"Spacetime may be filled with wormholes, which are shortcuts through the universe." This captivating idea, born from the equations of Albert Einstein's theory of general relativity, has fueled both scientific inquiry and the imaginations of science fiction enthusiasts.
Wormholes, also known as Einstein-Rosen bridges, are hypothetical tunnels that could connect distant points in spacetime. They offer the tantalizing possibility of cosmic shortcuts, potentially shrinking vast distances and even enabling time travel. However, their existence and feasibility remain a subject of intense debate.
The concept of wormholes was first proposed in 1916 by Austrian physicist Ludwig Flamm. He explored the equations of Einstein and suggested the existence of a "white hole" as the counterpart to a black hole. These structures could act as gravitational tunnels, but their stability and size pose significant challenges.
One major hurdle is the fragility of wormholes. Ordinary matter attempting to traverse them could cause the tunnel to collapse due to gravitational attraction. To keep them open, exotic matter with negative energy density would be required, a type of matter only observed in certain quantum field theory states.
Furthermore, wormholes are predicted to be microscopic, with an estimated size of 10^-33 centimeters, making them impractical for human transit. Despite these limitations, recent research has explored methods to stabilize these structures.
In 2017, physicists Ping Gao, Daniel Jafferis, and Aron Wall proposed a method based on quantum entanglement, a phenomenon Einstein famously called "spooky action at a distance." This theory suggests that entanglement could provide the exotic ingredient needed to keep wormholes open, albeit only at a microscopic level.
This approach has inspired new studies, such as those by Juan Maldacena and Alexey Milekhin, who suggest that dark matter could play a crucial role in forming larger wormholes, though these ideas are still unproven. The interest in wormholes extends beyond their potential for space travel.
Recent research has linked wormhole formation to quantum entanglement and string theory, potentially offering clues about the nature of spacetime and gravity. Physicist Julian Sonner has shown that the entanglement of quarks, the fundamental building blocks of matter, could theoretically generate a wormhole.
This finding suggests that gravity, as we understand it, could be an emergent consequence of quantum entanglement. However, the possibility of using wormholes for time or space travel remains highly speculative. While wormholes could connect different points in time, turning them into time machines would require a monumental effort.
Moreover, the laws of physics likely prohibit human travel through these structures. As Stephen Hsu, a physicist and professor at the University of Michigan, stated, humans are not going to be doing this in the near future, which refutes past beliefs about this theory.