Toggle light / dark theme

Universe to go through a cosmic Poincare Recurrence? In other words, can the universe repeats itself? Will the same history happen again at some distant future? If the universe is closed and isolated, which indicates that it’s probably qualified for experiencing a Poincare Recurrence in cosmic scale, will the entire history of our universe happen for an infinite number of times? If cosmic Poincare Recurrence can take place, does it mean that the entropy of the entire universe will decrease at some point? Isn’t that the violation of the second law of thermodynamics?

===
Sources:
(K. Ropotenko) The Poincar´e recurrence time for the de Sitter space with dynamical chaos.
https://arxiv.org/abs/0712.

(Don N. Page) Information Loss in Black Holes and-or Conscious Beings.
https://arxiv.org/abs/hep-th/9411193

(Julian Barbour) Arrows of Time in Unconfined Systems.
https://arxiv.org/abs/1602.

(Lisa Dyson, Matthew Kleban, Leonard Susskind) Disturbing Implications of a Cosmological Constant.
https://arxiv.org/abs/hep-th/0208013

Leonard Susskind (Stanford University, USA), James Lindesay (Howard University, USA)

Researchers at Uppsala University have formulated a new model for our universe to solve the mystery of dark energy. The study proposes a new way to assemble a dark energy cosmos where our universe rides on an expanding bubble in an extra dimension. In a study, Swedish physicists pointed out the existence of another dimension in the universe we live in. Scientists propose that our universe exists within an expanding bubble in an extra dimension. Studying the cosmos in the last 20 years has shown that the cosmos is constantly expanding. Additionally, the speed of its expansion increases.

The conventional explanation for this goes through a type of energy (dark energy), which permeates everything and “pushes” the universe to expand more and faster. In physical cosmology and astronomy, dark energy is a still-unknown form of energy that is hypothesized to permeate all of space, tending to accelerate the expansion of the cosmos The mysterious dark energy poses more questions than answers, functioning as a cosmic wildcard in some explanations of theoretical physics.

Researchers from the University of Uppsala have proposed a new concept. This includes another dimension and other universes to avoid this problem. In their study, published in the journal Physical Review Letters, physicists from Uppsala University argue that our universe is “mounted” on a bubble that expands in an additional dimension. Our entire universe fits on the edge of the expanding bubble. All matter in our cosmos corresponds to the endpoints of strings that extend into the extra dimension. The researchers also show that expanding bubbles of this kind can be created within the string theory framework.

Physicists have purportedly created the first-ever wormhole, a kind of tunnel theorized in 1935 by Albert Einstein and Nathan Rosen that leads from one place to another by passing into an extra dimension of space.

The wormhole emerged like a hologram out of quantum bits of information, or “qubits,” stored in tiny superconducting circuits. By manipulating the qubits, the physicists then sent information through the wormhole, they reported today in the journal Nature.

The team, led by Maria Spiropulu of the California Institute of Technology, implemented the novel “wormhole teleportation protocol” using Google’s quantum computer, a device called Sycamore housed at Google Quantum AI in Santa Barbara, California. With this first-of-its-kind “quantum gravity experiment on a chip,” as Spiropulu described it, she and her team beat a competing group of physicists who aim to do wormhole teleportation with IBM and Quantinuum’s quantum computers.”


The unprecedented experiment explores the possibility that space-time somehow emerges from quantum information, even as the work’s interpretation remains disputed.

Imagine you are at a museum. After a long day admiring the exhibitions, you are exiting the museum. But to be able to get out, you will need to exit through the gift shop. The layout of the gift shop can be set up in several ways. Maybe you can take a short and direct path to the exit, maybe there are long winding corridors stuffed with merchandise you need to pass through. If you take the longer path, you are more likely to lose more of your money before you get outside. The scientists at the CMS collaboration have recently observed a similar phenomenon in high-energy heavy ion collisions, as those illustrated in the event display.

The life of the tiniest particles making up ordinary matter — quarks and gluons — is governed by the laws of quantum chromodynamics. These laws require quarks and gluons to form bound states, like protons and neutrons, under normal conditions. However, conditions like in the early universe, when the energy density and temperature far exceeded those of ordinary matter, can be achieved in giant particle accelerators. In the Large Hadron Collider at CERN this is done by colliding lead nuclei that are accelerated close to the speed of light. In these conditions, a new state of matter, called the quark-gluon plasma, is formed for a tiny fraction of a second. This new state of matter is special, since within the volume of the matter, quarks and gluons act as free particles, without the need to form bound states.

Figure 1: A schematic presentation of a non-central (left) and central (right) heavy ion collision. The outlines of the ions are presented by dashed lines, while the overlap region in which the quark-gluon plasma is produced is colored in orange. The red star shows a position where two quarks might scatter, and green and blue arrows are alternative paths the scattered quark can take to escape the quark-gluon plasma.

This would be great for teleporting objects for shipping across the planet or cosmos eventually. 😀


Scientists have created a “holographic wormhole” inside a quantum computer for the first time.

The pioneering experiment allows researchers to study the ways that theoretical wormholes and quantum physics interact, and could help solve some of the most difficult and perplexing parts of science.

The wormhole is theoretical: researchers did not produce an actual rupture in space and time. But the experimental creation of one inside the quantum computer – which saw a message sent between two simulated blackholes – nonetheless allows scientists to examine how they might work, after almost 100 years of theory.

Conventional light sources for fiber-optic telecommunications emit many photons at the same time. Photons are particles of light that move as waves. In today €™s telecommunication networks, information is transmitted by modulating the properties of light waves traveling in optical fibers, similar to how radio waves are modulated in AM and FM channels.

In quantum communication, however, information is encoded in the phase of a single photon – the photon €™s position in the wave in which it travels. This makes it possible to connect quantum sensors in a network spanning great distances and to connect quantum computers together.

Researchers recently produced single-photon sources with operating wavelengths compatible with existing fiber communication networks. They did so by placing molybdenum ditelluride semiconductor layers just atoms thick on top of an array of nano-size pillars (Nature Communications, “Site-Controlled Telecom-Wavelength Single-Photon Emitters in Atomically-thin MoTe 2 ”).

In the new study, Spagnolo and his colleagues instead developed a quantum memristor that relies on a stream of photons existing in superpositions where each single photon can travel down two separate paths laser-written onto glass. One of the channels in this single-qubit integrated photonic circuit is used to measure the flow of these photons, and this data, through a complex electronic feedback scheme, controls the transmissions on the other path, resulting in the device behaving like a memristor.

Normally, memristive behavior and quantum effects are not expected to coexist, Spagnolo notes. Memristors are devices that essentially work by measuring the data flowing within them, but quantum effects are infamously fragile when it comes to any outside interference such as measurements. The researchers note they overcame this apparent contradiction by engineering interactions within their device to be strong enough to enable memristivity but weak enough to preserve quantum behavior.

Using computer simulations, the researchers suggest quantum memristors could lead to an exponential growth in performance in a machine-learning approach known as reservoir computing that excels at learning quickly. “Potentially, quantum reservoir computing may have a quantum advantage over classical reservoir computing,” Spagnolo says.