Download The Heavens Proclaim Astronomy and the Search for God Br. Guy

The Heavens Proclaim
Astronomy and the Search for God
Br. Guy Consolmagno SJ
Vatican Observatory
Since I am standing up by an altar, wearing a clerical collar, let’s begin this morning’s
lecture with some readings from the letters of St. Paul. The first, Paul’s first letter to Timothy,
chapter 2, verse 5 and 6: “For there is one God; there is also one mediator between God and
humankind, Christ Jesus, himself human, who gave himself a ransom for all this was attested at
the right time.”
In Paul’s letter to the Ephesians, from the end of Chapter 1 and the beginning of Chapter 2
we read:
“God put this power to work in Christ when he raised him from the dead and seated him at
his right hand in the heavenly places, far above all rule and authority and power and dominion,
and above every name that is named, not only in this age but also in the age to come ... You were
dead through the trespasses and sins in which you once lived, following the course of this world,
following the ruler of the power of the air, the spirit that is now at work among those who are
disobedient. ”
And again, we hear from St. Paul, in his letter to the Colossians, Chapter 1, verses 15-20:
“He is the image of the unseen God, the first-born of all creation, for in him were created all
things in heaven and on earth everything visible and everything invisible, thrones, ruling forces,
sovereignties, powers - all things were created through him and for him.”
Now, one of the remarkable things about the letters of St. Paul, especially when they are
read aloud (as we do nearly every Sunday), is how utterly forgettable they are. I mean, you hear
all these pleasant words whooshing by, and two minutes later if someone asked you what Paul
said, you’d go – huh? Maybe, if you were trying hard, you might remember some catch phrases
like “mediator” or “the ruler of the power of the air” or “thrones, dominations, powers”… but
without a context, for most of us we’re scratching our heads wondering, “what was that all
about?”
What it is about, is cosmology. Paul could assume that his readers would be very familiar
with these terms. But they come from a cosmology very different from ours.
Most of us are probably familiar with the classical view of the universe, with the Earth at
the center and the planets going around it. But even when we say that, we are bringing to that
picture our own modern sense of what “earth” and “planets” means…
... we’re still thinking of our bright blue dot, and having the Moon and its craters, or Saturn
and its rings, whizzing about us as if we were the center of the universe. But that idea is as fake
(and as widespread) as this picture. It’s not what ancient cosmologies were really talking about.
Cosmology is more than just how the pieces are arranged; it’s about the very nature of the pieces
themselves.
Good science starts with observation. Ancient cosmologies started with the obvious
observation that the sky looks like a dome over a flat disk on which we humans live.
And so the first chapter of Genesis describes God creating “a dome in the midst of the
waters” separating the “waters” above and below the land on which plants, animals, and people
are eventually placed.
Many ancient cultures developed a similar picture by postulating a number of different
heavens, or layers of heaven, in accordance with their spiritual beliefs. I recall once, a few years
ago, giving a talk about meteorites to a group of native Americans in northern Wisconsin. I was
trying to explain what a meteorite was by describing it as a rock that has fallen out of the sky,
when an older woman in the group stopped me, and asked, “which sky?” The cosmology she was
operating out of is different from mine, but not all that different from the Ptolemaic view. Every
one of those dots of light that we wandering among the stars — the Greek word “planet” means
“wanderer” — is its own sphere, its own sky. So in one sense, her asking me “which sky” is
comparable to a scientist asking “which planet”... and yet, it really is a very different question,
because it has packed within it very different ideas of what those worlds or skies really mean.
The Greek philosophers Parmenides, Pythagoras, and Plato established that the Earth was a
sphere and that the planets, the Moon, and the Sun were bodies moving between the Earth and
the stars. The Pythagorean mathematician Eudoxus explained the motions of the planets by
describing the universe as an elaborate system of interlocking transparent spheres whose axes of
rotation pass through the Earth. Aristotle, a generation later, referred to this system in his
geocentric cosmology.
About 400 years after Aristotle, Ptolemy used the observations of the Babylonians and
Greeks to flesh out Aristotle’s geocentric cosmology with mathematical rigor. He was able to
provide mathematical tools that correctly predicted the positions of the planets, and so for the
next millennium philosophers accepted his cosmological premises and conclusions as correct.
