Tom Petty, the rock 'n roll guitarist who first gained fame in the late 1970's with his band, The Heartbreakers, and maintained his popularity ever since, went into cardiac arrest before dying Monday night. But what is cardiac arrest, and how does differ from a heart attack? We explain.

A little girl sitting near the field at Yankee Stadium got hit in the face with a baseball travelling 105 miles an hour. This type of tragedy doesn't occur frequently, but when it does the results are catastrophic. And the solution – protective netting – is simple and extremely effective. It's time that all teams enact this public safety measure prior to the start of next season.

During the long runs we've been doing to train for the upcoming marathon, we've had some time to think. It made us wonder: Why is a marathon the distance that it is? Here's how it happened, and why it's remained that long.

Organic chemistry can do all kinds of cool things, like making drugs and also detecting them. One drug it can detect – instantly –  is methamphetamine. A bit of urine, an immediate chemical reaction, and a very clear color change. And also a change in your auto insurance rates. Behold a chemistry lesson and a cautionary tale. 

Here's some of what we've been up to over the last seven days, trying to change hearts and minds.

Peer review has been around for quite some time. But its history features interactions with the technology and forms of sharing information, with censorship, the rise and fall of generalists as well as concerns about marketing. 

At last, a bit of science in the form of observational data. That science can more meaningly inform guidelines for prescribing opioids (at least by surgeons) than the unsupported advice of the Centers for Disease Control. 

It's time to get your flu shot. Every year, the medical community emphasizes the importance of getting the vaccine. And every year the same excuses pop up as to why many won't. Let us explain why one of those excuses – that the flu vaccine will give someone the flu – is simply not possible.

The origin of life is a profound mystery. Once life arose, natural selection and evolution took over. But the question of how a mixture of various gases created life-giving molecules that arranged into structures capable of reproducing themselves remains unanswered.

Zika virus has been around since at least 1947, causing mild symptoms. All of a sudden it went full-beast mode and started producing shrinking heads in babies, and other terrible neurological outcomes. Scientists may have figured out that one little amino acid could responsible for flipping the script.