xkcd.WTF!?

Explanation ➲

This comic is a comparison between black holes and regular, everyday holes.

	Black hole	Regular hole	Explanation
Usually formed by...	Supernovas, colliding stars	Shovels, small mammals	When a sufficiently large star has consumed nearly all of its low-atomic-weight "fuel", it collapses. This triggers an explosion of what "fuel" remains, creating a supernova. If enough mass remains after the explosion, it becomes a black hole. A black hole can also be formed if enough mass in a small volume accumulates by two stars, especially neutron stars, colliding. On the contrary, regular holes are often created by a variety of natural and anthropogenic causes including, but not limited to: humans using shovels, small mammals such as moles or dogs, the shift or evaporation of underground water, volcanic processes, etc. Of course, this is by no means limited only to small mammals. Many animals, from elephants to ants, are also known to sometimes create this kind of hole.
Falling in is...	Definitely fatal	Sometimes fatal	Falling into a black hole is almost always fatal, because of the shearing effect created by tidal forces and/or radiation from its accretion disk. If the black hole was extremely massive (on the order of many galaxies' worth of mass) and had a very large event horizon, the tidal forces at its event horizon would not be very strong, nor would there be a noticeable accretion disk (what you experience beyond that point is subject to serious conjecture). On the other hand, only if a regular hole is deep enough (or someone falls incorrectly), is it possible for someone to die by falling into it.
Created by the Big Bang	Maybe	No	Like many other celestial objects, black holes may have been created by the Big Bang, especially given that black holes and a base singularity theoretically share many qualities. However ordinary holes were almost definitely not directly created this way. Technically, though, because the entire universe started with the Big Bang, everything in it (including ordinary holes) could be argued to be indirectly "created" by it.
Created by children playing at the beach	I really hope not	Yes	The creation of black holes may cause many unfortunate events to occur, and is very difficult to do. Hence, Randall really hopes that children are not accidentally, let alone intentionally, creating black holes on the beach, as this would be cataclysmic for our planet. On the other hand, children commonly dig holes in sand at beaches, and this is a normal thing for them to do. Alternatively, it could refer to some Eldritch Abomination children playing at a cosmic beach. In that case, "hopefully not" is also a good response.
Source of many precious metals	Indirectly	Yes	Both the supernovae that create black holes and various events involving black holes, such as black hole/neutron star mergers, produce large quantities of heavy elements, including precious metals found on Earth, and hence are an indirect source. These metals are often underground, and are thus recovered by digging a regular, though very deep, hole called a mine.
Einstein imagined falling into one	Yes	Probably at least once	The thought experiments of Albert Einstein, particularly in relation to general relativity, involve consideration of what happens when one falls through gravitationally-curved space, a general way in which black holes can be analysed (as black hole physics was very rudimentary in Einstein's time). Aside from this, almost everyone has had a reason to consider the possibility of falling into a normal hole, and thus includes Einstein as well.
A component of dark matter	Maybe	Probably not	Dark matter is a theoretical part of the universe, a large amount of its total calculated mass which cannot (yet) be directly seen (or easily interacted with on a non-negligible level). It is considered possible that at least some of this 'missing mass' is in the form of black holes. It is not generally considered an option that ordinary holes have anything to do with this.
Created by the Large Hadron Collider	No	Yes	There were concerns when the Large Hadron Collider (LHC), a particle super-collider, was put into operation that it would create a black hole and destroy the Earth. This obviously hasn't happened yet, and is unlikely ever to happen at all. However, many regular holes were created by the LHC, primarily during its construction. This is because it is mostly underground, and holes are an efficient way to get underground. This provides additional humor of such an important and large device creating something so mundane.
Massive stars often collapse into them	Yes	No	If a star is large enough, when the star dies, it may still have enough gravity to collapse back into itself, thus creating a black hole. Additionally, any star passing in range of a black hole, such as those near the supermassive black hole in the center of the galaxy, may also fall into it, where it would have collided with the 'original' massive star. Other things may collapse into regular holes in a different sense - for example, a house may collapse into a sink hole. However, most regular holes are not large enough for a star to collapse into in this way (unless one considers the near vacuum of space itself to be a 'hole').
