Order out of chaos

When I was an undergraduate, I sang in the University of Louisiana Choir in a production of Franz Josef Haydn's spectacular choral work The Creation.

The opening is a quiet, eerie orchestral passage called "The Representation of Chaos" -- meant to evoke the unformed "void" that made up the universe prior to the moment of creation.  Then the Archangel Raphael sings, "In the beginning, God made Heaven and Earth; and the Earth was without form and void, and darkness was upon the face of the deep."  The chorus joins in -- everything still in a ghostly pianissimo -- "In the spirit, God moved upon the face of the waters; and God said, "Let there be light.  And... there... was...

...LIGHT!"

The last word is sung in a resounding, major-chord fortissimo, with the entire orchestra joining in -- trumpets blaring, tympanis booming, the works.  

Even if you don't buy the theology, it's a moment that sends chills up the spine.  (You can hear it yourself here.)

Of course, the conventional wisdom amongst the cosmologists has been that the universe didn't begin in some kind of chaotic, dark void; quite the opposite.  The Big Bang -- or at least, the moment after it -- is usually visualized as a searingly hot, dense fireball, which expanded and cooled, leading to a steady entropy increase.  So by our current models, we're heading toward chaos, not away from it.

Well, maybe.

A recent paper by the pioneering Portuguese physicist and cosmologist João Magueijo has proposed a new model for the origins of the universe that overturns that entire scenario -- and far from being ridiculed off the stage, he's captured the attention even of hard-nosed skeptics like Sabine Hossenfelder, who did a video on her YouTube channel about his paper a few days ago that is well worth watching in its entirety.  But the gist, as far as a layperson like myself can understand it, goes like this.

It's long been a mystery why the fundamental constants of physics have the values they do, and why they actually are constant.  A handful of numbers -- the speed of light, the strength of the electromagnetic interaction, the strength of the gravitational force, the fine-structure constant, and a few others -- govern the behavior of, well, pretty much everything.  None seem to be derivable from more fundamental principles; i.e., they appear to be arbitrary.  None have ever been observed to shift, regardless how far out in space (and therefore how far back in time) you look.  And what's curious is that most of them have values that are tightly constrained, at least from our perspective.  Even a percent or two change in either direction, and you'd have situations like stars burning out way too fast to host stable planetary systems, atoms themselves falling apart, or matter not generating sufficient gravity to clump together.

So to many, the universe has appeared "fine-tuned," as if some omnipotent deity had set the dials just right at the moment of creation of the universe to favor everything we see around us (including life).  This is called the anthropic principle -- the strong version implying a master fine-tuner, the weak version being the more-or-less tautological statement that if those numbers had been any different, we wouldn't be here to ask the question.

But that doesn't get us any closer to figuring out why the fundamental constants are what they are.  Never one to shy away from the Big Questions, that's exactly what Magueijo has undertaken -- and what he's come up with is, to put it mildly, intriguing.

What he did was to start from the assumption that the fundamental constants aren't... constant.  That In The Beginning (to stick with our original Book of Genesis metaphor), the universe was indeed chaos -- the constants could have had more or less any values.  The thing is, the constants aren't all independent of each other.  Just as numbers in our mundane life can push and pull on each other -- to give a simple example, if you alter housing prices in a town, other numbers such as average salaries, rates of people moving in and moving out, tax rates, and funding for schools will shift in response -- the fundamental constants of physics affect each other.  What Magueijo did was to set some constraints on how those constants can evolve, then let the model run to see what kind of universe eventually came out.

And what he found was that after jittering around for a bit, the constants eventually found stable values and settled into an equilibrium.  In Hossenfelder's video, she uses the analogy of sand grains on a vibration plate being jostled into spots that have the highest stability (the most resistance to motion).  At that point, the pattern that emerges doesn't change again no matter how long you vibrate the plate.  What Magueijo suggests is that the current configuration of fundamental constants may not be the only stable one, but the range of what the constants could be might be far narrower than we'd thought -- and it also explains why we don't see the constants changing any more.

Why they are, in fact, constant.

Stable pattern of grains on a vibrating pentagonal Chladni plate [Image licensed under the Creative Commons Matemateca (IME USP), Chladni plate 16, CC BY-SA 4.0]

Magueijo's work might be the first step toward solving one of the most vexing questions of physics -- why the universe exists with these particular laws and constants, despite there not seeming to be any underlying reason for it.  Perhaps we've been looking at the whole thing the wrong way.  The early universe really may have been without substance and void -- but instead of a voice crying "let there be light!", things simply evolved until they reached a stable configuration that then generated everything around us.

It might not be as audibly dramatic as Haydn's vision of The Creation, but it's just as much of an eye-opener.

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Baby Bear's universe

The idea of Intelligent Design is pretty flimsy, at least when it comes to biology.  The argument boils down to something the ID proponents call irreducible complexity -- that there are some features in organisms that are simply too complex, requiring too many interlocking parts, to have evolved through natural selection.  The problem is, the ones most commonly cited, such as the vertebrate eye, have been explained pretty thoroughly, with nothing needed but a good understanding of genetics, biochemistry, and physiology to comprehend how they evolved.  The best takedown of biological ID remains Richard Dawkins's The Blind Watchmaker, which absolutely shreds the arguments of ID proponents like Michael Behe.  (Yes, I know Dawkins has recently made statements indicating that he holds some fairly repulsive opinions; I never said he was a nice guy, but there's no doubt that his writings on evolutionary biology are on-point.)

