
Why have so many physicists shrugged off the paradoxes of quantum mechanics? - bradstreet
https://www.thenewatlantis.com/publications/make-physics-real-again
======
gus_massa
> _Bohr postulated a distinction between the quantum world and the world of
> everyday objects. A “classical” object is an object of everyday experience.
> It has, for example, a definite position and momentum, whether observed or
> not. A “quantum” object, such as an electron, has a different status; it’s
> an abstraction. Some properties, such as electrical charge, belong to the
> electron abstraction intrinsically, but others can be said to exist only
> when they are measured or observed._

This is a common error. Macroscopic "everyday" objects don't have a definite
position and momentum. Macroscopic objects are quantum objects. But when the
mass is big enough, the position and momentum can be defined simultaneously
with an error that is so small that you can just ignore the uncertainty and
approximate them as classical objects.

(Looking at them as classical objects is just a good approximation, like
ignoring the gravity force of the Moon in most common situations.)

Anyway, the measurement problem is a real problem and nobody knows how to
solve it. The current fade is to use decoherence to explain it. It is a
promising idea, so I hope that in a few years/decades/centuries we can give a
good explanation of the measurements that avoid anything that looks like
magic.

~~~
Sylos
> This is a common error. Macroscopic "everyday" objects don't have a definite
> position and momentum. Macroscopic objects are quantum objects. But when the
> mass is big enough, the position and momentum can be defined simultaneously
> with an error that is so small that you can just ignore the uncertainty and
> approximate them as classical objects.

To put this into simpler terms:

Whenever we measure something, we need to throw something at it and then have
that something rebound and hit us again. In most experiments, we throw photons
and have them rebound into our eyes.

Throwing a photon against a "classical object" \- a chair, a ladder, bacteria
- is like throwing a tennis ball against a skyscraper. You throwing that does
not have no effect at all, but it's very much negligible.

But when trying to measure quanta, you're now throwing your tennis ball at a
football, or at another tennis ball. You're gonna be lucky, if it rebounds at
all, instead of just pushing the object that you're trying to measure out of
the way. (You also don't have any smaller balls to throw.)

That's why when you measure something in quantum physics, you only know that
it has this exact value in the moment that you measure it. It's going to be
pushed away because you threw something at it, so after your measurement it
has a different value.

You also can't observe it over a longer period, so there's no way to know
whether it was only in that moment at your measured position or a long time
beforehand.

~~~
dave_sullivan
I don’t think this analogy holds up. Consider the double slit experiment:
throw a bunch of basketballs at a wall and see what pattern of hits they leave
by looking at where they hit the wall. If the wall is being looked at
(observed), we see one pattern. If we look away, conduct the experiment, then
check it, we find another.

To me that suggests the act of “observance” effects the probability
distribution of likely states. If a tree falls in a forest and no one is
around, then it doesn’t really fall, it just has a probability of having
fallen that is not resolved until someone goes to check. How does your analogy
account for those effects? For me, it looks like quantum collapse is causing
the states of these objects to become “resolved” where at first they were
“unresolved” and this suggests we live in a universe that knows how to save on
memory and is fundamentally probabilistic.

~~~
gus_massa
There are two walls. One wall has two slits, the other wall is where the
particles/waves/balls/whatever colide and form the interference pattern (or
not).

You don't need someone observing the second wall to get the interference
patters. You can replace the person with a photographic plate, a CCD sensor of
a camera, or other equipment. All off them are more precise, reliable and even
cheaper than a graduate student with paper and pencil.

The problem is if you try to add some type of equipment to first wall to
collect information about how the particles/waves/balls/whatever passed thru
it. Whatever equipment you add it will disturb the flow and it will kill the
interference pattern.

This is not a technological problem. It is how the universe work. If you
propose to use some particular method (like using light to detect the balls)
you will sooner or later find that there is something that gets broken (see
the former comment).

An important detail is that if you use a macroscopic object like a basketball,
the slits size and the slits separation must be tiny (less than a millionth of
the size of the nucleus of an atom, probably much less). So you intuition
about how thinks work in the macroscopic level is not a good guide to how
thinks work in the microscopic level. In the macroscopic level you can
approximate the basketball as a perfect classic solid. It's just an
approximation, a very good approximation.