The Ptolemaic system was a far cry from the water-covered dome described in Genesis. St.
Augustine noted this in his book On the Literal Interpretation of Genesis and warned that “even
a non-Christian knows something about the earth, the heavens, and the other elements of this
world, about the motion and orbit of the stars and even their size and relative positions, about the
predictable eclipses of the Sun and Moon, the cycles of the years and the seasons . . . and this
knowledge he holds to as being certain from reason and experience. Now, it is a disgraceful and
dangerous thing for an infidel to hear a Christian, presumably giving the meaning of Holy
Scripture, talking nonsense on these topics.”
(Notice the irony here — the “knowledge that he holds to be certain from reason and
experience” that Augustine cites here is in fact the Ptolemaic system that we have long since
abandoned as being untrue.)
Rather than leading to a crisis comparable to the Galileo affair, however, most theologians
at that time sill saw in this Aristotelean physical cosmology a reflection of the nonphysical
universe. Even after the adoption of a cosmology based on a spherical Earth, a common feature
of most cosmologies was the belief that the physical universe mirrored the spiritual realm.
By the middle ages, it was assumed that the home of the saints and the biblical firmament
were the outer spheres of the universe; below them were the spheres of each planet, moved by
angels, and their perfect eternal circular motions stood in contrast to the irregular and finite
movements of objects on Earth, which stood not at the center of the universe but at the bottom of
the “chain of creation,” only one level removed from the Inferno. Higher layers of the physical
universe were assigned to different elements, different gods, or different ranks of angels. Those
different ranks were given names – thrones, dominions... That’s what St. Paul was referring to in
that reading we started with.
As C. S. Lewis described it in his book The Discarded Image, “...the spheres are moved by
the love of God...each sphere, or something resident in each sphere, is a conscious and
intellectual being, moved by “intellectual love” of God...the planetary Intelligences, however,
make a very small part of the angelic population which inhabits... the vast aetherial region
between the Moon and the Primum Mobile [thrones, dominations, etc.] ... below the Moon is the
[realm] of the arial beings, the daemons.” In some sources, the daemons can be good or bad;
others divide the good into the upper air, the bad into the lower air; by the time of the Middle
Ages, Lewis tells us, “the view gained ground that all daemons alike were bad; were in fact
fallen agents, or “demons”.” And in fact this is only the beginning of census of the all the
different kinds of inhabitants of the universe as understood in the medieval cosmology, a
complexity that is only faintly echoed in modern fantasies like the Lord of the Rings.
It was, in fact, a beautiful system that underlay not only the physics and astronomy of its
day but also provided the framework for great literature music. You can’t read Chaucer or Dante
without knowing the cosmology they assumed, and which they assumed their readers would also
know. Again to quote Lewis: “Few constructions of the imagination seem to me to have
combined splendour, sobriety, and coherence in the same degree. It is possible that some readers
have long been itching to remind me that it had a serious defect: it was not true.”
And this was the point of those passages we read from St. Paul’s letters. Brian Purfield, a
writing for the British Jesuit website Thinking Faith.org, interprets Paul’s letter here as a reaction
against that cosmology. He writes “People in Ephesus ... [and in] nearby Colossae, already had a
view about this world and their place in it. According to this worldview, the gods were ‘up there’
beyond the sky and the people were ‘down here’ on earth. Between the gods and themselves
were a whole host of intermediaries. Furthermore, if you were to live a happy life ‘down here’,
you had to keep all these intermediaries happy as they were in charge of some area of your
earthly life. Paul had received word from Colossae about how the people were adapting
Christianity to their culture. When the Gospel is preached to the Colossians they are told that
Jesus is their mediator before God – but they already had many mediators before God and life
seemed to work very well. They therefore asked the question: ‘where does Jesus fit into our
system?’ In other words, they were trying to take the Gospel and super-impose it upon their
already-existing worldview.”
When the Islamic university in Toledo, Spain, was captured by Christian forces in 1085, its
library was translated into Latin and the ancient knowledge was finally reintroduced into
European universities. At that time, certain aspects of it, such as Aristotle’s championing of an
eternal universe, were seen as a challenge to the concept of an omnipotent Creator God. These
theological issues gave philosophers, like Nicholas of Cusa (who was later made a Cardinal in
the church) and the great Jewish rabbi Maimonedes, the incentive to look beyond the ancient
cosmology.
