.

[1] - [http://www.tcm.phy.cam.ac.uk/~mdt26/tti_talks/deBB_10/bush_t...](http://www.tcm.phy.cam.ac.uk/~mdt26/tti_talks/deBB_10/bush_tti2010.pdf)

<comment><AUTHOR> The best place to find the answer to this question that I know of it David Z. Albert's excellent book, "Quantum Mechanics and Experience." But the short answer to your question is that Bohmian mechanics has two problems:

1\. In order to account for the outcome of Bell-type experiments on entangled particles it has to assign a temporal ordering to space-like separated events. The technical term for this is that you have to choose a "preferred foliation of space-time". There has to be a preferred reference frame. But you can never actually know what the preferred reference frame actually _is_.

2\. Yes, particles "have positions", but you can never actually know what those position are (which is why I put "have positions" in scare quotes). This is where all the quantum randomness hides in Bohmian mechanics. It's all "pre- computed" in the infinite precision of a particle's position, but that position is necessarily hidden from observation. I call this an IPU, an Invisible Pink Unicorn. It's exactly the same thing as universe-weights in MWI -- a set of numbers that are part of the theory but rendered immune from observation not by practical limitations on technology, but by the theory itself.

This is the fundamental problem with _all_ attempts to make quantum mechanics look deterministic. The simple fact of the matter is that it's not deterministic, so any attempt to make it look deterministic that makes the same predictions as QM has to hide the randomness somewhere. Bohm hides it in particle positions, and MWI hides it in universe weights. But it doesn't matter what you _call_ the place in the theory where you've hidden the randomness. What matters is that there is a place in the theory where you've hidden the randomness, where it must forever remain hidden from the prying eyes of experiment. So the claims that both Bohm and MWI make of being deterministic are misleading at best.

<comment><USER16> >but that position is necessarily hidden from observation. I call this an IPU, an Invisible Pink Unicorn.

But why expect that all state of the universe be open to observation? This seems counter-intuitive to me. It seems far more reasonable that there necessarily are facts about an implementation that no supervening system can determine from within that system. For example, there are facts about a physical computer that no software running on that computer could deduce. So the fact that a QM theory posits state that is in principle off-limits to observation doesn't seem like a reductio, but the expected case.

<comment><AUTHOR> That's a good point, but remember, this is about rhetoric, not physics. The question is not whether hidden state exists (it clearly does) but what kind of _story_ you want to tell about it. If you find it enlightening to think about hidden state as position, and you don't mind accepting all of the difficulties that entails (like having to choose a preferred foliation), then by all means go for it. But that is very different from saying that this story is actually _true_. The only reason to prefer Bohm over a similar story that ascribes the randomness to a literal invisible pink unicorn making decisions about experimental outcomes is aesthetics.

</comment></comment></comment></comment></comment></comment><comment><USER17> Anyone else read Neal Stephenson's _Anathem_? It drew heavily from Deutsch, so it's not totally surprising, but this argument seems pretty close to "Did you read _Anathem_? Because _Anathem_."

</comment><comment><USER18> This has got me thinking about MW and the speed of light .... a quantum event occurs here and the universes split, that split propagates out at the speed of light ... at roughly the 'same' time a quantum event happens at Alpha Centuri ... the universe splits there and that change propagates out at the speed of light .... 2 years later half way in between the splitting universes meet - what does that mean?

<comment><USER12> "Splitting" does not propagate, or happen with any locality - it's the wave function of the entire universe doing the splitting, so there's nowhere for it to propagate!

<comment><USER4> It makes sense to talk about the split propagating. A subsystem which is spatially located at a distance from the splitting event will not immediately become involved in the superposition, but may do once information about the event has traveled.

<comment><USER12> When we talk about MWI as the asker is trying to more fully understand, we are explicitly not talking about subsystems. There's just the one big evolving state (of the universe).

<comment><USER4> That's true, but that global state of the universe can be written in terms of its reduced states on spatial subsystems. From this perspective we can talk meaningfully about propagating superpositions. For example, take a toy example in one dimension with three spatial subsystems A, B and C representing disjoint intervals arranged in order. Immediately after a splitting event the combined wavefunction over all subsytems might be:

(psi_1 + psi_2)_A x phi_b x rho_C

(ignoring normalisation for convenience) then after a certain amount of time it becomes

(psi_1 x phi_1 + psi_2 x phi_2)_AB x rho_C

and then eventually

(psi_1 x phi_1 x rho_1 + psi_2 x phi_2 x rho_2)_ABC .

Now, all of that is certainly happening within the realm of some joint superstate, but it still makes sense to talk about how fast the split propagates, surely?

<comment><USER12> All depends on the context. Does it make sense to talk about propagating splitting in this context? Surely no - for three reasons:

1\. You're describing a time evolution _of the subsystems_, which isn't really a thing in the MWI.

A many-worlder would say, instead, that the Universe has split a bunch more in the interim. He would point to the time evolution of the state of the Universe, and perhaps there have a discussion about how the inseparability of particular subsystems has propagated over time. Put differently, the many- worlder might say the correlations of these particular relative states with one another propagated over time.

What you've done, Everett would call characterizing branches of the universal state in a space-like locality.

2\. Split != superposition. Frequently, splitting in MWI is identified with decoherence, so in that sense there is a self-consistent way to describe local splitting - but then you'd really mean, when you referred to the splitting of "an object" or "a system", that Universal splitting had occurred in such a way as to cause the object to exist in some particular multiple new branches.

3\. None of this line of discussion helps the parent gain an understanding of how MWI is importantly different from (and the same as) other interpretations of QM. It's far too shallow to amount to any real expert insight and yet too technical to amount to any real layperson insight.

What can a discussion on propagating splitting illuminate here? It seems to me that it is a less than useful idea for the parent and readers like him/her, and many-worlds is more clearly understood without it.

<comment><USER4> > You're describing a time evolution _of the subsystems_

In my head I'm thinking about the time evolution of the global state, but examining the reduced state over certain subsystems at specific points in time.

> Split != superposition. Frequently, splitting in MWI is identified with > decoherence

Decoherence is a superposition effect, is it not? Entanglement with the environment, i.e. a superposition of system-environment states.

> then you'd really mean, when you referred to the splitting of "an object" or > "a system", that Universal splitting had occurred in such a way as to cause > the object to exist in some particular multiple new branches

Yes, this is what I mean.

> What can a discussion on propagating splitting illuminate here?

Tbh I think it's unlikely that the parent is still following but I'm continuing for the selfish purpose of trying to better understand your point. That said, I believe that considering my toy example of a global quantum state in one dimension _would_ illuminate their question about superpositions propagating from here and alpha centauri and meeting in the middle.

