If you ever happen to fall through a wormhole, you won’t be coming back. It will snap shut behind you. But on the way,you may have just enough time to send one last messagehome. That’s the finding of a new analysis.
A wormhole is a tunnel in the fabric of space. It would link two points in the cosmos. Wormholes are just theoretical. That is, scientists think they could exist, but no one has ever seen one. If they do exist, wormholes could provide shortcuts to distant parts of the universe. Or they might serve as bridges to other universes.There even may be multiple types of wormholes, each with different features.
One of the most commonly studied types of wormholes is thought to be highly unstable. Physicists have expected it would collapse if any matter entered it. But it wasn’t clear just how fast that collapse might be. Also unknown: What would it mean for something, or someone, heading into the wormhole?
Now, a computer model has shown how this type of wormhole would respond when something travels through it. Researchers shared the results in the November 15 Physical Review D.
In theory, says Ben Kain, you could build a probe and send it through. Kain is a physicist at the College of the Holy Cross in Worcester, Mass. “You’re not necessarily trying to get [the probe] to come back, because you know the wormhole is going to collapse,” Kain says. “But could a light signal get back [to Earth] in time before a collapse?” Yes, according to the model he and his colleagues have created.
No need for ‘ghost matter’
Some past studies of wormholes hinted that these cosmic tunnels could stay open for trips back and forth, Kain says. But in those studies, wormholes needed a special trick to stay open. They had to be supported by an exotic form of matter. Researchers call the stuff “ghost matter.”
Like wormholes, ghost matter is only theoretical. In theory, it would respond to gravity in exactly the opposite way that normal matter would. That is, a ghost matter apple would fall up from a tree branch instead of down. And ghost matter passing through a wormhole would push the tunnel outward, rather than pull it inward to collapse.
The existence of such “ghost matter” would not break the rules of Einstein’s general relativity. That’s the physics that describes how the universe works on large scales. But ghost matter almost certainly doesn’t exist in reality, Kain adds. So, he wondered, could a wormhole stay open for any length of time without it?
In his team’s model, Kain sent probes made of normal matter through a wormhole. As expected, the wormhole collapsed. The probes’ passage caused the hole to pinch shut, leaving something like a black hole behind. But it happened slowly enough for a fast-moving probe to send light-speed signals back to our side — just before the wormhole completely sealed off.
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Possible, but plausible?
Kain doesn’t imagine ever sending people through a wormhole (if such tunnels were ever found). “Just the capsule and a video camera,” he says. “It’s all automated.” It would be a one-way trip for the probe. “But we can at least get some video seeing what this device sees.”
Sabine Hossenfelder is skeptical that such a thing would ever happen. She’s a physicist at the Munich Center for Mathematical Philosophy in Germany. Sending a space probe into a wormhole to report back requires the existence of things not yet proven, she says. “Lots of things you can do mathematically have nothing to do with reality.”
Still, Kain says, it’s worthwhile to learn how wormholes that don’t rely on ghost matter might work. If they can stay open, even for fleeting moments, they might someday point to new ways to travel throughout the universe or beyond.
Power Words
More About Power Wordsblack hole: A region of space having a gravitational field so intense that no matter or radiation (including light) can escape.
computer model: A program that runs on a computer that creates a model, or simulation, of a real-world feature, phenomenon or event.
cosmos: (adj. cosmic) A term that refers to the universe and everything within it.
exotic: An adjective to describe something that is highly unusual, strange or foreign (such as exotic plants).
gravity: The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its gravity.
mass: A number that shows how much an object resists speeding up and slowing down — basically a measure of how much matter that object is made from.
model: A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes.Or an individual that is meant to display how something would work in or look on others.
philosophy: A field of research where people investigate the nature of basic truths, knowledge and codes of social behavior. A philosopher might, for instance, search for “the meaning of life,” “what is truth” or “how people should select between two good or equally bad options that are offered to them.”
physical: (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another). (in biology and medicine) The term can refer to the body, as in a physical exam or physical activity.
physics: The scientific study of the nature and properties of matter and energy. Classical physics is an explanation of the nature and properties of matter and energy that relies on descriptions such as Newton’s laws of motion. Quantum physics, a field of study that emerged later, is a more accurate way of explaining the motions and behavior of matter. A scientist who works in such areas is known as a physicist.
point: (in mathematics) A precise point in space that is so small that it has no size. It merely has an address.
relativity: (in physics)A theory developed by physicist Albert Einstein showing that neither space nor time are constant, but instead affected by one’s velocity and the mass of things in your vicinity.
scenario: A possible (or likely) sequence of events and how they might play out.
skeptical: Not easily convinced; having doubts or reservations.
theoretical: An adjective for an analysis or assessment of something that based on pre-existing knowledge of how things behave. It is not based on experimental trials. Theoretical research tends to use math — usually performed by computers — to predict how or what will occur for some specified series of conditions. Experimental testing or observations of natural systems will then be needed to confirm what had been predicted.
theory: (in science) A description of some aspect of the natural world based on extensive observations, tests and reason. A theory can also be a way of organizing a broad body of knowledge that applies in a broad range of circ*mstances to explain what will happen. A theory in science is not just a hunch. An idea or conclusion that is based on a theory — for which there are not, as yet, firm data or observations — are referred to as theoretical. Scientists who use mathematics and/or existing data to project what might happen in new situations are known as theorists.
universe: The entire cosmos: All things that exist throughout space and time. It has been expanding since its formation during an event known as the Big Bang, some 13.8 billion years ago (give or take a few hundred million years).
wormhole: (in biology) The burrow (often through wood) made by a worm-shaped animal. (in physics) A tunnel or bridge formed by the warping of spacetime that would allow objects to take a shortcut path between two distant places in space and time. Although none has yet been witnessed, Einstein’s theory of general relativity predicted that they could exist
Citations
Journal: K. Calhoun, B. Fay and B. Kain.Matter traveling through a wormhole.Physical Review D. Vol. 106, November 15, 2022, 104054. doi: 10.1103/PhysRevD.106.104054.
About James R. Riordon
James Riordon is a freelance science writer who covers physics, math, astronomy and occasional lifestyle stories.