However, Thomas Aquinas so successfully reconciled the philosophy of Aristotle with
Christian theology that by the time of the Renaissance many people almost assumed that
Aristotle was a Christian; certainly they saw any challenge to Aristotle as a challenge to the
principles on which Christian theology itself was based. This gave rise to the well-known
conflicts between the Church and Galileo Galilei over the latter’s support of the Copernican
system.
It is worth noting, however, that there were also serious scientific and philosophical
objections to the Copernican system at that time. The Danish astronomer Tycho Brahe, for
example, carefully observed stellar positions and saw no evidence of the kind of parallax
motions that would be expected if the Earth were actually moving. Instead, he proposed that the
planets orbit the Sun, but that the Sun orbited a stationary Earth. Because of his improved
observations, his predictions of planetary positions were even more accurate than Copernicus’s
tables, and they were therefore preferred by contemporary astronomers. In addition, his system
was consistent with Aristotle’s physics.
Johannes Kepler, who inherited Brahe’s data, adopted a personal cosmology that, like the
medieval “chain of creation,” drew connections between the physical and supernatural worlds.
Recall that Copernicus had proposed a system where the sun was the center of the solar
system and Earth moved around it, but the Copernican system was still a system of circular
orbits. And so just like Ptolemy before him, in order to match the actual observed positions of
the planets, he had to assume “epicycles”—the planets moved in little circles around their
“average” circular orbits. And he had to assume “eccentric” circles, circular orbits that were
centered not exactly on the center of the solar system but on some point offset from that center.
Even the sun itself did not sit at the exact center but rather did a small circular dance about its
average position.
None of this was satisfactory to Kepler. The problem for him wasn’t one of inelegance;
rather, it was a theological problem. Kepler, you see, had a very peculiar notion of God’s place
in the universe. Unlike the standard theologies of his day, Catholic or Protestant, Kepler’s
personal mysticism told him that everything in the physical world exactly mirrored, or paralleled,
the spiritual realm. Thus to him the light of the sun represented in some real way, more than just
symbolically, the Holy Spirit pouring itself upon Earth. And the source of this light, the sun, was
to his thinking the physical manifestation of God the Father himself!
As he explained in a letter to his friend Herwart von Hohenburg (quoted in Job Kozhamthadam’s
wonderful book The Discovery of Kepler’s Laws), among the reasons for adopting his theory for
the orbits of the planets was the mystical significance of the structure of the celestial sphere:
“The center is the origin and beginning of the sphere. Indeed, the origin has precedence
everywhere and is by nature always the first. When we apply this consideration to the most Holy
Trinity, the center refers to the image of God the Father. Hence the center of this material worldsphere should be adorned by the most ornate body, that is the Sun, on account of light and life.”
It would hardly be fitting, reasoned Kepler, for God the Father to make this eccentric
little dance around the center of the universe. God the Father had to be the center, in a literal
sense. So Kepler went searching for an astronomical system that allowed the sun, and therefore
God the Father, to remain fixed. Eventually, he hit upon replacing the circles and epicycles of
Copernicus with elliptical orbits, and the rest is history.
Notice a common trait in all these different ways of putting the pieces of the universe together.
Up to this point, there is an unspoken assumption that when you’re talking astronomy, you’re
also talking religion. One tells you how to go to heaven, the other tells you how the heavens go -to quote the famous quip of Cardinal Baroneus, a defender of Galileo’s -- but they are still
referring to the same heaven. The physical and the metaphysical have not yet divided.
The new physics of Isaac Newton provided a viable replacement for Aristotle’s system. It
successfully reproduced Kepler’s elliptical orbits by using formulae based on physical laws that
acted in the same way on both celestial bodies and objects as humble as an apple falling from a
tree. The Earth and everything on it, no longer at the bottom of a chain of creation, were raised to
a level equal to that of the other planets.
The success of this new way of looking at the universe gave rise to an assumption raised to
the level of a cosmological principle: there is no privileged place in the universe. Thus, the laws
that govern the universe are the same everywhere, and deductions about the universe derived in
one place based on observations from that place should also be true in any other place. This
assumption forms the basis of modern cosmology.