While biological ID isn't worth much, there's a curious idea from physics that has even the reputable scientists wondering.  It has to do with the number of parameters (by some estimates, around thirty of them) in the Standard Model of Particle Physics and the Theories of Relativity that don't appear to be derivable from first principles; in other words, we know of no compelling reason why they are the values they are, and those values are only known empirically.

[Image licensed under the Creative Commons Cush, Standard Model of Elementary Particles, CC BY 3.0]

More eye-opening is the fact that for most of them, if they held any other values -- in some cases, off by only a couple of percent either way -- the universe would be uninhabitable.

Here are a few examples:

• The degree of anisotropy (unevenness in density) of the cosmic microwave background radiation.  This is thought to reflect the "clumpiness" of matter in the early universe, which amounts to about one part in ten thousand.  If it was only a little bigger -- one part in a thousand -- the mutual attraction of those larger clumps of matter would have triggered early gravitational collapse, and the universe would now be composed almost entirely of supermassive black holes.  Only a little smaller -- one part in a hundred thousand -- and there would have been insufficient gravitational attraction to form stars, and the universe would be a thin, cold fog of primordial hydrogen and helium.

• The fact that electrons have a spin of one-half, making them fermions.  Fermions have an odd property; two can't occupy the same quantum mechanical state, something called the Pauli Exclusion Principle.  (Bosons, such as photons, don't have that restriction, and can pass right through one another.)  This feature is why electrons exist in orbitals in atoms.  If they had integer spin, there would be no such thing as chemistry.

• The masses of the various subatomic particles.  To take only one example, if the quarks that make up protons and neutrons were much heavier, the strong nuclear force would all but evaporate -- meaning that the nuclei of atoms would fly apart.  (Well, more accurately, they never would have formed in the first place.)

• The value of the fine-structure constant, which is about 1/137 (it's a dimensionless number, so it doesn't matter what units you use).  This constant determines, among other things, the relative strength of the electromagnetic and strong nuclear forces.  Any larger, and atoms would collapse; any smaller, and they would break apart into their fundamental particles.

• The value of the gravitational constant G.  It's about 6.67 x 10^-11 meters cubed per kilogram per second -- i.e., a really tiny number, meaning gravity is an extremely weak force.  If G was larger, stars would burn through their hydrogen fuel much faster, and it's doubtful they'd live long enough for planets to have time to evolve intelligent life.  If G was smaller, there wouldn't be enough gravitational pull to initiate fusion in the first place.  No fusion = no stars.

• The flatness of the universe.  While space near massive objects is curved as per the General Theory of Relativity, its overall shape is apparently Euclidean.  Its makeup -- around 5% conventional matter and energy, 25% dark matter, and 70% dark energy -- is exactly what you'd need to generate a flat universe.

• The imbalance between matter and antimatter.  There appears to be no reason why, at the Big Bang, there weren't exactly equal numbers of matter and antimatter particles created.  But in fact -- and fortunately for us -- there was a very slight imbalance favoring matter.  The estimate is that there was about one extra unpaired matter particle out of every one hundred million pairs, so when the pairs underwent mutual annihilation, those few extra particles were left over.  The survivors became the matter we have today; without that tiny imbalance, the entire universe today would be filled with nothing but photons.

• The cosmological constant -- a repulsive force exerted by space itself (which is the origin of dark energy).  This is the most amazing one, because for a long time, physicists thought the cosmological constant was exactly zero; Einstein looked upon his introduction of a nonzero cosmological constant as an inexcusable fudge factor in his equations, and called his attempt to shoehorn it in as his "greatest blunder."  In fact, recent studies show that the cosmological constant does exist, but it's so close to zero that it's hard to imagine -- it's about a decimal point, followed by 121 zeroes, followed by a 3 (as expressed in Planck units).  But if it was exactly zero, the universe would have collapsed by now -- and any bigger than it is, and the expansion of space would have overwhelmed gravity and torn apart matter completely!

And so on and so forth.  The degree of fine-tuning that seems to be required to set all these independent parameters so that the conditions are juuuuuust right for our existence (to borrow a phrase from Baby Bear) strikes a lot of people, even some diehard rationalist physicists, as mighty peculiar.  As cosmologist Fred Hoyle put it, "It looks very much as if a super-intellect has monkeyed with physics as well as with chemistry and biology."

The idea that some Master Architect twiddled the knobs on the various constants in physics, setting them exactly as needed for the production of matter and ultimately ourselves, is called the Strong Anthropic Principle.  It sets a lot of people's teeth on edge -- it's a little too much like the medieval idea of humanity's centrality in the universe, something that was at the heart of the resistance to Copernicus's heliocentric model.  It seems like all science has done since then is to move us farther from the center -- first, the Earth orbits the Sun; then, the stars themselves are suns, and our own Sun is only a smallish and rather ordinary one; then, the Sun and planets aren't central to the galaxy; and finally, our own galaxy is only one of billions.

Now, suddenly, the fine-tuning argument has seemingly thrust us back into a central position.  However small a piece of the cosmos we actually represent, was it all set this way for our benefit?

