Quantum physics is NOT fine

An interesting article from the ever-provocative Ethan Siegel on the nature of reality and all that.

On the one hand, I believe very firmly in the value of interpretation and being able to describe things without using equations. I tend towards the old saying that if we can't explain it except with maths, you haven't really understood it. On the other hand, I'm equally firmly convinced that there's absolutely no reason the Universe should make sense to me; what right does a short blonde Welshman have to tell the rest of the Universe what to do ? As Terry Pratchett wrote in Soul Music :

“You could say to the universe, this is not fair. And the universe would say: Oh, isn´t it? Sorry.”

But this doesn't for one second stop me from desperately wanting an intuitive-ish view of the Universe I can understand. I suppose I think that quantum physics really points to some horrible problem we've yet to resolve, I hope it won't turn out that we've already scraped the bottom of the barrel and have reached the parts of reality we're never going to be able to understand. That'd suck.

So I hope when Ethan says :

For more than a century, however, nature has shown us that the rules governing it aren't local, real, and deterministic after all... Despite what we might have intuited beforehand, the Universe showed us that the rules it obeys are bizarre, but consistent. The rules are just profoundly and fundamentally different from anything we'd ever seen before.

... that this really reflects our theories having reached an impasse. Now, other people will tell you that dark matter represents such an impasse - a failure of the models that needs to be explained. I say it's probably just a fact of life and we can no more explain it away than we can explain away rocks or electrical charge or Piers Morgan. But for quantum weirdness... that's where I draw the line. That I think is something we should try and reconcile with intuition, if we can. It's possible we might not be able to, but I'm unwilling to give up just yet. A century of investigation is too short to decide if God plays dice.

Reality, if you want to call it that, isn't some objective existence that goes beyond what's measurable or observable. In physics, as I've written before, describing what is observable and measurable in the most complete and accurate way possible is our loftiest aspiration. By devising a theory where quantum operators act on quantum wavefunctions, we gained the ability to accurately compute the probability distribution of whatever outcomes might possibly occur.

Cue link to long post where I try to get at the fundamental assumptions of science, namely that the world is objective, measurable, real, causal, and finite. A world without such constraints cannot be analysed scientifically. Perhaps some replacement for science could be constructed, but we aren't there yet.

In science, this is what we call an assumption, a postulate or an assertion. It sounds compelling, but it might not be true. The search for "a complete description" in this fashion assumes that nature can be described in an observer-independent or interaction-independent fashion, and this may not be the case. While Sean Carroll just argued in Sunday's New York Times that physicists should care more about (and spend more time and energy studying) these quantum foundations, most physicists — myself included — don't agree.

I am more than happy to say, "yes, these are unprovable but potentially falsifiable assumptions". I just think that if you're going to throw out the most fundamental assumptions of science, if you're going to say that observation directly affects reality or that some physical properties are fundamentally unmeasurable or not even real, you'd better have a damn good reason for it. "Shut up and calculate" is not good enough. Calculation is not the same as explanation, and explanation is the whole point. Modern science is and should be philosophical, not a latter-day Babylonian calculation of eclipses without knowledge of the Moon passing in front of the Sun. How empty and cold would a "science" of pure calculation be ! How pointless would be pure knowledge without understanding ! Knowledge without meaning is hardly knowledge at all.

So to this :

Understanding the Universe isn't about revealing a true reality, divorced from observers, measurements, and interactions. The Universe could exist in such a fashion where that's a valid approach, but it could equally be the case that reality is inextricably interwoven with the act of measurement, observation, and interaction at a fundamental level.

I cannot but disagree. If the tree falling a forest doesn't make a sound with no-one to hear it, then I fall back on intuition and say to the Universe, without fear of what the Universe will say back, "now you're just being silly". It is wholly daft to suppose that reality depends on us - this notion, I say, is not science at all. And if reality is indeed like that, then it's not something that holds much interest for me. What would be the point of knowing the result of a calculation without understanding what's actually going on ? None that I can see. No, for me, understanding the Universe is inherently and unavoidably exactly about revealing a true reality.

There is a strange and wonderful reality out there, but until we devise an experiment that teaches us more than we presently know, it's better to embrace reality as we can measure it than to impose an additional structure driven by our own biases. Until we do that, we're superficially philosophizing about a matter where scientific intervention is required. Until we devise that key experiment, we'll all remain in the dark.

A very fair point. As in the last post about quantum madness, and interpretation should not only offer understanding but guidance on how to proceed. Though, as with dark matter and other oddities in cosmology where observation runs ahead of theory, I think this need for more observation doesn't mean we should stop theorising but the exact opposite. Maybe it will never be possible to reconcile the quantum world with the everyday one... good for me I study galaxies, which never have to experience the godforsaken double slit experiment.

Quantum Physics Is Fine, Human Bias About Reality Is The Real Problem

When it comes to understanding the Universe, scientists have traditionally taken two approaches in tandem with one another. On the one hand, we perform experiments and make measurements and observations of what the results are; we obtain a suite of data.