The dark energy pushing our universe apart may not be what it seems, scientists say

Distant, ancient galaxies are giving scientists more hints that a mysterious force called dark energy may not be what they thought. Astronomers know that the universe is being pushed apart at an accelerating rate and they have puzzled for decades over what could possibly be speeding everything up. It is so vast it is thought to make up nearly 70% of the universe — while ordinary matter like all the stars and planets and people make up just 5%.