Oddbean

As a former theoretical physics grad, I want the nostrverse to know that dark energy and dark matter are not "bullshit" or "fiat science". The whole point of real science is to find the model that best accounts experimental measurements and better predicts future ones. Such model is not required to have a "satisfying" semantic/philosophical human "explanation". This is not a Netflix movie or some shit. Science is about the how, religion is about the why. Dark matter and dark energy really accurately explain the redshift from observerd galaxies better than anything else. Like it or not, it's the best we have until something else comes along. Many "made up" things eventually got so normalized no one thinks they are bullshit anymore: atoms (like everything is legos, seriously?!), neutrons, neutrinos, etc. /rant over

I agree dark matter and energy are not bullshit, but science does deal in why. Even the dark matter theory contains a why component. Why does the redshift happen? Because there's matter there, even if we can't see it.

We often use the word "why" when we really mean "how". Such is the case in the questions you phrased. A model can have a metaphysical "why" component, but that is not mandatory. In fact, the most intellectually satisfactory models are most often disproved or unfalsifiable.

Yeah, the line between how and why does get awful blurry. Sometimes we keep using theories even if we know they're wrong/incomplete. We keep using quantum and relativity, even though they don't unify nicely. We await a better theory. Other times we keep using falsified theories in particular situations, i.e. video game physics engines using Newtonian gravity.

You make some observations that existing theory can't explain So you invent a new concept to explain these observations This is a hypothesis Now you have to go do actual science and test your hypothesis You have to understand this thing you've postulated and explain it "Dark matter" as a stand-in for unobserved matter that is hypothesized to affect gravity is totally fine and scientific But it's not a theory or law of science or any such thing And treating it as a real, known entity on par with regular matter is in fact deeply unscientific

Our knowledge of atoms started as spherical marbles. You're nitpicking over the fact if something is an hypothesis, a model, a theory ot a law. I'm not that interested in those sorts of semantic discussions since they are fairly subjective and contextual. Physics most of the time moved forward by people "making stuff up" to fill unexplained observations. I can take your argument and extend it to neutrinos shortly after they were discovered. By your logic, equating them to "real" matter does not make sense.

The neutrino particle was never hypothetical. It was made up to explain an observation. Half a century later that hasn't changed. The Higgs Boson was hypotetical. When proposed, it did not explain any measurement at the time.

"The neutrino particle was never hypothetical. It was made up to explain an observation." From wiki: "A hypothesis (pl.: hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it." Something made up to explain observations is literally the definition of a hypothesis.

You're correct. When I said "hypothetical", I really meant "speculative" or "conjectural". That definition of hypothetical is a bit broad, but ok, I'll take it. With that definition, every scientific model is hypothetical since it is proposed and requires continuous testing and validation. Nothing remains proven forever. Back to the original example: dark energy is a "hypothetical" scientific model, not conjectural. We are not waiting or looking to observe it, we already did measure it. It's a simplist shallow model, but the best one so far.

How independent is galaxy redshift from whatever phenomena produced the dark energy theory in the first place? Based on the wiki for Dark Energy, DE was theorized to explain supernova redshift In which case I am very skeptical that further redshift observations confirm anything positive about the nature of DE as an explanatory factor

DE is an integral part of the Standard Cosmology Model as a whole, without it it would fall apart. The LCDM together with the Friedman equations, explain most expansion measurements fairly well. https://en.m.wikipedia.org/wiki/Lambda-CDM_model

The hypothesis is tested, ideally many times by many people In each case, the test produces results consistent with the hypothesis These tests form a body of evidence that serves to disprove competing hypotheses and (until some sort of contradictory evidence is found) makes the theory well-established So you observe something, then you form a hypothesis to explain the observation, but that's not enough to be scientific. You have to actually test the hypothesis and try to explain what's happening. Merely positing a hypothesis is not good enough. A hypothesis which serves to "explain" without producing understanding is also not good enough. In creationism / intelligent design debates there's a notion of "god of the gaps" where god is invoked to fill in a gap in knowledge, which doesn't really explain anything so much as give a label to our ignorance. The same thing happens in physics where some particle or phenomenon is posited to "explain" observations that are inconvenient / inconsistent with existing theory. Unless those hypothetical particles / phenomena can be tested and their mechanisms understood, they are just other ways of naming our ignorance.

I like your argument here but the "something that produces understanding" part is fairly subjective and fragile. Ofc I know what you mean there and don't mean to gaslight but it's still not a solid definition.

I suspect we will mostly agree when we drill down on terminology, but to make a point: "The whole point of real science is to find the model that best accounts experimental measurements and better predicts future ones." I can create a model that predicts that every time a magician reaches into his hat, he pulls out a rabbit. The model can be insanely accurate, matching past data and predicting future rabbit pulls, still just having a model like that is an intellectual dead end. A model is nice and all, but what we really need is an explanation of how the hell the magician is doing it. We need an explanation for what is going on "in reality". Once we start conjecturing explanations for that, and critiquing them, that will lead us to more problems and questions, which will further expand our knowledge.

I agree, a model can have more or less depth. But if all we have is a shallow model, then that's all we have. It's not bullshit or unscientific, that was my point. The alternative is to subjectively gatekeep which models are intellectually satisfying enough to be worthy.

Great discussions in the comments. I really love the pushback, that's really what I'm here for. I wish we can have more of these. nostr:nevent1qqsf4gm7z8yjsvxw3yu3ku0ugw47pjgkmgtfdp554tj6ckqfg066ekqp2emhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtmwwp6kyvfkwgc8gmpcvyenj6rgvdexzurpxqen2dfe0psksum2w94rgues0ym8gvnwx4nhqertxc68vvpkdf6xwettw9jxk734wpkqygxsm6lelvfda7qlg0tud9pfhduysy4vrexj65azqtdk4tr75j6xdspsgqqqqqqscx6xt2

I think it's best to stick with Popper's definition of a good scientific theory: it needs to make falsifiable predictions and have them not falsified by future experimental data. General Relativity, e.g., passed this with flying colours (perihelion of Mercury, atomic clocks on airplanes etc). From what I've heard, string theory, e.g., doesn't. An interesting example of where it gets tricky is the neutrino. Iirc it was postulated to explain an energy deficit in a nuclear reaction. But then people were able to use it to predict other experimental results. Is dark matter like that? Cosmology is really tough from this point of view.

You seem to be suggesting the need for at least 2 different phenomenona to be explained by a model. You cannot falsify DE since DE it's not a model by iteself, but an integral part if one. You can falsify the whole model though. The most likely scenario is not that DE is disproven but that what we know about it improves. Just like the neutrino was initially just a momentum deficit.