In 2006, a tiny percentage of astronomers took it upon themselves to change the definition of "planet" and so Pluto was out. Chaos ruled, the 237 astronomers who made the ruling dug in their heels, and for the most part they were ignored.

After all, there are now nearly 5,000 planetary bodies orbiting stars other than ours. But astronomers don't know what exactly we should call them. Today at an American Astronomical Society meeting, UCLA professor Jean-Luc Margot described a simple test that can be used to clearly separate planets from other bodies like dwarf planets and minor planets and replace the  "definitional limbo" those bodies are in. 

Think of how often sit with your phone, tablet, or computer, quietly shopping or reading the latest headlines. Browsing the internet certainly feels like a solitary activity, but as a new paper reveals, you may be surprised by just how many companies are observing.

Tim Libert, a doctoral student at the Annenberg School for Communication at the University of Pennsylvania analyzed the Alexa top one million websites, finding that 88 percent leak user data to third parties -- sites that would be unfamiliar to most users.

"There's some suggestion that it's anonymous data," says Libert, "but when you have big data sets that can be combined with other big data sets, you can be identified pretty easily."

A new cholesterol-lowering vaccine leads to reductions in 'bad' LDL cholesterol in mice and macaques, according to research published in Vaccine. The authors of the study say the vaccine has the potential to be a more powerful treatment than statins alone.

The body produces cholesterol to make vitamin D, some hormones and some of the molecules that help us digest food. Cholesterol is also found in foods. LDL cholesterol is a fat-like substance that circulates in the blood; if there is too much cholesterol, the arteries can become blocked, leading to heart disease and stroke.

While most people associate the mathematical constant π (pi) with arcs and circles, mathematicians are accustomed to seeing it in a variety of fields. Two University of Rochester scientists have found it lurking in a quantum mechanics formula for the energy states of the hydrogen atom.

"We found the classic 17th century Wallis formula for pi, making us the first to derive it from physics, in general, and quantum mechanics, in particular," said Tamar Friedmann, a visiting assistant professor of mathematics and a research associate of high energy physics, and co-author of a paper published this week in the Journal of Mathematical Physics.

Though 97 percent of climate experts believe in climate change, the public remains less convinced, including teens, who are most likely to believe what they are told and so are heavily marketed toward. Only 46 percent of teens think climate change is anything but a natural fluctuation while 57 percent aren't concerned about it.

Humanities scholar Diego Román of Southern Methodist University thinks more control over textbook content used by teachers is the answer. A new study measured how four sixth-grade science textbooks adopted for use in California frame the subject of global warming. Sixth grade is the first time California state standards indicate students will encounter climate change in their formal science curriculum.

Why would anyone agree to a higher tax? The most common technique is to convince enough citizens that someone else will pay for it. Vermont is happy with higher taxes when voters know they will get far more money from the federal government than they ever pay but most people are more skeptical. Social Security is always a decade away from insolvency because the money is spent right now.

And sometimes voters can be convinced that a tax on X will only be used on Y. California recently had a referendum on education funding, which was going to be narrowly applied - but politicians did not tell voters that it was going to be narrowly applied so they could use other education funding for other purposes.

An international research team has a hypothesis regarding the mystery of why the Mediterranean Sea dried up around 5.6 million years ago. The event, known as the Messinian Salinity Crisis (MSC), saw the Mediterranean become a 1.5 kilometer deep basin for around 270,000 years, and left a kilometers-deep layer of salt due to seawater evaporation.

The cause of the MSC has been the subject of speculation and debate, but now an international team of researchers

Right now, in any American hospital, about half of the patients have a prescription for an acid-reducing drug called proton-pump inhibitors (PPIs) to reduce heartburn or prevent bleeding in their stomach and gut. 

But that well-intentioned drug may actually boost their risk of dying during their hospital stay, a new study finds, by opening them up to infections that pose more risk than bleeding would. 

Researchers have identified factors that spark the formation of pluripotent cells. Their findings, published in Developmental Cell, shed light on human embryonic development and help research into cell reprogramming and assisted conception.

By Kate Gammon, Inside Science --Without risky ideas in science, the world wouldn't have new cancer treatments, an understanding of dark matter – or even the World Wide Web. But as scientific disciplines mature, scientists in them choose to go for small, incremental advances rather than risky leaps – and those choices lead to a system that's slower and more expensive than it needs to be, according to the study authors.

The problem?