Just as Earth was one planet among several, the Sun was but one star among many. Thus,
speculations about “other worlds,” which in medieval philosophy essentially referred to other
universes, took on a new meaning. Galileo’s telescope had already revealed the Milky Way
galaxy to be composed of many individual stars. The lack of parallax in the stars (which was
Brahe’s argument against Copernicus) argued that those stars must be immensely far away,
compared not merely to the size of the Earth but even in comparison with Earth’s orbit around
the Sun. To be visible at all, stars could not shine from reflected sunlight, as the planets do, but
must be themselves suns, perhaps with other planets around them.
Immanuel Kant, writing his Universal Natural History and Theory of the Heavens in 1755,
carried the Newtonian view of the universe to a new dimension by arguing that nebulous clouds
of light seen by telescopes were in fact galaxies, or “island universes” analogous to our own
Milky Way. Though his suggestion was hotly debated well into the early twentieth century, it
served to expand the size of the universe to previously unimagined distances across the cosmos,
whose origins science was attempting to describe.
Then in 1916 Einstein described in his general theory of relativity how space, time, matter,
and energy were interrelated, and how the force of gravity could be understood as a warping of
space-time by mass. Given than such a warping should tend to attract all matter together, this
observation revealed a paradox: assuming (as had been done since Aristotle) that the universe is
infinite and eternal, why hadn’t all of this mass had time to warp itself together into one point?
Einstein suggested that there could exist another force, previously unknown, that held mass
apart and allowed the universe to be divided into individual galaxies, stars, and planets. He noted
that such a force could be introduced into his equations as a “cosmological constant.” In 1922 the
Russian physicist Alexander Friedmann proposed that a universe that had as its initial condition a
sufficiently large expanding velocity could continue to expand indefinitely, even against the
force of gravity, thus removing the need for a cosmological constant. The concept of an entire
cosmology based on such an expansion of the universe from a single highly dense quantum state
is generally attributed to a 1927 paper by the Belgian astrophysicist and Catholic priest Georges
Lemaître.
The theory of a universe expanding from a singular point was proposed at an opportune
time. Along with relativity, the 1920s saw the development of quantum mechanics, which
describes the interior state of subatomic particles even at extreme conditions, such as the
enormous pressures and energies at the proposed initial state. Further, in 1929 Hubble reported
that galaxy clusters showed exactly the kind of motion predicted by the theory of an expanding
universe. The confluence of these three breakthroughs both motivated the big bang theory and
gave cosmologists the tools they needed to predict of the kinds of effects that could be observed
if the theory were correct.
Both atheists and apologists have attempted to read a theological significance into the big
bang theory, either as a substitute for or a confirmation of the biblical story of creation.
The Big Bang theory means that there would have been a particular point in time when
everything got started. This flew in the face of the common assumption, going back to Aristotle,
that the Universe was eternal and unchanging -- on average, at least. Fred Hoyle, a contemporary
and friend of Lemaître, was suspicious that this Belgian priest had only come up with this theory
as a way of rescuing the biblical story of creation; he mocked it, and called it the “Big Bang”
theory.
Lemaitre denied this. And indeed he was very upset when Pope Pius XII noted in 1951, in
an address to the Pontifical Academy of Science, that with the big bang theory, "it would seem
that present-day science, with one sweeping step back across millions of centuries, has
succeeded in bearing witness to the primordial Fiat lux..." However, in the same address the
Pope makes it clear that "the facts established up to the present time are not an absolute proof of
creation in time" and that such proofs are "of themselves... outside the proper sphere of the
natural sciences."
Still, the idea of a creation point, like you’d find in the Bible, may well have suggested the
idea of the Big Bang to Lemaître. Seeing how it worked there, may have made him unafraid to
consider it here.
It is in this context of “cosmology”, and especially remembering how our cosmologies
have changed over time, that it is interesting to revisit one of the questions we astronomers
working at the Vatican Observatory get asked all the time… about the Star of Bethlehem. It
illustrates how the very nature of the question “what was the star of Bethlehem” -- what we
actually mean, without realizing we mean it, when we ask such a question today -- reflects the
assumptions we have, often without realizing we have them, about the universe and how it
works. (And noting that this question is often asked of Vatican astronomers, I would like to
acknowledge the contribution in the remarks that follows from my fellow Vatican astronomer,
Fr. Paul Mueller SJ, a historian and philosopher of science.)
