Lifeboat Foundation

When stars like our Sun die, they tend to go out with a whimper and not a bang – unless they happen to be part of a binary (two) star system that could give rise to a supernova explosion.

Now, for the first time, astronomers have spotted the radio signature of just such an event in a galaxy more than 400 million light-years away. The finding, published today in Nature, holds tantalizing clues as to what the companion star must have been like.

Dark matter, matter in the universe that does not emit, absorb or reflect light, cannot be directly detected using conventional telescopes or other imaging technologies. Astrophysicists have thus been trying to identify alternative methods to detect dark matter for decades.

Researchers at Tsinghua University, the Purple Mountain Observatory and Peking University recently carried out a study exploring the possibility of directly detecting dark photons, prominent dark matter candidates, using radio telescopes. Their paper, published in Physical Review Letters, could inform future searches for dark photons, which are hypothetical particles that would carry a force in dark matter, similarly to how photons carry electromagnetism in normal matter.

“Our previous work studied the conversion of dark photons into photons in the solar corona,” Haipeng An, one of the researchers who carried out the study, told Phys.org.

This may sound like a science fiction scenario, but some physicists have proposed that this could be the case. In this article, we will explore the idea that our universe may be inside of a black hole, and what implications this would have for our understanding of cosmology and physics.

A black hole is a region of space where gravity is so strong that nothing can escape, not even light. According to Einstein’s theory of general relativity, black holes are formed when massive stars collapse at the end of their life cycle. The resulting singularity is a point of infinite density and zero volume, where the laws of physics break down.

Scientists discover possible connection between human brain and cosmos on a quantum scale.

The theory of relativity works well when you want to explain cosmic-scale phenomena—such as the gravitational waves created when black holes collide. Quantum theory works well when describing particle-scale phenomena—such as the behavior of individual electrons in an atom. But combining the two in a completely satisfactory way has yet to be achieved. The search for a “quantum theory of gravity” is considered one of the significant unsolved tasks of science.

This is partly because the mathematics in this field is highly complicated. At the same time, it is tough to perform suitable experiments: One would have to create situations in which phenomena of both the relativity theory play an important role, for example, a spacetime curved by heavy masses, and at the same time, quantum effects become visible, for example the dual particle and wave nature of light.

At the TU Wien in Vienna, Austria, a new approach has now been developed for this purpose: A so-called “quantum simulator” is used to get to the bottom of such questions: Instead of directly investigating the system of interest (namely quantum particles in curved spacetime), one creates a “model system” from which one can then learn something about the system of actual interest by analogy. The researchers have now shown that this quantum simulator works excellently.

Imperial College researchers have created a spinning disk of plasma in a lab, mimicking disks found around black holes and forming stars.

The experiment more accurately models what happens in these plasma disks, which could help researchers discover how black holes grow and how collapsing matter forms stars.

As matter approaches black holes it heats up, becoming plasma—a fourth state of matter consisting of charged ions and free electrons. It also begins to rotate, in a structure called an accretion disk. The rotation causes a centrifugal force pushing the plasma outwards, which is balanced by the gravity of the black hole pulling it in.

Dibaryons are subatomic particles composed of two baryons. Their formation, which occurs through interactions between baryons, is fundamental in big-bang nucleosynthesis, nuclear reactions including those happening within stars, and bridges the gap between nuclear physics, cosmology, and astrophysics. Fascinatingly, the strong force, responsible for the formation and the majority of the mass of nuclei, facilitates the formation of a plethora of different dibaryons with diverse quark combinations.

Nevertheless, these dibaryons are not commonly observed — the deuteron is currently the only known stable dibaryon.

To resolve this apparent dichotomy, it is essential to investigate dibaryons and baryon-baryon interactions at the fundamental level of strong interactions. In a recent publication in Physical Review Letters.

A spinning plasma ring mimics the rotating structure surrounding a black hole.

Astronomers have spotted the largest cosmic explosion ever witnessed, and it’s 10 times brighter than any known exploding star, or supernova.

The brightness of the explosion, called AT2021lwx, has lasted for three years, while most supernovas are only bright for a few months.

The event, still being detected by telescopes, occurred nearly 8 billion light-years away from Earth when the universe was about 6 billion years old. The luminosity of the explosion is also three times brighter than tidal disruption events, when stars fall into supermassive black holes.

It could be a strange way of achieving immortality—or at least, everlasting life for copies of you.