<comment><USER12> > Decoherence is a superposition effect, is it not? Entanglement with the > environment, i.e. a superposition of system-environment states.

The point I'm trying to make is that "splitting", while sometimes identified with decoherence, isn't superposition (or any other well defined traditional QM phenomenon). It's a term peculiar to MWI and it importantly has no clear canonical technical definition. It generally refers to something just considered abstractly: the branching of a single _universe_ into multiple. If you use "split" and "entanglement" or "superposition" or any other QM term interchangeably, you are bound to invite misunderstanding.

> ...illuminate their question about superpositions propagating...

Agreed... if that was their question. But their question didn't reference superposition at all, it was about a split propagating:

> ...a quantum event occurs here and the universes split, that split > propagates out at the speed of light...

Which is why I responded as I did. It is understandably confusing to wonder what it means for propagating split universes to meet years later, if you start talking about splits in this way. Propagating superposed particles? Much easier to make sense of.

<comment><USER4> Thank you for bearing with me for so long. I think I understand the point of contention, i.e. that "split" is a slightly nebulous term which depends not only on splitting but somehow on there being a negligible likelihood of future interference between branches. In this context I agree it doesn't make sense to speak of a split being spatially localised.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER19> The idea of branch-counting seems untenable when we consider irrational probabilities (which they are, of course, overwhelmingly likely to be),though I think it would be begging the question to say, on that basis alone, that branch-counting is the wrong way to look at it. I think the example used to motivate branch indifference would be more persuasive if it used irrational probabilities.

<comment><AUTHOR> > it would be begging the question to say, on that basis alone, that branch- > counting is the wrong way to look at it.

Exactly right.

> I think the example used to motivate branch indifference would be more > persuasive if it used irrational probabilities.

What matters actually is not the probabilities but the branch weights/amplitudes (because you have to square those to get the probabilities). And those _are_ irrational if the probabilities are 2/3-1/3.

<comment><USER19> I take your point about the amplitudes not being rational, but in the examples of branch counting that I have seen, including this particular example, the counting is being done from the probabilities, not the 'raw' amplitudes.

</comment></comment></comment><comment><USER20> I did not like this article. I think the author incorrectly has some idea that many worlds asserts the multiverse undertakes a real "splitting" activity when observing the outcome of an experiment.

It does not. Rather all the different branches have always already existed all the time, and you merely observe what branch "you" are on.

When you see the outcome of an experiment, it doesn't mean "you branched" as if the branches wouldn't have existed if you hadn't done the experiment.

It only means your brain got knowledge about which subset of all possible universes you happen to be in.

The probabilities in quantum outcomes, like all probabilities, are about subjective degrees of belief, as in they are about the state of a mind and not objective attributes of nature.

<comment><AUTHOR> > all the different branches have always already existed all the time

How many branches are there?

The answer is: there's no way to know because what constitutes "a branch" is not well-defined. So saying that "all the different branches have always already existed all the time" is meaningless because the phrase "all the different branches" is meaningless.

> The probabilities in quantum outcomes, like all probabilities, are about > subjective degrees of belief

No, they aren't. When you listen to a geiger counter, the number of clicks it produces is an objective fact, completely independent of any sentient being's beliefs. It is also random.

<comment><USER20> There would have to be an uncountably infinite number, and the surface of branches would be smooth, likely differentiable, because many experiments can have outcome spaces of uncountably infinite cardinality.

> "No, they aren't. When you listen to a geiger counter, the number of clicks > it produces is an objective fact, completely independent of any sentient > being's beliefs. It is also random."

You are simply incorrect about this. Did the Geiger counter click or did you hallucinate or did the counter misfire or did your friend replace it with a joke Geiger counter that always clicks or did a cosmic ray hit the circuitry at just the right moment etc.

The probabilities around these things are about your subjective state of knowledge, always.

<comment><AUTHOR> > Did the Geiger counter click or did you hallucinate or did the counter > misfire, etc.

Doesn't matter. What matters is that objective observers listening to the counter independently will all _agree_ on how many clicks it made in a given period of time. It is this _agreement_ that needs explaining. One possible explanation is that the counter did, in point of physical fact, click that many times. In fact, that seems like a very _plausible_ explanation for the agreement to most people. That plausibility doesn't necessarily make it _correct_ , but it does mean that you cannot dismiss it as "simply incorrect." If I hallucinated the clicks, why then do I agree with all the other observers, including inanimate ones like electronic counters? Are we all experiencing the same hallucination? If the counter "misfired" then why do geiger counters give the _appearance_ of producing random clicks in response to radiation?

<comment><USER20> Huh? If the counter is broken, you'll all agree on the wrong number, because of your mistaken brain state (believing the counter to be functioning correctly). You may use a lot of italics, but the statement doesn't add up to anything.

<comment><AUTHOR> > If the counter is broken, you'll all agree on the wrong number

In what way will this number be "wrong"?

</comment></comment></comment></comment></comment></comment><comment><USER21> I love the post. As time passed, I've come to think of our Universe differently.

When I was out of school and Physics was cool: The Universe existed, created me, I observe, things change.

When I am older and all the things are being unravelled: I existed, I begin to observe, The Universe around me changes.

I am not on drugs, it's how I approach our world today.

</comment><comment><USER22> What has the human brain to do with anything? This whole thing is philosophical at best. Physics is real whether we observe it or not. I think we settled on that one. Using subjective experience in trying to explain physical systems is bonkers.

<comment><USER8> On the contrary, decades of experiments violating Bell's inequality have shown that the statement "Physics is real whether we observe it or not" can only be true if we abandon locality. Non-local interpretations of QM, such as Bohmian mechanics, are however incompatible with the Standard Model which is by far the most accurately tested theory in physics.

<comment><USER23> There is no incompatibility between orthodox quantum mechanics and Bohmian mechanics, the latter makes exactly the same predictions as the former. As does any other interpretation of quantum mechanics. That's why they're called interpretations, they're ways of ascribing an ontology to or making sense of the mathematical models that are known to work so well to make experimental predictions. They're not supposed to be competing theories.

There is nothing inconsistent or inherently problematic about abandoning locality, quantum mechanics has some intrinsically non-local components anyway. It speaks in favor of Bohmian mechanics that it explicitly describes this non-locality and isolates it.

<comment><USER8> The point is that non-relativistic quantum mechanics and therefore also Bohmian mechanics are wrong. They cannot even describe hydrogen atoms correctly! Solving this issue required developing relativistic quantum field theories. So far nobody managed to create a convincing relativistic version of Bohmian mechnics.