In his book The Cosmic Landscape: String Theory and the Illusion of Intelligent Design, theoretical physicist Leonard Susskind answers this with a resounding "no."  His argument, which is sometimes called the Weak Anthropic Principle, looks at the recent advances in string theory, inflation, and cosmology, and suggests that the apparent fine-tuning is because the cosmos we're familiar with is only one pocket universe in a (much) larger "landscape," where the process of dropping into a lower energy state triggers not only expansion, but sets the values of the various physical parameters.  Afterward, each of those bubbles is then governed by its own physics.  Most would be inhospitable to life; a great many probably don't have atoms heavier than helium.  Some probably have very short life spans, collapsing almost immediately after formation.  And the models suggest that the number of different possible configurations -- different settings on the knobs, if you will -- might be as many as ten to the five-hundredth power.

That's a one followed by five hundred zeroes.

Susskind suggests that we live in this more-or-less friendly one not because the constants were selected by a deity with us in mind, but because if our universe's constants had any other value, we wouldn't be here to ask the question.  It might be extremely unlikely that a universe would have exactly these settings, but if you have that many universes to choose from, they're going to show up that way somewhere.

We only exist because this particular universe is the one that got the values right on the nose.

While I think this makes better sense than the Master Architect idea of the Strong Anthropic Principle -- and I certainly don't want to pretend I could argue the point with a physicist of Susskind's caliber -- I have to admit feeling a twinge of discomfort still.  Having all of those parameters line up so perfectly just seems like too much of coincidence to swallow.  It does occur to me that in my earlier statement, that the constants aren't derivable from first principles, I should amend that by adding "as far as we understand at the moment."  After all, the geocentric model, and a lot of other discredited ideas, were discarded not because they overestimated our importance, but because we got better data and used it to assemble a more accurate theory.  It may be that some of these parameters are actually constrained -- they couldn't have any other value than the one they do -- we just haven't figured out why yet.

After all, that's my main criticism of Intelligent Design in biology; it boils down to the argument from incredulity -- I can't imagine how this could have happened, so it must be that God did it.

That said, the best models of physics we now have don't give us any clue of why the thirty-odd free parameters in the Standard Model are what they are, so for now, the Weak Anthropic Principle is the best we can do, at least as far as scientific approaches go.  That we live in a Baby Bear universe is no more mysterious than why you find fish in a lake and not in a sand dune.  Our hospitable surroundings are merely good fortune -- a lucky break that was not shared in the other ten-to-the-five-hundredth-power universes (minus one) out there in the cosmic landscape.

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Odd number

A regular reader of Skeptophilia had an interesting response to a recent post wherein I considered the strong and weak versions of the Anthropic Principle -- the idea that the universe has its physical constants, and thus its overall conditions, fine-tuned to be conducive to the development and sustenance of life.  The Strong Anthropic Principle considers that fine-tuning to be the deliberate dialing of the knobs by a creator of some sort; the Weak Anthropic Principle more takes the angle that of course the constants in our universe are set that way, because if they hadn't been, we wouldn't be here to comment upon it.  The weak version, which has always made considerable sense to me, looks upon the particular values of the physical constants as either being (1) a happy accident, or (2) constrained by some mechanism we have yet to understand (in other words, there's a scientific reason why they are what they are, and they'd be the same in all possible universes, but we haven't yet figured out what that reason is).

The reader picked up on my citing the fine structure constant as an example of one of those perhaps-arbitrary physical constants, and wrote:

Interesting you should choose the fine structure constant as an example, because that's the one that has even the physicists perplexed as to why it has the value it does.  There doesn't seem to be any a priori reason it is equal to 1/137, and it shows up in all sorts of seemingly unrelated realms of physics.  Maybe God is trying to tell us something?  If so, it very much remains to be seen what he's trying to tell us, but it's a curious number to say the least.

See if you can find what Richard Feynman and Wolfgang Pauli had to say about it, if you want a chuckle, albeit a rueful one.

He's not exaggerating that the fine structure constant comes up all over the place.  The usual definition is it is a measure of the strength with which charged particles interact with electromagnetic fields.  The formula for it connects four other physical constants -- the charge of an electron, Planck's constant, the speed of light, and the electric permittivity of a vacuum.  But this is where things start getting odd; because unlike all the other constants in physics, the fine structure constant is dimensionless -- it has no units.  No matter what system of units you're using for the four constituents, everything cancels out and you get a unit-free constant -- 1/137.  (Actually, 1/137.035999206, but 1/137 is a decent approximation.)  You can throw in the speed of light in furlongs per fortnight, and as long as you are consistent and have all the other distances in furlongs and all the other times in fortnights, it doesn't matter.  It always comes out 1/137.

The fine structure constant also shows up in some mystifyingly disparate applications.  It's in the formulae used to determine the size of electron orbits in atoms.  It is used to explain the odd splitting of spectral lines in the emission spectrum of elements, due to electrons with opposite spins interacting slightly differently with the orbitals they sit in.  It shows up in calculations of optical conductivity of solids.  It's used to figure out the probability of an atom absorbing or emitting a photon.  It relates the speed of motion of an electron as it orbits the nucleus to the speed of light.

