Via IFLScience: ‘Picture the Arctic and you’re probably imagining vast expanses of pure, white ice or enormous cliffs of jagged glaciers surrounded by icy waters. However, the ice sheets of the Arctic are melting so quickly and in such large amounts that maps of the world must reflect these momentous changes. Atlas of the World makers National Geographic announced last year that there would be major changes made to the 10th edition of its map. In his announcement of plans to fight global warming, President Obama referred to these changes in a speech given at the White House. “Shrinking ice caps forced National Geographic to make the biggest change in its atlas since the Soviet Union broke apart,” Obama said….’
Via IFLScience: ‘It’s pretty hard to fathom just how big some things in the universe are, but this possible feature is so large that it borders on the ridiculous.
Astronomers think they have found a ring of nine gamma ray bursts (GRBs) inside galaxies that, together, measure 5 billion light-years across. For a comparison, that’s about 50,000 times bigger than the Milky Way, or more than one-ninth the size of the observable universe. The research was published in the journal Monthly Notices of the Royal Astronomical Society.
A GRB is an intense flash of gamma rays caused by a supernova, the dramatic death of a fiery star, and thus their detection indicates the presence of a galaxy – suggesting all nine of the GRBs are in separate galaxies. They are the brightest electromagnetic events in the universe, releasing more energy in a few seconds than the Sun in its entire 10 billion-year lifetime, and thus they can be used to detect distant galaxies.
While it is not one physical whole structure, the Hungarian-American team who made the discovery think the nine galaxies are gravitationally bound to each other – just as our Local Group contains the Milky Way and a few dozen other galaxies.
In this case, all the GRBs studied by a variety of observatories are about 7 billion light-years away from Earth, suggesting that we are seeing the structure “face on.” Alternatively, we may be seeing a projection of a “sphere.”
But there’s one problem. The structure, if confirmed, would break our current models of how large things can be; a previous theoretical limit stood at 1.2 billion light-years. On large scales, the cosmos should be uniform and not have structures like this….’