While we commonly understand concepts like length, depth, width, and time, these dimensions are fundamental to how we perceive the world. But beyond these, both science fiction and reality have led us to search for hidden dimensions that could surround us. From exploring the physics of animated shows to theories of an ever-expanding universe, we've stumbled upon some strange and mind-boggling ideas.
10. The Super-Sargasso Sea

In 'The Book of the Damned,' Charles Hoy Fort introduced the idea of the Super-Sargasso Sea, a dimension where all the missing things from our world are gathered before being mysteriously returned. One of his main pieces of evidence for this theory was the bizarre phenomenon of animals raining down from the sky, a strange occurrence he attributed to this proposed dimension.
The Super-Sargasso Sea is believed to either orbit alongside our world or stay stationary above us while we move. Fort envisioned a future where aviators might venture into this newly discovered dimension to find vast fishing areas filled with creatures from Earth or other objects swallowed by the sea—even interplanetary messages.
By analyzing the strange patterns of animal rains, Fort proposed that the Super-Sargasso Sea extended from Britain to India, though he acknowledged that future evidence might reveal a different range.
9. Hammerspace

You’ve likely seen it in cartoons: a character pulls something out of thin air for comedic effect. This mysterious dimension, where these objects are kept, is known as Hammerspace.
The term 'Hammerspace' was coined by fans of *Ranma ½*. It's a dimension that exists out of the camera's view. It’s also what enables clowns to keep emerging from tiny clown cars, suggesting they have knowledge of what Hammerspace looks like—potentially explaining a lot about clowns.
The smallest form of this pocket dimension is Basic Hammerspace, which can only store a few items. Then there’s Game Hammerspace, which is used in role-playing games, and Infinite Hammerspace, the dimension that characters traverse when they open a door in one location and appear on the opposite side of the world.
8. Paraspace

Paraspace was introduced by author Samuel R. Delany to describe a recurring element in science fiction: when a character is transported from their own world to another, those alternate locations exist within paraspace.
Actions within paraspace influence the character's real-world experience. Before the term was coined, these alternate dimensions were referred to as subspace. Delany and other writers aimed to distinguish this, emphasizing that paraspace is just as real as the character's original world.
This concept has evolved to describe scenarios where the experience of a strange, otherworldly place is so bizarre that it overwhelms the individual’s awareness of their real surroundings. It has also been defined as a foreign dimension existing within a more familiar one, or a space within a space, where there is no clear “in-between.”
7. Flatland

In 1884, Edwin Abbott Abbott, a minister and scholar, wrote a book that envisioned a world with only two dimensions. *Flatland: A Romance of Many Dimensions* tells the story of A Square, a character living in a society where the more edges and angles you possess, the higher your social status.
Flatland is a world within a world, and every 1,000 years, it is visited by a being from another dimension—the third. This being, known as Sphere, attempts to convince the inhabitants of Flatland of the existence of a whole new world. Abbott describes this flat world in exquisite detail, from how cardinal directions are established without the help of a Sun or stars to the laws of inheritance and the role of women in society. His portrayal serves as a satirical critique of Victorian-era Britain.
6. The Time Vortex

*Doctor Who* frequently explores the concept of traveling through space, time, and the fabric of space-time, all with the aid of the TARDIS. Recently, a pair of real-life scientists proposed rules for a “Traversable Achronal Retrograde Domain in Spacetime” and outlined how time travel could be feasible with a TARDIS.
A TARDIS (which, by design, is larger on the inside than it appears on the outside) is essentially a bubble separated from its exterior by the curvature of space-time. From an outside perspective, two bubbles would first drift apart before coming back together, while the person inside would experience a steady journey in one direction. This occurs because they are following a circular path (similar to the movement we observe in the night sky), which explains why planets sometimes appear to shift direction in retrograde motion.
Although this concept is theoretically possible, it will never happen due to the type of matter required to violate the fundamental rules of energy use and consumption.
5. L-Space

Terry Pratchett proposed a perfectly logical equation that defines the connection between knowledge and power: “Books = Knowledge = Power = (Force x Distance) / Time,” and this is where L-Space comes into play.
L-space is a dimension that links all libraries, and it’s possible to be in it without even realizing. Massive libraries, in particular, might transform into L-space, filled with endless rows of books that extend into infinity. This dimension holds every book ever written, every book that will be written, and even the books people intended to write but never got around to.
Anyone who masters the art of navigating L-space can locate and read any book within it, but they must adhere to strict rules. Only senior librarians are aware of these rules (such as maintaining silence, returning books on time, and preserving the integrity of causality) and are taught how to avoid perilous books, like those filled with cliches.
4. Hyperspace

Hyperspace is a key concept in science fiction, based on the theory that tapping into energy from other dimensions creates a shortcut for traveling faster than light, covering vast distances in a short amount of time. The methods for this dimension-hopping travel vary, and while concepts like wormholes are common in modern fiction, some ideas have been around for centuries.
The notion of rapid space travel can be traced back to 1634, when Johannes Kepler wrote *Somnium*. In his story, humans travel to an island located 80,000 kilometers (50,000 miles) above Earth, accessing this place via an interdimensional path opened by demons. Kepler depicts these demons initiating the journey according to the phases of the Moon. They administer opium to keep travelers in a state of sleep and use an unspecified accelerating force to move them across space.
3. The Theory Of Ten Dimensions

We experience the physical world in three dimensions—length, width, and depth—and the fourth dimension, time, is universally accepted. According to superstring theory, there are several other dimensions that directly affect us, even though we might not be aware of them.
The fifth dimension exists alongside our reality, differing enough to allow us to measure its contrasts. The sixth dimension is a realm where all possible universes and pocket universes reside, though only those that began in a similar way to our own universe. The seventh dimension consists of worlds that originated in a completely different manner from our universe, and the eighth dimension holds infinite histories for the worlds in the seventh dimension.
In the ninth dimension, there are worlds that follow entirely different physical laws than ours. The tenth dimension encompasses everything imaginable—and beyond. Since it contains far more than our minds can grasp, the theory suggests that we cannot fully comprehend or conceive of more than ten dimensions.
2. Pocket Universes

Alan Guth, a theoretical physicist at the Massachusetts Institute of Technology, introduced the concept of cosmic inflation. One aspect of this theory suggests that the universe is continually expanding, and as it does, it creates more and more space. This includes an infinite number of pocket universes—distinct realms where anything that is possible, will happen, endlessly.
Guth proposes that we exist within one such pocket, while countless other pockets are layered all around us. The term “pocket universe” is essentially the plural form of “universe” and refers to areas where the laws and constants of nature remain constant. However, if we move beyond our pocket universe, the laws of nature, constants, and dimensional boundaries begin to shift.
1. Five-Dimensional Black Holes

In 2002, theoretical physicists introduced the concept of ring-shaped black holes, but it wasn't until 2016 that supercomputers were able to simulate their behavior. The theory suggests that such black holes develop a series of bulges, which eventually detach to form new black holes, resembling water dripping from a faucet. This process would result in a naked singularity, causing the collapse of the Theory of Relativity, which underpins all of our scientific understanding.
A black hole of this nature could only exist in five dimensions, where a naked singularity might emerge on our side of the event horizon. General relativity posits that singularities only exist within the confines of black holes, but the idea of ring-shaped black holes opens the possibility for a singularity that destroys the laws of the universe as we know them.