Even before the humble beginnings of philosophy in ancient Greece, humans have been obsessed with the idea of substances, where one material ends and another begins, and the general building blocks of life. But over the thousands of years that we’ve studied various materials, we’ve developed a good idea of what’s what. With the science of chemistry and the periodic table, we’ve come to figure out and predict how basic substances or materials work.

Some materials have bizarre and abstract traits and are frankly quite weird. Nature seems to operate by strict rules, where things are seemingly predictable and fit wonderfully into neat little explanatory packages. This gives us the ability to categorize things in different ways and understand them for what they are.

Here are 10 absolutely strange materials that have been discovered by scientists throughout the years.

10 Triiodide

While triiodide itself refers to one chemical which can be mixed with many others to create different chemicals, triiodide, short for triiodide ion, isn’t inherently very interesting. It’s often a yellowish substance that turns red when prepared in such a way to create nitrogen triiodide, with the inorganic compound designation of NI.

What makes nitrogen triiodide so special? It’s ridiculous explosiveness.

Most explosives use chemical processes which are quite complex, or heat and combustion. But not nitrogen triiodide, which is explosive on contact. That’s right. Take a simple gram or so of this powder, set it on a table, touch it with nearly anything, and watch the show.^[1]

All that’s required for it to blow up is simple contact, or friction. This material is so unusual due to its volatility that even touching it can cause it to explode.

9 Vantablack

Vantablack is an artificial material that was developed by Surrey NanoSystems. This coating goes on many things, from paint to carbon objects. It’s the material equivalent of a black hole in that it traps light, so much so that three-dimensional objects coated with the material appear to be two-dimensional as the refraction of any light is so heavily reduced.

It holds the world record for the darkest artificial substance and the darkest black you can buy. The material absorbs 99 percent of all light it comes into contact with.^[2]

People even coated a building with it in South Korea to create “the darkest place on Earth” in a mimicry of the deepest recesses of space. The goal was to create an experience of being absorbed into blackness—a deep, dark cloud of black.

Three-dimensional objects coated in Vantablack actually look like shadows from the profile view. Definitely an interesting material, to say the least.

8 Ultrahydrophobic Material

Ultrahydrophobic material isn’t the stuff we buy to coat leather and suede products or the spray coatings that protect our outdoor wood projects from the rain and other elements. An ultrahydrophobic coating actually causes water to encase itself into tiny spheres that look like gemstones or marbles.

It’s so water-resistant that if you sprayed your old windshield with it, you could drive in the rain at up to 64 kilometers per hour (40 mph) and your windshield wouldn’t get wet.^[3] Goodbye, trusty windshield wipers.

In fact, ultrahydrophobic material repels almost all liquids, causing them to shrivel up into little balls that you can even roll around as if they were actual marbles. This material is genius and has a lot of applications, including those for high-tech industries. It’s also ultra-weird.

7 Ferrofluid

Ferrofluids are a type of liquid that can easily be formed into strange shapes without even touching them. Often dark, blackish, reddish, or grayish liquids, ferrofluids act very much like any other liquid when they’re outside the presence of a magnetic field.

The moment the fluids come into contact with a magnetic field, they become highly magnetized, morphing shapes, bending, or pulling. They do everything our usual solid magnets do, only as a liquid state.

This stuff looks like a dark, liquid metal. It can be purchased online or even made with readily accessible Internet instructions. Like so many other wonders of physics, it’s truly an amazing sight to see ferrofluids in action as they respond to the magnetic field and fall right in line with it. Then they disperse randomly once the magnetic field is removed.^[4]

6 Supercritical Fluid

Supercritical fluid is a material created under certain circumstances of temperature and pressure. It suspends the dividing lines of physical properties as we know them. In short, supercritical fluid is a substance somewhere between liquid and gas. It is a mixture of both, and yet it is neither liquid nor gas.

It occurs when any fluid gets heated above its critical temperature and pressure. Critical temperature is the point where a substance has been heated to such a degree that you cannot liquefy it. Critical pressure is the pressure that’s needed to turn a gas into a liquid at a high temperature.

Supercritical fluid is a gas-like substance with highly liquid properties.^[5] If you were to delve into the atmospheres of some planets, like Jupiter or Neptune, you would be immersed in it. It’s a super-freaky version of all liquids . . . or is it a gas?

