Spacetime tagged posts

Why the Universe might be a Hologram

Why the universe might be a hologram
The colored circle represents the hologram, out of which the knotted optical vortex emerges.
Credit: University of Bristol

A quarter century ago, physicist Juan Maldacena proposed the AdS/CFT correspondence, an intriguing holographic connection between gravity in a three-dimensional universe and quantum physics on the universe’s two-dimensional boundary. This correspondence is at this stage, even a quarter century after Maldacena’s discovery, just a conjecture.

A statement about the nature of the universe that seems to be true, but one that has not yet been proven to actually reflect the reality that we live in. And what’s more, it only has limited utility and application to the real universe.

Still, even the mere appearance of the correspondence is more than suggestive...

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Wormholes help Resolve Black Hole Information Paradox

Figure 1: As depicted in science fiction, a wormhole is a shortcut connecting two points in spacetime. A RIKEN physicist and two collaborators have used a new spacetime geometry with a wormhole-like structure to show that information is not necessarily irretrievably lost from black holes as they evaporate. © MARK GARLICK/SCIENCE PHOTO LIBRARY

A RIKEN physicist and two colleagues have found that a wormhole—a bridge connecting distant regions of the Universe—helps to shed light on the mystery of what happens to information about matter consumed by black holes.

Einstein’s theory of general relativity predicts that nothing that falls into a black hole can escape its clutches...

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Much like White Light, Spacetime is also Composed of a Certain Rainbow

Quantum particles of different energies sense different properties of spacetime. The effect is similar to the dispersion of light in prism: photons of different energies sense the same prism as having slightly different properties. (Source: FUW, jch) Credit: Source: FUW, jch

Quantum particles of different energies sense different properties of spacetime. The effect is similar to the dispersion of light in prism: photons of different energies sense the same prism as having slightly different properties. (Source: FUW, jch) Credit: Source: FUW, jch

When white light is passed through a prism, the rainbow on the other side reveals a rich palette of colors. Theorists from University of Warsaw have shown that in models of the Universe using any of the quantum theories of gravity there must also be a ‘rainbow’ of sorts, composed of different versions of spacetime. The mechanism predicts that instead of a single, common spacetime, particles of different energies essentially sense slightly modified versions thereof.

We have probably all seen the experiment: when white l...

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