The mysterious origins of the universe’s biggest black holes

More than 40 quintillion black holes are estimated to exist in the universe, including about 100 million in the Milky Way, each with masses up to hundreds of times that of the sun.

Black holes 101

At the center of our galaxy, a supermassive black hole churns. Learn about the types of black holes, how they form, and how scientists discovered these invisible, yet extraordinary objects in our universe. This three-minute video from National Geographic tutors the viewer on the basics regarding the universe's most mysterious residents.

Research suggests that about 1% of all matter in the universe is locked inside black holes, millions of which are likely to lurk undetected near us in space.

13 unanswered questions about black holes

Here's a quick rundown on black hole basics, the cosmic enigmas digesting massive swaths of the universe and destabilizing our fundamental ideas of space, time, and matter. Learn how they got their name, what happens in the unfortunate instance you fall into one, and more with this list of 13 questions about black holes.

Hawking suggested studying black holes could reveal truths about the universe's start

After predicting black holes could evaporate and before undergoing a tracheotomy, Stephen Hawking conducted interviews in his voice, explaining phenomena like black holes and the Big Bang. In this clip, he explains how curiosity drives humans to become “masters of the universe.”

How black holes form

Don’t let the name fool you: A black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City.

What lies inside a black hole remains one of the universe's greatest mysteries

At the center of black holes is a theoretical point of infinite density called a singularity. Alternatively, one theory suggests a black hole's core could form a Planck star—a mind-bogglingly tiny object just a trillionth trillionth trillionth of a meter in size.

Black holes do not 'suck' matter and energy in like a vacuum cleaner

Despite its immense magnitude, the force of gravity exerted by black holes acts in the same way as provided by stars and planets, allowing objects to maintain stable orbits around them. Even in cases where tidal forces and friction cause objects to change their orbit and fall towards a black hole, they are more likely to glance by, be whipped around, and get ejected rather than absorbed.

Black holes are formed from massive stars collapsing under their own gravity

This creates a region where spacetime curves infinitely, known as a singularity. Black holes' intense mass and energy allow them to trap light, distort time and space, and present challenges with reconciling Einstein's theory with quantum mechanics.

Nearly 50 years before the first observational evidence, a soldier fighting on the Eastern Front in World War I found a mathematical solution to Einstein's equations that suggested the existence of black holes.

The first-ever image of a black hole

The Black Hole at the center of galaxy M87 is ready for its close-up, becoming the first black hole to have its image directly captured. The Event Horizon Telescope caught the distant yet massive object—it's more than 55 million light years away—recording its gravity's effect on nearby hot gases.

Attempts to 'fix' black hole physics have led scientists to theorize new types

Along with their spin and charge, mass is used to categorize black holes as supermassive, intermediate, or stellar-mass. However, ongoing research suggests various additional types may exist, including primordials that formed one second into the universe's birth, fuzzballs—tangles of vibrating strings—and gravastars, which have a shell of dense matter around repulsive vacuum energy.

The black hole information paradox comes to an end

Quanta Magazine provides a deep dive into black holes and the black hole information paradox. For a very long time it was believed nothing could escape a black hole. Therein lies the paradox. Per quantum mechanics, whatever falls into a black hole should not necessarily be lost forever, and may eventually return. In a landmark series of calculations, physicists have proved that black holes can shed information.

A black hole with the mass of the observable universe would be larger than the observable universe, leading some theorists to suggest that we may live inside a black hole.

The universe might have emerged from a quantum fluctuation—not absolute nothing

Traditional physics breaks down at the moment of the Big Bang, but quantum theory suggests that “empty” space is never truly empty. In 1973, physicist Edward Tryon proposed that our universe began from a quantum energy blip in the quantum vacuum.

Explaining 'impossible' black holes

When stars collapse, the black holes they form can have the mass of either 50 suns or over 120—but current models claim strongly that no black hole should have a mass that falls in between that range. But in 2019, gravitational wave observatories detected two within it: one at 66 solar masses, the other at 85. The discovery disrupted established science and left researchers questioning the Standard Model of physics.