5 Nitinol

Nitinol is a trade name for nickel titanium, a metal alloy with some extremely unusual (and important) properties. Nitinol is often used in the medical industry, but it has other applications.

The weird thing about this metal is that it’s almost like the liquid metal featured in the movie Terminator 2: Judgment Day in that it can always return to its original shape. Nitinol has superelasticity, or a memory for its original form.

So if you make an object out of nitinol and then bend it completely out of whack, it’ll automatically crawl and form back into its original shape before your eyes (aka pseudoelasticity). These shape memory properties make it both fun and practical.^[6]

Stents are a great application as nitinol can bend within the human body when needed, has the durability of a metal, and can return to its original form every single time after the force which causes it to warp is released. Nitinol’s bending, shape-shifting properties are activated by heat. At some temperatures, it will bend out of its original state. At others, it will return to its original state.

This temperature difference can be controlled within 1 degree Celsius (1.8 °F). From algae that remembers the light shined upon it to nitinol which always remembers its original shape and returns to it under the right conditions, materials with a “memory” are definitely fascinating and weird.

4 Gallium

Gallium is a metallic element with the atomic number of 31, which even more closely resembles the liquid metal from Terminator 2: Judgment Day. Gallium’s particularly strange characteristic is the low temperature at which it liquefies, which is only a tad shy of 30 degrees Celsius (86 °F). That’s close to room temperature in many places.

This metallic element is bright, shiny, and silvery white in color. When you handle gallium, there’s no ambiguity that you’re handling a liquid metal. As a liquid, this metal can be played with—it rolls and forms into various shapes in your hands.^[7]

Gallium has many practical uses, like LED lights, cabling, and pharmaceuticals. It’s an extremely soft metal, even in its solid state. In fact, it’s so soft that you could slice into it with a knife without much resistance at all. If you made a solid sphere, a ball of gallium, and then picked it up, it would melt in your hand. That’s one fascinating metal.

3 Hydrogel

Hydrogels are a fascinating group of substances, not unlike supercritical fluids. However, instead of being suspended somewhere between a liquid and a gas, hydrogels are suspended somewhere between a liquid and a solid.

A hydrogel maintains its shape and doesn’t flow around objects like a solid does, but it bends amazingly like a liquid with an extremely soft pliability. JELL-O is one famous hydrogel that we all know about. It’s a fun snack for people around the world. But there are other types of hydrogels and other uses for them besides foods.

Due to their flexibility and durability, hydrogels are showing great promise in the world of science for biomaterials, which go on or in the human body. Their ability to completely liquefy, fill a space, and then solidify and still be flexible is mind-blowing.^[8]

Hydrogels are a series of polymers that contain both chemical and physical properties which change their state from solid to liquid seamlessly. When heated, the polymer proteins dissipate and travel more freely. When cooled, those same proteins harden again but not quite as drastically as when water hardens into ice. These proteins make hydrogel one of the most unusual feeling and visually entertaining substances.

2 Graphene Aerogel

Graphene aerogel is the lightest material on Earth and definitely the lightest solid material that we know of. It weighs in at just 0.16 milligrams per cubic centimeter, almost lighter than air. Its density is even lower than helium, although slightly higher than hydrogen, the lightest of all the gases.

Graphene aerogel is created by taking a hydrogel and replacing the liquid contents with air, making the substance 99.98 percent air by volume. This is why it’s so light—it’s empty. There aren’t a lot of the dense atoms of a solid or a liquid to weigh it down. As a result, graphene aerogel is the least dense of all known solid materials.^[9]

On top of being used today for many adhesives, coatings, and fillers, graphene aerogel is also being developed as a lightweight material for 3-D printing that produces precise results. The future of graphene aerogel shows much promise, and this substance is going to be a staple of the future for printing items like lightweight coffee cups or even jewelry.

1 Dark Matter

Dark matter is one of the most elusive substances in the currently known universe, and that makes it arguably one of the most fascinating. Dark matter makes up about 27 percent of the physical universe. It cannot be detected by its luminosity, the refraction of light that we use to “see” and detect regular matter with our eyes and instruments.