</comment></comment></comment></comment><comment><USER24> Using decision theory to explain quantum mechanics seems like a huge mistake for a very simple reason: It confuses "ought" for "is". Decision theory makes statements about what one _should_ do if one _wants_ a certain outcome. As the author points out, what statements are we making about what we want? We are free to decide that dividing ourselves and dividing an outcome are not equivalent. But really the whole idea should look silly long before we come up with such a specific counterexample: the laws of physics have no dependency on the wants of human beings, in fact the wants of human beings are fully dependent on the workings of physics (humans being physical systems), so an explanation of physics in terms of statements about wants should appear absurdly circular.

There does not need to be an agent optimizing outcomes in order for the predictions of quantum mechanics to be correct. There doesn't need to be agents _at all_ , since the laws of physics worked just fine in the billions of years before there were people. This seems a bit like dressing up the problematic Copenhagen notion of a privileged "observer" in different clothes.

I have never understood what is left to be explained in many worlds, and maybe someone with deeper understanding can explain it: what is the problem with simply saying that the squared amplitude gives the fraction of the wavefunction that has evolved from the initial state into the final state? What need is there to bring probability into the physics? If we are accepting the initial wavefunction state as a premise x, and we associate each configuration in the final state y with an experience we might have, then isn't asking the "probability" of experiencing y given x, in a Bayesian sort of way, naturally, emergently the same thing as asking the fraction of [the wavefunction that evolved from all the configurations associated with x] which is associated with y? What is missing and what is the dispute?

Last, what is this talk of "splitting"? I thought it was true that the wavefunction is "incompressible", in that if some measurable that becomes more confined, there is always some other measurable that becomes correspondingly less confined? That is to say, if there is some axis in state space which splits (distinguishes) universes by narrowing possibilities, there must always be some other axis that merges (confuses) universes by widening possibilities? That is to say, if ever you know more about what universe you are in, you must know less (along some orthogonal axis) about what universe you came from? I.e. for every "branch" there is a "merge".

</comment><comment><USER25> It appears that a similar issue crops up in the interpretation of classical mechanics.

That is, suppose we have our laws of classical mechanics. Hence, we have a nice way of propagating states along time. Now we want to understand thermodynamics and the arrow of time. Maths tell us that, if we slice-and-dice microstates and macrostates in a certain way, then thermodynamics is correct. In a certain way means "any non-crazy way with respect to Liouville measure" and the entire thing only holds "for sufficiently chaotic/ergodic systems".

We observe (empirically / subjectively) that thermodynamics holds, and we have an arrow of time. In order to explain this observation, we need an additional axiom:

(A) The universe looks like it has Liouville-random but phantastically low- entropy initial state in the far past. Liouville-random means something like "absolutely continuous wrt Liouville-measure".

We could split that into

(A1) Thermodynamics makes sense. The universe cares about Liouville-measure. (A2) With respect to Liouville-measure, we have a low-entropy state at some point in time (hence we can define "past (noun): In the time-direction of the designated point in time with low entropy").

In the overwhelming majority of such universes (classic trajectories), observers see things that are compatible with both thermodynamics and an arrow of time (and there is a possibility for conscious overservers to evolve).

Mathematically, there are many ways of measuring phase-space volume, in a way that is invariant under time-evolution. Assuming ergodicity/chaoticity/mixing, there is only a single such way that has bounded density function with respect to "ordinary n-dim volume" (SRB-measure), and all these converge to Liouville. But it would have been mathematically conceivable to take the same evolution equations, and use a different measure that is supported on weird subsets of low fractal dimension, and end up with different thermodynamics. Hence, we need an extra axiom to separate observed reality from mathematical possibility, and single out Liouville / ordinary volume.

Nobody takes issue with accepting this axiom. So why do people have issues with accepting the Born rule as an axiom?

It is clear that we must add axioms to the evolution equations to explain that we care about squared-amplitude and that we have an arrow of time. Sure, you can try to prove theorems showing that alternatives to the Born rule are crazy-weird, and make the axiom weaker ("if we care about anything at all, and the thing we care about is not batshit insane then the Born rule holds"). For example, MWI tries to replace copenhagen "if humans do experiments, use squared-amplitude" with axiom "the universe cares about squared-amplitudes in a non-crazy way" plus pseudo-theorem "human-scale experiments can be approximated by Born rule". Certainly more elegant, because the universe doesn't need to care about squishy emergent approximate concepts like "humans" anymore. But it is the same axiom in the end, modulo some plausible not-quite- proven maths for the pseudo-theorem.

Not-quite-proven even in the classical case: Formally proving unique ergodicity / chaoticity / fast mixing is far beyond us for almost all non- trivial systems. Just like e.g. complexity theory (we don't even have a formal proof of P!=NP, so the name of the game is "mathematical plausibility" that is spot-checked by tiny little theorems).

<comment><AUTHOR> > why do people have issues with accepting the Born rule as an axiom

Because it offends people's intuitions about what must be happening behind the scenes to make it true. Thermodynamics is mathematically complicated, but intuitively very straightforward: you've got a bunch of billiard balls bouncing around. People can visualize that. QM is fundamentally different. For starters, the wave function operates in configuration space rather than physical space, and is not always separable (which is what produces entangled states). Furthermore, in classical mechanics, the limitation on knowing the complete state of a system is merely technological. If we had accurate enough measuring equipment the state of any system could be known in principle. In QM this is no longer true. QM makes the true state of a system inaccessible even in principle.

BTW, with respect to the arrow time, you might enjoy this:

[http://blog.rongarret.info/2014/10/parallel-universes-and- ar...](http://blog.rongarret.info/2014/10/parallel-universes-and-arrow-of- time.html)

<comment><USER25> Yeah, QM offends my aesthetic sensibilities as well. I cannot but shake my head in disgust at creation.

But it does not get better by attempting to derive the Born rule. Of all things to get offended by, why do people single out the Born rule? For example, non-locality (e.g. Aharanov-Bohm) is imo much easier to understand and already disqualifies reality from "believable theory-building". I genuinely don't get it.

Re your link: I don't understand why the linked post talks about QM at all. The arrow of time is a perfectly classical phenomenon; phrasing it in terms of QM only helps us understand the formalism of QM if we already understood the classical arrow of time. Or am I misunderstanding something?

<comment><AUTHOR> > it does not get better by attempting to derive the Born rule.

Well, it _would_ get better if you actually _could_ derive the Born rule without begging the question. But you can't so it doesn't.

> Of all things to get offended by, why do people single out the Born rule?

I guess you'd have to ask someone who was actually offended by it.

