How to make a bomb out of a black hole

 

It's been portrayed in books, Star Trek movies, superhero movies, and probably in other media.  Ostensibly, if one could create a black hole on Earth, it would constitute a pretty powerful weapon.

Two articles, sourced to the same study, discuss how to do this. It's not something that should be tried at home. Because apparently, like in good schlocky sci-fi movies, things actually do explode in the lab.

Key word here:  superradiance. Sounds like the red beams that come out of Superman's and Supergirl's eyes, but it is actually defined as "Directional and coherent radiation pulses that result from an ensemble of coherently prepared states in an optical medium."

or

Superradiance is defined as the phenomenon where an ensemble of identical two-level systems, when arranged at specific intervals, emits radiation collectively, leading to an increase in the radiative decay rate and polarization decay compared to an isolated system. This effect arises from constructive interference of emitted fields among the resonances."

(Of course.)

How to Build a Black Hole Bomb (Scientific American)

" “This work shows that a ‘black hole bomb’ can actually be built in the laboratory,” says physicist Vitor Cardoso of the Niels Bohr Institute in Denmark, who was not involved in the study. “It thus provides a solid basis for studying the entire physics of black holes.” ...

"The team then turned its attention to electromagnetic superradiance. “The experimental setup itself is quite simple: it consists of a rotating cylinder and the stator coils of a commercially available induction motor, combined with some capacitors and resistors,” Cromb says. These devices were placed around the metal cylinder to generate a magnetic field inside it, which produced electromagnetic radiation. At the same time, these devices also served as mirrors because they reflected the electromagnetic waves back toward the cylinder.

“The biggest difficulty was that things were constantly exploding,” Cromb says. “It was a balancing act between measuring a reasonable signal and overloading the system. When the current through the coils became too high, the resistors in the circuit exceeded their rated voltage and burned out. This interrupted the electrical circuit, thus destroying the ‘mirror.’”

"The researchers initially feared that these overloads would prevent any observation of superradiance. But they were lucky. “The reinforcement was large enough to overcome the loss and enter the area of instability,” Cromb says. In fact, the team was able to show that the voltage in their structure increased exponentially, as predicted by Zel’dovich. This underpins the researchers’ claim of the first-ever lab-based demonstration of an electromagnetic version of a black hole bomb."

Physicists create 'black hole bomb' for first time on Earth, validating decades-old theory (Live Science)

"In their new research, the scientists harnessed the Zel'dovich effect to create their experiment. They took an aluminum cylinder rotated by an electric motor and surrounded it with three layers of metal coils. The coils created and reflected a magnetic field back to the cylinder, acting as a mirror.

As the team directed a weak magnetic field at the cylinder, they observed that the field the cylinder reflected was even stronger, demonstrating superradiance.

Next, they removed the coils' initial weak magnetic field. The circuit, however, generated its own waves, which the spinning cylinder amplified, causing the coils to amass energy. Between the cylinder's rotational speed and amplified magnetic field, the Zel'dovich effect was in full swing. Zel'dovich had also predicted that a rotating absorber — like the cylinder — would change from absorption to amplification if its surface moves faster than the incoming wave, which the experiment verified.

"Our work brings this prediction fully into the lab, demonstrating not only amplification but also the transition to instability and spontaneous wave generation," study co-author Maria Chiara Braidotti, a physics research associate at the University of Glasgow, told Live Science in an email.

"We sometimes pushed the system so hard that circuit components exploded," study co-author Marion Cromb, a researcher at the University of Southampton, told Live Science in an email. "That was both thrilling and a real experimental challenge!"

Obviously I think the exploding circuits is the most exciting part of this research. The prospect of destroying the entire Solar System and every living thing in it ... well, this is about black holes, right?