Instead, dark matter can only be detected by its gravitational pull. We know it’s out there, but we can’t see it. So we can only perceive its presence by its pull on other objects that we can see.

With its existence first hypothesized in the 1970s, dark matter set the stage to explain the mysterious movements of many objects being pulled in its gravitational field—like galaxies which seemed to miraculously escape the gravitational pull of the larger galaxy cluster to which they belonged.

Gravitational lensing occurs when a substance in space distorts the space fabric and “bends” light from behind it. Even though we can’t see dark matter, this is how we know it exists. It bends the passing light rather than emitting or reflecting light.^[10]

For a frame of reference, dark matter makes up about 27 percent of the observable universe, but observable matter only comprises 5 percent of our universe. About 68 percent of the universe is “dark energy,” a mysterious, elusive energy.

This means that about 5 percent of our universe can actually be seen and detected using observation of the actual substance itself. It can only be perceived by its effect on the tiny sliver of the universe we can see. This makes dark matter one of the strangest substances detected by modern science.

I like to write about dark stuff, fun stuff, weird stuff, history, and philosophy. Here’s a fun one about weird and wacky substances.

Comic book plots are not restrained by the scientific laws that govern the real-world universe. Of course, ironically, the imaginary atomic and subatomic particles, chemical elements, and substances of the Marvel Comics and DC Comics universes often either have actual real-world counterparts or borrow from one or more of them, usually with an unlikely or impossible twist.

This is true whether we’re talking Wolverine, Captain America, Thor, the Metal Men, Superman, Deathstroke, Flash, Dr. Doom, Wonder Woman, Luke Cage, or the Fantastic Four or whether we’re referring to superpowers, costumes, or weapons. If we take a closer look, we find that one or more of the 10 real counterparts of comic book particles and elements on this list come into play in these comic book characters’ lives and universes, and what a difference they make!

For better or worse—or, actually, for better and worse—the real-universe counterparts of these particles and elements, in most cases, lack the properties of the ones in the Marvel Comics and DC Comics universes.

Related: Video: 10 Comic Book Heroes Who Could Theoretically Exist

10 Adamantine

Where would Wolverine be without adamantine? The same place that Captain America and several other Marvel Comics superheroes would be—a lot less dangerous and a whole lot more vulnerable, that’s where. Wolverine’s skeleton and Freddy Krueger-like retractable claws are both bonded to the virtually indestructible alloy. Captain America’s disc-shield, which is both a defensive instrument and an offensive weapon, is also made, in part, from adamantine, alloyed with vibranium, another element that exists only in the Marvel universe. Adamantine is both impervious and all-but-indestructible. There’s no other element quite like it in the Marvel universe.

Adamantine exists in the real world too. However, it’s nothing like the Marvel version. It is an ingredient in a veneer; it is also a mineral known as adamantine spar.

The celluloid veneer is used in clockmaking. A product of the Celluloid Manufacturing Company of New York City, the veneer was available in black, white, and “colored patterns such as wood grain, onyx and marble” and was patented on September 7, 1880. A year later, the Seth Thomas Clock Company acquired the right to use it and, beginning in 1882, glued it, as a facing, to the wood cases of their clocks.^[1]

9 Star Core

One version of Thor’s mystic hammer Mjolnir is—by his father Odin’s command—forged by elves from the core of a star. What, exactly, is the core of a star? In the Marvel universe, who knows? Even in the actual universe, it’s not easy to pin down the exact meaning, especially if we expect the definition to include an object.

The core of a star is actually more a place than it is anything else, a place in which enormous temperatures and pressures “ignite nuclear fusion, converting atoms of hydrogen into helium,” which results in the release of “a tremendous amount of heat.” The Universe Today website uses our own sun as an example. It’s a fairly normal star measuring 1,391,000 kilometers (864,938 miles) across.

Our sun’s core, which is about 278,000 kilometers (172,000 miles) across, makes up approximately “20 percent of the solar radius.” It is inside the solar radius that temperatures as high as “15,000,000 degrees Kelvin occur and nuclear fusion [takes] place.” The bigger the star, the bigger and hotter its core. Obviously, human technology couldn’t forge a hammer or anything else out of a star’s core, but, apparently, elvish technology is up to the task.^[2]

8 Iron, Gold, Lead, Tin, Mercury, and Platinum

Since the Metal Men form a group of adventurers, we treat them as a single entity on our list.

