Category: Astronomy

The Giant Bubble of No Space

Cosmology is the science of the origin and development of the universe, and this post is about a book on Cosmology, “What’s Eating the Universe?: And Other Cosmic Questions” by Paul Davies.

What’s eating the Universe is one of the 30 questions answered in this book. It refers to the mysterious gigantic super-voids we’ve found. Could they be the result of collisions with other universes? Could they be the result of expanding giant bubbles with no space at all in them? That’s not just empty bubbles with empty space, but bubbles in which space itself is missing. Try to imagine that. Some of the 30 questions have answers, others just feature several guesses.

The goal of this blog is to create a list of what I call super facts. Important facts that we know to be true and yet they are surprising, shocking or disputed among non-experts. Super facts are special facts that a well-informed person may want to know.

However, I sometimes create posts that are not super facts but just interesting information, such as this one. What’s eating the Universe is a relatively short and easy read. I bought the hardback version of it.

  • Hardcover –  Publisher : University of Chicago Press; First Edition (September 22, 2021), ISBN-10 : 022681629X, ISBN-13 : 978-0226816296, 208 pages, item weight : 12.2 ounces, dimensions : ‎5.67 x 0.71 x 8.58 inches, it costs $19.84 on Amazon. Click here to order it from Amazon.com.
  • Paperback –  Publisher : University of Chicago Press; First Edition (September 30, 2022), ISBN-10 : 0226823873, ISBN-13 : 978-0226823874, 183 pages, item weight : 9.6 ounces, dimensions : ‎ ‏ : 5.5 x 0.46 x 8.5 inches, it costs $15.67 on Amazon. Click here to order it from Amazon.com.
  • eTextBook –  Publisher : University of Chicago Press; First edition (September 22, 2021), ASIN : B096L2WP51, 172 pages, it costs $14.89 on US Amazon. Click here to order it from Amazon.com.
Front cover of What’s Eating the Universe? Click on the image to go to the Amazon page for the hardcover version of the book.

Amazon’s description of the book

Combining the latest scientific advances with storytelling skills unmatched in the cosmos, an award-winning astrophysicist and popular writer leads us on a tour of some of the greatest mysteries of our universe.

In the constellation of Eridanus, there lurks a cosmic It’s as if something has taken a huge bite out of the universe. But what is the culprit? The hole in the universe is just one of many puzzles keeping cosmologists busy. Supermassive black holes, bubbles of nothingness gobbling up space, monster universes swallowing others—these and many other bizarre ideas are being pursued by scientists.

Due to breathtaking progress in astronomy, the history of our universe is now better understood than the history of our own planet. But these advances have uncovered some startling riddles. In this electrifying new book, renowned cosmologist and author Paul Davies lucidly explains what we know about the cosmos and its enigmas, exploring the tantalizing—and sometimes terrifying—possibilities that lie before us.

As Davies guides us through the audacious research offering mind-bending solutions to these and other mysteries, he leads us up to the greatest outstanding conundrum of Why does the universe even exist in the first place? And how did a system of mindless, purposeless particles manage to bring forth conscious, thinking beings? Filled with wit and wonder, What’s Eating the Universe? is a dazzling tour of cosmic questions, sure to entertain, enchant, and inspire us all.

This is my five-star review for What’s Eating the Universe?: And Other Cosmic Questions.

Cosmology explained the easy way

This book is organized into 30 cosmological questions that the author is answering or clarifying. His explanations are naturally not in depth but high level and easy to understand for anyone with an interest in the topic. He manages to keep the topic fascinating and the book is a real page turner. I read the book in a little bit more than one day.

The book discusses cosmology, relativity, the standard model, black holes, the big bang, the CMB, dark matter, dark energy, multiverses and the fate of our Universe, extraterrestrials, and much more, and he gives us insight into the very latest discoveries and views of cosmology.

I especially enjoyed reading chapter 20 & 21 “Can the Universe Come from Nothing” and “How Many Universes Are There”. He tells us that most cosmologists he knows believe there are infinitely many universes. One model is eternal inflation, a space/time mechanism beyond our universe that keeps causing new universes to bubble up and initially expand rapidly, but there are other models. I was surprised that he didn’t mention Roger Penrose’s model, cycles of time, with one Universe giving rise to another (after full expansion and heat death).

However, if there’s only one Universe and time came into existence with it (singularity) it doesn’t help those who want to insert a creation moment. If time didn’t exist before the big bang, the concept of a prior physical cause is meaningless. Asking what was before the big bang is like asking what lies north of the North Pole.