> am I misunderstanding something?

Yes, I think so. The arrow of time is _not_ a purely classical phenomenon. Perhaps it _could_ be, i.e. if we were living in a purely classical universe there might still be an arrow of time, but this is a moot point because we are not living in a classical universe, so classical thermodynamics is not what creates the arrow of time in our universe. It's more fundamental than that. It _impossible_ to extract a classical universe from quantum dynamics without establishing an arrow of time in the process.

<comment><USER25> Ah, ok, with "purely classical phenomenon" I meant "the classical limit h->0 also exhibits an arrow of time; observing the arrow of time and thermodynamics is not enough to distinguish between a classical and quantum universe". Therefore we gain no additional understanding of the phenomenon by looking at QM; at most, we gain understanding of the mathematical framework of QM by seeing how its formalism describes the classical arrow of time.

The arrow of time is a phenomenon that is robust under changes of underlying theory; may as well discuss the simplest models that exhibit it, and these are classical. Just like you would explain chaos with simple models first, e.g. horseshoe, Lorentz, 3-body, before going into highly specific 1000 dimensional systems.

edit: "Deriving the Born rule". An insightful "derivation" would be a pseudo- theorem "if you want QM to limit to classical mechanics + Liouville Axiom, then you must adopt the Born rule". But afaik this has been mostly done, so there is nothing to explain anymore?

<comment><AUTHOR> > the classical limit h->0 also exhibits an arrow of time

That is certainly true empirically. But it is much more difficult to explain _why_ this happens in classical terms without begging the question -- you can't just invoke the second law of thermodynamics here. You have to _derive_ the second law from Newtonian mechanics. That is an unsolved problem.

<comment><USER25> No, deriving the second law from Newton+Liouville is easy (in the form of "mathematically plausible pseudo-theorem", that's late 19th century physics). If you don't adopt Liouville measure as axiom, then it is impossible by (more modern) counter-example: Thermodynamics looks different if you pre-suppose that god cares about weird measures; and it is unavoidable if you pre-suppose that god cares about Liouville measure.

<comment><AUTHOR> OK... but this seems to me simply like trading one assumption for another. Is there any reason why adopting the Liouville measure as axiom is any less arbitrary than just adopting the second law directly?

<comment><USER25> Of course it is trading one assumption for another.

It basically comes down to "absent other specifications, one state is as probable as another". As good Bayesians, we should reject this sentence: We always, always need a prior; and if the prior is too crazy (e.g. has zero probability mass on the correct hypothesis), then no amount of observation will ever help us.

Since we deal with a continuous system, this is also a nonsensical sentence on purely mathematical grounds: It could be "absent other specifications, one state has as large probability density as any other, measured relative to Liouville". An easy calculation shows that this state of affair (thermodynamic equilibrium) is preserved by the flow. Furthermore, "If any state has as large probability density as any other, measured to a small (absolutely continuous) distortion of Liouville, and you wait long enough, then it all evens out to Liouville", i.e. small distortions decay (mixing).

Large distortions do not need to decay. For example, you could single out one specific crazy periodic trajectory (there are many crazy periodic trajectories, but the set of crazy trajectories has small ordinary phase- space-volume), and our large distortion is "I am somewhere on this specific periodic trajectory". If we start on the periodic trajectory, then we stay on it; hence, this state of affairs is preserved as well.

In order to separate the two, we need an axiom, like "Liouville is a good prior". The equations of motion don't tell us that the first corresponds better to reality than the second! This is an empirical observation.

Now start with Liouville, but prescribe that our initial data are in a specific low-entropy macro-state. This means that we cut out some non-crazy region of phase space and say "start anywhere here, but then count all states as same probability". Then the second law holds (this is pseudo-theorem).

If we initially started with our crazy measure (concentrated on a single periodic trajectory), then the second law fails / is vacuous. If we permitted to cut out a crazy region of phase space, then it would also fail (crazy region: Take a sane region R0 at time T0 and a sane region R1 at time T1, and our crazy region consists of all points in R0 that will end up in R1 after time T1-T0. All these points will end up in R1, so no second law for you).

This general program is as strong as it gets, and all the "non-crazy" caveats are imo much less arbitrary than just adopting the second law directly. Of course this opens a giant can of worms: What exactly does non-crazy measure mean? What is a non-crazy way of slicing-and-dicing phase space into macro- states? For which systems of physical thermodynamic interest can we formally prove chaoticity / fast mixing?

Ok, I actually know the answer to the last question: Almost none. But I also know the answer to "for which such systems of interest does anyone seriously doubt that we have chaoticity / mixing": Almost none.

<comment><AUTHOR> > Of course it is trading one assumption for another.

Why "of course"? If would only be "of course" if it were _impossible_ to derive the second law from Newton's laws. AFAIK that hasn't been proven impossible.

But I think you may have misinterpreted my objection. It's not that I object to substituting one axiom for another _in general_. That can often represent progress. For example: before Einstein, it was observed that inertial mass and gravitational mass were very close to each other, lending considerable weight to the reasonableness of assuming that they were in fact the same. It turns out that you don't have to assume this. There's another set of axioms that allow you to prove this, and these axioms are "better" because they provide a much larger scope of explanatory power for the same axiomatic price.

By way of contrast, Turing machines and the lambda calculus are "the same" in some deep sense that makes it silly to argue about which one is "the right model" of computation.

It's not clear to me whether adopting Liouville really represents progress a la relativity, or whether it's arguing potato-potahto a la Turing vs Church.

BTW, it just occurred to me that there is a fundamental difference between the thermodynamic and quantum arrows of time: the thermodynamic arrow of time is reversible in a non-isolated system. The quantum arrow is not.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER26> My rule of thumb with regard to objections to Many Worlds is that if the article discusses consciousness, or brains, in any way, it's not about Many Worlds, but about consciousness, or brains, and I will stop reading it at once.

<comment><USER27> Your comment enticed me to actually read the first few paragraphs of the article, skim the rest, and ctrl+f for "conscious" and "brain". In my humble opinion, your rule has raised a false positive here. The post is extremely well written and sourced, weaving a story straight from highly technical research papers. I'd suggest judging this article by itself, not a string- matching filter.

Besides, isn't discussion of brains and consciousness perfectly relevant in the context of QM, given the requirement for rigorous definitions of observation, observers, etc.?

<comment><USER26> Following your suggestion, I've read it now in its entirety and I'm considering adding "subjective experience" to my axiom, but that might be too aggressive.

<comment><AUTHOR> It is the nature of subjective experience that is the source of all the trouble with interpreting QM. If you ignore subjective experience, there is no problem at all: the universe is quantum, and that's all there is to it.