DC Comics’ Metal Men had their origins in response to a real-life emergency. As Don Markstein’s Toonopedia article points out, The Atom had moved up from the ranks of the minor leagues of characters to the big league, meaning he was given a title of his very own. His promotion left Showcase, the comic book series in which he’d appeared, without a principal. To make matters worse, the next “issue was due at the printer in two weeks.”

Fortunately, writer-editor Robert Kanigher came to the rescue, creating a group of adventuring robots, scripting “a story for them in a single weekend.” Penciller Ross Andru and inker Mark Esposito also proved up to the task and drew the comic just before the deadline. Not expecting them to grace the pages of Showcase or any other DC comic again, Kanigher killed them off at the end of their debut story.

He then resurrected them, and they continued their adventures after Dr. Will Magnus collected their remains and forged the team anew, complete with their life-giving “responsometers.” In all, the Metal Men number six.

Of course, each of them has a counterpart in the actual universe as well as in the DC Comics universe. The actual properties of gold are reflected in Gold’s personality and abilities. The leader of the Metal Men has a golden hue and the physical properties of the metal. Armed with these qualities, Gold can “stretch into a thin wire miles long or flatten into a sheet four-millionths of an inch thick.”

“Big-hearted” Lead often shields his teammates from harmful rays and radiation. Iron, “the Metal Men’s strongman,” can be shaped and formed into an infinite variety of objects that help the team carry out their missions. Vain, arrogant Mercury boasts of his being the only metal that is a liquid at room temperature. Tin, the smallest and weakest of the Metal Men, feels “inadequate [and] stutters, although this impediment often vanishes in the heat of battle.” Bright and beautiful Platinum falls in love with her maker.^[3]

7 Kryptonite

Depending on its color, chunks of kryptonite have various effects on Superman (and other Kryptonians, including Supergirl). The chunks of the crystalline mineral are remnants of the planet Krypton, from which Kal-El’s parents dispatched him, as a baby, in a tiny spaceship just before the planet exploded. Kryptonite may be green, red, blue, gold, silver, black, or white.

Green weakens, causing severe pain and fatigue, and is ultimately “lethal to all Kryptonians.” Red weakens, causing extreme mood swings and mutations. Blue negates the effects of red kryptonite. Gold strips Kryptonians of their superpowers. Silver causes extreme hunger, “intense delusions and hallucinations [and] paranoia.” Black has a Jekyll-and-Hyde effect, splitting a Kryptonian’s identity into good and evil personalities or even good-twin, bad-twin versions of themselves. White kryptonite kills any plants in the universe.

As Bill Christensen reports in a LiveScience website article, kryptonite also exists in the real universe! Except for its lack of fluorine, it has the same chemical composition as the varieties of Superman’s crystalline mineral. However, Earth’s sodium lithium boron silicate mineral doesn’t exhibit the same array of colors that the Kryptonian version does. Instead, it fluoresces a pinkish-orange under ultraviolet light. Fortunately, unlike the type that plagues Superman, real kryptonite is also harmless.^[4]

6 Promethium

As the DC Universe Infinite website article on Deathstroke indicates, his “origin has been revised and reimagined several [times] over the years.” In DC Comics’ original story of his origin, Col. Slade Wilson participates in an experiment. As a result, he develops superhuman physical and mental powers and becomes a black ops agent. His friend and executive officer, scientist David Isherwood, develops a “‘gravity sheath’ bodysuit” for Slade. However, Slade rejects it in favor of custom-made promethium armor, which “absorbs kinetic energy and blocks it, making it impervious to bullets or the fist of a superhuman opponent.”

Although promethium exists in the actual universe as well as the DC cosmos, the real-world element has none of the properties or uses described in DC Comics. Instead, as the Royal Society of Chemistry points out, most of the radioactive element is used in research, although “a little promethium is used in specialized atomic batteries…the size of a drawing pin…[and] for pacemakers, guided missiles, and radios.” It is also used as “a source of X-rays,” and its radioactivity is employed in measuring instruments.^[5]

5 Molybdenum

In an issue of DC Comic’s Flash, as the superhero closes in on Alchemy while the villain seeks to force information from a victim, the Scarlet Speedster is puzzled. “I don’t get it,” Flash thinks. “Alchemy must know I’m chasing him—and yet he’s standing right out in the open. He’s unprotected!” The reason for Alchemy’s apparent lack of concern is revealed when Flash discovers that his foe has laced the entire area with strands of molybdenum. Had Flash not noticed the nearly invisible filaments, his charging through them at super-speed “would have been like running through a vegematic.”