For one thing, the whole idea of asking “what was the Star of Bethlehem” to a Vatican
astronomer has itself hidden within it all sorts of wildly wrong assumptions. It assumes that our
position at the Vatican gives us some special insight into the issue. (It doesn’t. There’s no reason
we would know anything more about the Star of Bethlehem than anyone else.) It assumes that
there is a simple factual “answer” that can be demonstrated, scientifically. (There isn’t; the
question is more complex than that, as we’ll see.)
And it assumes that the astronomical question is the question that’s most interesting.
For example, why do we have such an interest in the star? What’s at stake here? If we
cannot prove that the story of the Magi happened, astronomically, does that mean that everything
else in Matthew’s Gospel is a tissue of lies? On the other hand, if we do find an astronomical
explanation for the story, does that prove that everything else in Matthew is true? Is the Star of
Bethlehem a test on which we can base our faith in the rest of the Gospel?
On reflection, it’s hard to believe that anyone would adopt either of these simple, extreme
conclusions. But the trouble is, most of us don’t reflect. There is an element of both attitudes,
fear and credulity, in people who are intent on an explanation for the Star of Bethlehem.
But in fact, the astronomy is merely the teaser to a set of a much deeper set of puzzles
about the whole Star of Bethlehem story. Among many other things, it is tied into the question of
what is a miracle. And that, ultimately, makes us wonder… how does God act in the world?
Especially given our modern cosmology with its seemingly rigid laws of physics and astronomy
that, you’d think, leave no room for God to act.
Nowadays, we take it for granted today that things that are “real” are the sorts of things
that maybe could be recorded by a video camera. And so we tend to think that a story is true only
if the things it reports and the events it recounts are somehow filmable: that’s our criterion for
what “really did in fact occur.”
But the nature of “reality” is more complicated that that. There is more to reality than that
which can be weighed and measured (or filmed). Ask anyone who owned a classic 1966
Volkswagen Beetle; there were more ingredients to that car than what you would find listed in
the Repair Manual.
Furthermore, sometimes when we ask whether a story is true, we’re not really asking
whether the events it recounts did in fact occur. You don’t need a professor of zoology to tell you
that tortoises and hares don’t actually talk, much less to each other. And they probably never
stage races. It’s a mistake to read scriptural accounts solely as if they were intended as historical
narratives – sometimes that’s just not the correct genre. It’s possible that the story in Matthew is
a parable with a message, not a factual account of an actual astronomical event. When we ask if a
fable is true, we’re not asking about what a videocamera would record; we’re asking whether the
moral at the heart of it rings true.
On the other hand, perhaps some videocamera would have recorded a totally miraculous
star, zooming about the sky like a UFO, guiding three kings to a stable in Bethlehem. Of course
such an unnatural event would sidestep astronomy altogether.
Of course, you might wonder why no one else in Jerusalem noticed a star like that.
But even more, I would argue, such a reading is theologically suspect. It is inconsistent
with the way we see God acting, over and over again, in history and scripture. God has the power
to create such a UFO, for sure. But for that matter, He also had the power to send Jesus into the
world fully grown, a Deity dressed up in a man-suit like some eastern avatar, surrounded by
unmistakable pomp and power: the image of the expected messiah that no one could have
mistaken.
Instead, as always, God showed what can only be called supernatural restraint: choosing
instead to come as an infant, born into the world as any other human, and subject to the very
laws that He had used to form this universe.
And science would be impossible if God did not show this supernatural restraint. Science is
possible only if natural phenomena are reasonably law-like and consistent. If God acted willy-
nilly in the world, “interfering” in natural processes right and left, there’d be no possibility of
doing science. Science is compatible only with a God who gives the world its own proper
autonomy – a God who supports and sustains natural laws, rather than interfering with them.
Which, in itself, tells you something interesting about God.
And yet as Christians we also accept that, at times, God has acted in our universe. And we
call those actions, miracles.
Recall how we saw that in the 17th century, once science was invented, there was a big
change in how people pictured the world: they began to describe it as a kind of mechanism or
machine – as something with parts that fit together and move with mathematical precision and
utter predictability. Isaac Newton’s mathematical theory of motion made it possible to predict,
accurately, how an object would move once the forces on it were known. And his mathematical
theory of gravity made it possible to predict (and retrodict, work out backwards) the motions and
positions of the planets and moons, far into the past and future.
