What Causes Hypnic Jerks?
Often when we are about to fall asleep, we experience a kind of a falling sensation which causes us to wake up with a start. It happens to almost everybody, and the sensation is known as a hypnic jerk. It also sometimes happens when you tilt the chair you’re sitting on too far—somehow you can sense when you’re about to fall, and you wake up with a hypnic jerk. We really have no idea what causes them or whether they serve any modern purpose, but science has come up with some interesting theories.One hypothesis suggests that our bodies developed this mechanism when we used to sleep on branches or high ground, and it was meant to help us avoid a fall. But there is no evidence to support it, and humans rarely slept on trees or precarious cliffs as a matter of habit. Other theories suggest that it happens because of the slowing down of the body’s processes when you fall asleep, but again, there are no scientific studies to support that claim either.
How Do Magnets Work?
Magnetism is a widely observed phenomenon in our universe, but a lot of things about it remain unexplained. For example, why do particles charged with electricity create a magnetic field strong enough to physically move things from far away? And when they do, why exactly do they align themselves to two poles, north and south?Explanations range from “it’s just one of those things” to particle movement at the quantum level, and MIT even has a whole laboratory dedicated to research on nothing but magnetism. We know that it’s happening, and we have a good idea of what exactly is happening, too—the particles align themselves in a way that adds up their charge in one direction, but it’s not very clear as to why the particles emit a magnetic field to start with. The fact that the Earth’s magnetic field is not well understood either further restricts our ability to understand magnetism.