Conditions for life may hinge on how fast the universe is expanding | Science | AAAS http://www.sciencemag.org/news/2016/02/conditions-life-may-hinge-how-fast-universe-expanding
Scientists have known for several years now that stars, galaxies, and almost everything in the universe is moving away from us
(and from everything else) at a faster and faster pace. Now, it turns out that the unknown forces behind the rate of this accelerating
expansion—a mathematical value called the cosmological constant—may play a previously unexplored role in creating the right conditions
That’s the conclusion of a group of physicists who studied the effects of massive cosmic explosions, called gamma ray bursts, on planets.
They found that when it comes to growing life, it’s better to be far away from your neighbors—and the cosmological constant helps thin
out the neighborhood.
“In dense environments, you have many explosions, and you’re too close to them,” says cosmologist and theoretical physicist Raul Jimenez
of the University of Barcelona in Spain and an author on the new study. “It’s best to be in the outskirts, or in regions that have not
been highly populated by small galaxies—and that’s exactly where the Milky Way is.”