I also especially enjoyed reading chapter 30 “What’s New on the Cosmic Horizon” in which he lists mysteries and recent exciting discoveries, the cold patch in Eridanus (CMB), the mystery with the Hubble constant, what’s beyond the standard model, the prospect of top-down models, etc. Well, all the chapters were interesting.

This book is a quick and easy summary of what’s going on in cosmology. It’s accessible and engrossing writing and the straightforward organization make the book a great introduction to the topic. I highly recommend this book.

Back cover of “What’s Eating the Universe?” Click on the image to go to the Amazon page for the paperback version of the book.

Finally, a list of the 30 questions

  • Journey from the Edge of Time
  • The search for the key to the Universe
  • Why is it dark at Night?
  • The Big Bang
  • Where is the Center of the Universe?
  • Why the Cosmos is Actually Fairly Simple?
  • What is the Speed of Space?
  • What is the Shape of Space?
  • Explaining the Cosmic Big Fix
  • Most of our Universe is Missing
  • What is Dark Energy
  • Where Does Matter Come From?
  • Gravity Conquers All
  • Warped Time and Black Holes
  • Is Time Travel Possible?
  • What is the Source of Time’s Puzzling Arrow?
  • The Black Hole Paradox
  • A Theory of Everything?
  • Fossils from the Cosmic Dawn
  • Can the Universe Come from Nothing?
  • How Many Universes Are There?
  • The Goldilocks Enigma
  • What’s Eating the Universe?
  • Is the Universe Actually a Botched Job?
  • Are We Alone?
  • Is ET in Our Backyard?
  • Why Am I Living Now?
  • The Fate of Our Universe
  • Is There a Meaning to It All?
  • What’s New on the Cosmic Horizon?

To see the Super Facts click here

The Betelgeuse Supernova

This is a submission for Kevin’s No Theme Thursday

Image by Kevin from The Beginning at Last

Supernova

A supernova is an explosion of a star so violent that it can outshine an entire galaxy. It can occur when a super massive star’s core contracts (the death of the star) and as it reaches a critical point it triggers nuclear reactions that cause the star to explode. Alternatively, it can occur when a white dwarf star is triggered into runaway nuclear fusion by a collision with another star.

Depending on how far away the supernova is it can be as luminous as a bright new star, the moon, or a second sun. It occurs suddenly and lasts for several weeks or months before fading away. If a supernova shines bright enough, the other stars in the sky will vanish from view. We can’t see the stars during the day, not because of the blue sky, but because of the ambient light from the sun. 

This is also one major reason photos from space often lack stars in the black sky. If a supernova is close enough to earth it could destroy earth. Luckily there are no super massive stars close enough to earth to pose a risk.

Supernova explosion in the center of the Andromeda galaxy “Elements of this image furnished by NASA” It is essentially an enhanced photo of a supernova explosion in a neighboring galaxy. Stock Photo ID: 2495486227 by muratart.

The Betelgeuse Supernova

Betelgeuse the bright red star in the constellation Orion is thought to be close to going supernova, and when it does it will be about as bright as half a full moon in our sky but concentrated in a point. What does “close” mean? Some astronomers say within decades, some say within a few thousand years. Could Kevin’s beautiful picture above depict this future event?

Illustration of the Orion constellation. To find Betelgeuse, first find Orion’s belt, then look up to the left. The reddish star is Betelgeuse. It is visible at this time of year (on a clear night). Stock Vector ID: 1631025025 by Tedgun.

We are stardust

The first stars in the Universe were made of 75% hydrogen and 25% helium and trace amounts of Lithium, just like the entire Universe at the time. Heavier elements that could form rocky planets or other solid celestial bodies did not exist.

However, inside the cores of these stars, heavier elements such as carbon, oxygen, and iron were formed by fusion. These early stars are referred to as first generation stars. They tended to be large and ended their lives in massive supernova explosions. The dusty remains of these explosions became the building blocks of the second and third generation stars we see today as well as the planets, our bodies and all life. We are stardust.

The first-generation stars consisted of 75% hydrogen and 25% helium and trace amounts of Lithium. A second or third generation star like our sun is still mostly hydrogen and helium but also many other elements. The rocky planets circling the sun are mainly elements heavier than hydrogen and helium. Image credit NASA, ESA, CSA, STScI.

Finally, a 33 second YouTube video illustrating a Supernova (the creation of the Crab nebula)

Would you like to see Betelgeuse explode into a supernova in your lifetime?

