sciencehabit writes Researchers working in Argentina have discovered the most complete skeleton of a titanosaur, a group of gigantic plant-eating dinosaurs that dominated the Southern Hemisphere beginning about 90 million years ago. The new dino, named Dreadnoughtus schrani, was 26 meters long and weighed about 59 metric tons—that is, twice as long as Tyrannosaurus rex and as heavy as a herd of elephants. That puts it on a par with other well-known giants such as Argentinosaurus (but it's four times as large as the perhaps better known Diplodocus). The researchers say that the beast was so big it would have had no fear of predators. And it was about to get bigger: A close examination of the fossils, especially its back and shoulder bones, indicates that the animal was still growing when it died.

mpicpp is one of many to point out that hackers broke into the HealthCare.gov website in July and uploaded malicious software. "Hackers silently infected a Healthcare.gov computer server this summer. But the malware didn't manage to steal anyone's data, federal officials say. On Thursday, the Health and Human Services Department, which manages the Obamacare website, explained what happened. And officials stressed that personal information was never at risk. "Our review indicates that the server did not contain consumer personal information; data was not transmitted outside the agency, and the website was not specifically targeted," HHS spokesman Kevin Griffis said. But it was a close call, showing just how vulnerable computer systems can be. It all happened because of a series of mistakes. A computer server that routinely tests portions of the website wasn't properly set up. It was never supposed to be connected to the Internet — but someone had accidentally connected it anyway. That left it open to attack, and on July 8, malware slipped past the Obamacare security system, officials said.

For seven seasons Dr. David Saltzberg has made sure the science on the CBS sitcom The Big Bang Theory is correct. As science consultant for the show he reviews scripts for technical errors, fixing any problems he finds. He also adds complex formulae to whiteboards on set. Before his life as a science advisor, Saltzberg received his Ph.D. in physics from the University of Chicago, performed post-graduate work at CERN, and currently is a Professor of Physics and Astronomy at UCLA. He writes The Big Blog Theory, where he explains the science behind each episode of the show. Dr. Saltzberg has agreed to answer any questions you have about the show or his previous scientific work. As usual, ask as many as you'd like, but please, one per post.

Rambo Tribble writes A team of British and Finnish scientists have used the common bacteria Escherichia coli to produce the environmentally-friendly fuel propane. By introducing enzymes to modify the bacteria's process for producing cell membranes, they were able directly produce fuel-grade propane. While commercial application is some years off, the process is being hailed as a cheap, sustainable alternative to deriving the gas from fossil fuel production. As researcher Patrik Jones is quoted as saying, "Fossil fuels are a finite resource and...we are going to have to come up with new ways to meet increasing energy demands."

coondoggie writes In five years the Defense Advanced Research Projects Agency (DARPA) wants to launch a robotic servicing mission to inspect, fix, refuel, or move satellites in geostationary Earth orbit. In order to move that plan along, the research agency today issued a Request for Information calling on commercial and private space groups to provide details on what it would take to accomplish that lofty goal. To expedite the mission, DARPA said it is considering the possibility of integrating DARPA-developed space robotics technologies onto commercial spacecraft to create a jointly developed GEO robotic service craft.

Nerval's Lobster writes As a trend, the ALS Ice Bucket Challenge seems a bit played out—who hasn't yet dumped a bucket of icy water over his or her head for charity? But that didn't stop Canadian chemist Muhammad Qureshi from executing his own sublimely scientific, potentially dangerous variation on the theme: After donating to the ALS Association, he proceeded to douse himself with a bucket of liquid nitrogen. Anyone who's taken a chemistry class, or at least watched the end of Terminator 2, knows that liquid nitrogen can rapidly freeze objects, leaving them brittle and prone to shattering. Pouring it on your skin can cause serious frostbite. So what prevented that bucketful of liquid nitrogen from transforming Qureshi into a popsicle? In two words: Leidenfrost effect. Named after 18th century scientist Johann Gottlob Leidenfrost, the effect is when a liquid comes near a mass that's much warmer than the liquid's boiling point, which (in the words of Princeton's helpful physics explainer) results in an insulating vapor layer that "keeps that liquid from boiling rapidly." In other words, the vapor makes the liquid "float" just above the surface of the object, rather than coming into direct contact with it.