Sunday, August 31, 2014

The ordinary weirdness of quantum mechanics

Raymond Laflamme's qubit.
Photo: Christina Reed.
I’m just back from our 2014 Workshop for Science Writers, this year on the topic “Quantum Theory”. The meeting was both inspiring and great fun - the lab visit wasn’t as disorganized as last time, the muffins appeared before the breaks and not after, and amazingly enough we had no beamer fails. We even managed to find a video camera, so hopefully you’ll be able to watch the lectures on your own once uploaded, provided I pushed the right buttons.

Due to popular demand, we included a discussion session this year. You know that I’m not exactly a big fan of discussion sessions, but then I didn’t organize this meeting for myself. Michael Schirber volunteered to moderate the discussion. He started with posing the question why quantum mechanics is almost always portrayed as spooky, strange or weird. Why do we continue to do this and is beneficial for communicating the science behind the spook?

We could just blame Einstein for this, since he famously complained that quantum mechanics seemed to imply a spooky (“spukhafte”) action at a distance, but that was a century ago and we learned something since. Or some of us anyway.

Stockholm's quantum optics lab,
Photo: Christina Reed.
We could just discard it as headline making, a way to generate interest, but that doesn’t really explain why quantum mechanics is described as weirder or stranger as other new and often surprising effects. How is time-dilatation in a gravitational field less strange than entanglement? And it’s not that quantum mechanics is particularly difficult either. As Chad pointed out during the discussion, much of quantum mechanics is technically much simpler than general relativity.

We could argue it is due to our daily life being dominated by classical physics, so that quantum effects must appear unintuitive. Intuition however is based on experience and exposure. Spend some time calculating quantum effects, spend some time listening to lectures about quantum mechanics, and you can get that experience. This does not gain you the ability to perceive quantum effects without a suitable measuring device, but that is true for almost everything in science.

The explanation that came up during the discussion that made the most sense to me is that it’s simply a way to replace technical vocabulary, and these placeholders have become vocabulary on their own right.

The spook and the weirdness, they stand in for non-locality and contextuality, they replace correlations and entanglement, pure and mixed states, non-commutativity, error correction, path integrals or post-selection. Unfortunately, all too often the technical vocabulary is entirely absent rather than briefly introduced. This makes it very difficult for interested readers to dig deeper into the topic. It is basically a guarantee that the unintuitive quantum behavior will remain unintuitive for most people. And for the researchers themselves, the lack of technical terms makes it impossible to figure out what is going on. The most common reaction to supposed “quantum weirdness” that I see among my colleagues is “What’s new about this?”

The NYT had a recent opinion piece titled “Why We Love What We Don’t Understand” in which Anna North argued that we like that what isn’t understood because we want to keep the wonder alive:
“Many of us may crave that tug, the thrill of something as-yet-unexplained… We may want to get to the bottom of it, but in another way, we may not — as long as we haven’t quite figured everything out, we can keep the wonder alive.”
This made me think because I recall browsing through my mother’s collection of (the German version of) Scientific American as a teenager, always looking to learn what the scientists, the big brains, did not know. Yeah, it was kinda predictable I would end up in some sort of institution. At least it’s one where I have a key to the doors.

Anyway, I didn’t so much want to keep the mystery alive as that I wanted to know where the boundary between knowledge and mystery was currently at. Assume for a moment I’m not all that weird but most likely average. It is surprising then that the headline-grabbing quantum weirdness, instead of helping the reader, misleads them about where this boundary between knowledge and mystery is? Is it surprising then that everybody and their dog has solved some problem with quantum mechanics without knowing what problem?

And is it surprising, as I couldn’t help noticing, that the lecturers at this year’s workshop were all well practiced in forward-defense, and repeatedly emphasized that most of the theory is extremely well understood. It’s just that the focus on new technics and recent developments highlights exactly that what isn’t (yet) well understood, thereby giving more weight to the still mysterious in the news than there is in the practice.

