You've probably seen some amazing medical images of the body over the years (or maybe just that childhood x-ray of your broken arm). But, don't they always seem a little...vanilla? Thankfully, we've got just the spice you've been looking for: This video reveals what it really looks like (yep, inside the body) when a man and a woman get it on — no creepy ceiling mirrors required.
To create these images, researchers used a magnetic resonance imaging (MRI) scanner. As the name implies, MRI makes use of a magnetic field to get an idea (non-invasively) of what's going on inside the body. That magnetic field causes your spinning hydrogen protons (found in water and fat) to line up like, well, magnets. Then, a radio wave is added to the mix, causing those protons to drift in a different direction. When the radio wave is turned off, the protons begin to relax back into their magnetic-field alignment and emit a signal, which the MRI scanner picks up. This way, the scanner is able to measure the degree to which the protons change their positioning — and how quickly they do so. And, the scanner can pick up different types of tissue within the body based on their compositions. So, although it's not a true "picture" of your insides, in most cases an MRI scan is a pretty excellent approximation.
The scans in this video cover research on everything from the musculoskeletal system to lungs inflating and hearts beating. But, the real draw is the footage — done for a 1999 paper that was published in The BMJ — that proves we can get MRI imaging of a man and woman having sex in the missionary position. (Because, weren't you wondering?) For their tireless search to answer this question, the study's authors received a (sort of) prestigious Ig Nobel prize in 2000.
Now that we've elevated the simple act of recording yourself during sex into this infinitely more fascinating representation, the next step is even more out-of-this-world. Get on it, science.