Explored by humans in famous sci-fi stories	Yes	Yes	Many sci-fi stories and movies explore black holes and regular holes alike. In particular, there's the eponymous classic The Black Hole and more recent films such as Interstellar, both about space missions that encounter a black hole. Journey to the Center of the Earth is a classic novel by Jules Verne (and made into various films) which involves going into a volcano tube (a kind of hole). H. P. Lovecraft's 1921 short story The Nameless City involves the explorer narrator venturing into an ancient tunnel (entered through a hole) dug by a pre-human civilization under the Arabian peninsula, and At the Mountains of Madness involves tunnels lost in the continent of Antarctica.
Fatal to get a big one in your body	Yes	Yes	If a black hole somehow appeared inside of a person's body (or even anywhere near it), they would almost definitely die instantly.[citation needed] The same goes for a regular hole - if you cut out a massive section of a human's body, they would likely bleed out. This also applies for the holes left by bullets and other high-speed projectiles.
Some of them are the mouths of wormholes	Maybe	Yes	Black holes are commonly portrayed to be the entrances of wormholes, especially in sci-fi stories. While wormholes remain purely theoretical, if they exist, some common models for them suggest one end would appear as a black hole, drawing matter in to be ejected from a 'white hole' elsewhere. On the other side, many species of worms live in shallow holes, with a "mouth" on the surface - the "mouth" of the "worm hole". This provides some additional humor by conflating the meanings of the word "wormhole". This could also be a reference to Star Wars Episode V: The Empire Strikes Back, when the Millennium Falcon spacecraft almost gets swallowed by a giant worm in an asteroid hole.
Stephen Hawking and Kip Thorne argued that any information that falls into them is lost forever	Yes	No	The Black hole information paradox is a paradox arising from a contradiction between two widely-accepted theories related to black holes. Scientist Stephen Hawking, famous for his research into black holes, said that black holes release their energy over time, eventually disappearing, through Hawking Radiation. According to this theory, if information was also to enter the black hole, it would be released alongside this radiation. On the other hand, the No-hair theorem (which was also explored in What If? 2 in Chapter 1: Soupiter), states that all black holes are completely identical outside of three key features: mass, spin, and electric charge. If information that fell into a black hole is released with Hawking radiation, then that means that there must be more than three properties of black holes. Issues also arise when considering the destruction of this information, which, according to the fundamental rules of physics, is impossible. The issue is that if black holes can only retain three features, with composition not being one of said features, then this rule would be violated, thus requiring a complete rethinking of the fundamental laws of the universe. Hawking and Kip Thorne famously made a bet with John Preskill over this paradox. On the other hand, information that falls into a normal hole is not lost forever, and can likely still be reobtained, especially if the information is stored physically. The science of recovering information from regular holes is called archaeology (or possibly mail sorting).
Commonly inhabited by meerkats	Undetermined	Yes	Meerkats commonly live in holes underground, being an example of a small mammal. It is highly unlikely that Earth mammals live in black holes, but because it is impossible to know what lies beyond the event horizon it is technically impossible to falsify the postulate that there are meerkats there. Additionally, some physicists have entertained the hypothesis that our universe exists inside a black hole. If this were to be true, there would indeed be meerkats inside a black hole at this point in spacetime.
(title text) Created by the collapse of:	Massive stars	Florida limestone bedrock	As mentioned before, Black holes are often created by the collapse of massive stars. On the other hand, many sinkholes in Florida are caused due to most bedrock in the state being made of limestone, which is very slightly soluble in water (although that still makes it drastically more soluble than most rocks). When rainwater and groundwater come into contact with this bedrock, it begins to dissolve it, leaving cavities. Eventually, this can dissolve the bedrock so thin that the weight of the ground above it causes the bedrock to collapse. Sinkholes from dissolved limestone are generally entrances to caves that explore further limestone dissolving from underground waterways. Florida is known for its warm underwater caves and opening sinkholes.