~~~
mercer
> This is not a technological problem. It is how the universe work. If you
> propose to use some particular method (like using light to detect the balls)
> you will sooner or later find that there is something that gets broken (see
> the former comment).

what confuses me in various explanations like this is that the whole 'act of
observing affects what you observe' thing seems to be rather particular in
that it turns the wave-like behavior into particle-like behavior, which
strikes me as rather weird/counter-intuitive. Why don't we just get slightly
different interference patterns? Or some spectrum of effect between wave-like
and particle-like?

Is my confusion mostly a result of the limits of the analogies presented to me
as a layman?

------
atomack
It's a bit ungenerous to physicists to suggest they've simply shrugged off the
paradoxes of quantum mechanics. The first couple of paragraphs outline reasons
why quantum mechanics has gained so much traction. The various attempts to
understand its more difficult results have turned out to be notoriously
difficult to substantiate or disprove experimentally.

I don't actually dispute the socialogical forces the author describes as they
apply to physics research but I don't think apparent lack of progress is due
to lack of concern amongst the physics community.

------
mathgenius
There have been several books recently that describe the saga of twentieth
century quantum physics, culminating in the realisation that entangelement is
a real thing that has consequences. My favourite is "The Age of Entanglement:
When Quantum Physics Was Reborn" by Louisa Gilder. It's a fun book.

The history is fascinating. I'm waiting for a book that describes the deeper
sociological aspect. A book with attitude. For instance, several of the
founders of quantum physics had mystico-philosophical things to say about the
quantum. But all of this was thrown out the window with the advent of the
second world war. Physics became overrun by calculations. It took quite a
while for people to get around to thinking about entanglement again. John Bell
struggled for decades to get people to notice his work on this. Even the guy
that invented the laser was met with stern disbelief when he presented his
results to the "elders". Partly this is science just doing its thing, but
there also does seem to be a history of science being dragged, kicking and
screaming. Especially with quantum physics.

------
aj7
Essentially because of Feynman’s teaching that quantum mechanics works
accurately to predict the results of experiments, that that is EVERYTHING, and
that “paradoxes” and “intuition” are suspect.

~~~
acqq
And we can actually listen here Feynman's answer to " _what is the meaning
of..._ " and " _why_ " questions:

[https://www.youtube.com/watch?v=36GT2zI8lVA](https://www.youtube.com/watch?v=36GT2zI8lVA)

Note, despite the title of somebody presenting this segment of his talk, he
definitely doesn't talk just about "magnets" but really about "the meaning"
and "why" questions (the youtube poster got it). About the needed "expected
framework" to avoid "perpetual why questions" etc. Even the things that we
take for granted, e.g. using electricity in our day to day life, or the
eventual "why" we don't fall through the floor _can 't_ be properly explained
using just our "common" intuition.

In another direction, it works, we are "used" to see some effects of the
electrical forces all the time, so that's what is "intuitive" to us because
we're familiar with it.

So back to the original title of the article submission here: "why ...
shrugged off the paradoxes..." it can be easily seen that once one is getting
an answer inside of the expected framework, one doesn't "shrug it off," one is
actually satisfied with the answer.

------
bhouston
I think the observes are in super position and measurement collapses us and
the world. Thus there are no nonlocal effects rather we just get rid of
multiple universes which were averages together and pick one, or at least the
subset of possible universes that correspond to that particular measurement.
Thus instead of non local effects one selects from multiple existing solutions
at present and discard the rest.

I think this makes a lot more sense.

The other alternative was we are in a simulation and it has variable levels of
resolution (wave verses particle) and it will computer higher resolutions on
demand (eg observers), but that these on demand increases in resolution affect
the simulation going forward. This seems to be overly complex thus I prefer
the first interpretation.

I am a layman in this area so I am probably wrong.

There must already exist a formal name for this? Isn't this where multiverses
comes into play?

------
platz
quantum mechanics has two different laws that describe how a system changes in
time.

Rule 1 says that except during a measurement, the wave evolves smoothly and
deterministically, exploring every possibility.

Rule 2 says that during a measurement of position, the wave collapses around
the position where it's seen, with a probability proportional to the square of
the height of the wave, before the collapse.

It is only Rule 2 that mentions probabilities at all.

And, Rule 1 and Rule 2 are in catastrophic tension with each other.

Rule 1 says that there are always all possible outcomes. Rule 2 says there is
only 1 outcome and it's picked out with some probability rule.

It's pretty contradictory - is there one outcome or all outcomes?

> youtube.com/watch?v=Zri9gS1w5ok Perimeter’s Lee Smolin will argue that the
> problems that have bedeviled quantum physics since its inception are
> unsolved and unsolvable for the simple reason that the theory is incomplete.

