kalkulat@lemmy.world to science@lemmy.world · 3 tháng trướcNASA's solar sail successfully spreads its wings in spacewww.space.comexternal-linkmessage-square65fedilinkarrow-up1464arrow-down10cross-posted to: technology@lemmy.worldspaceflight@sh.itjust.worksworldinprogress@lemmy.worldastronomy@mander.xyz
arrow-up1464arrow-down1external-linkNASA's solar sail successfully spreads its wings in spacewww.space.comkalkulat@lemmy.world to science@lemmy.world · 3 tháng trướcmessage-square65fedilinkcross-posted to: technology@lemmy.worldspaceflight@sh.itjust.worksworldinprogress@lemmy.worldastronomy@mander.xyz
minus-squareMonkderViertelinkfedilinkarrow-up1·3 tháng trướcSo photons only have no mass if they don’t move? Do they even exist if they don’t move?
minus-squaremarcos@lemmy.worldlinkfedilinkarrow-up4·3 tháng trước Do they even exist if they don’t move? No. Or, at least not from our point of view. They only exist moving at the speed at light. All particles with no rest mass only exist moving at the speed of light.
minus-squareMonkderViertelinkfedilinkarrow-up1·3 tháng trướcElse they don’t. We are talking quantum here.
So photons only have no mass if they don’t move? Do they even exist if they don’t move?
No. Or, at least not from our point of view.
They only exist moving at the speed at light. All particles with no rest mass only exist moving at the speed of light.
So photons do have mass?
only as long as they exist
Else they don’t. We are talking quantum here.