Cosmic Censorship Principle

Imagine an interferometer as a giant ear listening to the radio whisper of a distant galaxy. Three antennas spread across continents capture the signal, and the difference in their phases combines into a quantity that is immune to atmospheric jitter. This quantity is called the closure phase.

A black hole pulls in anything that gets too close. But if you toss in not one object but a pair, one of them can fly back out, carrying off some of the hole's rotational energy. This trick, devised by Roger Penrose in 1969, works only because a black hole has a horizon — a boundary beyond which nothing returns. Now it turns out the horizon isn't necessary.

A black hole pulls in anything that gets too close. But if you toss in not one object but a pair, one of them can fly back out, carrying off some of the hole's rotational energy. This trick, devised by Roger Penrose in 1969, works only because a black hole has a horizon — a boundary beyond which nothing returns. Now it turns out the horizon isn't necessary.

A neutron star is the ultra-dense remnant of a supernova: the mass of the Sun packed into a sphere the size of a city. For billions of years, it travels through space, gathering around itself invisible matter, dark matter, which emits no light but pulls with gravity.

In the far reaches of space, there exists a hypothetical object: an ultracold black hole. It is charged and resides in an expanding universe (de Sitter space). Its temperature hovers just above absolute zero — about one trillionth of a degree above it.

A black hole's shadow isn't just a black circle. Usually, we see a dark void surrounded by a glowing ring of hot gas. But if a black hole wasn't born from a dying star but has existed forever, its shadow might hide a surprise. An eternal black hole is a solution to Einstein's equations with no past and no collapse.

A black hole is like a perfectly smooth sphere. It has no features — only mass, charge, and spin. This rule is called "no-hair." But nature loves to complicate things: sometimes a cloud of a scalar field (a special field described by a single number at each point) spontaneously appears around a black hole.

Light freezes at the edge of the abyss: that's what the event horizon of an ordinary black hole looks like. But at the center of this abyss lurks a singularity, a point where the laws of physics break down. What if, instead of a point, there were a hard shell? A gravastar is not a black hole.

A star circles a rotating black hole like a figure skater at the center of a rink. While it is far away and can be treated as a point, the dance remains predictable: the orbit follows clear laws, like music that is easy to glide to. But as it approaches, gravity begins to act unevenly.

Gravity is a remarkably weak force. A small magnet holds a paperclip against the pull of an entire planet. Physicists have long sought the reason for this weakness, and one guess leads us into hidden dimensions. Perhaps gravity 'leaks' into them, losing strength in our three-dimensional world.

A star runs out of fuel and rapidly collapses under its own gravity. According to classical ideas, it collapses into a point of infinite density — a singularity. But what if nature abhors infinities? In models of regular black holes, instead of a singularity, a dense core of unknown matter forms at the center.

The death of a massive star is not just the flash of a supernova, but also the birth of a black hole.

A black hole usually hides its singularity behind an event horizon — an invisible boundary from which not even light can escape. But sometimes this 'cloak' is absent, and the singularity, a point where familiar physics breaks down, is exposed to an outside observer.

An ordinary black hole hides a singularity at its center — a point where density and curvature become infinite and the laws of physics break down. The authors of the new work built a model of a rotating black hole that, instead of a singularity, contains a calm "core" resembling ordinary flat space.

The quantum world is often compared to a musical instrument. Each system, whether an atom or a chain of particles, sounds at its own frequencies, which physicists call energy levels. In chaotic systems, like an orchestra without a conductor, these frequencies usually fill the entire available range without gaps.

At the center of a classical black hole lurks a singularity — a point where the density and curvature of spacetime become infinite. Physics goes silent there.

The boundary of a black hole is like the edge of a waterfall: cross it, and there's no way back. But unlike a waterfall, this boundary can be very fragile: a light nudge is enough to make it vanish. Physicists have found that the horizon's stability is set by an imaginary 'light flow' coming from the past. Invisible streams pierce spacetime.

At the center of a black hole, classical theory paints a point where density and spacetime curvature shoot to infinity — like an infinitely sharp needle. But quantum corrections, tracing back to the work of Karl Schwarzschild, add a tiny “pillow”: space cannot collapse to zero.

The cosmological principle – the notion that the Universe is homogeneous and isotropic on large scales – has guarded our understanding of the world since the time of Edwin Hubble and Georges Lemaître, whose ideas formed the basis of the Big Bang model.

