Aliens, the Risk of Medical Care & More: 5 Things We Learned This Week

From the danger of overprescribing antiobiotics to why we don't delete annoying Facebook friends, here are five things we learned in Tech & Science this week:

• They're out there. Intelligent, alien life forms almost certainly existed on a distant planet, according to a study published in the journal Astrobiology. Using NASA data, the study found stars with planets at temperatures that would support life. Given that, the researchers estimate there only is a one in 10 billion trillion chance humans are the only intelligent life form to have existed.
• Medical errors kill more people annually than do strokes and pneumonia and are the third leading cause of death in the U.S., according to a study in the BMJ. Some 250,000 people die each year from medical errors, and the authors of the study argue for an overhaul in how the Centers for Disease Control and Prevention collect data on causes of death.

• Surprise? Promoting abstinence does not lower HIV rates or prevent unwanted pregnancies. Researchers studied data on 500,000 people in 22 countries from 1998 to 2013 in countries served by the U.S. President's Emergency Plan for AIDS Relief (PEPFAR), which provided abstinence education, and data from countries without such lessons. They concluded that there was little to no difference in sexual behavior, regardless of whether people had been exposed to abstinence programs or not.

• It turns out there is a reason we don't unfriend the annoying Facebook "friend" who constantly fills our feeds with idiotic memes and their uninformed rants: We worry about the social repercussions, regardless of how little contact we have with them in real life. Researchers at Nottingham Trent University had Facebook users rate randomly selected friends for closeness and the degree to which they disagree with their online presence. It turns out "they don't want to communicate with the troublemakers online for risk of damaging their own reputation, but at the same time they don't appear to want to unfriend them either."

• We are being overprescribed antiobiotics, and the practice is helping us all to develop a resistance to the often life-saving medication. A study in JAMA found that approximately 30 percent of antiobiotics prescriptions from 2010 to 2011 were unnecessary; the consequences include the inability to beat back illness and the development of severe allergies that leave antibiotics unsafe to use.