This new Newtonian physics was an amazing accomplishment. But it resulted in a kind of
“catch-22” for miracles. In the new Newtonian world-view, a lot of people of a scientific bent
started to understand miracles in a much narrower way. They saw miracles as being acts of God
in which the laws of physics were suspended or violated. Without God’s intervention, events in
the world would unfold inexorably, in accord with physical law – an exception to or violation of
a law of nature was an indication of a miraculous intervention in the world on the part of God.
But wait a minute: If God is all-powerful, all-knowing, and all-good, why would He ever
create a world in which He needed to suspend the laws? Wouldn’t He instead create a world in
which the laws of physics were so perfect to begin with that later on He’d never need to meddle
or tinker? This way of thinking led many people in the 17th and 18th centuries into Deism.
Deists have a “watchmaker” conception of God: God creates the world and then leaves it
alone – God sustains the world in being, but has no other interaction with it. For Deists, a God
who did anything more than this would be undercutting Himself – He would be showing that He
was something other than all-powerful, all-knowing, and all-good.
The problem here is with the Deist’s narrow and simplistic understanding of “miracle”.
The heart of the scriptural understanding of a miracle is that it is a remarkable event that
functions as revelation of God. On this understanding, a miracle might, or might not, involve a
violation of physical law – that’s not really the point. The important thing about a miracle is that
it is a sign that reveals. Something can be a sign that reveals without being a violation of the
laws of physics. No violation of physical law was involved when Noah saw the rainbow after the
flood – but that rainbow is taken to be one of the most important signs ever given.
Still, ever since the 17th century, people of a “scientific” bent have tried to explain strange
or unusual events in accord with the known laws of science. If the known laws of science cannot
explain some reported strange or unusual event, our tendency is to doubt the report: if it can’t be
explained in terms of science, then probably it didn’t really happen.
But before the 17th century, strange and unusual events were understood in a different sort
of way. Instead of thinking of things in the world as being like parts of a machine that fit together
with mathematical precision, people thought of them as being like parts of a larger living
organism, or like people who are part of a larger culture.
A given human being may have certain characteristic ways of behaving, but that doesn’t
mean they always act the same way. We know that Uncle Charlie hates cats. So one day he
shows up holding a cat, petting it and talking sweetly to it. This is contrary to Uncle Charlie’s
usual character and way of behaving. What’s going on, we ask. It is a sign that something
unusual or important is happening in his life. (Maybe he’s got a new cat-loving girlfriend. Maybe
he’s had a stroke.)
But it would not involve any sort of violation of physical law – that question would never
even occur to us.
Before the 17th century, it was understood that things in the world have normal or
characteristic ways of behaving, just as a person has a certain kind of character or personality.
But it was also understood that the world has a built-in variability: although things usually
behave in certain ways, sometimes they behave differently – that’s just the way the world is.
Accordingly, when something really unusual happened, it was not understood as a
violation of physical law. It was just taken to be a wonder or a “prodigy”. And if a wonder or
prodigy happened to reveal something important about God or about the Kingdom of God, it
would be understood as a miracle.
If we want to know whether or not the star of Bethlehem was a miracle, then, the important
question is not whether it involved some sort of violation of physical law – though, of course,
perhaps it did. Instead, the important question is whether it was remarkable, and whether it
revealed something important about God or the Kingdom of God. If the star is something
remarkable that gives us a powerful “Aha!” moment with respect to God and the Kingdom, then
it’s miraculous – on an understanding of miracle that is scriptural rather than Deistic.
After all, there’s nothing particularly out of line with the thought that God could have
timed this birth with a chance arrangement of stars and planets. The miracle, the prodigy, the
message God is trying to tell us, would not have been in the star itself, but in the coincidence of
its appearance with the birth of Jesus.
People have suggested all sorts of possible things in the sky, from the flash of light of a
supernova to the appearance of an ominous comet. However, most attempts at working out a
possible astronomical explanation for the star of Bethlehem look for interesting or unusual
chance conjunctions of the planets. Johannes Kepler in the early 17th century, armed for the first
time with accurate positions of the planets and his new theory for planetary motions in ellipses
about the Sun, immediately tried playing this game by making tedious calculations of planetary
positions for the time of Christ. Nowadays, of course, anyone with a laptop can plug the date
“December 25, 1 BC” (or whenever you think is a more likely birthday) into your favorite
planetarium software package and see where the planets would have been that night.