Not only does molybdenum really exist, but its use in the Flash comic book is a rare instance in which the element actually could do what the writers depict it as doing. One use of molybdenum is to make wire rope resistant to corrosion. Specifically, we’re referencing Type 316 wire rope, which is used in severe environments that require a higher level of “resistance to corrosion” than is afforded by Type 304 wire rope, a “basic stainless steel alloy” variety that includes chromium, nickel, and carbon. The addition of molybdenum allows Type 316 wire rope, a chromium-nickel alloy, to fare better against many industrial chemicals and solvents and, in particular, “inhibits pitting caused by chlorides.”

It’s hard to say just how thick the strands of molybdenum shown in the Flash comic book are, but wire rope containing the element is usually stocked in diameters ranging from 1/16 of an inch to 4 1/2-inches. It’s possible that Alchemy cast thinner strands, which appeared nearly invisible to Flash. It’s also possible that Flash, whose speed afoot matches or exceeds that of Superman, might run so fast that he would streak through Alchemy’s molybdenum filaments without seeing them, in which case he would most definitely learn what it is like to be sliced to pieces.^[6]

4 Titanium

As Shawn S. Lealos points out in his CBR.com website article, Dr. Doom’s armor, made of titanium, has been upgraded several times over the supervillain’s career. Ironically, the supervillain’s original armor was forged by monks and was later embedded with splinters of the true cross. His armor is equipped with several high-tech weapons and further enhanced by magic, too, but it’s the element of titanium we’re concerned about here.

The Royal Society of Chemistry website is one of several sources that give visitors the lowdown on titanium, a real-world element with several practical applications, none of which, alas, is related to armor. Although some of its qualities suggest that it could be used for such a purpose. For starters, the element is as strong as steel but much less dense and can be used as an alloying agent with iron and other metals. In fact, alloys, including titanium, are used primarily in aircraft, spacecraft, and missiles because of their “low density and ability to withstand extremes of temperature,” the website notes.

According to the Society, The titanium pipes used in power plant condensers resist corrosion even in seawater, which makes the element ideal for use in the hulls of ships as well as submarines. It is also used in desalination plants. Since titanium “connects well with bone,” it also has medical uses, including joint replacements and tooth implants. It is most often “used as a pigment in house paint, artists’ paint, plastics, enamels, and paints,” but it is also an ingredient in sunscreens.

Titanium also has an incredibly high melting point (1,670 degrees Centigrade, or 3,038 degrees Fahrenheit) and an even higher boiling point (3,287 degrees Centigrade, or 5,949 degrees Fahrenheit). If Victor von Doom is reading this, perhaps has given the Fantastic Four’s nemesis some new ideas for armor upgrades.^[7]

3 Photons

DC Comics featuring the Amazonian princess doesn’t specify from what material her magical sword was forged, but Wonder Woman: The Ultimate Guide to the Amazon Princess by Scott Beatty informs us that its blade is sharp enough to sever electrons from an atom.

In Alexis Ross and Mark Waid’s graphic novel Kingdom Come, Wonder Woman’s sword cuts Superman when the Man of Steel draws her weapon before she can warn him of its effects. In one of Kyle Hill’s YouTube videos, he explains the stunning effects that such a sword would have if it existed in the real-world universe. An ordinary blade cuts objects (and people) by “applying more pressure than a material’s structure can withstand,” thereby separating the material’s molecules.

Wonder Woman’s sword, however, slices through the spaces between atoms and their orbiting electrons, “applying pressure directly to the ionic and covalent bonding [that holds] materials together,” notes Hill. In the process, her sword swings “separate atmospheric atoms from their electrons and ionizes them,” which would leave a trail of lightning behind each stroke. Her sword would be the sharpest thing in the universe, capable of slicing through Luke Cage’s bulletproof skin, Wolverine’s adamantine skeleton, or Captain America’s vibranium shield.

