Clifford Algebra and its contributions to physics

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Discussion Overview

The discussion centers around the role of Clifford algebra in physics, exploring its applications, relevance, and the challenges faced by learners in understanding the topic. Participants express varying levels of enthusiasm and skepticism regarding its utility compared to other mathematical tools.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants express uncertainty about the contributions of Clifford algebra to physics, questioning whether it offers significant advantages or is merely a reformulation of existing concepts.
  • Others argue that while Clifford algebra has applications in physics, many of these can be addressed using more common mathematical tools, leading to perceptions of it as an accessory.
  • A participant highlights Geometric Algebra (GA) as a notable aspect of Clifford algebra, suggesting it consolidates various mathematical constructs and simplifies complex physics concepts, such as Maxwell's equations.
  • Concerns are raised about the learning curve associated with GA and the difficulty in translating traditional specialized algebras into GA.
  • Several participants share resources and suggest books for studying Clifford algebra, with mixed opinions on their readability and depth, particularly regarding Hestenes' work and Macdonald's texts.
  • There is a discussion about the differences in notation across various texts on Geometric Algebra, with some participants noting that this can affect comprehension.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the overall utility of Clifford algebra in physics. There are competing views on its significance, with some advocating for its advantages while others suggest it may not be essential compared to other mathematical frameworks.

Contextual Notes

Limitations include the varying levels of familiarity with Clifford algebra among participants, differing opinions on the effectiveness of various texts, and the potential for confusion due to inconsistent notation across resources.

Phylosopher
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Hello,

I see a lot of people enthusiastic about Clifford algebra and its future role for physics, yet I also see a lot of people frustrated opinions about it. Contents in the internet seems really really small compared with other mathematical topics, not to mention less books about it.

All this makes me less confident about learning this topic.

Well, this is what I feel honestly! Now I can ask some questions.

1 Does Clifford algebra brings any good to physics or is it just reformulation?

2 If it did/does, then in what areas of physics does Clifford algebra work as master tool above all others. (I will appreciate it if you provided me with resources, especially scientific papers)
--------------------------------------

Background: I am an undergraduate physics student "interested in mathematical physics" considering taking my senior project on Clifford algebra. My supervisor is really enthusiastic about, but I feel that it might not be a good project! Since I am not yet convinced with it, because of all the controversial opinions in the internet.
 
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jedishrfu said:
The wikipedia article on Clifford Algebras has some Physics examples:

https://en.wikipedia.org/wiki/Clifford_algebra#Applications

I am not an expert, but from what I read. A lot of these applications can be achieved with other mathematical tools that are more common and not just clifford algebra (some people claims). Which makes people think about it as an accessory.

"That what I understood from people discussions on the internet"
 
Often times in math its necessary to have different tools available to approach a problem.

Sometimes you will hear of a mathematician seeing a connection to another body of mathematics and recasting the problem in that new form and then go on to proof it.

Clifford algebras is one such tool.
 
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One of the interesting Clifford Algebras is Geometric Algebra (GA). GA consolidates a lot of mathematical constructs involving different dimensions into one construct and the mathematics of that construct. The result is that it includes many specially derived algebras that were invented for specific applications. It helps greatly to consolidate all the mathematical manipulations into one logical, methodical system. Then it turns out that so much of physics is just the mathematical manipulations and the basic physics concepts are much simpler in the form of GA. For instance, Maxwell's equations become one simple GA equation. That one GA equation might represent many mathematical manipulations (like a simple matrix equation represents a lot of multiply/adds), but those manipulations are routine and systematic.

That being said, there is a learning curve to master GA and the payoffs are not immediate. Also, a lot of the traditional specialized algebras developed for specific applications are not always easy to translate into GA.
 
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Thank you for your answers, they were helpful. I will suggest for people interested in Clifford Algebra to look at this too:
https://www.reddit.com/r/math/comments/5bd2ei/lets_talk_about_geometric_algebra_not_algebraic/

One more question! What is the best book to study Clifford Algebra from a Mathematical point of view(Most of the books out there are for applications). There is "Clifford Algebra to Geometric Calculus" By Hestenes but it seems that it is a hard one to read.
There is also Macdonald's books "Linear and Geometric Algebra" and "Vector and Geometric Algebra", but I don't know how good they are.
 
I was not impressed with the Hestenes book. He seemed to be talking in a different language. The Macdonald books seem good. (That's Vector and Geometric Calculus) I got them but have not read very far into them. They do not seem to go very far into the applications. Macdonald put a good summary article on the internet at http://faculty.luther.edu/~macdonal/GA&GC.pdf )
 
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FactChecker said:
One of the interesting Clifford Algebras is Geometric Algebra (GA). GA consolidates a lot of mathematical constructs involving different dimensions into one construct and the mathematics of that construct. The result is that it includes many specially derived algebras that were invented for specific applications. It helps greatly to consolidate all the mathematical manipulations into one logical, methodical system. Then it turns out that so much of physics is just the mathematical manipulations and the basic physics concepts are much simpler in the form of GA. For instance, Maxwell's equations become one simple GA equation. That one GA equation might represent many mathematical manipulations (like a simple matrix equation represents a lot of multiply/adds), but those manipulations are routine and systematic.

That being said, there is a learning curve to master GA and the payoffs are not immediate. Also, a lot of the traditional specialized algebras developed for specific applications are not always easy to translate into GA.
I spend three years working on applications of geometric algebra to rigid body dynamics in which is is extremely powerful and far superior to anything out there at the moment. The book by Doran and Lasenby is becoming a classica but my feeling that it is not well written in some places as it should be and a much better job can be done.
 
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  • #10
Phylosopher said:
Thank you for your answers, they were helpful. I will suggest for people interested in Clifford Algebra to look at this too:
https://www.reddit.com/r/math/comments/5bd2ei/lets_talk_about_geometric_algebra_not_algebraic/

One more question! What is the best book to study Clifford Algebra from a Mathematical point of view(Most of the books out there are for applications). There is "Clifford Algebra to Geometric Calculus" By Hestenes but it seems that it is a hard one to read.
There is also Macdonald's books "Linear and Geometric Algebra" and "Vector and Geometric Algebra", but I don't know how good they are.
They're actually quite readable. They're a little quick for my liking but the exercises are relatively straight forward and can be done rather easily.
 
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  • #11
hunt_mat said:
They're actually quite readable. They're a little quick for my liking but the exercises are relatively straight forward and can be done rather easily.

Does they (Macdonald's books) use the same notation as Hestenes books? The notation in which Geometric Algebra is written in, differ from book to book I believe.
 
  • #12
Phylosopher said:
Does they (Macdonald's books) use the same notation as Hestenes books? The notation in which Geometric Algebra is written in, differ from book to book I believe.
I have found that notations differ from book to book. It is still a very readable text though.
 

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