Spectral line splitting in deuterium, one of the first phenomena explained by the fine structure constant [Image licensed under the Creative Commons Johnwalton, Fabry Perot Etalon Rings Fringes, CC BY 3.0]

It pops up so frequently, in fact, that people involved in the search for extraterrestrial life have suggested that if we want to send a low-information-content, compact message out into space that will communicate to any intelligent species that we have reached the age of technology, all we need to do is send a message that says "1/137."

That's how ubiquitous it is.

It's a lucky thing, too -- to go back to the Anthropic Principle arguments -- that it has the value it does.  If it were only a few percent larger, electrons would be so strongly bound by their nuclei that they wouldn't be able to interact with each other to form molecules; a few percent smaller, and they'd be bound so weakly atoms wouldn't form at all, and the whole universe would be a sea of loose elementary particles.

Weirdest of all, the current understanding of the fine structure constant is that it was much higher at the enormous energies immediately after the Big Bang, but then began to drop as the universe expanded and cooled.  It decreased to 1/137 -- and then stopped there.

Why did it stop at that value, and not keep sliding all the way down to zero?

No one knows.

As my reader pointed out, even luminaries like Richard Feynman were deeply perplexed by this number.  In his book QED: The Strange Theory of Light and Matter, Feynman wrote:

There is a most profound and beautiful question associated with the observed coupling constant, e – the amplitude for a real electron to emit or absorb a real photon. It is a simple number that has been experimentally determined to be close to 0.08542455.  (My physicist friends won't recognize this number, because they like to remember it as the inverse of its square: about 137.03597 with an uncertainty of about 2 in the last decimal place.  It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it.)

Immediately you would like to know where this number for a coupling comes from: is it related to pi or perhaps to the base of natural logarithms?  Nobody knows.  It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by humans.  You might say the "hand of God" wrote that number, and "we don't know how He pushed His pencil."  We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out – without putting it in secretly!

Wolfgang Pauli was even more direct:

When I die my first question to the Devil will be: What is the meaning of the fine structure constant?

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A hostile beauty

William Shatner, of Star Trek fame, wrote some profoundly moving words in his book Boldly Go, about his experience riding into space on Jeff Bezos's Blue Origin shuttle:

I love the mystery of the universe.  I love all the questions that have come to us over thousands of years of exploration and hypotheses.  Stars exploding years ago, their light traveling to us years later; black holes absorbing energy; satellites showing us entire galaxies in areas thought to be devoid of matter entirely… all of that has thrilled me for years… but when I looked in the opposite direction, into space, there was no mystery, no majestic awe to behold... all I saw was death.

I saw a cold, dark, black emptiness.  It was unlike any blackness you can see or feel on Earth.  It was deep, enveloping, all-encompassing.  I turned back toward the light of home.  I could see the curvature of Earth, the beige of the desert, the white of the clouds and the blue of the sky.  It was life.  Nurturing, sustaining, life.  Mother Earth.  Gaia.  And I was leaving her.

Everything I had thought was wrong.  Everything I had expected to see was wrong.

I had thought that going into space would be the ultimate catharsis of that connection I had been looking for between all living things—that being up there would be the next beautiful step to understanding the harmony of the universe.  In the film Contact, when Jodie Foster’s character goes to space and looks out into the heavens, she lets out an astonished whisper, "They should’ve sent a poet."  I had a different experience, because I discovered that the beauty isn’t out there, it’s down here, with all of us.

He's right in one sense; the vast majority of the universe is intrinsically hostile to life.  It's why I've always found the Strong Anthropic Principle a little funny.  The Strong Anthropic Principle claims that the physical constants which are, as far as we currently understand, not derivable from anything else -- such as the strength of the four fundamental forces, the masses of the subatomic particles, the speed of light, the fine structure constant, and so on -- were set with those values in order to make the universe accommodate matter and energy as we know it, and ultimately, life.  The words they use are "fine tuned."  If any of those constants were even a little bit different, life would be impossible.

Typically, the argument progresses from "fine tuning" to "implies a fine tuner" to "implies God."

This whole line of thought, though, ignores three things.  First, of course we live in a universe that has the physical constants set such that life is possible; if they weren't, we wouldn't be here to discuss the matter.  (This is called the Weak Anthropic Principle.)  Second, when I said those constants are not derivable from anything else, you should place the emphasis on the phrase that came before it; as far as we currently understand.  It may be that physicists will eventually find a Grand Unified Theory showing that some -- perhaps all -- of the physical constants are what they are because of a single fundamental principle stating that they aren't arbitrary after all, that they couldn't have any other values.

Third, as Shatner points out, most of the universe -- even most of the Earth, honestly -- is pretty fucking hostile to life as it is.

But I question his statement that this makes the universe any less beautiful.  I was in Iceland this summer and got to see an erupting volcano -- the whole nine yards, with jets of orange lava fountaining up and cascading down the side of the cinder cone.  I could feel the heat on my face from where I stood, about a hundred meters away; much closer, and my skin would have blistered.  The sulfur fumes were only made tolerable by the fact that it was a windy day.  The hillside beneath my feet was vibrating, the air filled with a roar like thunder.  Standing there, I was in no doubt at all about my own frailty.

It was also incredibly, devastatingly beautiful.

