5 Trippy Optical Illusions (And The Science Behind Them)

5 Concave Surfaces Screw With Your Brain

The Mona Lisa is one of the most overrated artworks (abstract art doesn't count) ever. Sure, its gaze follows you around the room like an inner-city mini-mart proprietor, but so does some random stoner's Bob Marley painting from Etsy (and that shit glows under blacklight). Plus, the effect can be easily replicated and enhanced with a wee bit of science:

The dinosaur illusion takes advantage of our brains' ability and desire to find patterns, especially faces. And our brains see faces all the time, both real and imagined--looking at you, Jesus apparition on a piece of toast.

And there's one thing that all faces have in common: they're convex, or they stick out toward you. Unless you take advice from pop-media "pickup artists," in which case the faces you see are (unscientifically speaking) concave because they're moving away from you.

But the T-Rex's face really is structurally concave. This inversion means that the features on the left side of the dinosaur's face are farther away from you, which is the opposite of what's expected. And as we move around it, our brain tries to make sense of this angular inversion, making it look like the dinosaur is turning its head.

You can make your own cut-out version of the illusion, which was originally concocted inside the optically perverted mind of the late great magician and illusionist Jerry Andrus, who used a dragon instead of a dinosaur. 

You can more clearly see "how the sausage is made" thanks to a display at the Franklin Institute, Philadelphia's only cultural site that doesn't involve cheesesteak or football. There, museum-goers enjoy a larger version of the dragon, which more clearly shows off its reality-bending curves:

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4 A Spinning Wheel Seemingly Defies Laws Of Motion

Nature is a cheapskate that wastes nothing. Like an old lady who drops a hard candy on the floor then surreptitiously places it back in the bowl with its ancient, melted-together brethren. That's how the universe works, with natural laws mandating that things are conserved, including mass, energy, and, amusingly, momentum.

Angular momentum dictates how hard it is for something to start or stop spinning: it takes lots of energy to spin something big, but to spin a human, it just takes a few double IPAs.

In the video, the person, wheel, and platform form a closed system that must conserve angular momentum, so the net effect is zero because things at rest like to stay that way. When the wheel is spun, suddenly there's motion added to the closed system, and nature doesn't like that. So it responds with an equal and opposite force, as per Newton's Third Law, spinning the person in the other direction. And so, the change in the person's angular momentum compensates for the change in the wheel's angular momentum, bringing balance to the force.

Like many scientific demonstrations, what seems like a fun little experiment to instill a love of STEM in bored jocks has significant real-world implications. Gyroscopes exploit angular momentum to correct a rocket ship's path. When the rocket turns, these gyroscopes spin in the opposite direction to right its course and prevent it from face-planting into a Martian crater or crash-landing back on Earth in some hapless homeowner's koi pond. 

It's relevant for sports lovers, too. A quarterback imparts angular momentum on a football to nail that super-precise, game-winning Hail Mary that left you $500 in the hole and explaining why the kids can't have new light-up Power Rangers sneakers.

3 Rolling Shutter Photography Distorts Movement

The invention of photography has allowed us to glimpse the otherwise hidden wonders of the cosmos, from the most distant galaxies at the edge of the universe to the infinite biological variety of the microscopic world. Hell, photography is even mind-blowing when it doesn't work right:

That's the rolling shutter effect, and it occurs with rapidly moving objects. 

Cameras use two types of shutters, a global shutter or a rolling shutter. Global shutters are found in top-end, fancy-schmancy expensive cameras. They "snap" once, capturing the entire image simultaneously in (generally) one-tenth of a second. But your regular ol' digital camera and smartphone utilize a rolling shutter, which snaps an image line by line from top to bottom.

So there's a tiny time difference between the top and bottom of the image. It also means that the photos you take don't capture a single moment in time but tens of moments spliced together. You've probably never noticed it in your home photography because only fast-moving objects are affected. You're basically seeing different parts of the motion at different times, based on when they were captured by the imaging device:

So no, this propeller doesn't need a Viagra refill; it's just videographic time lag.

And if a camera's frame rate is synced with a moving object, it creates an equally trippy effect. Like locking a hummingbird's supersonic wings in place, resembling a floating dragon glitch caused by downloading too many Skyrim porn mods:

Similarly, capturing a helicopter's rotors when they're at the same exact position makes it look like glitch in the Matrix:

2 Refraction Makes Light Do Trippy Things

Light refracts when it passes through different materials, with the bending changing its speed. In fact, your vision even isn't possible without your eyes' ability to correctly refract light through numerous membranes, tissue types, some gooey shit, and onto the retina. And much of the light entering our eyes has been refracted multiple times, potentially producing some wonky optic tomfoolery:

This woman's convincing Marie Antoinette impression is caused by the multi-stage refraction of light as it passes through the curved wall of the swimming pool and the urine-and-feces-saturated water. After the light gets bent, it enters your eyes at a different angle, seemingly changing an object's position in space.

Sometimes, refraction totally inverts beams of light to seemingly reverse an image:

As beams of light travel through the glass of water, they bend inward and converge at a central point. This focusing of parallel light beams is why magnifying glasses allow you to incinerate ants or zoom in on disconcerting lower-body rashes.

But after the light beams converge, they keep on truckin' in the same direction and cross each other—those that came in from the right are now traveling to the left, and vice versa, as per this handy-dandy diagram.

So there you have it: our brain, the magnificent, stupendously sophisticated result of billions of years of cumulative evolution, is easily outfoxed by a lowly glass of water and a Sharpie.

1 The "Magic Angle" Reveals Hidden Images

The universe was thought to be three-dimensional until Einstein made the world shit itself by announcing that time, inseparable from space, is the fourth dimension. The next advance in our cosmic understanding may be additional dimensional discoveries, but what would they look like? Not like shit. At least at first, according to John Muntean, who devised Magic Angle Sculptures to prove it:

John Muntean is a solid-state nuclear magnetic resonance spectroscopist ("scientists" it is) at the Argonne National Laboratory. He understands terms like "chemical shift tensors" and studies the orientation of spinning molecules in "amorphous solids." This means he's smart, and he wants to pass on that smart to regular folk like us. Or should it be "like ourselves"? See, we don't know. But John Muntean would know; he's smart.  

So Muntean created Magic Angle Sculpture to demonstrate the "magic angle" of rotation: on a microscopic scale, a molecule that's rotated at the magic angle shows its three orientations as it switches between its x, y, and z axes.

And so do Muntean's Magic Angle Sculptures, whose shadows take three distinct forms as the amorphous, jumbled mass is lit from above and rotated at the magic angle of 54.74 degrees. Muntean's work explores "how perception influences our theory of the universe." Do we see existence as it truly is, or are we all unwitting participants in a grand Allegory of the Cave, who only glimpse shadows of unknowable realities? And it poses an unnerving philosophical question: could a 2D being ever know the actual shape of a 3D object based only on the shadows it casts? And how can we, 3D beings, ever know that we aren't just seeing a simplified version of a higher-dimensional universe that we can never hope to witness or understand?

Whoa, that's a lot to digest in an internet comedy article. Enjoy more Lego instead:

Top Image: Soren Ragsdale