Is There a Method to the Madness of Theoretical Physics?

[Fascheue]

What exactly does a theoretical physicists do? Do they come up with hypotheses, and then do calculations to see how things would work if those hypotheses were true.

If that is correct, how exactly do you come up with a hypothesis? Is there a lot of creativity involved?

Also, when physicists speak about a theory being able to correctly make predictions about the world, do these predictions have to be of something we haven’t tested before? For example, the higgs particle was predicted and then we did experiments and found that it existed. Would it have been valid if the experiments were done first, and then the Higgs particle was theorized to explain what has already been observed?

 

[ZapperZ]

What exactly does a theoretical physicists do? Do they come up with hypotheses, and then do calculations to see how things would work if those hypotheses were true.

If that is correct, how exactly do you come up with a hypothesis? Is there a lot of creativity involved?

Also, when physicists speak about a theory being able to correctly make predictions about the world, do these predictions have to be of something we haven’t tested before? For example, the higgs particle was predicted and then we did experiments and found that it existed. Would it have been valid if the experiments were done first, and then the Higgs particle was theorized to explain what has already been observed?

You need to realize that there isn't just one way of doing things. You are forgetting that a lot of advances in theoretical physics were made AFTER an unexpected experimental discovery. No one predicted the existence of superconductivity in 1911. In fact, it is only in 1957 that a satisfactory theory of superconductivity was developed. And there is the infamous Rabi's exclaim of "Who Ordered That?" to denote experimental results that were never expected.

But at the same time, there have also been theoretical predictions made before any type of experimental observations. Positrons and neutrinos are clear examples. When theories came first, they make very specific predictions (energy range, decay channels, how many should be observed, etc.). So experimenters know where to look and what to look for, i.e. they don't just predict "what goes up must come down", they also predict "where and when it comes down". This is how and why we can verify or falsify a theory.

But theorists also work alongside experimenters, especially in framing experimental data. Data are meaningless without a way to interpret and analyze them, and this is where theory, and theorists, are of value. If you look at many large-scale experiments, there will always be theorists in the midst, because they are needed.

There are many ways and many different working scenario for theorists. In fact, the same can be said for experimentalists as well.

Zz.

 

[gianeshwar]

It all started with homosapien brain development.That is logic.With the development of mathematics somethings observed physically could be put into mathematics language format and it further could give more and varied possibilities and further experimentation was directed.In this way science develops (Not only Physics).Theoretical science and experimental science go hand in hand.
Ovservations of quantum science needed a framework of advanced algebra.Further advanced algebra xab give further experimental directions.

 

[Fascheue]

You need to realize that there isn't just one way of doing things. You are forgetting that a lot of advances in theoretical physics were made AFTER an unexpected experimental discovery. No one predicted the existence of superconductivity in 1911. In fact, it is only in 1957 that a satisfactory theory of superconductivity was developed. And there is the infamous Rabi's exclaim of "Who Ordered That?" to denote experimental results that were never expected.

But at the same time, there have also been theoretical predictions made before any type of experimental observations. Positrons and neutrinos are clear examples. When theories came first, they make very specific predictions (energy range, decay channels, how many should be observed, etc.). So experimenters know where to look and what to look for, i.e. they don't just predict "what goes up must come down", they also predict "where and when it comes down". This is how and why we can verify or falsify a theory.

But theorists also work alongside experimenters, especially in framing experimental data. Data are meaningless without a way to interpret and analyze them, and this is where theory, and theorists, are of value. If you look at many large-scale experiments, there will always be theorists in the midst, because they are needed.

There are many ways and many different working scenario for theorists. In fact, the same can be said for experimentalists as well.

Zz.

So a theoretical physicist could develop a theory that doesn’t have to be tested after its development to be prove true? Or in other words, in the superconductivity example you gave, did our knowledge of how superconductivty works come immediately after theoretical physicists did some calculations that worked out rather than after an experiment verified it?

 

[ZapperZ]

So a theoretical physicist could develop a theory that doesn’t have to be tested after its development to be prove true?

Where did I imply such a thing?

EVERY theory must be experimentally verified. There is no exception, despite what String Theorists think.

But this doesn't mean that one cannot develop a theory and have it published first. The scientific process can be long and arduous. The Standard Model made many predictions that didn't get verified till many years later.

