Why are some theories in physics falsifiable?

[trees and plants]

Hello. Do you know why some theories in physics are falsifiable?If we take for example Newtonian gravity and general relativity, we see that a more exact approximation or theory in physics can be proposed. Why does this happen?

More phenomena can be described from the new approximation, but why does this happen? Thank you.

 

[Dale]

All scientific theories are falsifiable. Falsifiable just means that it makes definite predictions for the outcome of an experiment so that results that differ from the prediction would contradict the theory.

If something is not falsifiable then it cannot be investigated using the scientific method and therefore is not scientific.

 

[sophiecentaur]

Do you know why some theories in physics are falsifiable?

Remember, falsifiable doesn't mean 'wrong'. It means that it actually capable of being tested and confirmed or disproved. Many hypotheses cannot actually tested and either proved or disproved.
And many people think that their (sometimes loony) hypotheses are actually theories. Our language really doesn't help in that context but that last statement is falsifiable. Just look up and down the lists of forum topics.

 

[Haborix]

Another side to the OP's question might be why we had to do Newton before we did GR (and other questions in that vein). I don't think there are any simple answers. To produce a theory of some phenomena that phenomena needs to be observable. Alternatively, the mathematical tools to formulate the theory may not exist yet. Lastly, from a utilitarian perspective, having the more sophisticated theory may not be efficient for the problem at hand. Why use GR when Newton will do?

To me, the real miracle is that our theories in particular domains can be shown to be coherent with each other. There are limits to be taken that the show the reduction of one theory to another.

The Unreasonable Effectiveness of Mathematics in the Natural Sciences by Wigner is a good re-/read.

 

[Fra]

As the mathemtical tools and theories evolve together, one could informally classify theories like you do with life forms, as beeing based on different or similar foundations etc. Usually revised theories are mutations (small or big) of previous theories say withing a similar familiy, that is en efficient way of progress. But sometimes revolutions occur and a whole family of spieces could die as its fundamentally unfit, that requires rewinding further back the hierarchy, and stalls progress.

Right now many physics theories have a lot in common, and perhaps some families are overbreeded, but maybe the TOE simply isn't the "mammal" we expect? This is also why some potential theories in other classes seem immature compared (and dismissed) to the evolved ones. So diversity is also a matter of effiency, overbreeding certain families is also a risk.

/Fredrik

 

[TruePath]

So no, actually pretty much no theories in the sciences are truly falsifiable in the overly simplistic sense often assumed (tho Popper wasn't an idiot and he recognized these complexities to a degree). I mean just think back to the supposed observation of superluminal neutrinos a few years ago. Did we throw out special relativity? No, rather we instead threw out our auxiliary assumption that the experiment was correctly measuring neutrino speed. One can do this in response to *any* measurement, merely with increasing degrees of implausibility (no no you aren't really measuring GPS signals from a satellite…government operatives have hacked your system and are faking it).You might think this is quibbling but, imo, it's actually pretty crucial. Science doesn't have a special status of being directly falsifiable. Rather, no different than other parts of our web of belief like the claim god exists it's merely that experiments put pressure on us to adjust some part of our web of belief and as we get more and more data it becomes harder and harder to retain a false thesis without being forced to accept increasingly absurd excuses. But if science isn't falsifiable (in this sense) it suggests that there isn't a difference in kind between claims about, say, the existence of god and a theory of gravity (just in degree of evidence).

 

[phinds]

So no, actually pretty much no theories in the sciences are truly falsifiable in the overly simplistic sense often assumed

Nonsense.

I mean just think back to the supposed observation of superluminal neutrinos a few years ago. Did we throw out special relativity? No, rather we instead threw out our auxiliary assumption that the experiment was correctly measuring neutrino speed.

Yes, that was done, provisionally, but that's because TONS of experiments had already verified special relativity and Occam's Razor said it was MUCH more likely that the experiment had a flaw somewhere.