I myself do not mind the attention-grabbing headlines, and that news focus on that what’s new rather than that what’s been understood for decades is the nature of the business. As several science writers, at this workshop and also at the previous one, told me, it is often not them inventing the non-technical terms, but it is vocabulary that the scientists themselves use to describe their research. I suspect though the scientists use it trying to adapt their explanations to the technical level they find in the popular science literature. So who is to blame really and how do we get out of this loop?

A first step might be to stop assuming all other parties are more stupid than the own. Most science writers have some degree in science, and they are typically more up to date on what is going on in research than the researchers themselves. The “interested public” is perfectly able to deal with some technical vocabulary as long as it comes with an explanation. And researchers are not generally unwilling or unable to communicate science, they just often have no experience what is the right level of detail in situations they do not face every day.

When I talk to some journalist, I typically ask them first to tell me roughly what they already know. From their reply I can estimate what background they bring, and then I build on that until I notice I lose them. Maybe that’s not a good procedure, but it’s the best I’ve come up with so far.

We all can benefit from better science communication, and a lot has changed within the last decades. Most notably, there are many more voices to hear now, and these voices aim at very different levels of knowledge. What is still not working very well though is the connection between different levels of technical detail. (Which we previously discussed here.)

At the end of the discussion I had the impression opinions were maximally entangled and pure states might turn into mixed ones. Does that sound strange?

29 comments:

Giotis said...

Weird based on what? What is normal and what is weird in the physical world? What is the baseline? These terms have psychological or social origin and thus they are not applicable in physics.

The origin of the problem is that it is not conveyed to the people the notion of effective phenomena/ theories in the Wilsonian sense. People don’t understand well enough that depending on the energy level we are probing we have access to different phenomena; our every world is coarse grained and described by effective theories and thus cannot serve as baseline for understanding Nature. Our intuition is worthless in that sense. The notions of fundamental, emergent and approximate are also not well understood by the public.

These notions and especially the Wilsonian notion of effectiveness and RG flow revolutionized our way of thinking about Nature and people simply don’t know them.

I blame physicists and journalists because they don’t explain well enough these concepts to the public or they don’t convey them at all.

And why they don’t convey these essential concepts? They simply don’t care; we are living in an indifferent world.

L. Edgar Otto said...

Another essay that seems to get to the heart of the issues. Some of my concerns so I really like your emphasis on the terms we use.
This may not mean it is just a linguistic issue. Between the information and the meaning at the frontier or borderland of the unknown to be explored we can find in uncertainty the sense of the uncanny.
The indians knowing every inch of the forest yet running silently chose the open and most direct path to their home, unless in this sense of the uncanny they moved along more hidden ways.
So in a sense the issue is what is between, in our words or symbols, what is the information and what is the meaning in search of some reasonable model of shifting unity.
The number 3 has a great deal of information but very little meaning, whereas the transfinite number alph 3 has deep meaning but gives us little information.
Thing is when we make such abstract necessary distinctions the opposite can be true, 3 contains all the meaning and alph 3 seems to tell us nothing practical as information.
But for most in the business of living and adapting to the mysteries and facts of this world who easily learn new languages (I mean I am just getting the feel of one bloggers terminology, enough to know his grounding view has evolved and changed lately) the pheneme is one with the phoneneme hidden or not in how we arrange them or exclude half seeing our equations.
Sometimes when there are many volcanoes spewing ash all over the earth some just let off a little steam covered over, their heat hidden within.
But it has been a long few decades since the thirty years that shook physics.

Richard Kriske said...

