October 16 is World Anesthesia Day, celebrating the 170th anniversary of the first successful demonstration of surgical anesthesia. Prior to then, surgery was really unpleasant, to put it mildly -- surgeons turned to alcohol, narcotics and even smacking their patients on the head to induce unconsciousness. Fortunately, anesthesia now allows tens of thousands patients every day to avoid the pain and memories of their procedures. But how does anesthesia work? This week, Reactions looks at scientists' current understanding of what happens when you go under.

Premenstrual syndrome, or PMS, affects the majority of women to some degree. A grab bag of unpleasant physical and psychological symptoms, PMS can be much more than an annoyance. This week, Reactions looks at how hormones including estrogen and progesterone interact with secondary chemicals, which can lead to symptoms of PMS.

Premenstrual syndrome, or PMS, affects the majority of women to some degree. A grab bag of unpleasant physical and psychological symptoms, PMS can be much more than an annoyance. This week, Reactions looks at how hormones including estrogen and progesterone interact with secondary chemicals, which can lead to symptoms of PMS.

Chemistry usually involves precise measurements and careful testing in order to get significant results. But a bunch of notable discoveries happened by accident. In the second edition of our accidental discoveries series, get to know the stories of how TNT, dynamite and even air bags were discovered totally by accident.

Speaking of Chemistry caught up with UCLA’s Hosea Nelson to learn about how chemists are trying to copy nature for a brighter future.

The new iPhone is slimmer and faster than ever. But like most new generations of smartphones, its battery has pretty much stayed the same over the years. Short of carrying an external battery all the time, is there any way to extend the life of your smartphone battery? In the latest Reactions episode, we explain the chemistry of lithium-ion batteries, why they occasionally explode, and share some tips to get the most from that smartphone battery.

Nothing kills snack time quite like staleness. With football season right in front of us, so we wanted to offer you some pro tips on how to revitalized your stale snacks. Oh and of course, with a whole lot of chemistry for you to chomp on.

Fans of Blade Runner have already caught a glimpse of world with super-powered humans secretly living among us, capable of physical feats far beyond your everyday person. But now, with the the CRISPR/CAS9 Gene editing system, are we looking at a future with real replicants? Check out this video to get an inside look at how CRISPR works, and the sorts of wild medical advances are just around the horizon.

The sun shines a massive amount of energy onto the Earth’s surface every day. What if humans could take a cue from plants and use sunlight to make their own food? From chloroplasts to carbon dioxide, Reactions creates a hypothetical photosynthetic human and gives a quick crash course on the chemistry of photosynthesis.

Come closer, lean in, and… inhale deeply. Some of our most valuable heritage objects—think old books, early film, and vintage plastic jewelry—have their own personal pong. But there’s more to their musk than nostalgia alone. Sarah Everts explains why conservators are starting to sniff out the compounds emitted by museum art and artifacts.