I was thinking about the beauty of the universe -- as unquestionably inimical as it is to our kind -- when I saw images from the Hubble Space Telescope of the Cat's Eye Nebula, along with a visualization of what it would look like close up, created by a team led by Ryan Clairemont of Stanford University:

The spirals are thought to be caused by two stars in the center of the nebula orbiting around each other, each emitting a pair of plasma jets that have been twisted by the stars' motion in the fashion of the jets of water sprayed from a spinning garden sprinkler.  But whatever the cause of the pattern, I was immediately struck by its awe-inspiring beauty.

I've never been to space, and I don't mean to gainsay Shatner's experience.  But I find the vast immensity of space to be beautiful even though I know my own existence in it is all but insignificant.  I can look up at the autumn constellations, as I did last night -- Perseus and Andromeda, Pegasus and Pisces and Aquarius -- and appreciate the beauty of those stars glittering in the night sky from the warm safety of my home planet.  Maybe some of them have planets harboring their own frail, fragile life forms, who just like us are dependent on the searing fires of their host stars to survive, and just like us look up into the night sky with awe and wonder.

Frightening?  Sure.  Dangerous, savage, unpredictable?  Undeniable.

But also deeply, overwhelmingly beautiful.

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The constancy of constants

One of the most enduring mysteries of physics is why the fundamental constants have the values they do.

I remember first thinking about this when I was a freshman in college, and we were looking at the Special Theory of Relativity in my intro-to-physics class.  The speed of light in a vacuum -- the ultimate speed limit, whatever Star Trek would have you believe -- was 299,792,458 meters per second.

What occurred to me was why it was exactly that number and not something else.  What if the speed of light was, say, twenty miles per hour?  Automobile travel would be a different game, and we'd have serious relativistic effects even riding a bicycle.  (Races would be an interesting affair; faster runners' clocks would move more slowly than slower runners' would, so by the end of the race, it'd be hard to get anyone to agree on what everyone's time was.)

All of which was delightfully silly stuff but didn't really get at the original question, which is why the speed of light has the value it does.  And it's not just the speed of light; in Martin Rees's wonderful book Just Six Numbers, he looks at how a handful of fundamental constants -- the gravitational flatness of the universe, the strength of the strong nuclear force, the ratio between the strength of the electromagnetic force and the gravitational force, the number of spatial dimensions, the ratio between the rest mass energy of matter and the gravitational field energy, and the cosmological constant -- have combined to produce the universe around us.  Alter any of these, even by a little bit, and you have a universe that would be profoundly hostile to life, if not to stable matter in general.

This has led some of the more religious-minded folks to what is called the Strong Anthropic Principle, sometimes called the "fine-tuning argument" -- that the universe has been fine-tuned for life, presumably by a Higher Power tweaking the dials on those constants to make them juuuuuuust right for us.  Which runs into two unfortunate counterarguments: (1) the vast majority of the universe is completely hostile to life, including much of our home planet; and (2) the fact that we live in a universe where the important constants have those particular values is unremarkable, because if they didn't, we wouldn't be around to remark upon it.

The latter is something known as the "Weak Anthropic Principle," a stance that doesn't tell you much except for the fact that the only kind of universe we could live in is one that has the conditions in which we could live.

[Image is in the Public Domain]

What I find intriguing is that none of these universal constants is derivable -- none come out of calculations based upon known physical laws... yet.  It might be that some of them are derivable and we just haven't figured out how.  Thus far, though, they seem completely arbitrary (except, as noted, that they have to have the values that they do in order for us to be here to consider the question).

A subtler question, and one that (unlike the fine-tuning argument) is actually testable, is whether those constants are the same everywhere in the universe, and whether they're constant over time.  Because if not -- if they vary either in time or space -- that strongly implies that they're not arbitrary, but derive from some underlying characteristic of matter, energy, and space/time that we have yet to uncover, and therefore in altered conditions could have a different value.  So a lot of time is being spent to determine whether any of these constants might be not so constant after all.

Just last week the results came in for one of them, one that is not on Rees's List of Six but is nonetheless pretty damn important; the fine-structure constant, usually written as the Greek letter alpha.  The fine-structure constant is a measure of the strength of interaction between electrons and photons, and is equal to 1/137 (it's a dimensionless number, so it doesn't matter what units you use).

The fine-structure constant is one of the numbers whose value is instrumental in the formation of atoms, so (like Rees's numbers) if it were much different, the universe would be a very different place.  It's one that can be studied at a distance, because one outcome of the fine-structure constant having the value it does is that it creates the spread between the spectral lines of hydrogen.

So a team of physicists looked at the spectrum of hydrogen emitted in the vicinity of a supermassive black hole -- a place where the fabric of space/time is highly contorted because of the enormous gravitational field.  In a paper in Physical Review Letters, we find out that the fine-structure constant in that extremely different and hostile region of space is...

... 1/137.

The authors write:

Searching for space-time variations of the constants of Nature is a promising way to search for new physics beyond General Relativity and the standard model motivated by unification theories and models of dark matter and dark energy.  We propose a new way to search for a variation of the fine-structure constant using measurements of late-type evolved giant stars from the S-star cluster orbiting the supermassive black hole in our Galactic Center.  A measurement of the difference between distinct absorption lines (with different sensitivity to the fine structure constant) from a star leads to a direct estimate of a variation of the fine structure constant between the star’s location and Earth.  Using spectroscopic measurements of 5 stars, we obtain a constraint on the relative variation of the fine structure constant below 10^−5.

