by Laura A. Brueckner

The idea of the “transportable” or “portable” hole that so fascinates Humayun and Babur in Guards at the Taj has a lively history in entertainment, especially in animation—but the idea has been around for millennia.

Prehistoric peoples built myths around the idea that holes or caves in the ground, hillsides, or rock faces might actually be passages to other places, especially the underworld. The Celts, for example, considered all caves sacred; at death, they believed that departed souls entered caves, returning to the womb of the earth for rebirth.

The idea of holes in the earth serving as doors to the unexpected is also explored in literature. Alice in Wonderland famously features a girl who falls down a rabbit hole and arrives somewhere quite different than the England she left behind. More recently, Neil Gaiman’s novel Neverwhere involves a young man who descends to the dystopian underworld below London through subway tunnels.

Often, when a traveler enters—willingly or inadvertently—one of these spaces, s/he encounters strange or supernatural beings (demons, gods, helpful spirits, tricksters, or monsters). Sometimes, as in Alice, the hole leads to a passageway—the traveler may emerge in a strange new land, with strange new rules of behavior.

Physics may operate strangely too. Time almost always passes differently inside these magical holes. A traveler may dash into a secluded cave to hide—only to find, upon reemerging, that a hundred years have passed in the ordinary world. Alternately, the traveler might enter the cave and discover a passageway to a fantastical country, where s/he embarks upon a decades-long heroic quest—but discover, upon return, that only a few seconds have passed in the ordinary world. Time is tricky in magical holes.

So is space...and gravity. In a delightful instance of science vindicating imagination, Albert Einstein and Nathan Rosen delivered a theoretical proof in 1935 that passageways between different universes might actually exist. “Einstein-Rosen bridges,” or "wormholes," seem to operate much like Alice’s rabbit hole, complete with bizarr-o physics and weird time.

Of course, whenever humans identify something as “sacred” (or “dangerous,”), other humans find ways to turn that anxiety into comedy. In 1955, Warner Brothers put out a “Looney Tunes” cartoon titled “The Hole Idea,” featuring a “portable hole” - an invention by a mild-mannered scientist that is soon stolen by a criminal and used to loot banks and luxury stores across town. The Looney Tunes portable hole - created by pouring a black liquid chemical onto a flat surface and allowing it to dry - can be thrown onto the ground, becoming a hole that varies in depth to apparently whatever the user needs. It can also be attached to vertical surfaces, enabling the user to pass or reach through walls or glided along glass, facilitating stealing jewelry from shop windows.

Driving the comedy in this clip, though, is the same anxiety provoked by the sacred and dangerous: that we can never fully understand or control nature. Generally, when a character assumes that s/he can use nature (in this case, manipulating how matter behaves) for selfish gain, something unexpected happens that proves him or her very comically wrong. The criminal in “Hole Idea” has the right tool, but it cannot save him; he places his last portable hole on a wall and leaps through to escape the police - only to land inside the state prison.

The good news is that characters who use a portable hole in a necessary, selfless, or heroic way often find success. In the 1988 film, Who Framed Roger Rabbit?, Bob Hoskins’ private-eye character - who is on a noble quest - uses an Acme Portable Hole to save himself from being crushed. In this video clip, he frees himself from a giant magnet by placing the portable hole on top of it, working within the same rules of cartoon physics established by “The Hole Idea” 33 years earlier.

The cartoon portable holes in “Hole Idea” and Roger Rabbit make actual holes in physical space, but not all portable holes do. The popular role-playing game Dungeons & Dragons, for instance, includes a magical object called a “portable hole” - but its opening, rather than cutting through existing matter, exposes to a ten-foot-deep “extradimensional space” that is entirely unrelated to ordinary physical reality. Objects may be placed inside the portable hole for safekeeping without adding weight to it, and no matter what’s inside, the hole can be folded up and put in one’s pocket. D&D also includes another magical tool that works in a similar fashion, the Bag of Holding – but to help players avoid the confusion that Huma and Babur experience, the D&D manual gives specific instructions that if players try to use them together, the objects will be destroyed.

Portable holes even appear in video games. The most popular example takes us all the way back to Einstein: a massively popular (and fascinating) video game from 2007 called Portal, where the player must escape from an Artificial Intelligence gone insane. The player carries a gun-like machine called the “Aperture Science Handheld Portal Device” which can be fired at various surfaces to create wormhole-like portals through which s/he can travel to another space in the game. The game incorporates some actual physics related to gravity and acceleration, allowing the player to use the portals in specific sequences to build up the speed needed to jump certain barriers.

As it turns out, Huma and Babur’s version of the portable hole is actually the most advanced of them all—like a cartoon portable hole, it bores through walls; like a D&D portable hole, it offers a place to hide (and to keep snacks); like a wormhole or portal, it can connect two remote locations. Sadly, their portable hole actually may be too much a good thing: when Babur asks, "But could the transportable hole…wouldn't it fall through its own hole?", the two men’s thought experiment falls apart. Without a way to keep the hole from falling through its own hole, their ultra-slippery “transportable hole” will defy any attempts to use it.