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"But from a scientific perspective, if you want to make progress in our understanding of natural law, I’d say it’s a waste of time exactly for that reason, beca
by beloch 4y ago
"But from a scientific perspective, if you want to make progress in our understanding of natural law, I’d say it’s a waste of time exactly for that reason, because you can’t test it."
Science is doing what works, and you can't tell what works if you rely on theories that aren't testable. (What does it even mean for an untestable theory to work?)
But...
What if some theories that aren't testable eventually lead to theories that are testable and useful? How do we know when to abandon a chain of inquiry? What about theories that are technically possible to test, but currently impractical? Do we stop developing them until the technology to test them exists, or might further work reveal easier tests?
For a long time, physicists were fairly ruthless about abandoning work that didn't quickly lead to something that could be tested experimentally, but not always (e.g. Bohmian mechanics was pursued quite ardently even though it's predictions do not differ from standard quantum mechanics.) In the last few decades, as we've increasingly searched for things like grand unifying theories that might bridge the chasms between fields, we've begun to tolerate an increasing amount of work that is not founded in anything testable. The key developments that will tie a field back into reality often seem just around the corner but never appear.
It boils down to a question of how we allocate resources. Work done on untestable theories that never become testable is wasted, so where do we draw the line?
- adastra22 4y ago> What if some theories that aren't testable eventually lead to theories that are testable and useful? The history of physics is such that this almost never happened. In fact I'm struggling to think of an example in which it did, though I'm sure there are some examples somewhere. The few things I can think of are stuff like antimatter, which popped out of the theory and weren't taken seriously until they were unexpectedly confirmed by experiment. On the other hand as you mention the history of physics is littered with theories and frameworks pushing beyond the experimental frontier, only to be discarded. String theory being only the most recent example.
- nl 4y agoShe points to both the big bang and the idea of a multiverse as things that cannot be tested.
- adastra22 4y agoWhich is factually correct, no? We cannot see beyond the cosmic microwave background, which post-dates the Big Bang by a significant amount. Barring the development of astronomical scale gravity wave detectors, we probably can’t probe further than the CMB, not directly at least. Things like the ratio of hydrogen to helium allow us to constrain our model of the Big Bang and early inflation, but that is parameter matching on the assumption of a big bang, not evidence for it. That’s a fine but important point. The Big Bang is still the simplest cosmological origin story we have that fits the evidence, and I don’t think Sabine is denying it. Nor does she deny multiverse theories which have even less of a leg to stand on. The case of multiverse theory is even worse as there are no testable predictions which come from them.
- fidgewidge 4y agoIssue is that the "we" in your final sentence is really governments and their science agencies. At some point there's a tradeoff between funding particle accelerators or stuff like defense, social care, medical subsidies, welfare, research in other areas. So only politicians can make this tradeoff. But we have a world where politicians aren't allowed to criticize scientists even if they're doing as Hossfelder calls it "ascientific" or even totally unscientific stuff. So the money will just continue flowing towards theoretical castles in the sky.