Discovered: Astronomers find the oldest known spiral galaxy; dolphins are good with numbers; Japan's nuclear disaster will probably result in 130 deaths; and laziness is on par with smoking.

Dolphins can do math. Aren't dolphins the best? They're second only to humans in intelligence, they display signs of culture, and they even play nice with cats. Now, thanks to a new study led by University of Southampton professor Tim Leighton, we also know that they can do math. Dolphins blow tiny bubbles around their prey, and by studying how their echolocation cuts through this bubble barrier (something human sonar isn't capable of), Leighton was able to prove that dolphins employ complex nonlinear mathematics while hunting. "Perhaps they have something amazing," says Leighton. [MSNBC

A spiral galaxy far, far away. Astronomers at the University of California, Los Angeles have spotted a spiral galaxy in the distant reaches of the early universe, believed to have formed billions of years before any other known spiral galaxy. The images captured by the Hubble Space Telescope show the spiral galaxy as it appeared three billion years after the Big Bang—the light from this newly discovered galaxy has taken over 10 billion years to reach Earth. "The vast majority of old galaxies look like train wrecks," says researcher Alice Shapley. David Law, lead author of the study says, "The fact that this galaxy exists is astounding." [UCLA]

Nuclear disaster will likely cause 130 deaths. Stanford researchers predict that radiation from the Fukushima Daiichi nuclear power plant disaster will cause anywhere from 15 to 1,300 cancer deaths, with 130 being the most likely number. These findings are considered low, considering that 81 percent of the radiation from the disaster seeped into the ocean. The researchers used atmospheric modeling to predict what the outcome would be if a similar disaster struck California's Diablo Canyon Power Plant. There would be 25 percent more cancer deaths, they found. [Los Angeles Times]

The similarities between sitting and smoking. An international team of researchers has found that physical inactivity causes just as many deaths as smoking. One third of the world's adults aren't exercising enough, which helps to account for the one in 10 deaths that stem from preventible diseases. Researchers consider the situation a pandemic, and they call for new campaigns to warn the public about the dangers of a sedentary lifestyle. But this can't all be pinned on laziness—governments also need to make exercise more convenient, affordable and safer for their citizens. "We need to do all we can to make it easy for people to look after their health and get active as part of their daily lives," says UK Faculty of Public Health president Lindsey Davies.  [BBC]