But most people want to know why, if the universe is quantum, does it present such a convincing illusion of being classical.

</comment></comment></comment></comment><comment><USER28> The whole "waves of differentiation" idea is quite an interesting one and certainly seems to me to be an almost physical description of philosophical concepts like free will and determinism. Perhaps these waves themselves interfering are what gives rise to what we consider consciousness, since what we experience subjectively is changing at every moment. Maybe the only reason we are able to "think" at all and remain "coherent" and "self-subjective" in our own brains is that these waves create images of the past on all their neighboring matter that have a continuous time-evolution. There certainly (to my mind at least) seems to be an element of randomness to thought that feels quicker and less coherent than could be easily explained even by a large-ish number of neurons with a comparable but larger number of interconnections.

I dunno, it seems a little overly-philosophical but surely there are meaningful connections to be made between physical reality and the transience of subjective experience.</comment>


The cost of scientific publishing - <AUTHOR> http://blog.banyan.co/the-cost-of-scientific-publishing/

<comment><USER2> Great infographic, but it doesn't address the fact that these publishing houses are actively lobbying to prevent open access. Furthermore, the open access requirement for NIH funded work was legislated away for a few years. This problem runs deep</comment>


Do typefaces really matter? - <AUTHOR> http://www.bbc.co.uk/news/magazine-10689931

<comment><USER2> I think they do matter.

Where I think they matter the most is with screen fonts in operating systems.

I still can't get myself to use a desktop Linux for any extended period of time, because there's something indescribable about the screen fonts that subconsciously irritates me. I still can't put my finger on it, but I don't get annoyed when using OSX or Windows.

I would also make the argument that the display of type on the very first iPhone, in combination with the screen, really separated it from the rest of the field. Their use of Helvetica made it look 'printlike', which added to the appeal of the phone. Clearly that was a good thing, because I see good use of type on the new generations of Android, WebOS and Windows Mobile phones. Unless you're a font snob, good typography is no longer a differentiator between the smartphone operating systems - a good thing.

</comment><comment><USER3> Back in the day, I dealt with them a lot. I disliked Univers & the Compugraphics version of Times. I don't care for books with body text in Palatino, Melior, or Optima. But the face on subtitles isn't spoiling movies for me.

The Greeks invented handwriting? The Phoenicians wrote with their feet, like the kid in the movie?</comment>


National Museum of Computing to hold live Enigma code-breaking demo with a Bombe - <AUTHOR> https://www.theregister.co.uk/2018/09/19/tnmoc_bombe_enigma_code_breaking_demo/ <comment><USER2> This demo is apparently using a bombe that is a recreation of the original. Does anybody know when it was made or how faithful it is to the originals? I recall reading that the bombes were essentially hand-built, one-offs, each one slightly different from the others as improvements were made and, what plans there were, weren't complete.

<comment><USER3> "In 1994 a group led by John Harper of the BCS Computer Conservation Society started a project to build a working replica of a bombe. The project required detailed research, and took 13 years of effort before the replica was completed, which was then put on display at the Bletchley Park museum."

...says Wikipedia

</comment></comment><comment><USER3> This was initially confusing to me and may be confusing to others who've visited Bletchley Park

The Bletchley Park site, containing the not terribly interested mansion building itself, and a large museum of WWII code breaking stuff, is one charity, but on their site, in another building, is a different charity, The National Museum of Computing, TNMOC.

Historically the Bombes (electro-mechanical devices used to help break Enigma) were part of Bletchley Park's museum, but apparently earlier in 2018 they moved to TNMOC.

This is weird because Bombes are really, really not computers, unlike Colossus, which TNMOC looks after but is open to the public from the other charity's site. Colossus is one of many machines on the cusp, it's an electronic computer, but it really only does one thing and "re-programming" it involves almost taking it to pieces. But Bombes are no more computers than, say, an old-fashioned mechanical cash register is.

So this demo will be hosted by TNMOC, but the machines shown will be ones you may have seen (unless you went there this summer) at the non-TNMOC Bletchley Park WW2 crypto museum. A miniature version of this (part breaking Enigma) used to be a demo that Bletchley would do live for visitors several times a day, but TNMOC may not be offering that demo any more on their tours, I'm not sure. I assume the demo for this stream will be far more complete than the average visitor to Bletchley was interested in watching although I doubt it will have a step where people try to guess German "cribs" for the message text.

A problem for this demo, and any dramatisation of breaking Enigma, is that it doesn't feel like very much. It's loud, and the Bombes are doing stuff because they're mechanical in nature, but ultimately you can neither experience what it's like to invent this extraordinary machine, nor what it is like to be the machine while it's working, so it's emotionally a bit empty. In a movie you can suppose that breaking the code will prevent our heroes being killed by Nazis or something, but it's still a bit arms-length really.

<comment><USER4> > This is weird because Bombes are really, really not computers

That's why it's generally called machines rather than computers. But the media plays loose with words to make the story more interesting.

Also, the british bombes were way too slow to be effective.

It was actually the US Navy that produced effective code breaking bombes.

[https://en.wikipedia.org/wiki/Bombe#US_Navy_Bombe](https://en.wikipedia.org/wiki/Bombe#US_Navy_Bombe)

You can see one at the National Cryptologic Museum in Maryland.

<comment><USER3> This rather depends on your perspective of what the word "effective" means.

Those US navy bombes are for Kriegsmarine "M4" Enigma, which didn't even exist when Bletchley Park began breaking Enigma. They came on line in mid-1943. So, by this point the Axis is defeated in Africa, and Barbarossa is failing, the German Army is in trouble on the Eastern Front, it has faced some big military defeats there and cannot continue to sustain these losses, but Russia hardly seems likely to accept a peace deal after being betrayed previously.

Now, the war wasn't _over_ in 1943 even in Europe. But there had been three years of code-breaking (including of Enigma) at Bletchley by that point. It's true that Huts attacking M4 sent data across the Atlantic to the US navy, but again, that's from mid-1943, prior to that the British were using their slower machines because you can't win wars by waiting until you have better equipment.

</comment></comment></comment><comment><USER5> You can see an original Bombe at the national cryptologic museum in Fort Meade Maryland. Best museum I've ever seen.

<comment><USER6> Indeed. A very underrated museum. Also the volunteer docents are, in some cases, retired NSA tech personnel and can share (the declassified parts of) some very cool stories. On a visit in 2010 or so we met an elderly woman that had pioneered some important aspects of satellite-based ELINT and SIGINT.

