Other side of universe



Obtain a book. Look at its dimensions—length, width, and thickness. They each relate to one of the three dimensions of space and, it seems to reason, to every thing there in.

The book's pages have two sides, and everything around you has two sides as you turn the pages.

You might forget that this insignificant detail is a property of spacetime. However, spacetime is a two-sided surface in and of itself.

The world's two-sidedness is maintained by a crucial characteristic of two-sided spacetimes: a clear orientation for the arrow of time. 

We think the world is two-sided because we perceive time as moving permanently from the past to the future.

Even so, there might be bias.
The tale has more to it. Time has no preferred orientation in a one-sided world; it can move from the past to the future or the other way around.

We might now wonder how to get to the opposite side of the cosmos and where it is. The recent work "Quantum entanglement, two-sided spacetimes, and the thermodynamic arrow of time," which was selected by MIT Technology Review as one of the best of the week and posted in the physics web archive arXiv, may have the solutions.

If we want to go into technical details, we must first convey the big picture by examining earlier scientific work, which is like putting together a puzzle. Interestingly, the answer to that conundrum lies in quantum entanglement.

Entangled quantum states


Two quantum systems (often two quantum particles) sharing the same existence is referred to as entanglement. Particles that interact in a quantum world can entangle one another so that they share a single quantum state. No matter how far away the particles are, a measurement on one of the particles can provide information about the other particle.

The missing puzzle component is Juan Maldacena


The revival of the gravity/quantum field correlation conjecture was revealed in 1997 by physicist Juan Maldacena, who is currently at Princeton's Institute for Advanced Study. This hypothesis states that some quantum gravity theories with fixed spacetime asymptotic behaviour are identical to conventional quantum field theories.

Maldacena proved in 2001 that by becoming entangled in.

Quantum entanglement expands spacetime.


Van Raamsdonk demonstrated in 2010 that the two quantum systems correspond to two distinct spacetime components provided they are not initially correlated, in accordance with the gravity/quantum field duality. Contrarily, according to the second Maldacena study, the two halves of spacetime are classically coupled when the quantum systems are originally entangled in a certain state.

What would happen to this classically connected spacetime, Van Raamsdonk asked, if the entanglement between the two dual quantum systems were broken? He provided an explanation based on a proposition put up in 2006 by Shinsei Ryu, who is currently a professor at the University of Illinois, and Tadashi Takanagi, who is currently a researcher at Kyoto University's Yukawa Institute for Theoretical Physics. Their calculations enabled him.


A dualistic world


Once every component is in position, the puzzle may be put together to reveal the entire picture. We begin with two uncorrelated quantum systems. These, as we have seen, are consistent with a spacetime consisting of two separate components. The time is directed in the typical thermodynamic direction—from the past to the future—because there are no beginning correlations. This finding is consistent with a spacetime that prefers to be oriented toward time, or a "time-oriented spacetime," on the dual gravity side.

Let's now assume that the two quantum systems are already entangled. There is no chance for one orientation of time to dominate the other because of the entanglement, which forces the individual entropies to decline. 
Other side of universe|A dualistic world-Sci Hub

Converging black holes

We go back to Maldacena's 2001 paper. Keep in mind that he defined the eternal black hole as the appearance of entanglement between particles on two black holes that are connected by a wormhole. In other words, Maldacena associates two black holes with the two parts of the spacetime in the Van Raamsdonk concept.


We can underline that the two black holes in the Maldacena conjecture are located in opposite sides of the spacetime, somehow connecting the sides of spacetime, since we have seen that the Van Raamsdonk's two components of spacetime correspond to two sides of spacetime.


We have now finished the puzzle! Consequently, time must flow backward on one side of our universe.