The "solar system bounce" or "galactic disk shockwave" is speculative hypothesis suggested Dr Daniel Whitmire and Albert Jackson (1985)in order to explain periodicity in extinction rates that were not linked to impacts from asteroids or comet. As of 2020 there was scientific evidence to support their conjecture. There also isn't any evidence which support it contributed towards the dinosaur's extinction about 65 million years ago, which is now understood to have been the primary caused by the Chicxulub meteor event .