View a timeline of the universe's major events, according to the Big Bang model.

Stars hold off gravitational collapse with the energy produced in nuclear reactions in their core, but when massive stars run out of fuel for these reactions, runaway collapse can produce a black hole.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

String theory replaces black hole singularities with fuzzballs of tangled strings

Black holes contain singularities where information about the material that fell in is lost, violating quantum mechanics. Instead, modeled as a bundle of strings, information is stored and slowly released as the black hole evaporates.

About 85% of the matter in the universe is dark matter—an invisible substance that only interacts with its surroundings through gravity.

Neil deGrasse Tyson explains wormholes and black holes

Much of the film Interstellar is centered on the existence of a wormhole and black hole, which happen to be two of the most perplexing things in the universe. Astrophysicist and StarTalk Radio host Neil deGrasse Tyson explains how wormholes and black holes work in real life in this two-minute video.

Research suggests that the small red dots in images of deep space captured by the James Webb Space Telescope since 2022 are black hole stars—black holes surrounded by enormous clouds of gas.

The Big Bang theory explains the universe’s expansion, not its origin

While we have strong evidence that the universe expanded from an extremely hot, dense state, we can only trace events back to a tiny fraction of a second after that point. Earlier stages, like inflation and potential force unification, remain unproven and unobservable with current tools.

There may be as many as four types of black holes, categorized by their mass

Three types are known to exist: stellar mass black holes, supermassive black holes, and intermediate black holes. A fourth type—micro black holes—is theoretical and would have the same mass as Mount Everest in a space the size of an atom.

Why the Big Bang theory is the most well-supported explanation for the origin of the universe

Multiple independent lines of evidence—galactic redshift, element ratios, cosmic microwave background radiation, and large-scale cosmic structure—all point to a single origin about 13.8 billion years ago. Before Edwin Hubble, many astronomers believed the entire universe was contained within our galaxy.

Despite fears of creating black holes, the Large Hadron Collider produces collisions with energies of 13.6 trillion electronvolts, about one million times smaller than the energy needed to create the lightest possible black holes.

The cosmic dark ages: before stars existed

The theories behind the Big Bang suggest the process of the universe beginning to the creation of stable, neutral atoms took just half a million years. But the transition from such atoms to star formation took surprisingly much longer, upwards of 100 million years. Why? This deep dive explores the science behind the unique physical composition of the so-called cosmic dark ages.

The mystery of the expanding universe

One of the most surprising discoveries about our universe over the past century is that it's expanding. Even more surprising is that it’s speeding up, and scientists aren’t entirely sure why. The rate should be roughly dependent on the total energy contained in the universe, but calculations keep coming up short. Explore the so-called “Hubble Tension,” along with potential candidates to solve the riddle.

Black holes can disrupt the formation of galaxies

A team of astronomers in Munich detected a gas cloud being stretched and torn apart by the supermassive black hole at the center of the Milky Way, preventing matter from coalescing into new stars. Energy released from siphoned gas produced warm winds that may also prevent surrounding gas from coalescing.

Mapping the universe's 1.3 million quasars

Quasars form the core of active galaxies where supermassive black holes devour unimaginable amounts of matter. You can see a map of all 1.3 million of these objects with this 3D map. It was assembled with data from the Gaia spacecraft and shows how the spread of dark matter across space matches that described by the Cosmic Microwave Background.

If particle accelerators did create black holes by packing tremendous energy into a small volume, then trillions would be created in Earth's atmosphere daily by cosmic rays.

From the Big Bang to present—a timeline

A timeline for everything, from the Big Bang to the beginnings of life on Earth. This article lays out, in spans of billions of years, what was happening in the universe as it became the universe. Starting from the Planck era, the earliest known meaningful time, to the probable "Big Crunch" 30 billion years from now, see how the universe has existed and persisted.

The universe's expansion is accelerating due to a mysterious force called dark energy

Astronomers discovered in the late 1990s that galaxies move apart faster over time, contradicting expectations that gravity should slow cosmic expansion. This prompted the revival of the "cosmological constant," a form of repulsive gravity first proposed by Albert Einstein.