I think the weirdness of Quantum Mechanics comes from the fact that the Theory is wrong. If you look at classical Angular Momentum, it is conserved because you can separate Space and Time under certain conditions. One of those conditions being that the Universe has a Positive Curvature and that a Horizon is formed, much in the same way the Earth's Horizon is formed--Objects with height tilt away from the observer and no matter how tall an object is, it will ultimately tend to a line (because the Earth is in the way). The same thing holds for the Universe as a whole--the Universe (the three dimensions of space) get in the way of the tall Time dimension and ultimately Time Redshifts into the CMBR--- So there you have separated Space from Time, so General Relativity has an Error in it. Another problem arises in that if this Curved Space exists and is in fact separate from time under some conditions, that Manifold--That film has two sides---On one side it is positively Curved as noted above and on the other side it is Negatively Curved (or Hyperbolic). It is the Hyperbolic side that gives us Quantum Mechanics, since it is a lot of time lines Converging to a single Point, whereas the other side the Time lines Diverge. So you can see that both Relativity and Quantum Mechanics come from the same Mechanism, it is really just the Theories themselves being incorrect, as to how a Manifold actually works (It blocks light by Redshifting Curved Surfaces, so it acts almost identical to the Earth's Surface, except that it allows Timelines to come into the Hyperbolic Side). So no spookyness, just unimaginative Physicists (but this is ok by me as it gave me the opportunity to construct the correct theory,and I owe them a debt that I can never repay for letting me have a chance to voice my Theory and be a member of the Greatest Scientific Society in History). So in short thank you everyone for letting me find a way forward, and hopefully no one else tries to take credit for my work, even though many of you came close to the solution on your own.
Gratefully Yours
Richard M. Kriske

Uncle Al said...

"Assume for a moment I’m not all that weird but most likely average." The other five sigma had better get with the program.

http://en.wikipedia.org/wiki/Rorschach_test#mediaviewer/File:Hermann_Rorschach_c.1910.JPG
1921? WHOA! If handed a blank card, look into the drone's eyes and say "it's upside-down."
http://natclegg.files.wordpress.com/2013/05/jung-seroent-medium-bookred.jpg?w=450
Carl Jung had loose threads.

Uncle Al said...
This comment has been removed by the author.
L. Edgar Otto said...

Neat comment Uncle AI

Bee's remark in the essay comes to mind as to if time dilation is any weirder. So wherefore this depth of weirdness? Eddington felt his ideas were no more bizarre than Dirac's so did not understand why his not more accepted.
Between Jung and Freud we have Adler which seems closer to todays explanation of society and perceptions.
At best we can assume that just perhaps what I think and how I am viewed could be rather simplistic or wrong from better seeing eyes and that a powerful abstraction to know and just as uncanny. Certainly we get the feeling there is something to Jung's thermodynamic model as synchronicity if we admit the experience as baffling.
These test seem to suggest in matters of bilateral symmetry between each other or within our self, with an sense of an up direction that the images observed are indeed reversed, as in how the focus is turned on head in our mind from our eyes. Or the reflection in a drone's eyes doubly reversed.
But if you mean a mechanical thing with the widest abstract symmetry that what is upside down objectively is indeterminate- that too is a powerful comment beyond the usual subjective or objective quantum interpretations.
How then do we apply Riemann's sphere 101 to ideas of curvature if what has one or two sides may not distinguish what is inward or outward, (maybe more thought, Richard Krisike? as if these not abstract enough)? Are supposed errors in the two physics or in their entanglement of math symbols?
Sometimes a snake is just a snake and curves around a healing baton we spin in the air and catch again or not as science marches on. Or two snakes entwined with wings as a symbol for health whether the healing hands of Apollo lets something pass through them or we do the best we can a little drunk in awe with the mystery of that laughing god of Nietzsche, Dionysian. Can a quantum cat who is somehow both dead and alive not represent this age with a myth of zombies? So too the blank cards presented in our ideas of chirality BTW.

Sabine Hossenfelder said...

Giotis,

I agree up to the point that you say they don't care. It's not that they don't care but that in the end it all comes down to money, and to how fucked up our economic system is. I have elaborated on that elsewhere, how we're not taking into account long-term benefits properly etc (the FQXi essay pokes on the same problem). However, I think that it's currently worse than it has to be in that one could convey more information than is presently done without being less profitable, it's just that it isn't even tried for the risk of possibly being less profitable. Best,

B.

MarkusM said...

"The spook and the weirdness, they stand in for non-locality ..."
Oh please, physics is local, through and through !!!
See:
http://www.youtube.com/watch?v=f-OFP5tNtMY 11:40-
or
"Local Quantum Physics: Fields, Particles, Algebras" - Rudolf Haag

Sabine Hossenfelder said...

Markus:

Depends on how you define the word. There's like 6 different definitions of it. And, see, this is one of the points that you don't get across when you just talk about weird or strange. Best,

B.

