Lake Superior is the largest freshwater lake in the world, by surface area, and it has something the other Great Lakes do not: stable populations of mostly native fish species.
But scientists say a key fish in Superior's food web is now in trouble because of mild winters and an appetite for caviar in Europe.
There wasn't much demand for lake herring 10 years ago. It used to be fed to mink and used as fertilizer, according to Craig Hoopman, a commercial fisherman in Wisconsin who fishes around Lake Superior's Apostle Islands.
"I have a hard time saying this with a straight face, but I will: You can teleport a single atom from one place to another," says Chris Monroe, a biophysicist at the University of Maryland.
His lab's setup in a university basement looks nothing like the slick transporters that rearrange atoms and send them someplace else on Star Trek. Instead, a couple million dollars' worth of lasers, mirrors and lenses lay sprawled across a 20-foot table.
"Starting a military AI arms race is a bad idea," says a group of researchers and concerned citizens who are urging a ban on offensive military weapons that don't rely on human control. The group signed an open letter that's being delivered at a conference on artificial intelligence this week.
The crash of a Virgin Galactic spaceship last fall in California's Mojave Desert was caused by pilot error and design problems, the National Transportation and Safety Board announced Tuesday after a nine-month investigation.