~~~
rohit2412
And I never understand what is a "measurement". Has it something to do with a
human being observing it? Isn't any measurement just electromagnetic or
gravitation forces acting on it, which act all the time?

~~~
cygx
A measurement is an interaction that crosses the Heisenberg cut separating the
quantum from the classical world. Eg you prepare an atom in a superposition of
states relative to some 'quantization axis' determined by a Stern-Gerlach
apparatus. The state will randomly 'collapse' into one of the available final
states, resulting in a macroscopic dot on some screen. You and all your
physicist buddies will agree on the placement of the dot.

There is no agreement on how this happens, complicated by the fact that there
is no such thing as a classical world I alluded to above, ie any interactions
with the apparatus and the conscious observers supposedly obey the laws of
quantum mechanics.

------
alkonaut
What is the general feeling among theoretical physicists when it comes to
breakthroughs in resolving these paradoxes? Decades ago there was great
optimism about string theory and similar, followed by a long period of
disillusionment . What is the guesstimates now for the next big breakthrough
such as unifying gravity and QM? Is it seen as something achievable in the
near/foreseeable future, or is it considered to be a far future achievement
comparable to say interstellar travel (“we’ll get there if we aren’t extinct
by then, but our current civilization will seem primitive by the time we do”)?

------
Muha_
As Wheller said "It from bit". It seems to me that when physicists can to
consider observation, collapse and physic phenomenas gennerally as some kind
of informatinal processes, then quantumn puzzles about reality will be
resolved. I think them not sussessed yet because this is incredible difficult
task; not because this wrong way. May be it will be something like
informational multiverse. Some principle like multiverse branches selection to
keep "information conservation law" (as another manifistation of unitarity)
can explain nonlocality ect..

------
q_revert
because it's really hard, and they need to publish :)

\-- phd in physics

~~~
tmoot
What, you don't want to be a 10th year grad student then post-doc till your
mid-to-late 30's?

Also, to be honest, those problems are kind of boring.

:)

\-- phd in physics.

------
zzo38computer
These idea is interesting, but, I had a different idea, is constraint
interpretation. Mathematics is the real reality. For example, some equations
can have multiple solutions, such as x^2+2x-3=0 can be 1 or -3. If you make
the experiment that you have a entangled photons and you are on a different
planet, you can measure it and if the people on other planet measure it in the
same way they will get the same answer; it doesn't go "instantly" or at any
other speed; the constraint is they are same, and this entanglement propagates
backward in time from the point of view from both experimenters; it doesn't
say if one is "before" or "after" another one. You can trace it backward in
time to the source and forward in time to the other experimenter, and that is
the line of the constraint.

