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These barrel sponges have one hell of a pedigree. (credit: Albert Kok/Wikimedia)

The earliest chapters in the history of life are in some ways the most interesting, but also the hardest to read. The pages are badly stained and tattered, and the print was terribly small to begin with. You can occasionally trip on a dinosaur femur, but any evidence that remains from the earliest animals is incredibly subtle.

Despite the challenges, we've learned that the “Cambrian explosion” was far from the start of multicellular life. The title for “most ancient animal” currently belongs to the sponge. A recently described fossil just a millimeter across appears to be a 600 million year old sponge—that’s 60 million years before the start of the Cambrian period. But we can find chemical traces going back another 50 million years that have been interpreted as a calling card for sponges. Some have challenged that interpretation, however, on the grounds that this chemical “biomarker” is not unique to sponges, and could instead have come from a type of algae.

The biomarker of interest is the remnant of a sterol (as in “cholesterol”), which is a key component in the cells of eukaryotes (as opposed to bacteria and archaea). With a small bit of the chemical structure lopped off, you get a sterane that can happily hang around in the rock record. A group of researchers led by MIT’s David Gold took a closer look at the sterol 24-isopropylcholesterol in sponges and other organisms to find out more about when the genes for it evolved—and what is most likely to have left it in 650 million year old rocks.

Venturi

VBB-3 on the sand at Bonneville.

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The Venturi Buckeye Bullet-3 combines two things we love here at Ars Technica: land speed records and electric vehicles. It's a collaboration between Venturi—a Monegasque electric car company—and the Ohio State University that aims to break 400mph (644km/h) on the Bonneville salt flats while simultaneously acting as a testbed for future electric vehicles and the young engineers who work on it. Fortunately Columbus, Ohio, is less than a day's drive from Washington, DC, so I took advantage and paid the land speed car a visit.

VBB-3—its nickname—is the third land speed car to come from the Center for Automotive Research (CAR) in Columbus. Its long, thin shape has been dictated by aerodynamics, unencumbered by the draggy intakes required to feed air-breathing engines. It has a pair of electric motors, each good for 1,500 horsepower (1,119kW) and powered by eight large lithium-ion battery packs. Earlier VBBs set records in 2009 and 2010, but last summer terrible salt conditions prevented VBB-3 from running a proper test program to 400mph and beyond.

Each axle is powered by its own electric motor. The starting point is the same EV motor Venturi builds for its sports cars, running here at a much higher voltage. In fact, there are actually two EV motors in each unit. "It's two motors sharing a cooling system and a common shaft," team leader (and former graduate student) David Cooke told us. "It makes more manufacturing sense to build smaller motors and couple them together than trying to build one big motor. Today that motor is putting out about 1,000 horsepower in the dyno, but it's capable of 1,500." The team is continuing to develop the powertrain—particularly the inverter control—to give VBB-3 the 3,000hp it needs.

DVDFab, a software tool for ripping and decrypting DVDs and Blu-ray discs, will not be upgraded to support newer Ultra HD (4K) Blu-ray discs.

Fengtao Software, which makes DVDFab, said in a statement that it "will not decrypt or circumvent AACS 2.0 in the days to come. This is in accordance with AACS-LA, (which has not made public the specifications for AACS 2.0), the BDA [Blu-ray Disc Association] and the movie studios." AACS-LA is the body that develops and licenses the Blu-ray DRM system.

Curiously, Fengtao's announcement comes just a day after SlySoft—the company that makes the ripping tool AnyDVD—ceased operations and vanished from the Web. All that's left is a cryptic message on SlySoft's website: "Due to recent regulatory requirements we have had to cease all activities relating to SlySoft Inc."

If the military forces you to destroy an alien species in space, your brain won't process it the same way it would if you chose to destroy the aliens of your own free will. (credit: Ender's Game)

We've known for a long time that people will do terrible things under orders—like hurt strangers. But why are we so easily persuaded to do things we wouldn't otherwise choose, even when nobody is holding guns to our heads? A new scientific experiment sheds light on this ancient ethical question.

University College London neuroscientist Patrick Haggard and his colleagues designed an experiment to measure what's happening in the human brain when ordered to do something, versus choosing to do something. In Current Biology, the researchers report on how they reenacted a famous twentieth century experiment to find out.

Back in the early 1960s, a Yale psychologist named Stanley Milgram conducted a now-infamous set of experiments about how far people will go to follow orders. He asked volunteers to deliver an electric shock to a stranger. Unbeknownst to the volunteers, there was no shock—and the people they were shocking were actors pretending to be terribly hurt, even feigning heart attacks. Milgram found that most people would keep delivering the shocks when ordered by a person in a lab coat, even when they believed that person was gravely injured. Only a tiny percentage of people refused.