So the variation between the fine-structure constant and the fine-structure constant near a humongous black hole is less than a factor of 0.00001.

Note that this still doesn't tell us anything about why the fundamental constants have the values they do, all it does is suggest pretty strongly that they are constant regardless of the conditions pertaining in the region of space where they're measured.

The universe is a strange and mysterious place, and we're only beginning to figure out how it all works.  I mean, think about it; while I don't want to denigrate the scientific accomplishments of our forebears, we've really only begun to parse how the fundamental laws of nature work in the last 150 years.  It's an exciting time -- even if we don't yet have answers to a lot of the most basic questions in physics, at least we're figuring out which questions to ask.

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One of my favorite people is the indefatigable British science historian James Burke.  First gaining fame from his immensely entertaining book and television series Connections, in which he showed the links between various historical events that (seen as a whole) play out like a centuries-long game of telephone, he went on to wow his fans with The Day the Universe Changed and a terrifyingly prescient analysis of where global climate change was headed, filmed in 1989, called After the Warming.

One of my favorites of his is the brilliant book The Pinball Effect.  It's dedicated to the role of chaos in scientific discovery, and shows the interconnections between twenty different threads of inquiry.  He's posted page-number links at various points in his book that you can jump to, where the different threads cross -- so if you like, you can read this as a scientific Choose Your Own Adventure, leaping from one point in the web to another, in the process truly gaining a sense of how interconnected and complex the history of science has been.

However you choose to approach it -- in a straight line, or following a pinball course through the book -- it's a fantastic read.  So pick up a copy of this week's Skeptophilia book of the week.  You won't be able to put it down.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Taming the multiverse

Online Critical Thinking course -- free for a short time!

This week, we're launching a course called Introduction to Critical Thinking through Udemy!  It includes about forty short video lectures, problem sets, and other resources to challenge your brain, totaling about an hour and a half.  The link for purchasing the course is here, but we're offering it free to the first hundred to sign up!  (The free promotion is available only here.)  We'd love it if you'd review the course for us, and pass it on to anyone you know who might be interested!

Thanks!

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I had a rather mind-blowing experience yesterday, as I was reading a BBC Online article called "Professor Stephen Hawking's Multiverse Finale," by Pallab Ghosh.

You know how sometimes when you're reading a book or watching a movie, and suddenly you realize that a major plot twist is about to happen?  At first, you're thinking, "No... no, that can't be what's happening...  Really?"  Then you think, "C'mon... wow... that couldn't be what this is leading up to!"  And finally, "OMG it actually happened!"

That's how I felt reading this article.

It'd have been interesting even without the sucker punch.  It's about Stephen Hawking's last academic paper, co-authored with American physicist James Hartle and submitted to the Journal of High-Energy Physics ten days before his death, which proposed a solution to the result of the Big Bang (and largely unrelated to the issue of cosmic inflation I wrote about in yesterday's post, except that they happened at the same time) that simultaneously solved several "loose ends" regarding the beginning of the universe.

The problem was, their first attempt at a solution generated another problem; an infinite number of parallel universes, each with their own physical laws, and seemingly no particular reason why a given universe had a given set of rules.

Thomas Hertog, of the Katholieke Universiteit Leuven in Belgium, who contributed to the research, wasn't satisfied with this.  "Neither Stephen nor I were happy with that scenario," he said in an interview with BBC News.  "It suggests that the multiverse emerged randomly and that we can't say very much more about that.  We said to each other: 'Maybe we have to live with it'.  But we didn't want to give up."

So they didn't.  And their investigations concluded something earthshattering:

The multiverse is only composed of universes with physical laws similar to our own.

[Image is in the Public Domain]

I first ran into the concept that the properties of the universe were controlled by a small number of seemingly arbitrary constants when I read Sir Martin Rees's book Just Six Numbers: The Deep Forces that Shaped the Universe, wherein we find out that there are six that seem "fine-tuned" to generate a universe that can support life: N (the ratio between the electromagnetic and gravitational forces), ε (the strength of the strong nuclear force), Ω (the ratio of the mass of the universe to the critical mass), λ (the cosmological constant), Q (the ratio of the gravitational energy required to pull a large galaxy apart to the energy equivalent of its mass), and D (the number of spatial dimensions).

Rees's book goes into the fascinating details of what a universe would look like if one of those constants was even slightly different than it is.  The end result for most of these nudges is a universe that would be profoundly uninhabitable; in many of them, stars couldn't form, and in some of them, there would be no atoms, only a homogeneous soup of quarks.  Rees himself seems inclined to use this seeming "fine tuning" as support for the Strong Anthropic Principle -- that our universe was created with the physical constants it has so that it will be conducive to the formation of matter, stars, and ultimately, life.

 

Predictably, that solution has never really appealed to me.  I'm much more inclined toward the Weak Anthropic Principle -- that of course our universe has constants set in such a way as to allow life, because if they hadn't been, we wouldn't be here to ask the question.