Zephir said...

Quantum mechanics isn't weird, but a straightforward consequence of the observation of vacuum with its own ripples. In AWT it's an analogy of the observation of water surface with its own waves. At large scale (where the influence of underwater can be neglected) it does lead into special relativity and general relativity phenomena. At short scales it does lead into quantum mechanics phenomena: all observations mediated with surface waves will get blurred with Brownian noise (density waves of underwater) and the perceived environment density will be proportional to its energy density (which leads into Schrodinger equation). Thanks to Couder/Fort/Bush we know about many water surface analogies of quantum mechanics already - so we can be sure, that the dense aether model works.

The quantum mechanics gets rather weird for rigorous relativists, as it implies the existence of hyperdimensional / superluminal phenomena for its interpretations - whereas the relativists doesn't bother with explanation of gravity, so they have (seemingly) no problem with it.

Zephir said...

The definition of "weirdness" can vary from labeling of every non-repeatable phenomena to labeling of all phenomena, which still don't have intersubjectively accepted logical explanation, analogy the less. From perspective of formal mainstream physics everything is "weird", because the mainstream physicists have no such an explanation for most of fundamental phenomena, which they're describing (from gravity to magnetic field).

L. Edgar Otto said...

What in the frontiers draws us, pushes us, as if the West Wind, intermittent up to chaos, my Zephir?

Why is it that being charmed by strangeness is enough? That beauty feels a measure of the truth? So struggle between sides turns the other's points upside down, top or bottom. Nature at some blank card state with indefinite inertia back to the black and white boards beginnings and endings up or down as if an Aether, luminoferous or not ?

Plato Hagel said...

"The whole experiment would fit snugly in a child’s bedroom, and as I looked at the table, I refrained from asking my first instinctual questions. “This is it? This is where you tested realism?” I already knew how unfair these questions were. It had taken a few months of tests, and almost two years for Zeilinger’s group to understand how this experiment tests realism. Before that, it had been more than 80 years since physicists began to argue about what quantum mechanics had to do with reality at all." See:Do we create the world just by looking at it?

Like anything there is an experimental trail that leads to one's understanding of the basics of entanglement?

Plato Hagel said...

Eventually, Wheeler discarded “everything is geometry” in favor of an ostensibly deeper idea: “everything is information.” It would be a fitting vindication of Wheeler’s vision if everything in the universe, including wormholes, is made of quantum correlations.

*Update: Commenter JM reminded me to mention Brian Swingle’s beautiful 2009 paper, which preceded Van Raamsdonk’s and proposed a far-reaching connection between quantum entanglement and spacetime geometry.
SEE:Entanglement = Wormholes

So one exploits the idea of, "everything is information?"

Arun said...

Does quantum mechanics firmly establish that a thing and its description are distinct?

Corollary: mathematics (some of it) describes our universe, but is not our universe.

Corollary: a simulation of a thing is distinguishable from the real thing.

Plato Hagel said...

For a child like Einstein in his youth the wonderment is to identify the forces that given a compass needle, and the impetus for such a thing to shape the future? We often hear of stories like this as we see the result, a scientist who have come a long way. So it may be like a mystery that grabs their attention, and then, becomes a paradigmatic device for the shaping of the individual in the future?

See how dreams were made of.:) W want good scientific censorship to at least present the issues in a story form?

kashyap vasavada said...

Such debates are interesting but unending!! People have to understand once for all that our intuition, our non-mathematical languages and conventional logic are based on our everyday experiences, which are classical. The book of universe is most likely written using a different logic. Although many of the readers may not agree, I would also include concepts of divinity in the realm, which is different from our everyday notions and logic!

Boris Borcic said...

Well, to put it bluntly, what I find weirdest in QM is how quantum mechanists can end up fighting GR in the name of information conservation over lifetimes of black holes despite the signature involvement of randomness in the lowliest quantum measurement.

To me they have succumbed to witchcraft. Or maybe it is that I am mistaken about something: would random events actually conserve information?!

JimV said...

