Background to the holy wars and the First Crusade's conquest of Jerusalem, a holy city for Jews, Christians and Muslims.
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Understanding the world of "dark" particles could be the key to explaining the origins and structure of the universe.
But after decades of research, scientists have yet to find direct evidence of the so-called "dark sector" - where an unknown matter exhibits gravitational force but cannot otherwise be detected. It is one the biggest mysteries in physics, and though invisible, the dark sector is believed to make up about 96 percent of the universe.
The idea of dark matter developed after astronomer Vera Rubin observed that galaxies rotate in a way that contradicts the laws of motion and gravity. This led scientists to believe that there is an unseen matter interacting with gravity.
In addition to monitoring outer space for dark matter interactions, physicists are attempting to crate dark matter particles in the lab. In this episode, we'll speak to scientists trying to answer one of the universe's biggest questions.
On this episode of The Stream, we speak with:
Alexandra Amon @astroalexamon
Astrophysicist and observational cosmologist
Stephon Alexander @stephstem
Theoretical Cosmologist, Brown University
Katie Mack @AstroKatie
Mauro Raggi @INFN_
Researcher, Sapienza University and National Institute of Nuclear Physics of Rome
Scientists hunt mysterious 'dark force' to explain hidden realm of the cosmos - Guardian
Voyage into the dark sector - Symmetry
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