Or in other words, in the superconductivity example you gave, did our knowledge of how superconductivty works come immediately after theoretical physicists did some calculations that worked out rather than after an experiment verified it?

I don't know what you mean here. Our knowledge of superconductivity (energy gap, Tc values, Meisner effects, etc.) were all known BEFORE the BCS theory was formulated. The BCS theory had to make quantitative predictions that match what we knew experimentally already by then.

But it doesn't end there. Often the new theory that explains a particular phenomenon makes even further predictions. We still see new experiments that test and verify far-flung consequences of classical E&M, which is a very old and established theory.

The path to discovery, advancement, and knowledge is never simple or clear or of one type only.

Zz.

 

[Fascheue]

Where did I imply such a thing?

EVERY theory must be experimentally verified. There is no exception, despite what String Theorists think.

But this doesn't mean that one cannot develop a theory and have it published first. The scientific process can be long and arduous. The Standard Model made many predictions that didn't get verified till many years later.
I don't know what you mean here. Our knowledge of superconductivity (energy gap, Tc values, Meisner effects, etc.) were all known BEFORE the BCS theory was formulated. The BCS theory had to make quantitative predictions that match what we knew experimentally already by then.

But it doesn't end there. Often the new theory that explains a particular phenomenon makes even further predictions. We still see new experiments that test and verify far-flung consequences of classical E&M, which is a very old and established theory.

The path to discovery, advancement, and knowledge is never simple or clear or of one type only.

Zz.

I don’t mean that a theory might be accepted without experimental verification, but whether or not the experimental verification can come from things we knew before the development of the theory. To go back to the Higgs example, the fact that we found the Higgs was used as experimental verification for the theory. But if we discovered the Higgs, and then developed the theory to explain it, would the fact that the theory and reality agree that you can get a Higgs particle from smashing together high energy particles still count as experimental verification?

 

[ZapperZ]

I don’t mean that a theory might be accepted without experimental verification, but whether or not the experimental verification can come from things we knew before the development of the theory. To go back to the Higgs example, the fact that we found the Higgs was used as experimental verification for the theory. But if we discovered the Higgs, and then developed the theory to explain it, would the fact that the theory and reality agree that you can get a Higgs particle from smashing together high energy particles still count as experimental verification?

No. The BCS theory was not an "experimental verification". Rather, it was a "theoretical explanation". Experimental verification means that an idea has been proposed, and THEN experiments are done to see if the predictions of that idea matches what is measured.

Now, that theoretical explanation, as I've said, may make further predictions beyond just the phenomenon that it was describing in the first place. This is true when the theory continues to be developed and expanded further. Often, they make more predictions than what was expected. Now, if experiments later come around to verify those new prediction, then sure, one can also claim that these are experimental verification of the new parts of the theory, or the untested parts of the theory.

Zz.

 

[Fascheue]

No. The BCS theory was not an "experimental verification". Rather, it was a "theoretical explanation". Experimental verification means that an idea has been proposed, and THEN experiments are done to see if the predictions of that idea matches what is measured.

Now, that theoretical explanation, as I've said, may make further predictions beyond just the phenomenon that it was describing in the first place. This is true when the theory continues to be developed and expanded further. Often, they make more predictions than what was expected. Now, if experiments later come around to verify those new prediction, then sure, one can also claim that these are experimental verification of the new parts of the theory, or the untested parts of the theory.

Zz.

In the case of superconductivty where did the experimental verification come from? Was it from the findings before the bsc theory or was there some sort of experiments that were required to verify the theory after the fact?

 

[ZapperZ]

In the case of superconductivty where did the experimental verification come from? Was it from the findings before the bsc theory or was there some sort of experiments that were required to verify the theory after the fact?

Superconductivity is one of those "Who Ordered That?" event. It was never predicted, and its discovery in 1911 was completely unexpected.

BCS theory came in 1957, more than 40 years later. So this is not the case of "experimental verification". However, BCS theory has many consequences, and it also has been extended and developed since the 1957 paper. So certain, various parts of it continue to be "verified". It is also being tested against the high-Tc superconductors discovered in 1986 (which was also not expected and was not due to any theoretical prediction).

Zz.