It’s Turtles All the Way Down

Hindu turtle Earth
Chukwa supports the elephant Maha-pudma who holds up the world.

I think I first saw the expression “Turtles all the way down,” when I read Carl Sagan’s Broca’s Brain: Reflections on the Romance of Science. He recounted it as a conversation between a Western traveler and an Oriental philosopher.

I don’t have that book handy, but it is also told in Stephen Hawking’s A Brief History of Time which is on a nearby shelf (I have both the nicely illustrated edition, and the “in a nutshell” versions which I found easier to understand).

A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the Earth orbits around the Sun and how the Sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: “What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise.” The scientist gave a superior smile before replying, “What is the tortoise standing on?” “You’re very clever, young man, very clever”, said the old lady. “But it’s turtles all the way down!”

If you search a bit online, you’ll also find this called “The Infinite Turtle Theory” and find that it has found its way into a good number of cultural works. I myself have pinned the saying to several web pages I have online.

Although Hawking relates the anecdote more to point out something about ridiculous theories, others actually use it as a way to discuss an infinite regression belief about the origin and nature of the universe.

When I encountered it, I immediately thought of it as a variation of ancient beliefs that our world moves through the universe on the back of an animal. In many Native American creation myths, it is a turtle that holds up the world which is called “Turtle Island.”

I also found that it is similar to some Indian classical texts, including the myth that the tortoise Chukwa supports the elephant Maha-pudma who holds up the world.

The reference to Bertrand Russell may be from a 1927 lecture he gave titled “Why I Am Not a Christian” during which he said:

“If everything must have a cause, then God must have a cause. If there can be anything without a cause, it may just as well be the world as God, so that there cannot be any validity in that argument. It is exactly of the same nature as the Hindu’s view, that the world rested upon an elephant and the elephant rested upon a tortoise; and when they said, “How about the tortoise?” the Indian said, “Suppose we change the subject.”

But you could go back to 1690 in John Locke’s “An Essay Concerning Human Understanding” where he refers to an Indian who said the world was on an elephant which was on a tortoise “but being again pressed to know what gave support to the broad-backed tortoise, replied — something, he knew not what.”

A more modern allusion to it supposedly came from William James (father of American psychology) who supposedly had a conversation with an old lady who told him the Earth rested on the back of a huge turtle.

“But, my dear lady”, James asked, “what holds up the turtle?”
“Ah”, she said, “that’s easy. He is standing on the back of another turtle.”
“But would you be so good as to tell me what holds up the second turtle?”
“It’s no use, Professor”, said the lady, avoiding a logical trap. “It’s turtles, turtles, turtles, all the way!”

Ah yes,  we will never get to the bottom of some things.

Infinite regressions. What existed before the universe existed?  If God created the universe, what created God?

It’s turtles all the way down.

The Metaverse Is Not the Multiverse

alternate worlds
(Image: Gerd Altmann)

Metaverse is a computing term meaning a virtual-reality space in which users can interact with a computer-generated environment and other users. It may contain derivatives or copies of the real world. But it is not augmented reality. So though “meta” (meaning beyond) and the “verse” (a backformation from “universe”) sound like something in the stars, it is really something online. I guess the idea is that an evolved Internet plus shared, 3D virtual spaces could create a virtual universe.

Does it sound like social media? Well, that’s what Facebook’s Mark Zuckerberg believes. He recently said, “In the coming years, I expect people will transition from seeing us primarily as a social media company to seeing us as a metaverse company… In many ways, the metaverse is the ultimate expression of social technology.”

So what does the Facebook chief executive mean by “metaverse company”? And what will the company look like if and when it gets there?

“Metaverse” showed up in 1992 in Neal Stephenson’s science-fiction novel, Snow Crash. In that metaverse, people move back and forth from the 3D virtual living space into real-time space. The protagonist, In reality, Hiro Protagonist, is a pizza delivery guy in real life but he is a warrior prince in the Metaverse.

Google and Apple and other tech companies have been working (and investing) in augmented reality (AR) which layers tech on top of the real world.Remember Google Glass back in 2013? Facebook seems to be moving in another direction and has the platform and number of users (almost 3 billion) to do something else. It seems that the vision is to have people move between virtual reality (VR), AR, and 2D devices as themselves or as realistic avatars.

The Facebook platform includes WhatsApp, Instagram and the VR headset maker Oculus. The company’s Reality Labs division has a lot of people who came from the gaming world. That is a world I have never really entered. Even early overarching goal across all of these initiatives is to help bring the metaverse to life.” Fortnite, Roblox, and others have metaverse-like elements.