<comment><USER5> Yassss! The hubby and I love going up there to hang out with them whenever we can. Don't forget to talk to the librarians! They have some amazing stories too but I suspect most people don't realize they can go in there.

</comment></comment></comment><comment><USER7> This machine was housed within the Bletchley Park museum for years. It has recently moved to the TNMOC

Thanks, James

</comment><comment><USER8> It looks like there won't be any silly Digital Ocean PR stunt disingenuously pretending to be ML-related this time, which is a relief.</comment>


Monkeys Don't Do Fair Use; News Agency Tells Techdirt To Remove Photos - <AUTHOR> http://www.techdirt.com/articles/20110712/01182015052/monkeys-dont-do-fair-use-news-agency-tells-techdirt-to-remove-photos.shtml <comment><USER2> _Michael, regardless of the issue of who does and doesn't own the copyright - it is 100% clear that the copyright owner is not yourself.

You have blatantly 'lifted' these photographs from somewhere - I presume the Daily Mail online. On the presumption that you do not like to encourage copyright theft (regardless of who owns it) then please remove the photographs._

The insidious assumption here is that someone must own these photos, if not the author then somebody else, because everything has an owner.

Once explicitly articulated and challenged, this assumption will be defended on the grounds that anything that is not owned is worthless, and assigning ownership gives it value. If this viewpoint is resisted, and if it eventually triumphs, we'll find that those who resisted it own nothing, and those who forced it on the rest of us own everything.

This has happened before.

<comment><USER3> My first thought, after reading my parent, was Native Americans (really, indigenous peoples worldwide) and European colonists. Is my parent referring to other cases as well?

<comment><USER2> Yep, that's the example I had in mind.

<comment><USER4> The other example is the Enclosure movement in Britain (<http://en.wikipedia.org/wiki/Enclosure_movement>), where nobles simply stepped in a seized land that had been for common use, in some cases throwing people out of their homes to do so.

</comment></comment></comment></comment><comment><USER5> (IANAL)

The lawyer's message doesn't appear to be a DMCA takedown notice at all, but rather a cease & desist, which has nothing like the same weight.

The lawyer's messages don't appear to be claiming that David Slater owns the copyright on the monkey's photos. In fact, they appear to be very carefully worded so as not to claim this.

<comment><USER6> Exactly. This is one of the best copyright disputes I've seen in years.

<comment><USER5> I'm not sure it even qualifies as a copyright dispute. (Although the copyright issues raised in techdirt's blog post last week are fascinating.)

The goal isn't copyright enforcement at all because noone (up to and including David Slater's own lawyers) is sure who does own the copyright.

Rather, it appears to be an attempt at preserving David Slater's revenue stream by paying lawyers to rattle a few sabers.

<comment><USER7> Don't assume that Slater authorized this. Lawyers on retainer do this sort of stuff all the time while make-working billable hours for themselves. One thing I've learned is that you _really_ have to watch what your lawyers are doing or they'll end up charging you $350/hour to publicly embarras you.

<comment><USER8> If that is the case you have your lawyers on a very sloppy retainer.

Going outside the terms of a retainer is classed as professional misconduct where I'm from. A lawyer should not take any action on your behalf without, at the very least, implicit instructions to do so.

</comment></comment></comment></comment></comment><comment> mkr-hn This is why I like Techdirt. It's what TechCrunch tries (and fails) to be: A rowdy tech blog that makes a good point without going too deep into hyperbole. I'm curious to see what the monkey has to say about all this. When will The Onion pick the story up?

</comment><comment><USER9> Considering the fact that it's fairly obvious that the monkey's took the photos themselves, everyone should quit fighting and marvel in the notion that a _fucking monkey took a picture of itself_. Next step, put it up under creative commons and call it a day.

<comment><USER10> If you don't own the copyright to a photo, you can't put it under Creative Commons.

</comment></comment><comment><USER11> Am I the only one too busy being unnerved by that first picture to worry about copyright? There's so many things going on there- the "smile", the "eyebrows". The way it looks so convincingly real that it's got to be fake, but it's real...

On a side note, I have always understood monkeys were smart. But I don't think I ever really grasped how cogent until I stared this monkey in the face. Besides being red, looking into that monkey's eyes feels just like looking at a person. Maybe that's why I'm unsettled.

</comment><comment><USER12> I think Techdirt should immediately write up a copyright assignment contract and see if monkeys like to scribble with pens.

Failing that, the monkeys' owner could be a real wild card here.

<comment><USER13> That would be the national park in Indonesia.

The monkeys are obviously under-aged.

</comment></comment><comment><USER14> The best rebuttal would be to send a cease and desist right back. I mean... they can't prove that they have the copyright either.

<comment><USER15> I don't think that would be a good idea either:

"...sending a takedown notice, if you are not the copyright holder, is what's actually against the law."

<comment><USER16> As noted in other comments, this notice does not even mention copyright, so that law is irrelevant.

</comment></comment></comment><comment><USER17> Perhaps adding the copyright notice to the photo makes it a derivative work, and is therefore protected by copyright?

Another take is that it is the news report that is copyrighted, and putting the main material of the report (the photo) which in itself wasn't subject to copyright represents the substance of the report rather than fair use.

<comment><USER18> Even if the report (containing the photos) is protected under copyright (and it is), quoting the article is still fair use. Extracting the photos to comment on them is still fair use. Reproducing a substantial part of the report would almost certainly infringe on the copyright. Arguing that the photos are a "substantial" part of the report would not convince a court.

<comment><USER17> > Arguing that the photos are a "substantial" part of the report would not > convince a court.

I'm reminded of a photo of the space shuttle taken by someone in a plane. Wouldn't the substance of a report about this event be the photo itself?

</comment></comment></comment><comment><USER19> If the monkeys have the copyright, then (in current legislation) no one may reproduce the photos, unless he somehow gets the monkeys to convincingly understand copyright and convincingly express their will to license him.

I think that this is absurd.

<comment><USER20> I imagine that the law would be interpreted to say that monkeys are not legally allowed to hold copyright, and the works in questions therefore have no copyright.

</comment></comment><comment><USER21> In this case, the monkey "borrowed" somebody else's camera, without permission, and took the picture in question. If I steal somebody's camera, and take photos with it, do I still own the copyright?

<comment><USER22> Yes.

If I break into your apartment and write a poem using your pen, do I own the copyright?

<comment><USER23> If I write code at work, do I own the copyright?

<comment><USER24> You have a good point. Did the monkey get any bananas? It could be a Work for Hire situation.

<comment><USER25> That is an offensive stereotype of monkeys.