The first image of a black hole was created from an international telescope network

The Event Horizon Telescope united radio observatories worldwide to image the supermassive black hole at the center of the Milky Way, known as Sagittarius A*. The team couldn’t transmit their massive dataset online, so they physically flew hundreds of terabytes of data to MIT aboard airplanes.

Nothing can enter white holes—the opposites of black holes

Although a mathematical possibility according to general relativity, there is no observational evidence for these objects, which would endlessly eject material into the universe via anti-gravity. It is also unclear how they would form or avoid collapsing due to the gravity of the ejected material.

Quasars are extremely luminous cores of distant galaxies, powered by supermassive black holes that consume as much as 100 Earth masses of gas and dust per minute.

Mars' orbit may provide evidence that dark matter is made of primordial black holes

Physicists at MIT have found that, statistically, one such microscopic black hole should pass through the solar system every decade, which they predict would introduce a detectable wobble in Mars' orbit. Such black holes would have formed in the early universe from collapsing gas clouds and scattered as the universe expanded.

Cygnus X-1 helped scientists confirm black holes are real and measurable phenomena

The 1964 discovery of Cygnus X-1 provided the first strong candidate, but it took decades—and a famous bet between Stephen Hawking and Kip Thorne—before scientists were certain it was a black hole. Hawking's thumbprinted concession was delivered after breaking into Thorne's office.

Studying 'sonic' black holes

If a fish screams as it falls down a cascading waterfall accelerating to ridiculous speeds, will his fish friends above hear him scream? This analogy, odd as it is, has become an essential tool in the astrophysicists kit for learning how enigmatic black holes operate. Lab experiments mirroring the so-called sonic black hole have achieved insights for their cosmic counterparts. Read how it works in this brief piece.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

Understanding how and when time began requires a theory of quantum gravity

Rewinding the universe to the big bang compresses all matter, energy, space, and time into a single point, necessitating a model that combines general relativity with quantum mechanics. Although physicists understand time to have begun when the universe did, a clear understanding of the mechanisms involved remains unclear.

One study suggests that dark matter may have originated from a dark Big Bang

A student-faculty team at Colgate University modeled the event as occurring months after the conventional Big Bang and determined the potential gravitational wave signal that would have been left behind. Future gravitational wave detectors are expected to be sensitive enough to observe this signal, if it exists.

LIGO confirmed Stephen Hawking's theorem about black hole surface areas

Black holes are known to grow with increased mass but lose energy during mergers through the emission of gravitational waves. Amid these competing factors, the black hole area theorem—confirmed in 2021 using LIGO data—states that a merged black hole's size cannot be smaller than the combined surface area of its progenitors.

Watch a simulation of a collapsing star becoming a black hole

When a massive star can no longer release enough energy through fusion in its core to fight off gravitational collapse, the dense core collapses first, producing an event horizon that traps light within it, including some light produced within the star at the time of collapse. As more material falls into the growing event horizon, the star will appear to eclipse itself from the inside.

Try to catch the 'sound' of black holes in gravitational wave detector data

In "Black Hole Hunter," users try to listen for gravitational wave signals from black holes in four sample data files that include substantial background noise. With each level, learn more about black holes while being faced with ever-quieter signals.

The first image of Sagittarius A*—the supermassive black hole at the center of the Milky Way Galaxy—was revealed in 2022, almost 50 years after its discovery.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Scientists are experimenting with ways to probe the multiverse theory

Researchers are simulating vacuum bubbles—the theorized starting points of universes—using quantum computers, digital models, and exotic lab setups to study how they form, expand, and possibly collide. One experiment aims to "blow" artificial universe-like bubbles inside ultra-cold quantum gases, potentially capturing real-time glimpses of cosmic birth processes in a lab.

TON 618, the largest black hole ever detected, has the mass of 66 billion suns

The supermassive black hole is 18 billion light-years away and emits radiation with the brightness of 100 trillion stars. It is so massive that light would take an entire week to travel from its edge to its center.