Tech companies don’t have totally free reign to move forward. In fact, Congress seems to be looking at Facebook and could make it split away from Instagram and WhatsApp, and limit future acquisitions which would impede a metaverse creation.

If the metaverse, as created by Facebook, Google, Apple, or whatever companies, scares you, maybe you should consider the multiverse.

The multiverse is not computers but cosmology. It is (for now) a hypothetical group of multiple universes. Put them all together and you have the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them.


The different universes Within the multiverse are different universes that are called “parallel universes”, “other universes”, “alternate universes”, or “many worlds”. Science hasn’t settled on a name yet.

I’m ignoring the “multiverses” in name only of DC and Marvel comics and films or Magic: The Gathering or Stephen King.

The idea of infinite worlds is not new at all. It existed in the philosophy of Ancient Greek Atomism. That posited that infinite parallel worlds arose from the collision of atoms.

I discovered that in the third century BCE, the philosopher Chrysippus thought that the world eternally expired and regenerated. That would mean that multiple universes exist across time.

Erwin Schrödinger, he of the cat, said that his equations seemed to describe several different histories. He did not think these were alternative histories, but that they all “really happen simultaneously.” This is called “superposition.”

Others in fiction, cosmology, physics, astronomy, religion, philosophy, psychology, and music, and the arts have used the term.

There are proponents and there are certainly skeptics. This is all far beyond most of us. This is the kind of science that seems like fiction. But I keep reading about multiverses, string theorysuperstring theory, M-theory, and others.

The metaverse is not the multiverse – but might the metaverse and multiverse somehow meet and merge, connect or allow passage from one to the other.  No ? there. I dare not ask.

That Dialogue on Opposing World Systems

Galileo, Copernicus
Galileo and Copernicus    (Gilgub/Flickr)

The title “Dialogue Concerning the Two Chief World Systems” certainly sounds like a heavy topic. It was heavy in 1632 when Galileo published it. The two systems were the Ptolemaic and the Copernican theories of cosmology. It is less controversial and easier to understand today.

Ptolemy, following the tradition of Aristotle, believed that the Earth was the center of the universe, and everything — Sun, Moon, planets, and stars — revolved around it.

Copernicus, on the other hand, posited that the Sun is the center of the universe, and though we seem to be standing still, we are in fact hurtling through space as we circle the star.

I used to have a quotation in my middle school classroom for my students that said “You are not the center of the universe” – Copernicus. Nicholas didn’t say exactly that quote, and he wasn’t specifically referencing my young teen students, but it was a good point-of-departure quote for discussion.

Galileo had spoken with Pope Urban VIII earlier and discussed his tide theory as proof that the Earth moved through space – not that the Sun was the center of the universe. The Pope granted him permission to write “Dialogue on the Tides” but that the Copernican theory should be treated as hypothetical in the book. Wisely, Galileo wrote the book as a series of discussions between two philosophers. One believed in Copernicus, one believed in Ptolemy, and a neutral but well-educated layman served as a moderator. That got it past the Catholic censors.

But Galileo was Copernican all the way and the popular book did not please Pope Urban VIII who had Galileo tried by the Inquisition. They ruled that he was “vehemently suspect of heresy” and too close to endorsing Copernican theory and the book was placed on the Catholic Church’s Index of Forbidden Books.

Galileo was ordered to recant and recite weekly psalms of penitence. He spent the rest of his life under house arrest, and none of his later books were permitted to be published in his lifetime.

The Dialogue on Opposing World Systems remained on the Index of Forbidden Books until 1835. Change is slow in religion – but not in science.

Further Reading

The Essential Galileo

The Big Bang Theory Comes to New Jersey


My father worked at Bell Laboratories in Murray Hill, NJ in the late 1950s and into the early 1960s.  Bell Labs was where the photovoltaic cell, the laser, the transistor and many other discoveries were born.

In 1961, my Dad wanted to move us to Holmdel, NJ where a new Bell Labs was located. That is where a 20-foot horn-reflector antenna was built to listen to the Milky Way. What the antenna was hearing was a constant hiss, though it had been built to avoid picking up extraneous interference.

This was in 1964.  Robert Wilson and Arno Penzias were two young astronomers working there and they couldn’t figure out what was hissing in their radio-wave measurements of the sky. Radio noise from New York City? Remnants of nuclear test detonations? Pigeons nesting in the antenna horn.

In 1931, the labs had made a foundation for radio astronomy when Karl Jansky was investigating the origins of static on long-distance shortwave communications and discovered that radio waves were being emitted from the center of the galaxy.