To see the Super Facts click here

Black Holes Monsters in the Sky

“This”Black Holes Monsters in the Sky” is a submission for Kevin’s No Theme Thursday

Image by Kevin from The Beginning at Last

Black holes, everyone has heard of them, no one understands them. They are inscrutable monsters in the sky. They are regions of spacetime wherein gravity is so strong that nothing can escape, not light, not anything. Some of them are small, only 15 kilometers across, and some have a diameter 27 billion times larger than that.

As you get close to a black hole your time will run slower. You won’t notice it, but others will see you move in slow motion. If you return from your close encounter an hour on your clock might correspond to years elsewhere. As you approach the event horizon, the boundary of no escape, you become invisible and time will stop, at least from an outside view.

Black holes are invisible. They are truly black. However, we can see them if they are consuming matter. The matter close to black holes will heat up and glow. The closer to the event horizon the redder it is. It is called an accretion disk as in the depiction above.

There are an estimated 100 million black holes in our galaxy, the Milky Way. At the center of the Milky Way is a super massive black hole called Sagittarius A-star. It is 4 million times more massive than our sun. There are supermassive black holes located at the center of most large galaxies. The supermassive black holes are considered to play a crucial role in the formation of galaxies.

I’ve looked up in the sky, and I’ve seen the spot where Sagittarius A-star is located. I’ve tried to look at it with my telescope, but I cannot see it. It is not possible to see it with a telescope, but it is there. The picture above may depict the view from a planet in the center of our galaxy. Three scientists received the Nobel prize in physics in 2020 for their research on black holes (Roger Penrose, Reinhard Genzel, and Andrea Ghez).

However, before them the tele evangelist Jack Van Impe won the 2001 Ig Nobel Prize in Astrophysics for his discovery that black holes meet all the technical requirements for Hell. The Ig Nobel prize is an alternative and less serious Nobel Prize. To find out more about Black Holes click here.

Below is an animation created by NASA that depicts what an observer falling into a black hole would see.

To see the Super Facts click here

The Bizarre Reality of Black Holes

3D illustration of giant Black hole in deep space. High quality digital space art in 5K – realistic visualization. Stock Illustration ID: 2476711459 by Vadim Sadovski.

Superfact 15: A black hole is a region of spacetime wherein gravity is so strong that nothing can escape it, not light, not anything. There are different kinds of black holes. We don’t fully understand black holes, which makes them very interesting to science. The boundary of no escape is called the event horizon.  Black holes are invisible. They are truly black. However, we can see what they do to their environment as they consume surrounding matter. Below are some bizarre facts about black holes.

  • Time runs much slower closer to a black hole.
  • An object falling towards a black hole will become redder, faint, then infrared, then invisible and all its movements and clocks will freeze.
  • From the perspective of an outside observer, time appears to stop for someone reaching the event horizon of a black hole. Time will continue for someone falling in.
  • At the center of a black hole may lie a gravitational singularity, a region where the spacetime curvature becomes infinite. However, since we cannot peer into a black hole we cannot know.
  • The largest known black hole (TON 618) is more than 287 million times more massive than the most massive known star (R136a1).
  • If our planet earth collapsed into a black hole, it’s diameter would  be 1.75 centimeters or 0.69 inches in diameter. The diameter of the largest known black hole (TON 618) is 242 billion miles, which is more than one million times larger than the distance from the earth to moon.
  • There are supermassive black holes located at the center of most large galaxies, including our Milky Way. The Milky Way’s black hole is about 4 million times the mass of the Sun.
  • Astronomers estimate that there are around 100 million black holes in our Milky Way.
  • When an object (maybe a spaceship, or a person) approaches or falls into a black hole the difference between the gravity on the parts closer to the black hole and those further away will be so large that the object is stretched and ripped apart. This is called spaghettification.
  • Stretching from the event horizon and out another half radius of the black hole is a region called the photon sphere. In the photon sphere light will travel in a non-stable circular orbit around the black hole. Light will go around and around for a while. If you are in the photon sphere you might be able to see the back of your head.
  • Above is just a small sample of weird black hole facts.
The understanding of black holes requires the General Theory of Relativity, and it is still a lot we don’t understand about them. Stock Photo ID: 2024419973 by Elena11

The Bizarre Reality of Black Holes

I chose the Bizarre Reality of Black Holes as a super-fact and included the ten facts above because these facts are shocking and yet not well known. Below is a photograph of a supermassive black hole at the center of the galaxy M87 taken by the event horizon telescope in 2017. To create the picture below image processing was needed. It is the first photograph of a black hole. This supermassive black hole is an estimated 6.5 billion times as massive as our sun, and 28 million times as massive as the largest known star.

