Interestingly, this kind of decoherence occurs wherever there is a horizon where information can only travel in one direction, creating the potential for causal paradoxes. The known edge of space, called the cosmic horizon, is another example. Or, think of the “Rindler Horizon” that forms behind an observer who continually accelerates to approach the speed of light. All these “killing horizons” (named after the late 19th century to his early 20th century German mathematician) Wilhelm Killing) causes the decoherence of quantum superposition. “These horizons are looking at you in exactly the same way,” said Satishandran.
It’s not entirely clear what exactly it means for the known edge of the universe to monitor everything within the universe. “We don’t understand cosmic horizons,” Lupsaska said. “Very fascinating, but much more difficult than a black hole.”
In any case, physicists hope to learn about the behavior of unified theories by posing thought experiments like this where gravity and quantum theory collide. “This could give us some clues about quantum gravity,” Wald said. For example, the new effect could help theorists understand how entanglement is related to spacetime.
“These effects should be part of the final story of quantum gravity,” Lupsaska said. “Well, would they be important clues for gleaning insight into the theory? It’s worth investigating.”
participatory universe
Wheeler’s notion of a participatory universe is becoming clearer as scientists continue to learn about all forms of decoherence, Danielson said. It seems to match. Clarity comes from interaction. “I think that’s what Wheeler had in mind,” Danielson said.
And the discovery that black holes and other killing horizons are always observing everything “whether you like it or not” is “more evocative” of a participatory universe than other types of decoherence. Yes, the authors say.
Not everyone is ready to embrace Wheeler’s philosophy on a large scale. “The idea of the universe observing itself? It sounds a bit like a Jedi to me,” Lupsaska said, although she noted that “everything is constantly observing itself through interaction.” I agree to
“Poetically, you can think of it that way,” Carney said. “Personally, the existence of the horizon means that the fields around it are hooked on the horizon in a very interesting way.”
When Wald was a student in the 1970s, when Wheeler first drew the “big U”, Wald didn’t think much of it. “I didn’t think Wheeler’s idea was very well founded,” he said.
and now? “A lot of what he did was enthusiasm and a few vague ideas that turned out to be really on point,” Wald said, noting that Wheeler had a long way to go when the effect was calculated. I mentioned earlier that we predicted Hawking radiation.
“He thought himself to be the one who held out the light of the lamp to light the way for others to follow.”
original story Reprinted with permission from Quanta Magazine, an editorially independent publication of Simmons Foundation Its mission is to advance public understanding of science by covering research developments and trends in mathematics, physical sciences, and life sciences.