But Stephen Hawking's final contribution toward physics may render all of this a moot point.  If the mathematics of quantum physics restricts the Big Bang from forming universes except those with physical constants like our own, it may have been constrained -- and these seemingly un-derivable constants may come from the physics of the Big Bang itself.

Which is mind-blowing.  From the chaos of an infinite number of universes with random physical laws, we have the possibility of a multiverse composed of universes much like our own.  Of course, it still seems certain that there is no travel between our home and these parallel worlds, which invalidates the premise of about half of the plots of Star Trek: The Next Generation (not to mention my own novel Lock & Key).  But that's a price I'm willing to pay.  The contribution of Stephen Hawking, along with his colleagues James Hartle and Thomas Hertog, have brought order to a universe that seemed random, and may have provided us the answer to one of the most fundamental questions -- why our universe has the laws it does.

What more fitting Swan Song could Hawking have had?

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This week's featured book is a wonderful analysis of all that's wrong with media -- Jamie Whyte's Crimes Against Logic: Exposing the Bogus Arguments of Politicians, Priests, Journalists, and Other Serial Offenders.  A quick and easy read, it'll get you looking at the nightly news through a different lens!

Unique, just like everyone else

There's this idea that the creationists just love, and it's called the Strong Anthropic Principle.  The idea of the Strong Anthropic Principle is that there are a lot of seemingly arbitrary parameters in the universe, all of which appear to be underivable from other basic principles, and which are uniquely set to generate a universe in which stable matter and life can exist.  The speed of light, the strength of the strong nuclear force, the fine structure constant, the strength of gravity, the strength of the electromagnetic force -- all of them are at values which, if you tweaked them a little bit in either direction, would result in an uninhabitable universe.

The problem is, the Strong Anthropic Principle seems to breeze right past two inherent flaws in reasoning.  The first is that the fundamental constants seem underivable from first principles -- emphasis on the word seem.  In other words, the conjecture that they are arbitrary, and that their value is an example of an intelligent deity's fine tuning, rests on our current state of ignorance about physics.

The second, of course, is that it's a completely untestable proposition.  Unless you're assuming your conclusion (that a creator exists) you can't tell anything from the fundamental physical constants except that they are what they are.  After all, we only have the one universe accessible to study.  It could equally well be that other universes are just as likely as this one, and have other physical constants (and thus are uninhabitable) -- and that we can ask the question only because if the constants in this universe were other than they are, we wouldn't be here to consider it.  (This latter framing of the problem is called the "Weak Anthropic Principle," and is usually the stance taken by non-theists.)

The general weakness of the Strong Anthropic Principle hasn't stopped it from being embraced wholeheartedly by people who are trying to bolster the creationist worldview, and it's the essence of the article that appeared on Answers in Genesis a while back called "Not Just Another Star."  The whole thing, really, can be summed up as "Aren't we special?"  Here's a sampling:

While the sun has many characteristics similar to stars, the Bible never refers to it as a star. This suggests that the sun may have some unique characteristics. Could that refer to its composition? The sun’s composition is a bit unusual—it has far less lithium than most stars do. Lithium isn’t very common in stars anyway, but the sun is among the most lithium-poor stars. Though this statistic is interesting, it isn’t clear whether it is significant... 

By God’s gracious design, the earth has a protective magnetic field that prevents the sun’s flares from disrupting life. The particles racing from the sun interact with the magnetic field, which deflects most of the particles. Yet we are periodically reminded about such imminent danger when the flares overload the ability of the earth’s magnetic field to protect us. Astronauts on the Space Station must enter protected sections of the station after a solar flare. 

Not all planets have strong enough magnetic fields to protect living organisms on their surfaces. Even on planets that do, the situation would be dire if the star’s magnetic activity were far higher than the sun’s. The much more frequent and far more powerful flares probably would compromise any reasonable magnetic field that a planet would have. Because this particle radiation would be harmful to living things, even secular astronomers recognize that variable stars probably can’t support living things... 

Our sun is just a tiny yellow star in a vast collection that could support life. You’ll hear this more and more. Don’t believe it. The minimum requirement of a life-supporting star is missing from all the other stars. Our God-given sun appears to be unique.

What makes this wryly amusing that the creationists are choosing this week to post the article all over the place (it was actually written a few months ago, but I've just seen it on evangelical websites in the last week or so) -- because two days ago, a study appeared over at Phys.org that suggests that not only might the Earth not be unique, we might be one of (get this) 100 million inhabitable planets in the Milky Way alone.

That, friends, is a lot of places to look for alien life.  And a pretty strong blow to anyone's impression that the Earth is The Chosen Place.  Here's what one of the paper's authors, Alberto Farién of Cornell University, had to say:

This study does not indicate that complex life exists on that many planets. We're saying that there are planetary conditions that could support it. Origin of life questions are not addressed – only the conditions to support life.  Complex life doesn't mean intelligent life – though it doesn't rule it out or even animal life – but simply that organisms larger and more complex than microbes could exist in a number of different forms.  For example, organisms that form stable food webs like those found in ecosystems on Earth.

Add that to the fact that as nice as the Earth is, even here we have a great many places that are pretty hostile to human life -- Antarctica, large parts of the Great Rift Valley, Australia's Nullarbor Plain, most of the Sahara -- not to mention 71% of the surface area of the Earth (i.e. the oceans) -- and the Strong Anthropic Principle is looking weaker and weaker.

