Behold! The Black Hole Collision Calculator!

Black holes have been the subject of intense interest ever since scientists began speculating about their existence. Originally proposed in the early 20th century as a consequence of Einstein’s Theory of General Relativity, black holes became a mainstream subject a few decades later. By 1971, the first physical evidence of black holes was found and by 2016, the existence of gravitational waves was confirmed for the first time.

This discovery touched off a new era in astrophysics, letting people know collision between massive objects (black holes and/or neutron stars) creates ripples in spacetime that can be detected light-years away. To give people a sense of how profound these events are, Álvaro Díez created the Black Hole Collision Calculator (BHCC) – a tool that lets you see what the outcome of a collision between a black hole and any astronomical object would be!

The BHCC is available at the Omni Calculator site, the same place where one can find calculators for determining how many alien civilizations could exist in our galaxy at any given time (the Alien Civilization Calculator), the time it would take to make an interstellar journey (the Space Travel Calculator), and the velocity needed to send a rocket into orbit (the Rocket Equation Calculator). And that’s just the Physics section!

Like the team that designed these calculators (Steven Wooding and Dominik Czernia), Diez is a physicist who parlayed his love of science into creating educational tools. After receiving his B.A. in fundamental Physics in his native Spain and completing two internships at CERN, he moved to Warsaw to pursue a master’s degree in computer modeling of physical phenomena.

During this time, Diez also worked for a series of Spanish blogs, writing about science and technology. Eventually, he would become inspired by the recent breakthroughs in astrophysics to create his own specialized calculator:

“In the last years, we’ve been learning exponentially more about black holes thanks to advancements in research like being able to detect gravitational waves. However, I’ve always found that these objects are surrounded by a mystery so I wanted to, ironically, shed some light into these obscure remnants of stars, but in a fun and interactive way. So I thought that an interactive calculator about black hole collisions could be a great way!”

“Mystery” is certainly an apt term when it comes to black holes. Put simply, these objects are the remnants of stars that have consumed the last of their fuel and undergone gravitational collapse. This causes them to shrink until they reach their Schwarzschild radius – which Diez also designed a calculator for! Also known as the “Event Horizon,” this is the boundary within which the laws of physics break down, resulting in a “singularity.”

Because of the extreme gravitational forces involved, even light cannot escape the surface of a black hole, which is why they are completely inaccessible and undetectable (aka. “black”). The only way to study them is by observing their effect on the space around them, like the bright accretion disks that form beyond their Event Horizon (which is how the first image of a black hole was taken).

But as Diez explains on the BHCC home page, black holes are actually deceptively simple. “In general terms, black holes are one of the simplest objects to work with in the Universe,” he states. “The details are what make them strange and complicated.” Diez explained how the calculator works as follows (directions are also available on the site), showing how with a few approximations, things can be kept simple:

“So what the calculator does is a “first-approximation” calculation to determine the energy released when a black hole “eats” another astronomical object. The basic procedure involves calculating the initial and final potential gravitational energy of the object falling into the black hole. From there I just assume that the black hole is a non-rotating one (for simplicity) and apply a known efficiency factor to know how much of that energy is released. The results truly show the magnitude of black holes and the energies they are capable of releasing during a collision.”

As a thought experiment, Diez offers a calculation of what it would look like if a black hole collided with and consumed a Sun-like star. Basically, if a main sequence G-type (yellow dwarf) star were to collide and be consumed by a black hole of 5 solar masses, it would produce 107.257 x 10¹⁵ Megajoules of energy waves, which is about 27.9 x 10²⁴ times what we consume here on Earth annually.

In terms of its intended purpose (making science fun vs. academic applications), Diez indicated that the calculator falls somewhere in between. In the end, his real goal was to make astrophysics accessible:

“I want it to be a stepping stone for people interested in science that haven’t had any formal training in astronomy or cosmology. The idea of this calculator is not to get research-level results but to make research results understandable for everyone. I’ve always loved doing scientific research but for me, nothing beats helping others see how amazing our universe is.”

In addition to the Black Hole Calculator and the Schwarzschild Radius Calculator, Diez also developed the Black Hole Temperature Calculator, which allows users to gauge the temperature of a black hole based on its mass. He also contributed an Exoplanet Discovery Calculator, which allows users to infer the mass and orbit of an exoplanet based on the star and the detection method involved.

He’s also the creator of the Hubble Law Distance Calculator and the Universe Expansion Calculator, which gives users the ability to calculate the speed any galaxy is moving at relative to us and cosmic expansion based on Hubble’s Law. He also partnered with Dr. Milosz Panfil, who holds a Ph.D. in quantum physics (also from the University of Warsaw), to create the Orbital Period Calculator – to determine the orbits of planets and binary stars.

What’s next, you might ask? Well, it turns out Diez has some thoughts on that as well. Mostly, they involve creating more calculators, which he feels are an underutilized resource when it comes to science communication. As he said, he’s also hoping to expand beyond the realm of physics:

“I’ve been working on some Coronavirus calculators to help people make better decisions in these difficult times, and I’m also working on a collaboration with universities all over Europe to include calculators as a way to make Researchers’ Night (the biggest science communication event I know of) be more interactive and appealing for everyone. Science works, and a scientifically-minded society works best!”

One of the greatest assets of the information age is the way it’s allowing educators and scientists to communicate directly with a wider audience. Through shared tools and apps, people are able to see for themselves just how some of the greatest scientific breakthroughs and concepts in history work. Like modern-day space exploration, accessibility is the key!

To learn more about the many, MANY, tools and apps they have, head on over to the Omni Calculator site and have a look around.

Addendum: The value for the Black Hole Mass (before Collision) is a set value. You can adjust it, but it will not affect the outcome. The author has indicated that this is by design for the sake of keeping this introductory calculator simple and the absence of relativistic effects is apparently for the same purpose. He further states that the energy approximation of 7% (of the object’s mass) is consistent with similar approximations made in a 2014 NASA study.

This was in response to criticism/concerns raised by Forbes senior science contributor Ethan Siegel.

Further Reading: Black Hole Collision Calculator