</comment></comment></comment></comment></comment><comment><USER26> Anyone considered the monkeys didn't take the pictures and it was just set up to look like they did. Now they're kinda stuck because the only reason for the interest in the photos is because they were taken by monkeys, so they can't say they were actually taken by a person who holds the copyright to them because they will lose all there value

Based on the 3 photos in that article they all seem to be in focus and well composed which seems a bit unlikely, although not impossible.

<comment><USER27> The original article talks about how hundreds(?) of photos were taken and only a few were in focus.

</comment></comment><comment><USER28> You should point them at Righthaven's (non) case. It's absolutely true that only the copyright holder can issue a takedown and its also true that you can't assign copyright to a lawyer for the purposes of suing people.

I also think the precedents from some of the Righthaven cases would bolster your case that you're use was covered by fair use (at least according to one judge :-)

<comment><USER29> > It's absolutely true that only the copyright holder can issue a takedown and > its also true that you can't assign copyright to a lawyer for the purposes > of suing people.

Neither of these statements is true.

<comment><USER28> Blue beat me too it but here is an Ars link: [http://www.wired.com/threatlevel/2011/06/fair-use- defense/?u...](http://www.wired.com/threatlevel/2011/06/fair-use- defense/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+wired%2Findex+%28Wired%3A+Index+3+%28Top+Stories+2%29%29)

I read the decision linked by Groklaw as I recall but can't find it right now.

Judge Pro ruled you could not sue for copyright infringement if you weren't the holder of the copyright.

Judge Hunt ruled that you could not transfer enough copyright to sue but not all copyrights.

I've not completely Sheperded that case but I'm coming up blank on any appeals for those particular points.

<comment><USER30> The way you worded it before, you made it sound like you couldn't sue over a copyright that was transferred to you. I don't believe that's true.

What is being said in the Rightshaven case is that you can't transfer just the right to sue without giving them any of the exclusive rights protected by copyright. I believe that, had they transferred the whole copyright, or at least some of the exclusive rights protected by the copyright, Rightshaven would have had standing to sue.

In short, I believe that bluedanieru's formulation is the correct one. IANAL, though, and this kind of stuff turns on hair-splitting interpretations of words.

</comment></comment></comment></comment><comment><USER31> If Cater's argument is correct, then surely Cater should also remove the photos because Cater also doesn't own the copyright.

<comment><USER32> His core argument is that their use falls under "fair use", so there is still no need to remove the photos.

<comment><USER33> In legal situations, you don't have a "core argument". You have as many parallel arguments as possible, even if they are somewhat contradictory. One argument is that the photos are un-copyrightable (public domain), as they are not the creative works of a human. Another argument is that _if_ the photos are copyright, it's "fair use". He's keeping one foot on both boats, in case one of them sinks.

<comment><USER31> Another argument is that neither Cater nor the camera's owner own the copyright. As a result, neither one can demand a takedown.

</comment></comment></comment></comment><comment><USER34> I can set my Canon to take a picture after a 10 second delay, so that I don't have to be in the presence of my camera to take a picture. Canon does not own the image, simply because it activated the triggering mechanism.

<comment><USER35> You activated the triggering mechanism. Its delay is inconsequential, whether it is 10ms or 10 minutes, since you are the proximate cause of the capture.

These primates composed and snapped the photos themselves, unaided, on their own initiative. The providence of the camera doesn't make the camera's owner the copyright holder, any more than using a rented camera makes the rental company owner of the resulting images. Composition and shot timing are the two primary creative acts in photography — the monkeys did both.

<comment><USER36> In further support of this, the photographer didn't "activate the triggering mechanism" by even intentionally leaving the camera in hopes to have them take the photos.

I'd argue that a tripwire or any other mechanism of photographer intent to have the animals photograph themselves, would be akin to setting the timer. But, he says it was accidental:

> _One of them must have accidentally knocked the camera and set it off > because the sound caused a bit of a frenzy, said Slater, 46._

</comment></comment></comment><comment><USER37> He misses the plot a bit with the last sentence in the article:

 _It's unfortunate that a company that has built a business around copyright appears not to understand these basic facts._

I think when it comes to copyright and other IP and the actions of rights holders, it has become safe to apply the inverse of Hanlon's Razor i.e. never attribute to stupidity that which can be adequately explained by malice. _Of course_ these assholes know what they're doing, they just _don't fucking care_. IP best practice is to assert virtually any right you can dream up, justified or not.

So, surely it is _unfortunate_ to have happened, but that is not to say it is not entirely expected. More newsworthy would be if it hadn't.

</comment><comment><USER38> I can only hope these instances get more and more ridiculous, with higher profile people, until _something_ finally gives.</comment>


Benchmarking QUIC - <AUTHOR> https://email@example.com/benchmarking-quic-1fd043e944c7 <comment><USER2> I actually wrote this article! Thanks for sharing this on Hacker News :)

</comment><comment><USER3> The original (simpler) implementation before standardization was far superior. After standardization it's however become pseudo TCP over UDP and all the gains seem to have been lost.</comment>


Octopus and Squid Evolution Is Weird - <AUTHOR> https://www.sciencealert.com/it-s-official-octopus-and-squid-evolution-is-weirder-than-we-could-have-ever-imagined <comment><USER2> Is there a better article we could link to? _" Mother Nature gave RNA editing a try, found it wanting, and largely abandoned it" ... "it looks like cephalopods didn't get the memo"_ What is that supposed to mean?

The Wired article is slightly better: [https://www.wired.com/2017/04/cephalopod-gene- editing/](https://www.wired.com/2017/04/cephalopod-gene-editing/)

The original Cell article uses lots of jargon: [https://www.cell.com/cell/fulltext/S0092-8674(17)30344-6](https://www.cell.com/cell/fulltext/S0092-8674\(17\)30344-6)

<comment><USER3> > Is there a better article we could link to? "Mother Nature gave RNA editing > a try, found it wanting, and largely abandoned it" ... "it looks like > cephalopods didn't get the memo" What is that supposed to mean?

The transcription process is DNA -> RNA -> Protein. In the vast majority of living systems mutations happen at the DNA and DNA -> RNA transcription levels, but once you've got RNA it's a relatively straight path to proteins. It's possible to edit RNA but quite unstable and fiddly, so most living systems only make limited use of it, and their "RNA edition pipeline" is quite fixed and limited.

coleoids however apparently edit RNA to an extent unknown of elsewhere, seemingly trading that off for DNA-based evolution: for RNA edition to keep working properly, the source RNA has to be pretty stable otherwise you're building on quicksand, that means DNA mutations will break RNA editions and thus probably viability.

Think of it this way: DNA is source code, RNA is compiler IR and proteins are object code.