I find most popular science books which aren't just histories frustrating because they don't contain enough math or examples or definitions to pin down for me what they are talking about. Perhaps they still serve a useful function of inspiring younger readers to study in that field, but I don't have the time or energy to take more academic courses at this point. So my understanding of things like quantum mechanics remains at a popular-science level - which is not very good.

L. Edgar Otto said...

JimV
perhaps you have the big picture, I mean what if after all the time and work it cannot be found yet in academia? History may be the best part of the story to tell things.

Plato Hegel,
good remarks, it makes me think that the wormhole-information thing is the myth now of our time both in the sci fi and the science.
As Arun asks a thing and its description distinct? Do we go for the witchery or the witch hunt?

I too played with powerful magnets as a child and was amazed at the force one could not see. Electrostatics seemed more real as once in awhile it would shock me. I even had spiral things spin in the magnetic field but what does a child know about external energy such as RF or autos vibrating the road? That damn magnet would attract my compass from all over the big yard, a toroidal shape.
Aristotle had his points too.

Wes Hansen said...

I believe the main "problem" is with the analogies used to explain the technical terms to laypersons. The most common lay explanation of entanglement I have encountered uses the analogy of two perfectly anti-correlated coins to represent a singlet state. Separate the coins by millions of light-years and, prior to flipping one coin, the outcome of either coin toss is completely random - probabilistically speaking - but as soon as you know the outcome of one you know the outcome of the other with 100% certainty. How is that not weird?

The reason "weirdness" enters into the discussion in the general case probably has something to do with the human tendency towards reification bias; people tend to look at an experimental setup as distinct, separate entities when, on an informational level, they're really no longer wholly distinct. You could say they're "telepathically" linked, Ha, Ha, Ha . . .

Quite frankly, I agree with Sir Arthur Eddington, "The world is not only stranger than we imagine, it's stranger than we can imagine."

“’Who ARE you talking to?’ asked the King (science), going up to Alice (metaphysics) and looking at the Cat’s head with great curiosity.

‘It’s a friend of mine – a Cheshire Cat,’ said Alice, ‘allow me to introduce it.’

‘I don’t like the look of it at all,’ said the King, ‘however, it may kiss my hand if it likes.’

‘I’d rather not,’ the Cat remarked.

‘Don’t be impertinent,’ said the King, ‘and don’t look at me like that!’ He got behind Alice as he spoke.

‘A Cat may look at a King,’ said Alice, ‘I’ve read that in some book, but I don’t remember where.’

‘Well, it must be removed,’ said the King very decidedly, and he called the Queen (mathematics), who was passing at the moment, ‘My dear! I wish you would have this Cat removed!’

The Queen had only one way of settling all difficulties, great or small. ‘Off with his head!’ she said, without even looking round.

‘I’ll fetch the executioner (Kurt Gödel) myself,’ said the King eagerly, and he hurried off.”

. . . of course this led to an argument!

“The executioner’s argument was that you couldn’t cut off a head unless there was a body to cut it off from; that he had never had to do such a thing before and he wasn’t going to begin at HIS time of life.

The King’s argument was that anything that had a head could be beheaded and that you weren’t to talk nonsense.

The Queen’s argument was that if something wasn’t done about it in less than no time she’d have everybody executed, all round (divide by zero).

Alice could think of nothing else to say but, ‘It belongs to the Duchess (Quantum Mechanics); you’d better ask HER about it!’”

. . . of course the Duchess was in prison under a sentence of execution because she had boxed the Queen’s ears, but regardless, during the commotion the Cheshire Cat disappeared, leaving nothing behind but a sinister grin . . .

Jerry Lisantti said...

Because, as has been stated, our intuition is based on our observation of the world around us which appears classical, some quantum effects stand out as weird. They just seem odd and different to our classical intuition maybe that's why science journalist report it that way. Also as stated it might be that's how the scientists interviewed might discuss some quantum effects. At least to me some quantum effects are weird or odd but when explained make sense. But as Bee related in an earlier blog post that is the challenge science journalist face is the explaining part without losing the readers. The explaining part needs to be accurate yet entertaining. That maybe a challenge

Richard Kriske said...