------
tus87
> Pascual Jordan, an important member of Bohr’s circle, cut the Gordian knot:
> An electron does not have a position until it is observed; the observation
> is what compels it to assume one. Quantum mechanics makes statistical
> predictions about where it is more or less likely to be observed.

The things physicists will say instead of "we don't know the answer".

------
jcoffland
All human models of reality are flawed. It is improbable that our small minds
will ever comprehend the nature of the universe in it's entirety. Each answer
uncovers more questions, more paradoxes.

That is not to say we should not continue to try to understand the world
around us. Only that logic dictates that we proceed with humility.

~~~
placebo
> _All human models of reality are flawed._

Definitely. I wholeheartedly subscribe to this view
([https://en.wikipedia.org/wiki/All_models_are_wrong](https://en.wikipedia.org/wiki/All_models_are_wrong)).
The thinking mind will always be confined to models. The way I see it, the
questions posed here are an expected wall one will eventually hit when the
mind attempts to explain something that is fundamentally inexplicable - i.e
the nature of existence.

My current intuition is that the hard philosophical questions posed by probing
deep into what matter essentially is are deeply linked to the hard problem of
consciousness.

I'll make an even bolder claim, which is that both of these questions arise
from a misunderstanding of what consciousness actually is and that no less
than a Copernican revolution in understanding its role is what's needed to put
them to rest.

Of course, that won't be the end of physics, as the mystery is endless - but
it might be the start of a deeper humility and appreciation of that mystery.

~~~
frolig
The rise in visibility of subjective science (science of
consciousness/spirituality) and integration of it with objective science will
accomplish that.

Luckily the subjective sciences are already highly developed, just look at
Kabbalah. You can read a thousand pages of it and you still won't understand a
single word!

------
danetch
I feel someone else may have said that, but simply said, what if the
phenomenon is a wave, and its observable effect a particle? Isn't it the fact
that the wave hits matter that makes it observable / measurable. Doesn't seem
incompatible, even with the monitors, with the double slits experiment

~~~
rohit2412
I think a lot of hidden variables theories have been discredited.

[https://physics.stackexchange.com/questions/374266/what-
are-...](https://physics.stackexchange.com/questions/374266/what-are-non-
local-hidden-variables)

------
ttlei
Correct me if I am wrong, the "paradoxes" described here are due to our lack
of understanding of the theory right and not because the theory is
inconsistent.

~~~
throwawaymath
In what circumstance does that _not_ describe a paradox?

~~~
lou1306
For instance, Russel's paradox arises from an inconsistent naive set theory.

~~~
throwawaymath
Ah, good example. I guess that's fair.

------
PaulHoule
They aren't paradoxes of quantum mechanics.

They are a paradox between how we intuitively expect the world to work and
reality. Our intuition is wrong.

~~~
mjfl
Yes there are. Even without invoking any philosophical issues, quantum
mechanics admits it's not self-contained. It takes measurement - the act of an
outsider interacting with a system, which collapses the wavefunction, as a
postulate. Measurement is not described by quantum mechanics.

~~~
btilly
No, there is not. The Everett aka many-worlds interpretation demonstrates that
you can explain the observed effects of measurement without invoking
"collapse" of the wave function, and without reference to anything outside of
QM.

~~~
gowld
Requiring the existence of something that is fundamentally impossible to
detect, is a poor resolution to the problem.

If there are many worlds, how is it decided which one we are in?

MWI is scientifically equivalent to collapse, it's just imagined as a
branching instead of a selection among alternatives.

~~~
firethief
MWI is what happens when you _don 't_ require the existence of anything extra
(collapse phenomenon). It's like how <the way sound emitters change pitch when
the observer is moving> isn't an unexplained phenomenon--it results from the
evolution of the observer's perspective. In MWI there is no event
corresponding to collapse for the same reason that Gallileo's model doesn't
have any correlate of epicycles.

~~~
TheOtherHobbes
In MWI the event corresponding to collapse is the supposed appearance of an
entire universe, which is - conveniently - impossible to detect. And which
"explains" any one timeline of experience as "Actually, that's still just
random."

So MWI goes from "That's random and we don't know why" to "That's random, we
don't know why, but now we've added a universe too, although we can't prove it
exists."

Something about this doesn't seem entirely convincing.