The photo of the supermassive black hole at the center of the galaxy M87 taken by the event horizon telescope in 2017. Uploader cropped and converted TIF to JPG – This file has been extracted from another file, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=77925953.

Below is an animation created by NASA that depicts what an observer falling into a black hole would see.

The fact that from the perspective of an outside observer, time appears to stop for someone reaching the event horizon of a black hole seems to prevent anything from falling into a black hole from an outside perspective. How does anything ever get inside the black hole if it freezes up at the event horizon? Black holes grow, they collide and merge, so clearly things can get inside, right? But how? As I tried to find the answer to this question, I found that I was far from the only one asking this question.

Realistic spaceship approaching a black hole. This content was generated by an Artificial Intelligence (AI) system. Stock AI-generated image ID: 2448481683 AI-generated image Contributor Shutterstock AI Generator.

I searched physics forums trying to find the answer to this question. There were a lot of discussions but no clear answers. Some said, nothing falls into a black hole. Everything accumulates on the event horizon from the outside perspective and that’s how the event horizon and the black hole grows. The observer crossing the horizon essentially jumps infinitely far into the future, or into a different universe, that’s how he can pass through the event horizon.

Others said that the black hole is not static, it grows, and it shrinks from Hawking radiation, and this complicates the equations so that objects can enter the black hole even from an outside perspective. I have a few physics books on black holes that I have not finished reading. If I learn something better, I will update this post.

AI-generated image Description : Space Black Hole Blue Illustration Gravity Geometry Vast Line. Stock AI-generated image ID: 2457551367 by AI-generated image Contributor Shutterstock.AI

In the image above the grid demonstrates how a black hole is distorting space-time. Other strange facts about black holes are that they are slowly evaporating through what is called Hawking radiation.

They come in different sizes. The smallest known black hole (XTE J1650-500) has a diameter of approximately 15 miles. Perhaps scariest of all, black holes are nearly undetectable unless they are feeding on star dust or tugging on nearby stars. That means one hungry black hole could be zipping right through our solar system without us knowing. Considering there are an estimated 100 million black holes in our Milky Way space travel might be scary.

Addressing a Good Question

After posting this post I received a question via email regarding this fact “If our planet earth collapsed into a black hole, its diameter would  be 1.75 centimeters or 0.69 inches in diameter. The diameter of the largest known black hole (TON 618) is 242 billion miles, which is more than one million times larger than the distance from the earth to moon.” The person who asked thought that 1.75 centimeters was pretty tiny and was wondering how a black hole could be that small.

To create a black hole, you need extremely strong gravity and one way to increase the force of gravity at the surface of a planet is to compress all its mass into a smaller volume.

If you compressed all of earth’s gravity so its diameter was only half of what it is, it would be more compact, and the gravity would be four times stronger at earth’s surface. If you compressed it further so that the earth’s diameter would only be a fourth of its original diameter the gravity at the surface would now be 16 times stronger. If you keep compressing the earth until its diameter is only 1.75 centimeters the force of gravity at the surface would be 132,000 trillion times greater than it currently is according to Newtonian physics, and you would get a black hole.

I should say that it comes out differently with General Relativity and that number is different for different sized black holes. However, this calculation is for demonstrative purposes. For relatively small masses like a planet, you would have to compress so much that it becomes tiny before gravity becomes large enough to make a black hole.

To see the other Super Facts click here

If you were an astronaut on an interstellar journey, would you be afraid of falling into a black hole?

David Lee Summers and the NEID spectrograph

A couple of weeks ago I made a post about exo planets. My blogger friend and Astronomer David Lee Summers stopped by and mentioned that investigating exo planets was his day job. He is working with the NASA-funded NEID spectrometer. He also happens to be an author of several science fiction books and scifi-horror books. Below is the front cover of one of his books. This is a reblog of one of his posts regarding NEID spectrometer. Head over there and check it out.

Weighing Planets
Portion of the NASA funded spectroscope that David works with. Above is an image of the NEID fiber feed (Port Adaptor) mounted on the WIYN telescope obtained during commissioning of the instrument. The Port Adaptor feeds light from the telescope to the NEID instrument, which is located on another floor of the building, below the telescope.
To see the Super Facts click here