Most species edit the source code, they can have optimisation passes on the IR (RNA edition) but it can't be too extensive because the pattern matching will easily break if the source changes too much, and that might break the software entirely.

However coleoids do most or all their coding as optimisation passes working on the IR. And the more these IR passes do, the more they rely on the source code not changing because all of a sudden your "optimisation" passes don't work anymore and it turns out they're absolutely critical to the software working.

<comment><USER4> The octopus is editing its RNA to deal with different temperatures. Sounds like an overly dramatic way of doing it. Maybe instead of using an `#ifdef TEMP_THRESHOLD 15` they should have used a `int temp_threshold = 15;`

</comment></comment></comment><comment><USER5> While this is cool, there is weird shit in every clade. Mammals have CpG methylation. We are also cool.

<comment><USER6> It should be noted that ethylation of humans is also cool, because it frequently leads to combination with external DNA.

<comment><USER7> I am ashamed that* I almost googled ethylation, before I got that.

* He says, fully ethylated... But unfortunately not tonight recombinated.

</comment></comment></comment><comment><USER8> It would be great if they test the memory hypothesis. Perhaps by trying to catch the line of RNA changes that allow a problem to be remembered from generation to generation?

</comment><comment><USER9> Octopi and squids are just weird.

So does this mean that they're basically the Lisp of the animal world.

<comment> bjelkeman-again I think of octopus as the closest to a truly alien intelligence we will be able to get until we can travel to the stars.

<comment><USER10> I just said the same thing to a friend yesterday. They are truly fascinating.</comment></comment></comment>


HAProxy 1.5 - <AUTHOR> http://www.haproxy.org/#news

<comment><USER2> This release contains a neat feature: you can now bind HAProxy to a specific FD opened by its parent process. This means that you can babysit your HAProxy processes underneath a parent process that opens ports and get hitless HAProxy restarts, which I've long desired.

<comment><USER3> Have you looked at einhorn? We've been running HAProxy under einhorn for a while now, using something like [https://gist.github.com/ebroder/36b2f4f3aa210b9d9f3d](https://gist.github.com/ebroder/36b2f4f3aa210b9d9f3d) to translate between HAProxy's signalling mechanisms and einhorn's signalling mechanisms.

<comment><USER2> Er, yes, hi Evan! Cooper here. I believe either you or Andy originally pointed this interesting HAProxy restart behavior out to me, in the context of explaining why you wrote Einhorn.

</comment></comment></comment><comment><USER4> We've been using HAProxy 1.5dev in production for a few month, including SSL. It's been one of the most simplest and stable parts of our infrastructure.

<comment><USER5> how much traffic are you passing in this environment?

we're still using stunnel for ssl, have been waiting for positive reports to let haproxy do it, but are optimistic.

<comment><USER6> A bit of self-promotion, but you may want to take a look at bud ( [https://github.com/indutny/bud](https://github.com/indutny/bud) ) too. It is basically a TLS terminating proxy, and does support some availability features (if you need them).

The bud is built on the top of the libuv, which empowers the node.js.

</comment></comment></comment><comment><USER7> This is embarassing. I'm getting a 502 Proxy Error.

<comment><USER8> Well. That means that HAProxy is still up when the backend servers aren't. "embarassing" isn't the terminology I'd use in this case.

<comment><USER9> How embarrassing for OP!

</comment></comment></comment><comment><USER10> If you're a curious Ubuntu (14.04) user, it looks like the PPA to get version 1.5 is ppa:vbernat/haproxy-1.5.

Based on this: [http://haproxy.debian.net/](http://haproxy.debian.net/)

<comment><USER11> Been using this in production for about six months now. Happy that the release version is finally out. The nicest feature of 1.5 is that you can easily do Redis failover using the new TCP check features.

<comment><USER12> I think the Redis checks are now native built in when looking at the changelog:

        - [MINOR] check: add redis check support

<comment><USER11> Nice. I'll look into it. The TCP check was still a bit of a dirty hack.

</comment></comment></comment></comment><comment><USER13> Impressive list of features. Does anyone know if HAProxy is used by any IAAS/PAAS providers?

<comment><USER14> I have the sneaking suspicion that Amazon's Elastic Load Balancer is based on HAProxy (and has been tracking the 1.5 series in development for some time). Nothing particularly evidentiary, but it's a glass slipper that fits very snugly.

<comment><USER15> I believe they use nginx. Traditionally ELB has been the most featureless LB's you'd ever encounter. That's in direct contrast with HAProxy. Truly a pain point with AWS IMO.

<comment><USER14> ELB has features that nginx does not (health checks for one), and does not take advantage of _many_ features that nginx does have. On the other hand, the feature set of HAProxy (1.5 branch, now "released") matches remarkably closely.

<comment><USER16> > ELB has features that nginx does not (health checks for one)

Check out Tengine, a Nginx fork made by Alibaba guys ;)

</comment></comment></comment></comment></comment><comment><USER17> I'm using HAProxy to load balance to an EC2 autoscaling group. I have to list all ip in the configuration file. It's still not possibile to put A.B.C.0/24.

</comment><comment><USER12>
        - [MINOR] checks: add PostgreSQL health check

A bit silent, but this is a very interesting change for us.

</comment><comment><USER18> Thanks for all hard work. I had checked 1.5 dev build 2-3 months ago, enabling SSL was causing very high CPU. Must have been good now.

</comment><comment><USER19> Kudos to loadbalancer.org team. Classy

</comment><comment><USER16> How come this is a news if 1.5.1 has already been released on June 24th?

<comment><USER20> June, even. I'm still interested, though. Fitbit uses haproxy but I set up my development machine with nginx because of SSL. It probably doesn't make a difference, but I'll still feel better when I can easily make my dev setup more closely mirror production.

<comment><USER21> What about SSL? HAProxy supports SSL offloading.

<comment><USER20> I didn't investigate deeply; I'd never heard of haproxy prior to Fitbit. Someone from site ops told me they use nginx + haproxy but it would be easier for me to just set up nginx.

This article does sound to me like SSL support in haproxy is brand new: [http://seanmcgary.com/posts/using-sslhttps-with- haproxy](http://seanmcgary.com/posts/using-sslhttps-with-haproxy)

<comment><USER22> SSL support has been around for a while, but 1.5 has been considered beta for a few years now, though that hasn't stopped it from being deployed in a _lot_ of production environments.

Before SSL was rolled into haproxy, nginx was often a good candidate to handle the SSL termination. Stunnel is also common, and stud was popular for a while, but seems it was abandoned once haproxy could handle the job.</comment></comment></comment></comment></comment>