In a “normal” electrocardiogram (ECG), the transition of the QRS axis in the precordial leads occurs between leads V 3 and V 4 (i.e., there is a dominant S in V 3 and a dominant R in V 4).

MOLINE, Ill. — We've all likely seen at least one tornado in our lifetime, whether it be via a video or in person. One thing the majority of those tornadoes have in common? The direction in which they ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

Discover the mind-blowing science behind a screw that works both clockwise and counterclockwise. Learn how its unique design makes direction irrelevant and explore the fascinating physics behind it!