So, yeah.  Nice try, but not so much.

It's been a continuous move out of the center for us, hasn't it?  First Copernicus knocks down geocentrism; then Kepler says that the planets don't move in perfect circles.  Darwin punches a hole in the uniqueness of Homo sapiens with The Ascent of Man, and various geneticists in the 20th century show that all life, down to the simplest, pretty much encodes information the same way.  Now, we find out that there may be 100 million places kind of like the Earth out there in space.

Some people may find that depressing, but I don't.  I actually think it's awesome.  For one thing, it would mean we're almost certainly not alone in the universe.  For another, I think that a lot of humanity's missteps have come from a false sense of superiority -- over the environment, over other species, even over other human groups.  Maybe this kind of thing is good for us; there's nothing wrong with adopting a little humility as a species, not to mention perspective.

The argument from design

I received a response to a recent post in the form of an (actually quite friendly) email that posed a question I've been asked before, and that I thought might deserve a post of its own.  Here is an excerpt of the email:

Many atheist/skeptics base their disbelief on a lack of evidence for a deity.  If God exists, there should be evidence in the world around us.  A universe created by an omnipotent power should be different than one that was created by random processes.  If you're being honest, you have to admit that the universe we live in seems pretty fine-tuned for life, isn't it?  Scientists have identified dozens of fundamental numbers whose values are just right for the existence of matter, space, planets, stars, and life.  If any of those numbers were any different, life couldn't exist.  Doesn't it look very much like some intelligence set the values of the dials just right so as to produce a universe that we could live in?

This argument has been widely trumpeted by Christians who are not biblical literalists -- who may, in fact, accept such empirically supported models as the Big Bang and organic evolution, and who buy that the Earth is not six thousand years old, as the biblical chronology would have you believe, but six-some-odd billion years old.  But despite these non-fundamentalists' buying the whole scientific process (which is all to the good), they still can't quite let go of the idea that a higher power must be behind the whole thing.  And the "fine-tuning of the universe" is one of their main arguments.

It's called the strong anthropic principle.  The universe is such a hospitable place, they say, that god has to have set it up just for us.  But there's just one flaw in the whole thing; the central contention, that the universe is hospitable... just isn't true.

I mean, it all sounds very nice, doesn't it?  God created the universe with us in mind, and this produced awesome places like Maui and the Florida Keys.  The problem is, even here on our home planet, things aren't all that... friendly.  Much of the Earth's land surface has a climate or topography that makes it pretty unsuitable for human life.  (Being that it's midwinter in upstate New York, I'd throw my own home town into that category.)  Even some of the more congenial places, places that are warm enough and have enough water and fertile soil to keep us alive, are prone to natural disasters like hurricanes, tornadoes, earthquakes, volcanoes, and mudslides.  And if you leave the Earth, things only get worse; most of the universe is damn near a vacuum, and what's not is filled with black holes, quasars, asteroid belts, supernovae, neutron stars, and Wolf-Rayet gamma ray bursters -- the last-mentioned being capable of emitting an outburst of radiation so powerful that it could blast an entire solar system into oblivion.

Yes, well, what about the fact that all of the fundamental constants are set just right to produce matter?  This was the subject of Sir Martin Rees' book Just Six Numbers, in which he describes what the universe would be like if fundamental constants such as the curvature of space, the fine-structure constant, Planck's constant, the speed of light, and so on, were different -- and all of these alterations produce a universe that would be inhospitable to the formation of stars and planets, much less life.  And because we can't at the moment see any other reason why the constants are what they are -- i.e., there is no fundamental principle from which they can be derived, they seem arbitrary -- Rees and others argue that this is evidence of fine tuning.

I see two problems with this.  The first is that it is an argument from ignorance; because we have not yet come up with a unified theory that shows why the speed of light is three hundred million meters per second, and not (for example) 25 miles per hour, doesn't mean that we won't eventually do so.  You can't prove anything from a lack of knowledge.

Second, it seems to me that the strong anthropic principle is a backwards argument; it's taking what did happen, and arguing that there's a reason that it must have happened that way, that if it weren't designed, it wouldn't have happened that way.  It's as if I were dealt a straight flush in poker (an exceedingly unlikely occurrence) and I argued that because it's unlikely, someone must have rigged the deck.

All we know, honestly, is that it did happen, for the very good reason that if it hadn't happened that way, we wouldn't be here to talk about it.  This is called the weak anthropic principle -- even if the fundamental physical constants are arbitrary, there's no design implied, because in a universe with different physical constants, we wouldn't exist to discuss the matter.  The only place such arguments are possible are universes where life can occur.  Physicist Bob Park summarizes this viewpoint with the Yogi Berra-like statement, "If things were different, then things would not be like things are."  Put that way, it's hard to see how it's an argument for a deity, much less an omnipotent one with our best interests in mind.

Anyhow, that's my response to the Argument from Design.  Like I said, the person who wrote to me was really quite friendly about the whole thing, which (although we disagree about some fundamental ideas) is certainly an improvement from the spittle-flecked responses I sometimes get that suggest Satan is, as we speak, sharpening up his torture equipment with me in mind.  So, for that, I'll just say, "Thanks for writing."  Civilized discussion is, as always, the goal around here.