According to Stephen Reucroft and John D. Swain, professors in Northeastern University’s Department of Physics, three things split electrons from atoms: electromagnetic radiation, particles, and heat. Heat is a form of energy; almost all particles are material objects; and radiation can be either energy or matter. Once all the electrons are stripped or cut away from the atom, only the nucleus remains.

We seem to be left with two possibilities, both rather broad: Wonder Woman’s sword is made exclusively of particles or of energy. The former state of affairs could allow the weapon to have a material form since most particles are matter, but could pure energy also have a form? The short answer is almost certainly no. As Ethan Siegel explains in his online Forbes article, with one possible exception, “energy is never seen to exist on its own, but only as part of a system of particles, whether massive or massless.”

The exception? Dark energy, which causes the expansion of the Universe to accelerate. It may also be the energy that is “inherent [in] the fabric of the Universe itself!” However, even if dark energy exists independently of matter, it cannot be generated by any technological means. As Siegel concludes, “Creating energy independent of particles? It might be something the Universe itself does, but until we learn how to create (or destroy) spacetime itself, we find ourselves unable to make it so.”

It seems, then, that Wonder Woman’s sword must be made of some sort of particles, such as those of light, which can be contained in the shape of a sword, the particles, or photons, of which knock electrons from their atoms. In magic, as in fantasy, after all, anything is possible.^[8]

2 Bulletproof Skin

Although Luke Cage’s bulletproof skin seems possible only in a comic book, a news headline, “Bulletproof Human Skin Made From Spider Silk,” suggests otherwise. Sort of. Obviously, spider silk is not the same as human skin itself. Still, the substance can make human skin bulletproof.

According to the online article, a Dutch team created a piece of “bulletproof” skin from special, U.S.-made spider silk and human skin cells and found that it indeed can repel bullets—as long as “they’re not traveling too fast.” If additional research allows improvements to the silk armor, soldiers may one day be impervious to bullets.^[9]

1 Cosmic Radiation

In comic books, exposure to various types of radiation has turned ordinary folks into superheroes (or, sometimes, supervillains). Among those who have developed superpowers due to such exposure are Reed Richards, Sue Storm, Johnny Storm, and Ben Grimm, better known, respectively, as Mr. Fantastic, The Invisible Woman, The Human Torch, and The Thing or, collectively, The Fantastic Four. They all developed their powers (super elasticity, invisibility, combustion, and superhuman strength) by being exposed to cosmic radiation during their testing of an experimental rocket ship.

Cosmic rays do exist outside the pages of comic books, and, yes, they could endanger space travelers. According to The Space Review website, galactic cosmic rays represent a “continuous background radiation to which the crew would be exposed, [and]…in an unshielded spacecraft, [such] radiation would result in significant health problems, or death, to the crew.” Shielding would absorb cosmic radiation, but it could also cause a problem even worse than the radiation itself: cosmic rays interact with the shielding and can create “secondary charged particles, increasing the overall radiation dose.”

Former astronaut Dr. Jeffrey Hoffman, who is currently a professor at MIT, believes Earth shows how to create more effective shielding to protect against cosmic radiation and other hazards such as solar flares: a hybrid system that employs both a magnetic field and passive absorption. “‘That’s the way the Earth does it,’ Hoffman explained, ‘and there’s no reason we shouldn’t be able to do that in space.’”

Although cosmic rays are real, they wouldn’t have conferred superpowers on Richards and his crew. As the host of the Reactions’ “Can Radiation Give You Superpowers” video and her guest Professor Dan Claes, Ph.D., point out, even on Earth, everyone is bombarded with cosmic radiation every day, as much as 115 times a second. In space, inside the Van Allen Belt, the foursome “were probably hit around 15 million times a second,” Claes adds, and “ten times that” if a solar flare occurred during the crew’s trip.

However, it is so extremely unlikely that all 75 trillion cells in the crew’s bodies could have been struck the same number of times by the cosmic rays “in the same superhuman way and giving them each a different ability,” Claes explains. It is much more likely, it seems, that Richards, Susan Storm, her brother Johnny, and Ben Grimm would have died instead of becoming The Fantastic Four.^[10]