Invariant quantities for antimatter

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Discussion Overview

The discussion revolves around the concept of invariant quantities in relation to antimatter, particularly focusing on the properties of antiparticles, proper time, and CPT symmetry. Participants explore theoretical implications and interpretations of these concepts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • One participant suggests that since antiparticles have reversed proper time, all invariants must also be reversed for them.
  • Another participant challenges the assertion about reversed proper time, questioning the validity of the term "anti-particle" and suggesting it merely refers to opposite properties of particles.
  • Concerns are raised about the meaning of "reversed proper time," with a participant arguing that proper time is defined for all tardyons and does not imply a reversal for antiparticles.
  • Some participants mention CPT symmetry as a relevant concept, with one suggesting the original poster may be confused about its implications.
  • A participant refers to Feynman's theory regarding positrons moving backwards in time, indicating a need for clarification on this interpretation.
  • There is a mention of negative energy and rest mass in relation to positrons, with an acknowledgment of the complexity of these ideas.
  • Discussion includes references to historical papers on negative mass, indicating interest in exploring unconventional theories.

Areas of Agreement / Disagreement

Participants express differing views on the nature of antiparticles and the implications of proper time, with no consensus reached on these topics. Confusion regarding Feynman's statements and the definitions of terms like "anti-particle" is evident.

Contextual Notes

Participants highlight limitations in understanding the definitions and implications of concepts like proper time and CPT symmetry, indicating that further exploration and clarification are needed.

actionintegral
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Since antiparticles have reversed proper time, can I conclude that all invariants are reversed for antiparticles?
 
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actionintegral said:
Since antiparticles have reversed proper time,..
What exactly do you mean by this? I can't see anything which would imply such an assertion. :confused:

There is really no such thing as an "anti-particle." The meaning of the term "anti-particle" refers to opposite properties of a particle. E.g. one could define the term "neutron" to refer to what we normally call a 'neutron' and then refer to the 'anti-neutron' as "neutron." Thus what we call the "anti-particle" refers merely the opposite of a given particle. I.e. the anti-particle of the anti-neutron is the neutron.

The term "reversed proper time" makes no sense. The phrase "proper time" refers to the time between two events as the time as measured by a clock which travels on a specified worldline between the two events. This is true of all tardyon's (i.e. particles which travel at v < c).

Perhaps you're confusing this with tachyons??

Pete
 
Gokul43201 said:
No, I think the OP is confused about CPT symmetry, or something along those lines - maybe even just the definition of the antiparticle of a given particle.
QUOTE]

Thank you for pointing out my confusion. Now maybe I can ask my question more intelligently.

I am referring specifically to Feynman's theory of positrons - that positrons they move backwards in time. Now that statement only makes sense if I am referring to the proper time of the positron. I also read that positrons have negative energy which I assume means negative rest mass.

I was referred to CPT symmetry but I am still reading about that.
 
actionintegral said:
I am referring specifically to Feynman's theory of positrons - that positrons they move backwards in time. Now that statement only makes sense if I am referring to the proper time of the positron.
I don't think Feynman said that positrons move back in time. I believe what he said was that one could view a positron as an electron which is moving backwards in time.


Pete
 
pmb_phy said:
I don't think Feynman said that positrons move back in time.
Pete

Yes, I think I made an oversimplification in my mind. Let's continue this
after I do some more learning.
 
There is an old paper by Bondi about negative mass. Since I only have negative money, can someone send it to me?
 
actionintegral said:
There is an old paper by Bondi about negative mass. Since I only have negative money, can someone send it to me?
Sure. PM your email address to me and I'll send it to you within a day or so (since I'll have to find it and then scan it and convert it to PDF).

Pete
 
  • #10
pmb_phy said:
Sure. PM your email address to me and I'll send it to you within a day or so (since I'll have to find it and then scan it and convert it to PDF).
Pete

Please send it to actionintegral@yahoo.com

Much, Much obliged!
 

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