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While reading about pair production, I came across the concept of negative energy. What is negative energy exactly? And can there be negative mass corresponding to this energy?

Mechanic
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  • Can you give a reference to where you were reading this? – my2cts Oct 20 '18 at 06:47
  • Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles

    Book by Robert Martin Eisberg and Robert Resnick

     – Mechanic Oct 20 '18 at 06:49
  • Its a pretty lengthy explanation as how Dirac explained pair production by considering the negative possibility of energy combining quantum mechanics and relativity. Please read it. – Mechanic Oct 20 '18 at 06:59
  • @my2cts Take a look at https://physics.stackexchange.com/questions/19378/what-was-missing-in-diracs-argument-to-come-up-with-the-modern-interpretation-o and related questions on the Dirac sea. – PM 2Ring Oct 20 '18 at 06:59
  • @PM 2Ring Thanks, interesting discussion. In my opinion the answers there are an interesting record of how the physics community was and still is wrestling with this. Also in my opinion the concern remains that Dirac theory predicts negative energy, for either matter of for antimatter, and that the Dirac Hamiltonian commutation with position x does not produce p/m but the nonsensical result of c. – my2cts Oct 20 '18 at 07:29
  • Corrected: How does this book explain the positive energy and mass of the positron? – my2cts Oct 20 '18 at 07:31
  • @Mechanic7 I don't own a copy. I have a lot of textbooks on the subject but not this one. Hence it would help me if you could outline the argument. I am curious how this lingering matter is dealt with in present university courses. – my2cts Oct 20 '18 at 07:32

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Matter and antimatter have positive energy and mass. Both the electron and the positron have a positive rest energy of 511 keV and a positive mass of $9.11\times 10^{-31} $ kg.

In my opinion the concern remains that Dirac theory predicts negative energy, for either matter of for antimatter, and that the Dirac Hamiltonian commutation with position x does not produce p/m but the nonsensical result of c.

In spite of it being wholly unphysical the concept of a bottomless Dirac sea of filled electron states is still entertained in modern textbooks like Reinhardt Quantum Mechanics 3ed (2003), even with a picture at page 382. It would be sarcasm to ask whether this Dirac sea becomes superconducting at low temperature.

my2cts
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