Physicists create ‘the crummiest wormhole you can imagine’

In an experiment that ticks most of the mystery boxes in modern physics, a group of researchers announced on Wednesday that they had simulated a pair of black holes in a quantum computer and sent a message between them through a shortcut in space-time called a wormhole.

Physicists described the achievement as another small step in the effort to understand the relation between gravity, which shapes the universe, and quantum mechanics, which governs the subatomic realm of particles.

“This is important because what we have here in its construct and structure is a baby wormhole,” said Maria Spiropulu, a physicist at the California Institute of Technology and the leader of a consortium called Quantum Communication Channels for Fundamental Physics, which conducted the research. “And we hope that we can make adult wormholes and toddler wormholes step-by-step.” In their report, published Wednesday in Nature, the researchers described the result in measured words: “This work is a successful attempt at observing traversable wormhole dynamics in an experimental setting.”

The wormhole that Dr. Spiropulu and her colleagues created and exploited is not a tunnel through real physical space but rather through an “emergent” two-dimensional space. The “black holes” were not real ones that could swallow the computer but lines of code in a quantum computer. Strictly speaking, the results apply only to a simplified “toy model” of a universe — in particular, one that is akin to a hologram, with quantum fields on the edge of space-time determining what happens within, sort of in the way that the label on a soup can describes the contents.

To be clear: The results of this experiment do not offer the prospect anytime soon, if ever, of a cosmic subway through which to roam the galaxy like Jodie Foster in the movie “Contact” or Matthew McConaughey in “Interstellar.”

“I guess the key question, which is perhaps hard to answer, is: Do we say from the simulation it’s a real black hole?” Daniel Jafferis, a physics professor at Harvard, said. “I kind of like the term ‘emergent black hole.’”

He added: “We are just using the quantum computer to find out what it would look and feel like if you were in this gravitational situation.” He and Alexander Zlokapa, a doctoral student at the Massachusetts Institute of Technology, are the lead authors of the paper.

Physicists reacted to the paper with interest and caution, expressing concern that the public and media would mistakenly think that actual physical wormholes had been created.

“The most important thing I’d want New York Times readers to understand is this,” Scott Aaronson, a quantum computing expert at the University of Texas in Austin, wrote in an email. “If this experiment has brought a wormhole into actual physical existence, then a strong case could be made that you, too, bring a wormhole into actual physical existence every time you sketch one with pen and paper.”

Daniel Harlow, a physicist at M.I.T. who was not involved in the experiment, noted that the experiment was based on a model of quantum gravity that was so simple, and unrealistic, that it could just as well have been studied using a pencil and paper.