![Dark Energy Image source: Large Synoptic Survey Telescope Dark Energy Image source: Large Synoptic Survey Telescope](http://www.timeone.ca/wp-content/uploads/2013/03/Dark-Energy.jpg)
Classification: concept
Chapter: What's the Matter
Dark energy is almost three quarters of the mass-energy in the universe. It cannot be detected directly. It seems to cause the observed expansion of space.
Classification: concept
Chapter: What's the Matter
Dark energy is almost three quarters of the mass-energy in the universe. It cannot be detected directly. It seems to cause the observed expansion of space.