query: How can a photon exist on its own without a mass?
positive_passages.docid: 12847
positive_passages.text: If photons have no mass, how can they have momentum?
negative_passages.docid: 90917
negative_passages.text: Why do we have an elementary charge but no elementary mass?
negative_passages.docid: 114290
negative_passages.text: Is it possible to have a singularity with zero mass?
negative_passages.docid: 53259
negative_passages.text: Do photons have mass?
negative_passages.docid: 48690
negative_passages.text: Does a photon interfere only with itself?
negative_passages.docid: 88637
negative_passages.text: Why can a particle decay into two photons but not one?
negative_passages.docid: 68726
negative_passages.text: Does photon have size measurement because of its particle nature
negative_passages.docid: 59601
negative_passages.text: Application of Heisenberg's uncertainty principle on photons
negative_passages.docid: 54193
negative_passages.text: Can light exist in $2+1$ or $1+1$ spacetime dimensions?
negative_passages.docid: 12433
negative_passages.text: How do $\pi^0$ particles exist?
negative_passages.docid: 38454
negative_passages.text: Do anti-photons exist?
negative_passages.docid: 42765
negative_passages.text: Stimulated emission and No cloning theorem
negative_passages.docid: 64286
negative_passages.text: How can gravitions exist without violating GR?
negative_passages.docid: 55085
negative_passages.text: How come a photon acts like it has mass in a superconducting field?
negative_passages.docid: 30422
negative_passages.text: Are photon energies universally quantized?
negative_passages.docid: 1537
negative_passages.text: Is a photon "fixed in spacetime"?
negative_passages.docid: 142081
negative_passages.text: Can something without mass exert a force?