The Scariest Things in the Universe Are Black Holes – Here’s Why

Supermassive Black Hole Pulls a Stream of Gas off Star

Falling into a black hole is easily the worst way to die.

Halloween is a time to be haunted by ghosts, goblins, and ghouls, but nothing in the universe is scarier than a black hole.

Black holes – regions in space where gravity is so strong that nothing can escape – are a hot topic in the news these days. Half of the 2020 Nobel Prize in Physics was awarded to Roger Penrose for his mathematical work showing that black holes are an inescapable consequence of Einstein’s theory of gravity. Andrea Ghez and Reinhard Genzel shared the other half for showing that a massive black hole sits at the center of our galaxy.

Black holes are scary for three reasons. If you fell into a black hole left over when a star died, you would be shredded. Also, the massive black holes seen at the center of all galaxies have insatiable appetites. And black holes are places where the laws of physics are obliterated.

I’ve been studying black holes for over 30 years. In particular, I’ve focused on the supermassive black holes that lurk at the center of galaxies. Most of the time they are inactive, but when they are active and eat stars and gas, the region close to the black hole can outshine the entire galaxy that hosts them. Galaxies where the black holes are active are called quasars. With all we’ve learned about black holes over the past few decades, there are still many mysteries to solve.

Disc of Material Circling a Supermassive Black Hole

Artist’s impression of a disc of material circling a supermassive black hole. Credit: ESA/Hubble, M. Kornmesser

Death by black hole

Black holes are expected to form when a massive star dies. After the star’s nuclear fuel is exhausted, its core collapses to the densest state of matter imaginable, a hundred times denser than an atomic nucleus. That’s so dense that protons, neutrons and electrons are no longer discrete particles. Since black holes are dark, they are found when they orbit a normal star. The properties of the normal star allow astronomers to infer the properties of its dark companion, a black hole.

The first black hole to be confirmed was Cygnus X-1, the brightest X-ray source in the Cygnus constellation. Since then, about 50 black holes have been discovered in systems where a normal star orbits a black hole. They are the nearest examples of about 10 million that are expected to be scattered through the Milky Way.

Black holes are tombs of matter; nothing can escape them, not even light. The fate of anyone falling into a black hole would be a painful “spaghettification,” an idea popularized by Stephen Hawking in his book “A Brief History of Time.” In spaghettification, the intense gravity of the black hole would pull you apart, separating your bones, muscles, sinews and even molecules. As the poet Dante described the words over the gates of hell in his poem Divine Comedy: Abandon hope, all ye who enter here.

First Image of a Black Hole

A photograph of a black hole at the center of galaxy M87. The black hole is outlined by emission from hot gas swirling around it under the influence of strong gravity near its event horizon. Credit: EHT

A hungry beast in every galaxy

Over the past 30 years, observations with the Hubble Space Telescope have shown that all galaxies have black holes at their centers. Bigger galaxies have bigger black holes.

Nature knows how to make black holes over a staggering range of masses, from star corpses a few times the mass of the Sun to monsters tens of billions of times more massive. That’s like the difference between an apple and the Great Pyramid of Giza.

Just last year, astronomers published the first-ever picture of a black hole and its event horizon, a 7-billion-solar-mass beast at the center of the M87 elliptical galaxy.

It’s over a thousand times bigger than the black hole in our galaxy, whose discoverers snagged this year’s Nobel Prize. These black holes are dark most of the time, but when their gravity pulls in nearby stars and gas, they flare into intense activity and pump out a huge amount of radiation. Massive black holes are dangerous in two ways. If you get too close, the enormous gravity will suck you in. And if they are in their active quasar phase, you’ll be blasted by high-energy radiation.

How bright is a quasar? Imagine hovering over a large city like Los Angeles at night. The roughly 100 million lights from cars, houses and streets in the city correspond to the stars in a galaxy. In this analogy, the black hole in its active state is like a light source 1 inch in diameter in downtown LA that outshines the city by a factor of hundreds or thousands. Quasars are the brightest objects in the universe.

Supermassive black holes are strange

The biggest black hole discovered so far weighs in at 40 billion times the mass of the Sun, or 20 times the size of the solar system. Whereas the outer planets in our solar system orbit once in 250 years, this much more massive object spins once every three months. Its outer edge moves at half the speed of light. Like all black holes, the huge ones are shielded from view by an event horizon. At their centers is a singularity, a point in space where the density is infinite. We can’t understand the interior of a black hole because the laws of physics break down. Time freezes at the event horizon and gravity becomes infinite at the singularity.

The good news about massive black holes is that you could survive falling into one. Although their gravity is stronger, the stretching force is weaker than it would be with a small black hole and it would not kill you. The bad news is that the event horizon marks the edge of the abyss. Nothing can escape from inside the event horizon, so you could not escape or report on your experience.

According to Stephen Hawking, black holes are slowly evaporating. In the far future of the universe, long after all stars have died and galaxies have been wrenched from view by the accelerating cosmic expansion, black holes will be the last surviving objects.

The most massive black holes will take an unimaginable number of years to evaporate, estimated at 10 to the 100th power, or 10 with 100 zeroes after it. The scariest objects in the universe are almost eternal.

Written by Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

Originally published on The Conversation.The Conversation

14 Comments on "The Scariest Things in the Universe Are Black Holes – Here’s Why"

  1. Edward R Williams | November 5, 2021 at 8:46 pm | Reply

    And black holes are places where the laws of physics are obliterated.
    I read this message in almost every article I come across on Black Holes. I am going to take exception to this statement in my comment. It seems to me that BHs hold court on the laws of our physical universe. Giving them the ULTIMATE AUTHORITY!

