Discovered: A record-breaking galaxy cluster; how squids change hue; the way our brains deal with waste; engineering better toilets. 

How squids get so flashy. Do you ever wish you could make a wardrobe change at any moment, changing your appearance through sheer will? Then envy squids, who are able to change the color of their glistening skin. Trevor Wardill of the Marine Biology Laboratory in Massachusetts  wanted to learn how squids do this, so he and his colleagues electrocuted the creature's skin. By watching the waves of electricity pulse through the squids' skin, they learned that a network of nerves allows squids to oscillate through a wide range of hues in mere seconds. These color-shifts aren't reflexes, but rather a behavior controlled by the central nervous system. The kicker? Squids are colorblind, so they can't even see the shades they're cycling through. Check out a mesmerizing video of this process below. [New Scientist]

Cerebral refuse. Even the brain has to deal with waste matter, and now Jeffrey Iliff of the University of Rochester Medical Center has discovered its mechanism for getting rid of mental garbage. Iliff and his colleagues have isolated cerebrospinal fluid as the agent for flushing out such unwanted materials as the amyloid beta protein, which is responsible for stoking Alzheimer’s disease. Cellular drains act like sewage pipes, carrying away the liquid slush.  [Science News]

Deep insights on the toilet. Approximately 3.7 billion people don't have access to sanitary toilets, making disposal of human waste a major problem in the developing world. The Bill and Melinda Gates Foundation created the Reinvent the Toilet Challenge to address the issue, and today they've announced the winner. The charity will give $100,000 to the California Institute of Technology, which has been working to build a solar-powered toilet that recycles water and generates electricity. The second-place prize went to a toilet that churns out charcoal, minerals, and clean water, and third place was awarded to a design that cleans faeces and urine, and filters waste materials into clean water. Bill Gates says, "Many of these innovations will not only revolutionize sanitation in the developing world, but also help transform our dependence on traditional flush toilets in wealthy nations." [Nature]

Giant galaxy. A newly discovered galaxy cluster, found by scientists at the University of Chicago’s Kavli Institute for Cosmological Physics using the National Science Foundation’s South Pole Telescope, is breaking all kinds of celestial records. SPT-CLJ2344-4243—nicknamed the "Phoenix Cluster"—exhibits the fastest rate of star formation in a galactic center, the most powerful X-ray output, and the largest rate of hot gas cooling yet recorded. It is also among the most massive clusters ever spotted. "The galaxy and its black hole are undergoing unsustainable growth," says research co-author Bradford Benson. "This growth spurt can’t last longer than about a hundred million years, otherwise the galaxy and black hole would become much bigger than their counterparts in the nearby universe." [University of Chicago]