Reconciliation between dark energy and dark matter
In astronomy and cosmology
dark fluid theories attempt to explain dark matter and dark energy in a single framework.The theory proposes that dark matter and dark energy are not separate physical phenomena
Nor do they have separate origins
But that they are strongly linked together and can be considered as two facets of a single fluid.At galactic scales
The dark fluid behaves like dark matter
And at larger scales its behavior becomes similar to dark energy.
A hypothesized galaxy with no, or very few, stars
A dark galaxy is a hypothesized galaxy with no stars.They received their name because they have no visible stars but may be detectable if they contain significant amounts of gas.Astronomers have long theorized the existence of dark galaxies
But there are no confirmed examples to date.Dark galaxies are distinct from intergalactic gas clouds caused by galactic tidal interactions
Since these gas clouds do not contain dark matter
So they do not technically qualify as galaxies.Distinguishing between intergalactic gas clouds and galaxies is difficult; most candidate dark galaxies turn out to be tidal gas clouds.The best candidate dark galaxies to date include
And numerous gas clouds detected in studies of quasars.
Novel trilogy by Philip Pullman
His Dark Materials is a trilogy of fantasy novels by Philip Pullman consisting of Northern Lights
The Subtle Knife (1997)
And The Amber Spyglass (2000).It follows the coming of age of two children
Lyra Belacqua and Will Parry
As they wander through a series of parallel universes.The novels have won a number of awards
Including :The Carnegie Medal in 1995 for Northern Lights and the 2001 Whitbread Book of the Year for The Amber Spyglass.In 2003
The trilogy was ranked third on the BBC's The Big Read poll.