I like the Experiments that MarkusM had pointed out about Pilot Waves, which I believe is from before David Boehm. Pilot Waves have been published before as exceeding the Speed of Light. Another thing that troubles me is what L. EdgarOtto said refering to the Manifold idea as being Riemann 101, probably from Gauss, "The Nature of Curved Surfaces" (probably got the title wrong). But you have to remember that although both Gauss and Riemann had some good ideas, parts are wrong, since they where talking about mapping the Earth with Conformal/NonConformal mapping. The wrong part about David Boehm came from his failure as with Gauss/Riemann that surfaces generally have two sides and the Inner side has different mathematics (Hyperbolic and a different speed of light) in the case of water when you Scuba dive and look upward. Anyway Gauss didn't Scuba dive, so not so abstract, he made maps. Anyway perhaps the inner side of Space-Time also has a different speed of light so Pilot Waves would be the answer. Thanks everyone for your input.

L. Edgar Otto said...

I looked up Raymond Laflamme's qubit as a perfect error correction code.
It has the right general formulas and clearly states the needed criteria as a generality, but is not radical enough to clear up what we intuit QM information can achieve in a gain as a mystery of computational power. Such methods may not eliminate the wierdness in relation to insulation and connectivities in environs as well ordered field binary sequences. So such parsing I distinguish as "quasic".
Error correction in complexity applies as if trivially to 64 or 256 coherent contiguous cells of such grids as higher dimensions can be reduced to 2 natural dimensions. Just as in DNA corrections and expressions, the quasic dimensions being 4 and 16 dimensions respectively.
So much of the weirdness vanishes unless extended ungrounded thus pure weirdness as string theory.
So do many unification problems we set up in the search for solutions ourselves.
The information, topology, and arithmetic relate to the same description of now ill defined symmetry models.
A key condition missing as Sabine intuits that expanding the quasic dimensions mirrored into exacting proof by descent quasi-infinite there are quasi- phase shifts we designate as she says of beginnings and endings, initiators and terminators.

hush said...

Alice,

Twin excursion
Zwilling Ausflug

The ordinary weirdness of Moms.


When we, the twins, talk to some moms, we typically ask them first to tell us roughly what they already know. From their reply we can estimate what background they bring, and then we build on that until we notice we lose them. Maybe that’s not a good procedure, but it’s the best we’ve come up with so far.

We lose moms all the time. From the very first reply.

Moms are not weird. Language is a problem. Either they learn or we do.

Blasphemous Bob

hush said...

Today's Predigt.

Let us read the information gathered.

(All bow heads)



What preoccupies all of them?

Map vs. Territory.

Who broke this?
Who broke what?
The symmetry.

Manish Balyan said...

Nice post with great information.

nikman said...

What's "weird" is experimental results, which tell us nothing about what actually "is" -- only what we measure or observe.

Our observations match models that are nonlocal and even nonrealistic. As long as experiments confirm those models we should stick with them ... not because they reflect "reality" but because, however weird some of their seeming implications are, they work in practice. And if all Bell loopholes are indeed closed in a single experiment this advice becomes more cogent still.

Kant warned about trying to suss out Things-In-Themselves. In more modern terms, there's a lot of very recently discovered stuff our brains simply haven't evolved to comprehend. Einstein ought to have realized that but maybe he was fed up with all the Ur-New Age stuff being propagated by his old champion Eddington and others.

Quantum Explorer said...

Concerning one aspect of quantum weirdness, "spooky non-locality", I believe the problem even started from physicists themselves. It is most likely a mistake, or widely spread misunderstanding about the Bell's theorem. Or put it this way: what exactly do physicists mean the non-locality in terms of precise mathematical language? The fact is:

(1) on one hand, in Bell's theorem and related experimental tests, it was clearly defined in one form of mathematical equation.

(2) On the other hand, many physicists took a jump step to discuss it in a totally different mathematical definition.

The math meaning in (1) is simply about the statistical correlation, while the math meaning in (2) is dramatically shifted to the instant "signaling" at a distance.

It is clear that the "non-locality" in definition (1) possesses much less weirdness than the non-locality in definition (2). But most time people, started among many physicists themselves, are involved in talking about quantum "non-locality" in terms of definition (2).

- peace :)