One elegant modern theory comes from a book by the American astronomer Michael
Molnar, Star of Bethlehem: The Legacy of the Magi. Molnar suggests that a key to the planetalignment idea is to have the planets rise in the east with the Sun – what is called a heliacal
rising. Such conjunctions of planets and Sun were long considered significant. For example, the
heliacal rising in August of the bright star Sirius of the constellation Canis Major, the Big Dog,
was a sign to the Egyptians to get ready for the flooding of the Nile. (And it’s the origin of our
phrase “dog days” for the heat of August). But only an astrologer who knew how to calculate
planetary positions on paper would be able to know when heliacal risings occurred, since the
presence of the Sun among the planets makes them impossible to actually see.
Molnar then shows that just such a conjunction of planets – Venus, Mercury and Saturn,
Mars, and Jupiter – all rise with the Sun and the new Moon. This is similar to what Caesar
Augustus had used to support the claim that he had a royal birth. This grouping occurred in the
constellation Aries, which he identifies astrologically with the area around Judea, in late March
and again in April of 4 BC – the year, we are told, that historians have identified as the most
likely year of Jesus’ birth.
It sounds quite convincing. It’s all quite neat. And indeed it’s rather startling to realize that
such an event really did occur in the sky about the time when Jesus may well have been born. If
you have a planetarium program, you can look it up for yourself, like I did here.
But was this really what Matthew was talking about?
John Mosley of the Griffith Observatory in Los Angeles also wrote a book about the star of
Bethlehem, The Christmas Star. He notes that a conjunction of Jupiter and Venus in August of 3
BC was the beginning of a series of close conjunctions would have been of interest to any
astrologer. The August conjunction took place in the constellation of Leo, which he informs us
was the astrological sign of Judah (think of the “Lion of Judah”). Later, Jupiter (king of the gods)
made three close passes by the brightest star in Leo, Regulus (the star of kings). Then, on June
17, 2 BC, Jupiter and Venus encountered each other again, so close that they would have
appeared to the naked eye to actually be merged into one “star. ” Recall, Matthew talks about the
Magi looking at a star, one star, not at a grouping of many stars. Such close conjunctions occur
less than one a century; the last one in our time, Mosley calculates, occurred in 1818 and the next
won’t occur until 2065. And, he says historians tell him that the most likely years for the birth of
Christ were 3 or 2 BC.
But wait… there was a series of spectacular conjunctions of Jupiter and other planets in the
year 7 BC. In his book The Bible and Astronomy, Fr. Gustav Teres points out that on November
12 of that year, Jupiter and Saturn met in the constellation of Pisces, the Fish, a constellation that
we are told was associated with Israel (and appropriate for One who would send out Fishers of
Men), in a location that may have been lined up with a thin cone of faint light called the Zodiacal
Light. That’s the faint reflection of sunlight off dust in the asteroid belt, almost impossible to see
nowadays with all our artificial lighting except in dark remote places like the American desert
southwest. But an observer in the dark skies of ancient Palestine would have seen a beam of light
from these conjoined stars that night, pointing down to the horizon! And Teres insists that 7 BC
is the year that his historians have identified as the most likely year of Jesus’ birth.
And those are only three of countless different theories you can find in books and videos or
on the internet. Type “Star of Bethlehem” into Amazon and you’ll find more than 400 books
listed. Each one proclaims that it has the true explanation for the Star.
Rather than astronomy ruling out the historicity of Matthew, we have too many possible
astronomical explanations. We can also conclude that nobody really knows for sure which
constellation really signified a king of the Jews, or when exactly Jesus was born. For all we
know, it actually did happen on December 25, 1 B.C.!
We had looked to astronomy as a source of objective truth, but it fails us – not for having
no answer, but for having too many possible answers. Ultimately, we have to concede: we
weren’t there. We don’t know. We’ll never know for sure. It’s a mystery...