This was a time when there were two competing theories of the origin of the universe. The Steady State theory proposed that the universe was essentially unchanging and would look the same from every vantage point within it. the opposing theory was called the Big Bang theory. Proponents of the Big Bang theorized that the universe had begun with a massive explosion that created immense amounts of radiation, which gradually cooled but continued to expand from the force of the explosion.

The hissing interference persisted and the astronomers decided to ignore it and continue with their measurements.

I only discovered this history via a recent article by Leslie Garisto Pfaff.


Robert Wilson with the horn-reflector antenna in Holmdel – Photo by Christopher Lake


Penzias was told that he should connect with Robert Dicke at Princeton University. He gave him a call and talked to him while he and his fellow physicists were eating lunch.  Dicke realized by the end of the call that the Bell Labs astronomers had found evidence of the Big Bang theory in their microwave radiation. The hiss was radiation left over from the Big Bang (Cosmic Microwave Background). Wilson and Penzias wrote a paper about their discovery for publication.

The 1960s are not so long ago but back then, cosmology—the study of the origin and development of the universe—was quite new.  There was a Nobel Prize for Wilson and Penzias’s discovery which made the Big Bang theory the accepted origin story. The universe had a discrete beginning some 13.8 billion years ago with a an infinitesimally small bundle of immense energy that exploded and has continued to expand ever since.

Holmdel’s Crawford Hill still is home to the horn-reflector antenna which Pfaff describes in her article as looking like “a prop out of a 1950s science-fiction film. It doesn’t turn its ear to the cosmos any more., but it reminds us that the Big Bang was confirmed in new Jersey.

Dark Matter


Dark matter and dark energy frighten me and fascinate me.

In astronomy and cosmology, dark matter is a type of matter that is hypothesized to account for a large part of the total mass in the universe.

I find different numbers online, but from the Planck mission team comes the percentages that the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. That means that 84.5% of the total matter in the universe is dark matter.

We can’t see dark matter with our telescopes because it doesn’t seem to emit or absorb light or other electromagnetic radiation at any significant level.

So, how can we even hypothesize that it exists? Scientists infer its existence from its gravitational effects on visible matter and from radiation. It is the kind of research physicists do using instruments like the Large Hadron Collider in Switzerland.


If you’re not a science reader, you can get a pretty technical but intelligible overview of dark matter and dark energy from Wikipedia. But I have to admit that my interest in the topic was piqued by references to it in fiction, movies and TV.

It pops up in all kinds of places. Dark matter fuels the starship in the comedy cartoon series Futurama. In the iterations iterations of Star Trek, it frequently was mentioned. In Next Generation and Deep Space Nine, the Enterprise encounters a dark matter nebula. Back in 1995, an episode of one of my favorite shows, The X-Files (“Soft Light”) a scientist exposed to dark matter is transformed so that his shadow destroys the molecules of anything it touches and converts it into a puddle of pure energy.

The books that really got me thinking about it were the His Dark Materials (The Golden Compass/ The Subtle Knife/ The Amber Spyglass) trilogy by Philip Pullman. His heroine, Lyra, is an orphan living in a parallel universe in which science, theology, and magic are entwined. In that world, dark matter is called “Dust. ” Dust/dark matter was more of a form of consciousness. It keeps our multiple worlds linked. It allows for precognition. That is covered in the first book in the trilogy The Golden Compass (I was disappointed with the the movie version – even though it had Nicole Kidman.) Interestingly, for a series that is quite anti-religion, dust is the matter of which angels are made.

Isn’t it fascinating to think that most of the universe we live in is not what we observe? It’s not the things we can touch but what is between the things we touch. It is hardly new or original to think that there is more than the eye can see, but that is what dark matter suggests.

It has been suggested that dark energy is one of the “failures” of general relativity. Apologies to Albert Einstein for that. More theories on dark energy have come from string theory, brane cosmology and the holographic principle. Just theories. Relativity and topics such as quintessence and the cosmological constant are beyond the scope of this blog.

Recently, I have been reading about research into WIMPs, weakly interacting massive particles. (Dark matter and energy is a more interesting term than WIMP.) These are also theoretical, and they almost never interact with normal matter. They may be another clue to the fundamental origin of matter and antimatter. Maybe it is no coincidence that the number of protons and neutrons in the universe is roughly equivalent to the number of WIMPs.

There is still much uncertainty and mystery about the nature of dark matter and of our universe. That’s good. I am glad we are still searching and sometimes finding answers. I think that is what was intended.