One can do this in response to *any* measurement, merely with increasing degrees of implausibility (no no you aren't really measuring GPS signals from a satellite…government operatives have hacked your system and are faking it).

Yes, one CAN, but so what. One can spout any nonsense one cares to but that has no bearing on actual science.

You might think this is quibbling

I don't, I think it's just flat wrong.

Science doesn't have a special status of being directly falsifiable. Rather, no different than other parts of our web of belief like the claim god exists

Again, nonsense.

 

[Dale]

So no, actually pretty much no theories in the sciences are truly falsifiable in the overly simplistic sense often assumed

That no theories are “truly falsifiable in the overly simplistic sense” in no way implies that scientific theories are not “falsifiable”. All of your additional words basically strip the term of its meaning.

Of course, falsifiability itself is better understood and implemented as a natural feature of Bayesian inference. I even use the specific example of the FTL neutrino measurement in the discussion.

https://www.physicsforums.com/insights/how-bayesian-inference-works-in-the-context-of-science/

Science doesn't have a special status of being directly falsifiable. Rather, no different than other parts of our web of belief like the claim god exists it's merely that experiments put pressure on us to adjust some part of our web of belief and as we get more and more data it becomes harder and harder to retain a false thesis without being forced to accept increasingly absurd excuses.

What you describe here is basically a non-rigorous version of Bayesian updating. I encourage you to read the Insights article.

Scientific theories are indeed falsifiable in the Bayesian sense. This is a sense that many other aspects of our “web of beliefs” are not. So scientific falsifiability is not an empty claim. Bayesian updating does apply to some non scientific beliefs, but not all.

 

[Nugatory]

just think back to the supposed observation of superluminal neutrinos a few years ago. Did we throw out special relativity? No, rather we instead threw out our auxiliary assumption that the experiment was correctly measuring neutrino speed

That is something of a misrepresentation of the process. Yes, we did immediately treat measurement error as by far the most likely hypothesis, based on Bayesian thinking that @Dale describes in #8 above.

But that’s not what settled the question. What settled the question was confirmation that there was a measurement error and the discovery and successful correction of the problem causing that error.

 

[martinbn]

The way I understand the first quesition is that the OP asks about completeness rather thatn falsification. For each theory there are fenomena that cannot be explained by the theory and a better one is needed, so the question is why?

 

[znepj]

Nonsense.
Yes, that was done, provisionally, but that's because TONS of experiments had already verified special relativity and Occam's Razor said it was MUCH more likely that the experiment had a flaw somewhere.

Yes, one CAN, but so what. One can spout any nonsense one cares to but that has no bearing on actual science.

I don't, I think it's just flat wrong.
Again, nonsense.

Not just wrong, but Pauli wrong.

 

[Fra]

The way I understand the first quesition is that the OP asks about completeness rather thatn falsification. For each theory there are fenomena that cannot be explained by the theory and a better one is needed, so the question is why?

In the evolutionary picture I suggested, theories can be thought of as "compressed" form of information/experience about our world and causal order, abduced from experienced interactions - encoded in its "host" (human science in this case). The theory defines our "expectations of the future", and thus influences are actions. So a good theory makes us more fit to survive. Technological development of human society for example.

In such a perspective, as theories lives one and evolves (keeps getting corroborated and improved), it will also naturally increase our capacity/ability to further refine and formulate more "complex" questions, creating the place for new theories.

So one should not generally think of falsified or revised theories as beeing "failures", they may still have played important roles, as evolutionary links and by definition constitutes the best expectations, they may have been necessary to reach the better theory. This is as long as diversity is taken innto account when investing the resources among hypothesis.

In this sense, our "best information" about the world (including its "state" as per some dynamical laws), and our "best theories" really stand on the same footing, except the latter form is a more compressed core of understanding, and the former represents the current contact surface to actions.

/Fredrik

 

[gmax137]

For each theory there are fenomena that cannot be explained by the theory and a better one is needed, so the question is why?

Because each theory is a model that makes predictions about what will happen next in the real world; key word being "model." A model is not the reality.