One who knows enough to think he is right, but not enought to.... ;)

[KosKallah]

How did you find PF?: Google search results... lots of them throughout my endless searches on subjects related to physics. :)

I love physics, even though I have no formal academic study on the subject. While wandering the Internet trying to get as much information as possible, I ended up more than once in PF.

Now I finally decided to join.

More specifically, I am an economist with MSC in electric engineering and working as a developer/data scientist... in other words: your run-of-the-mill crackpot. :D

My love for physics started when I was 11 and my dad came up with a scientific dissemination magazine, at which moment I instantly fell in love (I can still see the half-smile in his face!). Despite that (and because we are too young when we choose our academic study) I decided I would get rich in the financial market (which I wouldn't) and so I had to devote myself to economics (yes, I was wrong, but I enjoyed the course).

Today, I read everything I can about physics, not focusing much on the math of things (which displeases many people, unfortunately), but on the interpretation of the concepts behind the math.

So, I would like to stimulate conversations here about those concepts, both because I want to learn from it and because I would like to see people thinking beyond "spacetime is a manifold". :)

Cheers!

 

[PeroK]

"Spacetime is a manifold" is just the beginning. All the relevant thinking comes after that.

 

[hutchphd]

How did you find PF?: Google search results... lots of them throughout my endless searches on subjects related to physics. :)

Today, I read everything I can about physics, not focusing much on the math of things

Welcome.
I fear you are likely to find some blowback here (as you have already imagined) and I thought I would elucidate preemptively. To not focus much on the math for physics is to study music by having it described in the closed captioning on the DVD. Or art viewed on a black and white TV. You will get a flavor but not really an understanding. So keep that in mind, but I hope it is useful.

 

[KosKallah]

Welcome.
I fear you are likely to find some blowback here (as you have already imagined) and I thought I would elucidate preemptively. To not focus much on the math for physics is to study music by having it described in the closed captioning on the DVD. Or art viewed on a black and white TV. You will get a flavor but not really an understanding. So keep that in mind, but I hope it is useful.

True!

Despite that, there is a lot of a "shut up and calculate" mentality and that also makes us lose track of the understanding itself.

Following on your metaphor, *only* expressing physics in mathematical terms is like trying to understand Picasso just by the shapes and colors in his pictures, without looking at the cultural context of his work.

 

[PeroK]

True!

Despite that, there is a lot of a "shut up and calculate" mentality and that also makes us lose track of the understanding itself.

Following on your metaphor, *only* expressing physics in mathematical terms is like trying to understand Picasso just by the shapes and colors in his pictures, without looking at the cultural context of his work.

This recent thread is a example of the problem. It's about the deflection of light due to the Sun's gravity.

https://www.physicsforums.com/threa...he-Newtonian-prediction.1003623/#post-6498123

Without the appropriate calculation there is very little to decide between one idea and another. The calculation isn't everything, but it is (from undergraduate physics onwards) an essential element.

 

[KosKallah]

Sure! I am not saying we should abandon all the mathematization we build around physics, as that would reduce us to the place of the old naturalist philosophers (with nothing but concepts and logic in their arsenal and very little to test outside their everyday experience).

Regardless, it is very relevant to look for the concepts or objective entities that lie below the math and about which calculations are made. We lose a lot, too, when thinking *exclusively* in mathematical terms.

In other words: I know we can model spacetime as a manifold and I will always keep that in mind... but what *is* spacetime itself? What, effectively, *has* the properties described by our models? There is insight to be taken from this approach.

 

[PeroK]

In other words: I know we can model spacetime as a manifold and I will always keep that in mind... but what *is* spacetime itself? What, effectively, *has* the properties described by our models? There is insight to be taken from this approach.

Technically that's metaphysics, which is more philosophy than physics.

 

[KosKallah]

Technically that's metaphysics, which is more philosophy than physics.

Well, metaphysics is a little broader than that, encompassing moral physics and existence itself, as an example.

I am talking in physical, not metaphysical terms.

Ex: We know that a photon is an oscillation between a magnetic and an electric field. That is a conceptual definition of a photon. If we only had Maxwell equations and no knowledge of what they were talking about, we would not be able to get so much insight on the nature of this phenomenon.

Putting in perspective: we know that spacetime can be stretched and shrunk and we have equations to describe such distortions... but *what* is being distorted? That discussion can bring insight.

 

[PeroK]

Ex: We know that a photon is an oscillation between a magnetic and an electric field. That is a conceptual definition of an electron. If we only had Maxwell equations and no knowledge of what they were talking about, we would not be able to get so much insight on the nature of this phenomenon.

There is no concept of a photon in classical electromagentism. That light was modeled as oscillating electric and magnetic fields was one reason there was so much reluctance to accept Einstein's "light quanta".

The photon is a concept from quantum electrodynamics - and heuristicaly as a massless particle in SR.

 

[PeroK]

Putting in perspective: we know that spacetime can be stretched and shrunk and we have equations to describe such distortions... but *what* is being distorted? That discussion can bring insight.

Thinking in terms of something being distorted is a mental block, not an insight. There is, however, spacetime geometry: the geometrical view of spacetime is the insight.

 

[Vanadium 50]

Despite that, there is a lot of a "shut up and calculate" mentality and that also makes us lose track of the understanding itself.

This sounds a lot like "I haven't studied physics myself, but I am sure those of you who have are doing it all wrong." Are you sure that's the position you want to advance?

 

[KosKallah]

This sounds a lot like "I haven't studied physics myself, but I am sure those of you who have are doing it all wrong." Are you sure that's the position you want to advance?

No, this is not my position. Don't worry. :)
This is a position held by many in the physics community and has even earned a quote attributed to Richard Feynman.

https://physicstoday.scitation.org/doi/10.1063/1.1768652
https://core.ac.uk/download/pdf/81622757.pdf
https://www.physicsforums.com/threads/shut-up-and-calculate.417509/
(...)

 

[DaveE]

I think those disagreeing with "shut up and calculate" aren't saying don't calculate. There isn't a whole lot to talk about without the calculation part first. Or maybe there's way too much to talk about with no "rules", IDK.

In any case, welcome to PF. I think you can learn a lot here by asking about stuff without the Math, as you saw above in the comments about photons and Maxwell's equations.

 

[KosKallah]

Thanks for the welcome! :)

I agree with you and I am not against the math, but for the inclusion of conceptual thinking together with math.

Truly, without math, we do not have the tools to perform meaningful experiments about anything in the level of knowledge we have today.

It is just a matter of "speak up AND calculate". ;)