The doomed galaxies would have been pulled apart like taffy if they plunged through the center of the galaxy cluster where gravitational tidal forces are strongest. (sciencedaily.com)
One explanation is that the long fractures in the ice crust experience more stress as gravitational tidal forces push and pull on the moon and so open vents at larger distances from Jupiter. (sciencedaily.com)
And the enormous gravitational tidal forces around the black hole would seem to prohibit stars from forming even if the material were there: it's hard for a cloud of gas to contract into a star under its own gravity when something that weighs as much as four million stars is sitting next door.» (creationscience.com)