    • Torbjörn Larsson | November 6, 2021 at 5:52 am | Reply

      It is unlikely they don’t follow nature (physics laws). They aren’t magical, merely hard to understand.

  2. Torbjörn Larsson | November 6, 2021 at 5:55 am | Reply

    The source is a one year old article. Still interesting of course, though the discussion of the Schwarzschild solution mathematical properties (including a singularity, and a coordinate system dependent ‘time freeze’) remains obscure.

  3. No. The scariest things in the Universe are not black holes. The nearest black hole which I am aware is about 30,000 light years away. Astronomers have real difficulty to see it or to detect its effects.
    The scariest are other people. People kill tens of thousands other people in the U.S. alone. Around the world people kill millions other people. People are the most dangerous.

    • Torbjörn Larsson | November 7, 2021 at 3:28 am | Reply

      “Millions”?

      US with its state killing institutions at home (death penalty) and abroad (drone murders) is a lamentable exception.

      Luckily the number of conflicts can be seen drop over time [ https://ucdp.uu.se/ ]. The number of people killed in conflicts were less 0.1 million – which statistics has been stable since 1995. The number of people killed in homicides is 0.4 million each year [see “Homicides” @ “Our World In Data”]. That is less than 1 % of deaths, and of the 55 million dead 2019 diarrheic diseases came in as death cause #8, meaning cholera et cetera is more dangerous (kills 2 million every year) [see WHO statistics]. An equally dangerous organism for humans as humans would be something like the malaria parasite that killed 0.4 million in 2019 [see WHO statistics].

      But this has nothing to do with black hole physics, of course.

  4. 2020 a year old article and lots has been discovered since then
    so take a black hole and its event horizon
    is it a flat black hole in two dimensions are u a flat earther
    or is it a 3d black hole in three dimensions are you a sphere earther
    so the secret to the black hole
    is the outer event horizon where part of you may escape and part of you will be dragged in you have half a chance of being sucked in or fired out
    lucky you if you are fired out
    the part of you that is sucked is then spagettified
    where you may or may not reach the inner event horizon the place where everything is travelling so fast that it remains bound to the boundary line and may fall inwards
    the sorry tale of the spagettified one is that now everything is stripped from you everything and you now become atoms in space your whole volume becomes a mass of atoms protons and neutrons thats all that left of u
    but the boundary of this zone is still not close to the scattering zone
    this zone of scattering is where your atoms are pulled apart and become protons and neutrons
    and still you have no escape
    until you reach the black hole point of maximum destruction
    the x ray zone where your protons and neutrons are pulled apart into leptons and quarks
    and then you may be the lucky one
    because the escape hatch is opened and you are launched skywards towards the polar point of a black hole
    remember there is no escape on the horizontal axis
    remember there is two escape hatches in the vertical axis
    but you are now leptons and muons carriers of quantum information into the milky way galactic void
    part ii to follow later

  5. The article is complete misinformation that only wild people can believe.
    1) There are no mystical black holes – there are centers of galaxies, which consist of quarks. Yes, they do not emit light;
    .Light is 10^ 14 – 10^ 15 Hertz, and quarks 10^ 32 Hertz.
    2) The centers of galaxies do not attract people, planets and other products from atoms – they have different frequencies of gravity.
    3) The centers of galaxies do not eat the stars – they give birth to them and keep them in orbits;
    The only half-truth in the last paragraph – the centers of galaxies become smaller. And this is because they give birth to hundreds of billions of stars and in the last stage themselves become super big stars.
    https://www.youtube.com/watch?v=tFUM3vAlaGc

    • Torbjörn Larsson | November 7, 2021 at 3:32 am | Reply

      Your comment is, as all your comments here, completely made up and unreferenced misinformation that only wild people can believe.

      Yes, your pseudoscience link do not constitute a source that pass peer review.

      • I drew conclusions from the new publications of Pavel Vasiliev and Max Planck, and did not repeat the petrified false truths of 100 years ago. I propose to replace the non-existent big explosion with a big synthesis, which continues today and build antigravity flying saucers .

  6. Why do people constantly write what would happen to you if you fall in a black hole. Isn’t it a bit pointless? Is there anyplace other than earth that you could be at that wouldn’t obliterate you? Imagine if you fell in Jupiter or a quasar. Just anywhere in space and your blood would immediately boil. Wouldn’t it be better to focus on how they seem to violate our known laws and not so much that they can kill you?

  7. Stable one minute then poof it is a black hole ? Black holes are scary not even heat can escape them, but are they stable and real ? Apparently they move but at what size does a star collapse to become a black hole ? I mean if it is about 1 million solar masses it is visibly stable then poof at 1.1 million solar masses it becomes unstable and collapses to become a black hole ? I was researching and found this out about white dwarfs from wikipedia…I hope the same is for black holes…: ” The material in a white dwarf no longer undergoes fusion reactions, so the star has no source of energy. As a result, it cannot support itself by the heat generated by fusion against gravitational collapse, but is supported only by electron degeneracy pressure, causing it to be extremely dense. ….Over a very long time, a white dwarf will cool and its material will begin to crystallize, starting with the core. The star’s low temperature means it will no longer emit significant heat or light, and it will become a cold black dwarf.”

    • Torbjörn Larsson | November 7, 2021 at 3:38 am | Reply

      If black holes weren’t real we could not observe them – see the black hole photograph in the article [!] – and do science on them.

      The collapse size is still an open question, complicated theory results in something like 2+ solar masses depending on progenitor nature (its spin, for example). Some LIGO and other black hole observations has pinned the collapse mass down to somewhere between 2 – 5 solar masses IIRC.

  8. Every comment section has a Torbjorn. Pure concentrated cringium.

  9. … but, if the black whole has a radius, then we might calculate the minimum distance in the fabric of space time…

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