The (not so) microscopic black hole of ‘Dark Empty Void’

I’ve been enjoying the mini-series Dark Empty Void from writer Zack Kaplan and artist Chris Shehan, published by Mad Cave Studios. As a physicist, the premise immediately piqued my interest: in a remote, secret complex in Alaska, scientists create and contain a stable, microscopic black hole. Of course, they lose control and instead of it immediately evaporating, as all of the scientists say should happen, strange things start to emerge from the black hole. Living things, including a teenage girl.

Looking past the obvious science fiction elements, is it really possible to artificially create and contain a stable, microscopic black hole on Earth?

The question, and the fear that the possibility brings, actually isn’t new. Shortly before CERN’s Large Hadron Collider (LHC) was completed, certain theories of new, as yet undiscovered physics (most involving the idea of extra space dimensions) hypothesized that the energies released in LHC experiments could potentially create a microscopic (and world-ending?) black hole. The leading scientists at CERN came to the conclusion that these worries were unfounded, and so far no microscopic black holes have ever been observed at the LHC.

What is a black hole, anyway?

Einstein’s general theory of relativity explains gravity as mass (or energy) bending the fabric of space (and time). The more massive the object, the stronger the bending. The attractive pull of gravity is then nothing more than an object “falling” down the slope of the curved space. It didn’t take long for physicists to realize that if an object is massive enough — or rather, dense enough — the bent spacetime becomes so steep that nothing can escape its gravity, not even light. So, within a certain radius, the super-dense object looks like a completely black, empty hole in space.

For the simplest type of black hole, this boundary, often called the event horizon, is referred to as the Schawarzschild-Radius, named after physicist Karl Schwarzschild, who first discovered it. The size of the radius is directly proportional to the mass of the object and can be calculated with the formula: R = 2GM/c², where M is the mass of the black hole, G is Newton’s gravitational constant and c is the speed of light.

Normally, black holes only occur when a supermassive star collapses in on itself and all of its mass falls within that special Schwarzschild-Radius. However, according to the formula above, any amount of mass could potentially create a black hole. It just has to be squeezed into a small enough space (i.e. made dense enough). Accordingly, scientists have conjectured about microscopic black holes.

Just how big (or small) would a microscopic black hole be?

Through the first three issues of Dark Empty Void, Kaplan wisely never reveals the exact radius of the fictional black hole. Shehan, however, draws it as an object that can definitely be seen in the secret complex’s large testing area. It makes for a wonderful, beautiful, and unnerving visual, but in actuality, this black hole would be unrealistically large. In fact, the scales involved when considering black holes of any size are so extreme, they’re basically unimaginable.

For example, a black hole with a radius of just 1 micrometer (one one-thousandth of a millimeter) would have a mass of 6.7 x 10²⁰ kilograms, approximately equivalent to the mass of half the oceans on Earth. How in the world are you supposed to get that much mass into a ball only 1 micrometer in radius?

Or if a black hole had a mass of 1 kg (approximately the mass of 1 liter of water), it would have a radius of only 1.5 x 10^-27 meters, a scale smaller than any scientific experiment has ever been able to reach. As a comparison, the 1 kg black hole would be approximately 500 billion times smaller than a proton.

Incredibly, the masses involved in these two examples are still much larger than what physicists actually think about when they discuss the possibility of tiny black holes.

Many physicists consider the smallest possible length, the scale at which physics as we currently know it starts to completely break down, to be the so-called Planck length, which is about 1.6 x 10^-35 meters (though this assumption should be taken with a healthy dose of skepticism). A black hole of this radius would have a mass of about 11 micrograms (11 millionths of a gram), which is on the scale of a small, single grain of table salt. Theoretically, any microscopic black hole created on Earth would probably have a mass and radius at this scale or smaller, much smaller than could be seen with the naked eye.

This isn’t how a scientist would actually create a microscopic black hole, though. Instead, the equivalent amount of energy, calculated according to Einstein’s most famous formula E=mc², would have to be produced in the collisions of a particle accelerator like CERN’s LHC. But the energy equivalent to 11 micrograms is way beyond any particle accelerators in use today. One fairly recent research paper suggests that any microscopic black hole created by a particle accelerator would need an energy billions of times greater than the maximum energy of the LHC.

Maybe that technology might exist in the far future, but for now, the creation of microscopic black holes seems unattainable.

Why would a microscopic black hole evaporate?

Interestingly, in Dark Empty Void, the scientists keep talking about how their microscopic black hole should’ve harmlessly evaporated away as soon as its energy source was shut off. But doesn’t a black hole suck everything in with its extreme gravity, growing bigger and bigger in the process?

Well, actually no. Microscopic black holes wouldn’t do that. The reason lies in one of the most important discoveries of the famous physicist, Stephen Hawking, that of the eponymous Hawking radiation.

It’s a bit difficult to explain, but basically, when a quantum mechanical pair of particles comes into existence directly on the event horizon, it’s possible that one of the pair falls into the black hole, while the other escapes outwards. The escaping particles are what’s known as Hawking radiation. A black hole is, in fact, not quite as black as originally thought. And since these escaping particles have mass and energy, which can’t just come into existence from nothing, the release of Hawking radiation causes the black hole to lose mass. Accordingly, if a black hole isn’t regularly sucking in more mass and energy, it will eventually evaporate away as Hawking radiation.

The time taken for evaporation is proportional to the cube of the black hole’s mass. Regular black holes “in the wild” have such a huge mass, it would take longer than the current age of the universe for one to completely evaporate. But, crunching the numbers, microscopic black holes would have a lifetime shorter than one can even imagine. The 1 kg black hole from before would evaporate in 4.65 x 10^-17 seconds, and the Planck length black hole even more quickly, at6 x 10^-41 seconds.

Therefore, in order to create a stable microscopic black hole, you’d have to continually feed it new mass (or energy) in an extremely fast, but also extremely exact and controlled way. Otherwise, it’d be gone before you knew it was there. The scientists in Dark Empty Void supposedly “solve” this problem by feeding their microscopic black hole entangled quantum particles. However, there isn’t any real science behind this; Kaplan chose this equally mysterious phenomenon to add symbolic meaning to the narrative.

So once again, the creation and stabilization of a microscopic black hole is way beyond any current technology. But, who knows if some future breakthrough will make the seemingly unattainable actually possible. Only then would the science-based premise of Dark Empty Void become a reality and microscopic black holes might become a normal field of scientific research here on Earth.

Every February, to help celebrate Darwin Day, the Science section of AIPT cranks up the critical thinking for SKEPTICISM MONTH! Skepticism is an approach to evaluating claims that emphasizes evidence and applies the tools of science. All month we’ll be highlighting skepticism in pop culture, and skepticism *OF* pop culture.

AIPT Science is co-presented by AIPT and the New York City Skeptics.