Jeans began with a large cloud of interstellar gas whose inward pull of gravity perfectly balanced the outward push of pressure from its own internal heat. (discovermagazine.com)
Sign of difficulty breathing, noted by inward pulling (retracting) of the chest muscles, causing an indentation of the middle of the chest and between the ribs. (womenandinfants.org)
With no more energy from hydrogen fusion to counteract the enormous inward pull of their gravity, the stars collapsed until all of their mass was compressed into a point of infinite density. (discovermagazine.com)