The explosion of a distant supernova told us something hard to believe: the universe is expanding faster and faster. The engine of this acceleration is dark energy — nearly 70% of everything that exists.

Ordinary gravity, as described by general relativity, behaves like a soft rubber membrane. When a massive star exhausts its fuel and collapses, it deforms this membrane so strongly that a black hole forms — a region where spacetime curvature becomes infinite, and nothing, not even light, can escape.

At the very beginning of the universe, when all of space was compressed into a point, the laws of physics break down. This point is called a singularity — an edge where our equations lose meaning. But what if it's not an end, but a special type of boundary? The authors of this work propose viewing the singularity as a free boundary.

A star contracts under its own gravity, and at some point its fate hangs on a razor-thin balance. Classical physics paints a grim picture: if the mass and the force of compression are tuned with terrifying precision, what emerges is not a black hole but a 'naked' singularity.

A black hole is not just a dark spot in space. It is a region where gravity compresses matter so intensely that even light cannot escape. Among all possible black holes, one stands out — the rotating Kerr black hole. Its description was long thought to be tied to Einstein's equations, like a recipe tied to a specific cookbook.

You toss pebbles into a whirlpool, trying to spin it faster and peer into its depths. A black hole is a cosmic whirlpool, where instead of water there is curved spacetime, and instead of a bottom there is a singularity — a point where the familiar laws of physics break down.

Picture a tightrope walker balancing over an abyss. Every step changes the rope's tension, and the slightest shift in center of gravity can prove fatal. That's roughly what the dance of an ordinary sun-like star around a black hole of ten solar masses looks like when the orbit is highly elongated.

If you squeeze a handful of sand, it gets denser, but at some point the grains press against each other: there's no more room to compress. Some theorists think space behaves similarly at ultra-small distances: it has a limit to divisibility, a kind of 'grain.' In this new study, that principle was applied to the birth of black holes in the early universe — the very ones that…

The Universe follows strict rules, like players at a table. One of them: gravity always attracts, and energy cannot be negative.

Drop a handful of sand into calm water — the ripples spread and fade. Drop it into a running blender — the vortices mix everything in an instant. Physics has a similar rule: chaos cannot grow faster than a certain rate.

When a massive star runs out of fuel, its core collapses under its own weight. A black hole forms — a region where gravity is so strong that even light can't escape. For a long time, it was thought that a point of infinite density, a singularity, lurks at the very center.

You can zoom into a high-resolution photo for a long time — until suddenly a smooth face dissolves into individual pixels. Something similar, according to a new study, happens to spacetime itself. The authors propose that tiny intervals of length are not pre-existing 'parts' of the universe but results of measurements.

The end of the Universe is not just the fading of light. If dark energy, the mysterious substance accelerating cosmic expansion, tears it apart in a Big Rip scenario, or if expansion reverses into a contraction that pulls everything back to a point like a big bang in reverse, a…

An ordinary magnet always carries two poles — north and south. Split it in half, and each piece immediately grows its own pair. But deep in particle theory lives a strange notion: the monopole — a particle carrying just one magnetic charge, a lone pole without a partner.

In the standard picture, black holes are the undisputed density champions: all their matter is squeezed into a single point. Imagine the entire mass of Mount Everest packed into a grain of salt. But physicists have found a theoretical trick.

A single graviton, a quantum of spacetime, is incredibly weak. For detectors like LIGO, built by Rainer Weiss and colleagues, quantum effects are suppressed by a factor of 10⁻³⁸: it's like trying to hear a grain of sand changing the wind's direction in a hurricane.

In the mid-20th century, Roger Penrose described a black hole using the concept of a “trapped surface” – a region where even a light ray directed outward inevitably falls inward. A situation familiar to everyone: water in a sink’s vortex is irretrievably sucked down the drain.

In the mid-20th century, Roger Penrose described a black hole using the concept of a “trapped surface” – a region where even a light ray directed outward inevitably falls inward. A situation familiar to everyone: water in a sink’s vortex is irretrievably sucked down the drain.

Two particles behave like a pair of unusual dice: thrown at opposite ends of the universe, they always land on the same face. Physicist John Stewart Bell calculated: if the dice had hidden rules, the frequency of matches would have a strict limit.

Modern detectors of gravitational waves confirm that black holes are real. Spacetime can be compared to a giant trampoline: massive stars make it sag.

Physics often resembles the construction of a giant ship — the Universe. The physicist-engineers have yet to agree on the basic blueprints.