The human body is a wondrous machine, breathing, burping, hiccupping, and hurdling through everything life throws at it. Much of the amazingness of our body's daily business is going on beneath our skin where we can't see it, at least not without our X-ray vision goggles, or you know, an MRI machine. So how do we learn about it?

The scientific method, of course! Humans have always been curious about how their bodies work, and that curiosity leads to forming scientific questions. For example, Edme Mariotte, a French physicist and priest in the 1600s, wondered what happened to light rays when they hit the base of the optic nerve, where it attached to the retina of the eye (who doesn't wonder that, really?).

Mariotte devised an experiment where he covered one eye and looked at white dots on a dark background. He noticed that as he backed away from the dots, one of them disappeared completely.

Say what?

Mariotte thought this was pretty weird too, so he asked some more questions about what may have caused the disappearing dot, came up with new hypotheses, and tested all kinds of different variables, like the color of the dot, which eye he covered up, and so on. Mariotte concluded that instead of cells being more sensitive where the optic nerve attaches to the eye, like most scientists thought, there aren't even any cells there to begin with, making it a blind spot on the back of our eye.

Mariotte's experiment is just one of millions of experiments scientists have done, and are in the process of doing, to learn more about the human body. Thankfully, our technology has improved since the 1600s, but our use of the scientific method to answer our questions is still in full effect.

We know the human body does some weird stuff, but what happens when something goes wrong? Can we still use the scientific method? Most of the time doctors don't actually need to use the scientific method. They've spent a huge portion of their life learning about the human body, so they're pretty much experts on how it works and how to fix what goes wrong. Typically, a doctor is able to assess a set of symptoms or look at test results and know exactly what problem is causing those symptoms. We don't need to do an experiment to determine if someone has a broken leg (thank goodness).

What about when doctors don't know, though? In this case, we could argue that doctors use the ideas behind the scientific method to help them make a diagnosis. They may observe their patient, collect evidence about their symptoms from the patient or run labs and tests, then form a hypothesis about what they think is causing those symptoms. At this point, they'll test their hypothesis by prescribing some form of treatment, which could range from a medication to simple exercise. If the symptoms disappear, the doctor's hypothesis was supported. If they stick around, or have unsavory side effects, it's time to run more tests, collect more evidence, and head back to the drawing board.

The human body is super complex, but luckily we've got the scientific method on our side when it comes to learning how it all works. Whether it's scientists researching a cure for hiccups to doctors attempting to diagnose a new disease, we know that asking testable questions and collecting as much accurate evidence as possible are the keys to understanding the human body.