6 ms·
QM is the new Ptolematic system: it makes good predictions, but because it puts Earth in the center, the orbits become needlessly complex and artificial.
by frongpik 6y ago
QM is the new Ptolematic system: it makes good predictions, but because it puts Earth in the center, the orbits become needlessly complex and artificial.
- vecter 6y agoExplain how QM metaphorically “puts Earth in the center”.
- shadowgovt 6y agoThat's the thing we don't know yet. It's probably a good bet that we are going to discover that to rectify the complexities of QM, there is some assertion most people have fundamentally accepted and is quite uncomfortable to let go but is necessary to simplify the equations. I can't really guess what it's going to be though.
- frongpik 6y agoPlato and a few others told about the world of ideas and the world of matter: both exist and are connected somehow. I wonder if QM is this bridge between the two worlds and the wrong assumption we make is that QM describes the world of matter. In other words, the probability waves may actually exist, but they exist in the world of math, and the real question is how exactly the two worlds are connected.
- vecter 6y agoThat's not good enough. I want a specific claim about how one or more of the postulates of QM are likely to be incorrect (or even stranger, how they have to do with "putting Earth at the center", whatever that means, or some anthropomorphism baked into the postulate). Saying "we don't know what we don't know" is both a tautology and completely useless. It's like my saying: "I believe that you committed a crime last week." You ask for more details about why I think that and what the crime was, and I reply "we just don't know." I hope you see how ludicrous that is.
- shadowgovt 6y agoIt's been awhile since I thought deeply about epicycles, but if my memory can be trusted... They weren't incorrect. They did a decent job of predicting the motions of the planets given the assumption that Earth was pegged at the center of the coordinate frame (which then required a whole bunch of "hidden behavior" in terms of non-apparent phenomena dictating the rotation of all other bodies). Re-framing the whole system to be heliocentric allowed for the massive simplification of Kepler's Laws (and, not too much later, the further simplification of describing Kepler's laws via Newton's law of gravitational attraction). We currently have an understanding of QM that doesn't reconcile well with macroscopic observation and requires a lot of intuitions to be broken (including, possibly, the singular nature of existence, time-forward causality, or lightspeed-constrained information locality). I can't help but wonder if there's some equivalent to "Assuming Earth is the center of the coordinate frame" that we currently do that forces these unintuitive (though working) solutions. The solar system moved in epicycles because "it just did," until several leaps of intuition allowed us to see how it didn't. I wonder if there are similar leaps of intuition waiting on the horizon to allow us to explain quantum entanglement without nonlocal information sharing (hidden variables, we have shown, is not it).
- vecter 6y ago> We currently have an understanding of QM that doesn't reconcile well with macroscopic observation and requires a lot of intuitions to be broken Why should physics care about human "intuition" at the macroscopic level? That's an incredibly anthropic point of view to take on a cosmos that couldn't care less if we didn't exist.
- shadowgovt 6y agoWhen Newton developed the theory of gravity it wasn't intuitive that all matter in the universe attracts all other matter. But also wasn't incompatible with our intuitions---it was learnable. What I see in QM right now "smells" like we're having to compromise too many intuitions to reconcile what the experiments are showing us with the way we expect the universe ought to be working. I agree that the universe is under no obligation to work the way we expect it to---problem, what we have right now in QM is a lack of agreement on how to even rework our intuitions to match our observations and the reality the theory describes. That suggests to me that---much like epicycles, or like gravity being separated from acceleration before relativity---the stories we are telling ourselves about what we see are still too complicated, and a simpler explanation that requires us to sacrifice fewer pieces of intuition has not yet been reached. This is, to be clear, extrapolation. I have no way to know whether such simplification exists or whether we have hit the boundary where nature actually refuses to conform in such a way to our senses and minds that we can change our intuitions to follow her. It's not impossible that this is the case. But if it is, it's a break from the pattern of physics discovery up to this point in human history.
- sls 6y agoHave you ever actually looked at the Schrödinger equation? [1] It's pretty simple. If you've had freshman physics, you can learn enough to derive it in a matter of days or at most weeks. There's not a lot of room in there for the kind of thing you are suggesting. It's much more plausible that the uncomfortable human-centric thing we need to let go is the idea that our perceptions about macroscopic reality should be indicative of how things actually are. [1] https://en.wikipedia.org/wiki/Schrodinger_equation https://en.wikipedia.org/wiki/Schrodinger_equation
- miltondts 6y agoCircles are also simpler than ellipses. Maybe that's a clue. Maybe we need a more complicated equation that makes the phenomena more understandable. EDIT: To stretch the metaphor a bit more. Maybe QFT is the analogous of the solar system described with epicycles.
- shadowgovt 6y agoThat would, indeed, be an uncomfortable thing to let go of, since they are our direct perceptions. Relativity tells us things get weird at high velocities, but our daily perception is basically correct. Quantum theory seems to suggest that solid, tangible reality isn't at all like our day-to-day experience. That's a pretty decent leap to ask of people.
- analog31 6y agoIndeed, early progress with QM in the first place required letting go of some expectations that were based on macroscopic phenomena. There was a certain effort to clarify those expectations so they could be gotten rid of. This is, at least, what I remember being taught about it. So, maybe it's time for another round. ;-)
- nine_k 6y agoThe system of epicycles was made of pretty simple, easy things: circles. It's when they were combined things went complicated. Same with Schrödinger equation: it's very simple for one particle in an empty Universe, but things go more complicated when more particles are considered. There is no guarantee that a different approach can replace QM and describe things in a simpler way. But I suspect that attempts to look for such approaches are not useless.
- Enginerrrd 6y agoIMO, that assumption is the idea that decoherence occurs at all. I really think Sean Carroll's ideas involving MWI and emergent spacetime from hilbert space provides a great deal of clarity.
- guerrilla 6y agoIt seems that way to me too but it (i.e. the notion that QM is needlessly complex and akin to the Ptolematic system) is nothing but conjecture without some candidates for assumptions that might need to be challenged. [edited for clarity]
- vecter 6y agoIt's quite the opposite. QM was discovered while we were trying to resolve certain problems such as the ultraviolet catastrophe. [0] To say it is "nothing but conjecture" is incredibly condescendingly dismissive and ignorant of the history of its evolution. [0] https://en.wikipedia.org/wiki/Ultraviolet_catastrophe https://en.wikipedia.org/wiki/Ultraviolet_catastrophe