From the perspective of science, the Star is a problem to be solved. Was there really
something remarkable in the heavens at the time of the birth of Jesus? If so, what kind of thing
was it – how can we explain it? These are questions that can be attacked with all the tools of
science and other human disciplines. These are questions that have answers – questions that
could be solved. In theory, if we had a time machine and a video camera, we could travel back to
the appropriate year and interview the Magi – or Matthew – and find out definitely what it was
they were talking about.
From the perspective of religious belief, however, the Star is mysterious in other ways. For
the Magi as described by Matthew, the Star was a point of encounter with the divine. It doesn’t
matter in this context if the Magi are real or allegorical; it’s this encounter of the human with the
divine that we’re talking about, and that is real. And the whole point of describing that encounter
in a story, historical or not, is that we can use the story to draw a deeper understanding about the
meaning behind the issues that the story illustrates.
And so it is crucially important, when asking “what is the star of Bethlehem,” to be keep
track of when we’re speaking of about whether events really transpired as reported by Matthew
(the question of historical fact), and when we’re speaking about what the star and its story mean.
The second question is closely related to the first, but you can’t reduce the one to the other. None
of the astronomical explanations really reflects directly on the truth (or falseness) of what
Matthew was saying with his story.
Indeed, whether the story is a pious tale or an imprecisely-described account of an
astronomical event, there is still the question of why Matthew chose to tell it. Of all the visitors
to Bethlehem, Matthew specifically talks only about shepherds and the Magi. Presumably he was
doing more than just name-dropping. Matthew was trying to make a point. What was that point?
And what truth does it contain?
So now, finally, let us ask ourselves again, what is the Star of Bethlehem? Notice how
we’ve changed the question. It’s not, what was the Star, in the past; it is rather, what is the Star,
now.
Would an electronic camera have recorded an unusual sight in the nighttime sky over
Bethlehem, two thousand years ago? We don’t know. There are plenty of possible candidates, so
we can’t rule it out; but we can’t prove that any of them are what Matthew is talking about.
On the other hand, we can see for ourselves that the story of the Star of Bethlehem surely
exists, and it has had an real effect for two thousand years on people hearing that story. That’s
more than you can say about most stories making the rounds two thousand years ago. That’s
even more than you can say about a lot of other stories in the Bible itself. Which raises the whole
other issue we have barely touched upon, of why this particular story is so fascinating to so many
people. That’s a mystery worth praying over.
But finally… just between us… you’re probably wondering. I’m an astronomer, and also a
believer. What do I really think? Was there really a star, or was it just a fable? Yeah, sure, you
don’t expect any proof, but … what’s my best guess?
Does it matter? Yes. Questions of fact matter, in science and for people of faith. After all,
Christianity turns on a question of historical fact about the resurection of Jesus. If it’s not the
case that something extraordinary happened at the time of the death of Jesus – something
mysterious which we don’t fully understand – then Christian hope is in vain. That’s why
Christians care so much about the story of the resurrection.
On the other hand, the story of the Star is not at all central to Christian faith – it’d pose no
great challenge to Christian faith if it turned out that the story of the Star has no basis at all in
historical fact.
But it could be fact.
And somehow, in some way, the story of the Star matters. We care; we want to know.
One reason why the story of the Star matters is that it gives us a hint of how God behaves;
about God’s personality, as it were. If God is happy to teach us with symbolic stories, OK, that’s
one kind of God, I can live with that. If God actually likes to set up cool little “divine
coincidences” to teach us things, that’s also OK, but it means we’re dealing with a slightly
different kind of God. And if God reall does intervene, suspending the laws of the universe that
He himself created, either willy-nilly when He feels like it or, at the very least, when it comes to
the clearly supernatural life, death, and resurrection of Jesus, that too gives me a different but
important view of how God has acted in the Universe.
So which do I think is it?
It could be any, or all, of the above.
God is someone who teaches us with stories. We can see that with Jesus and all his
parables; experiencing the strange surprises and plot twists in the parables is an essential part of
being a Christian. But God is also someone who on occasion is not afraid to show us Who’s in
charge; we can see that with Jesus and his miracles.
Maybe… what the Star of Bethlehem is telling us, is that He is a God who calls to us from
afar, in and through the things of this world. He’s a God who challenges us to use our intellect to
understand this world. But he’s also a God who is known through the experience of hearing and
telling stories.
And He’s a God who likes to keep us guessing.