According to our best understanding, the universe is expanding – and is doing so at an accelerating rate. This is believed to be caused by something called the “cosmological constant”, which was first proposed by Albert Einstein in his theory of general relativity. In recent decades, it has become better known as dark energy, which is believed to make up about 70% of the universe.
Crucial to this realisation were studies of Type Ia supernovae – exploding white dwarf stars. These are thought to emit a specific amount of light, which allows astronomers to determine their distances very accurately and thereby track the expansion of the universe. This work was awarded the 2011 Nobel prize in physics.
The accelerating expansion of the universe is thought to be due to negative pressure, an unusual property of dark energy that allows it to overcome the attractive force of gravity. Yet the exact nature of dark energy remains a puzzle. It cannot be explained by our best theory for the fundamental building blocks of the universe – known as the standard model of particle physics.
What if everything we know — every galaxy, every star, every atom — is actually inside a black hole? In this video, we explore the fascinating possibility that our entire universe could exist within a black hole embedded in a larger “parent” universe. This idea isn’t science fiction; it arises from real solutions to Einstein’s equations in general relativity and from modern efforts to connect gravity with quantum mechanics. We examine what physics predicts happens inside a black hole, how space and time behave at an event horizon, and why the Big Bang might resemble the birth of a black hole from the outside.
We also explore the deeper implications of this theory: whether a collapsing star in another universe could create a new expanding universe on the inside, how spin and entropy might relate to cosmic expansion, and what this could mean for the concept of a multiverse. Could every black hole be the seed of a new universe? And if so, what does that say about where we came from and the true structure of reality? This is one of the most mind-bending ideas in cosmology — and it challenges our very notion of what “inside” and “outside” even mean.
Scientists have found the oldest quasars ever seen, revealing giant black holes blazing across the universe when it was only 670 million years old. Astronomers have uncovered 31 of the oldest known quasars, including the two earliest ever detected, shining from a time when the universe was only about 670 million years old. Powered by supermassive black holes billions of times the Sun’s mass, these incredibly bright objects challenge scientists’ understanding of how such enormous black holes formed so quickly after the Big Bang.
Quasars rank among the brightest and most powerful objects in the universe. They are fueled by supermassive black holes that consume surrounding material at the centers of galaxies, producing so much energy that they can be seen across billions of light years.
Now, an international team of researchers has identified 31 of the oldest quasars ever discovered, including the two earliest known examples. These extraordinary objects were already shining with the light of roughly a trillion suns when the universe was only about 670 million years old. The discovery, published in Astronomy & Astrophysics, offers an unprecedented glimpse into one of the earliest chapters of cosmic history.
The Sachdev-Ye-Kitaev (SYK) model describes information scrambling in black holes and an unusual metallic phase in high-temperature superconductors. Despite those and other far-reaching applications, realizing the model in the lab has been extremely challenging because the particle interactions required are intricate and long-ranged. Now Charles Creffield at the Complutense University of Madrid and his colleagues have detailed how this model could be simulated in existing cold-atom setups [1]. Their strategy provides a practical path to exploring quantum phenomena that are currently confined to theory.
Rather than engineer the requisite particle interactions from the outset, the team started with a much simpler setup emulating the Hubbard model, which is used to understand how electrons moving in a lattice give rise to superconductivity and other phenomena. Ultracold atoms are placed in a one-dimensional optical lattice, where they hop between lattice sites and mutually repel each other when occupying the same site. The lattice is then periodically shaken to make the rate of hopping oscillate in time. This modulation suppresses the atoms’ ordinary motion and generates effective interactions between all the atoms at once, closely resembling the particle behavior of the SYK model.
Using detailed numerical simulations, the researchers went on to show that their Hubbard-based system reproduces several key features of the SYK model, including its characteristic chaotic dynamics and fast spreading of quantum information. The team emphasizes that its approach could be enacted straightforwardly using currently available cold-atom technologies. Such an implementation would offer a controlled, versatile platform for simulating the SYK model and possibly for probing the uncertain physics of quantum chaos and quantum gravity.
A black hole may be stirring a “pot” of gas containing a neighboring galaxy in the early universe, according to a new study published in Astronomy & Astrophysics that used observations from NASA’s Chandra X-ray Observatory. The galaxy slowly being “cooked” is named MQN01 J004131.9–493704, but astronomers have nicknamed it the “red potato” because of its appearance in images from NASA’s James Webb Space Telescope.
The red potato galaxy is located about 11.7 billion light-years from Earth at an intersection where gigantic web-like structures of galaxies and gas meet. Astronomers targeted this area with Webb because they knew it contained one of the heaviest concentrations of galaxies and growing supermassive black holes yet identified in the early universe.
The star that formed the Jellyfish nebula may have had a partner star that exploded 100,000 years earlier, according to international researchers, who say that this may be the first known discovery of a binary star system in which both stars have gone supernova.
The Jellyfish nebula, known as IC 443, is the remnant of a star exploding in a supernova and leaving behind an expanding cloud of debris. IC 443 is located in the Gemini constellation, approximately 6,000 light-years from Earth, and researchers have now discovered that it occupies the same physical environment as another supernova remnant called G189.6+3.3. The findings are published in the journal Nature Communications.
Supernova remnants are expanding clouds of debris left behind after supernovae (stellar explosions). While hundreds of such remnants are known in our galaxy, identifying relationships between them is difficult, particularly in crowded regions of the Milky Way. IC 443, a remnant in the constellation Gemini approximately 6,000 light-years from Earth, sits close to other astronomical structures and within a complex cloud of gas and dust, making its surrounding region difficult to study.
Stars and galaxies make up much of the universe’s ordinary, observable matter. But for decades, scientists have wrestled with a cosmic conflict: There should be much more.
Physicists have good estimates of how much matter was present in the early universe. Shortly after the Big Bang, roughly 83% of all matter in the universe was composed of invisible dark matter, with ordinary matter making up the rest. And yet, these estimates exceed the amount of ordinary matter seen in stars and galaxies today. Where, then, did all the missing ordinary matter go?
Now MIT scientists, as part of the CHIME/FRB Collaboration, are using far-off radio signals to reveal missing matter in the vast space between galaxies. The team has developed a new method to search out missing matter by combining locations of galaxies with detections of fast radio bursts.