~~~
dghf
> In MWI the event corresponding to collapse is the supposed appearance of an
> entire universe, which is - conveniently - impossible to detect.

My layman's understanding was that MWI doesn't postulate multiple universes.
Rather, it posits that all particles are always in superpositions of states.
What looks like a collapse to a single state is actually the particles under
observation getting entangled with the particles that compose the observer:
so, in the case of the double-slit experiment, you have a combined particle-
observer system in a superposition of the states (particle goes through left
slit / observer sees left detector activated) and (particle goes through right
slit / observer sees right detector activated). Nothing has actually changed
other than that entanglement: nothing is created or appears, certainly not an
entire new universe.

ETA: like I say, I'm a layman, so I'd welcome any correction.

~~~
cygx
Your description looks right to me. Note that the many-worlds interpretation
was originally named the theory of the universal wave-function. You get there
by trying to eliminate wave-function collapse and Heisenberg cuts.

------
gxwmg
For the same reason psychologists have shrugged off the fact that most papers
cannot be replicated.

~~~
hjk05
Quantum mechanical experiments get replicated time and time again. There is
nothing even resembling the reproducibility crisis in quantum mechanics. The
issue discussed in the article is only about interpreting why the results
always come out exactly like we predict, not any issues with the results or
reporting of them.

------
combatentropy
It seems to me that the resolution of the quantum mysteries might come from
three sources: (1) the Holographic Principle, (2) Dark Matter, and (3) the
Planck Length.

1\. The Holographic Principle. The universe looks three dimensional but
fundamentally it is different. 3-D space is a projection from some 2-D circuit
board. If I believe that, then I have no problem hearing about (a) hidden
variables or (b) spooky action at a distance.

2\. Dark Matter. The universe is 98% unaccounted for. Could it be that space
is not a vacuum? Perhaps we are like fish in water, moving through it but
taking it for granted. How can "something" have travelled through "nothing" (a
vacuum) anyway? Maybe there's an aether after all.

3\. The Planck Length. Space is not an infinitely smooth line but instead
there is a fundamental bit size. We thought atoms were it, that's how they got
their name ("atom" means uncuttable). Later we found inside them protons and
neutrons, and within those, quarks. Someone therefore might imagine that we
could go on subdividing forever. But the Planck Length is a hard stop:
0.000000000000000000000000000000016 of a millimeter.

If we are immersed in invisible water, then it's unsurprising that there are
"waves." And yet if there is a fundamental smallest size, like the grains of
photographic film, then it's not all that weird to say that you can think of
matter as particles. Perhaps that's all that a "particle" is, a piece of the
water.

~~~
gus_massa
2) As far as I know, Dark Matter is totally unrelated to the quantum mysteries
(uncertainty principle, measurement problem, ...)

3) In elementary particles, the magnetic moment is twice the expected value of
a fake classical particle of the same mass and charge (for a complete accurate
explanation see
[https://en.wikipedia.org/wiki/G-factor_(physics)](https://en.wikipedia.org/wiki/G-factor_\(physics\))
) For elementary particles the number is 2. For non elementary particles, it
can be any number.

For electrons/muons/quarks the number is almost 2, and the difference is
caused because the elementary particle has a cloud of virtual particles
around. We can calculate this correction quite well. So there is a high chance
that electrons/muons/quarks are actually elementary particles.

Anyway, I don't understand how the subdivision of the current elementary
particles is related to the quantum mysteries. You get the same mysteries with
electrons (that are probably elementary) and with protons (that are
definitively not elementary).

~~~
l33tman
You're correct, particle physics or QFT is not needed to appreciate the
fundamental QM "mysteries", any non-trivial evolving measurable observable
will do.

