in an instant; in a flash

(physics) (attributive) transient

in a flash; twinkling; ephemeral

instantaneous

nictitating membrane (zoology)

in a blink; in a twinkling

prompt neutron

prompt radiation

in an instant a myriad changes (idiom); rapid substantial change

(idiom) in the wink of an eye; in a flash

prompt radiation

teleportation