I would like to have this discussion on this forum.

Can we fire some particles to mid-air to explode to light after particle's lifetime ends? Is there a way to give a particle a lifetime, a color and a trajectory to fly?

  • $\begingroup$ unfortunately, this is not how particle physics works. Have you looked into some of the core principles of particle physics? If so, what are your ideas of realizing one of your points? (trajectory, color etc.) $\endgroup$
    – DomDoe
    May 7, 2018 at 9:00
  • 2
    $\begingroup$ @DomDoe choosing a particle with a decay including photons of a particular wavelength with a large branching ratio gives a colour. Given the half-life one can choose a momentum so that most decays will occur in a certain region of space. Modulo some extra details and the fact that it can't be tuned arbitrarily like the OP seems to imply, it's not as far fetched as you seem to claim. $\endgroup$
    – Kyle Oman
    May 7, 2018 at 9:19
  • $\begingroup$ This is not a discussion forum. $\endgroup$ May 12, 2018 at 4:45

1 Answer 1


The fundamental issue is that colour is a layman's terms for wavelength (hence energy) of the photon. A particle that gives you green light for instance, would have to decay to two photons of wavelength around 550nm. This corresponds to a particle with a rest-mass energy of around 4 eV. For comparison, the electron (which is the lightest lepton) has a rest mass of 511 keV.

So basically, there are no particles with a low enough mass to convert directly into optical wavelength light.

  • $\begingroup$ Note that this limitation is not necessarily true if you consider condensed-matter quasiparticles, whose masses can be much lower. I don't know if quasiparticles can be reliably coaxed to decay to photons, though. $\endgroup$ May 7, 2018 at 11:18
  • $\begingroup$ My bad. I did not consider condensed matter quasiparticles... Have you seen Spectral, by any chance? $\endgroup$ May 7, 2018 at 12:51
  • $\begingroup$ Well, I realized that it doesn't really answer the question as written, because the OP specified this had to be done "mid-air," which doesn't allow for a condensed-matter setting. In any case, no, I haven't seen Spectral. $\endgroup$ May 7, 2018 at 13:45
  • $\begingroup$ Drifting a bit off-topic, but if you're a condensed matter physicist, you might enjoy/detest/die laughing at Spectral (it's on Netflix). $\endgroup$ May 8, 2018 at 5:54

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