How to Predict a Scientific Revolution
Sarah Jones Nelson
Consultant and Adviser to the Vatican
Pontifical Lateran University
IRAFS: International Research Area on Foundations of the Sciences
International Symposium on Science and Theology: The Challenge of Quantum Gravity in
Modern Cosmology
October 20-21, 2022
For historical perspective on this historic occasion, let us turn to the twin revolutions of science
and theology — of facts and values — simmering in early modern Europe.
On June 4, 1539 in Wittenberg, Germany at his dinner table with colleagues and students, Martin
Luther called Galileo that fellow who wants to prove the earth moves and turns all astronomy
upside down. Luther had already turned religion upside down. In 1517 he catalyzed the
Protestant Reformation by proclaiming 95 points of public debate against indulgences or cash
donations in exchange for salvation during a papal campaign to fund needed repairs to St Peter’s
Basilica.
Pope Leo X excommunicated Luther, a professor of biblical interpretation. On the authority of
scripture, Luther later agreed with Galileo’s inquisitors that the sun revolves around the earth.
Their official proof text, Joshua 10:12-14, narrates Israel’s victory over the Amorites; Joshua
commands a rotating sun to stand still at Gibeon, and the moon at Aijalon. Because of his
dissenting proof of the laws of motion, Galileo spent the rest of his life from 1633 onward a
heretic under house arrest at his villa near Florence.
This first crucible of political and biblical theology turned the ground of certainty spinning
upside down in all directions. Science and theology would never be the same: a foretaste of the
way testable proof — and strong emotions — can cause revolutions.
Fast forward September 18, 2019, to my seminar table talk on the physical foundations of theory,
Department of Physics, Princeton University. A small group took on quantum gravity. Gerard ‘t
Hooft, one of our esteemed speakers today, spoke of quantum mechanics as a tool to solve
problems. Turning quantum mechanics upside down, he said, is a solution.
String theorist Edward Witten responded: The fact that quantum mechanics can be used to solve
non-quantum mechanical problems suggests that quantum mechanics is more powerful than
classical mechanics.
Christopher Tully: With all the great achievements of quantum mechanics we are not certain that
our discussion of origins is on solid theoretical ground. What if you have an infinite number in
initial conditions? Does that mean your initial state and properties in only one state make a
superposition? Initial conditions are special. Why hasn’t gravitational instability taken over?
Why hasn’t everything collapsed into a black hole?
James Peebles: We are in one giant wavefunction from the start. And we don’t know what’s
beneath quantum mechanics. We do not have the state under quantum mechanics. What is the
deeper underlying theory? How deep do you go? How do you know when to stop?
Intense discussion: Are observables in the early universe fixed initial conditions? Are all sets of
initial conditions consistent with what we observe today? Suppose you do an EPR experiment to
test the hypothesis. You measure two CMB photons at the same time. Do they have some level of
entanglement consistent with initial conditions?
Wavefunction initial conditions are hidden, and it’s unclear that the numbers are well defined.
Questions: Are the laws of nature definable? If you deny definability do you deny the existence
of pure, precise laws of nature? Are we using the right concepts? What’s up with free will, initial
conditions, and nonlocality? Do ontological states exist with zero uncertainty at an entangled
initial state wired for infinite expansion?
Being in one giant wavefunction from the start means that we exist in a wavefunction that caused
the quantum state of physical reality. Thus the wavefunction is foundational to quantum
mechanics as the sine qua non of any progress in observational cosmology.
Roger Penrose, one of our online seminar participants, published with Stephen Hawking a
mathematical description of the gravitational collapse which produces black holes. He now
believes that the Copenhagen interpretation of quantum mechanics is subjective and therefore
uncertain because of observer dependence on the collapse or state reduction of the wavefunction.
The wavefunction quantum state up to proportionality, he says, should be given the objective
ontological status of a physical object.
Here we encounter the challenge of quantum gravity, with the help of the right tools, to turn
quantum mechanics upside down. More on this in a few minutes.
What if the wavefunction is not simply a mathematical formulation of all possible or probable
observable states determined by observation and measurement? Perhaps gravity or dark matter
induces the state reduction of the wavefunction. Catalina Curceanu, also an online seminar
participant, runs a laboratory in Gran Sasso. She is constructing a wavefunction model relating to
physical reality and, importantly, to nonlocality. Her experiments will advance our knowledge of
entanglement and quantum gravity.
Experimental work of this nature can give us a better understanding of the wavefunction at the
initial state. It can inform models of quantum gravity. It will help modify the standard model to
give us more precise laws of nature toward a consistent ontology of quantum mechanics and its
underlying nature, not just new mathematics where the axioms of arithmetic are unprovable.
The new physics must solve a deeply problematic conflict of interpretations for one universe
governed by two sets of contradictory laws. That conflict explains why so many in the theoretical
community believe that our standard concepts of spacetime will have to change. This means
revolution with profound consequences for cosmology.
Why cosmology? The standard cosmological model requires testable initial conditions to predict
certain outcomes. At the initial state, however, no tools or instruments yet exist to test or probe
the initial conditions of spacetime emerging, say, from an entangled quantum state to the
classical universe described by Einstein’s gravity.
This is why any foundational claim to a consistent ontology of quantum and classical mechanics
at the initial state is uncertain. Even if we can infer rightly that the Big Bang was a singularity, it
is still conjectural. We have no testable evidence for the initial causal mechanisms of structure
formation and expansion from the first singularity. Why? Because the initial state is
unintelligible without predictive theory of confirmed, observable initial conditions. Without the
evidence of observables we have metaphysics — holograms, strings — not ontology.
The good news is instrumentation on the order of Galileo’s 1609 retooled Dutch telescope. Now,
from the mountaintops of Chile, Princeton University’s CMB telescope team has confirmed
testable observables from the cosmic microwave background radiation: fossil evidence of the
early universe 380,000 years after the initial state. What happened before that state, however, is
vigorously contested.
Contested also is the nature of quantum mechanics at the primordial regime, before CMB
evidence, at all scales such as the Planck scale of primordial pure quantum black holes. Here
again we encounter the challenge of quantum gravity. How can primordial black holes at the start
of structures emerge with interior properties of such laws as gravity which will necessarily break
down? Published images of black holes show that the blackhole boundary confirms general
relativity. What else can we infer about the interior of this unitary physical object? Did quantum
mechanics apply at initial conditions of pure-state quantum black holes at the Planck scale?
If the wavefunction describes the quantum state of everything that exists, it describes the
quantum state of black holes, now given objective status by the Event Horizon Telescope (EHT)
directed at Harvard University by our speaker Shep Doeleman, collaborating with Peter Galison,
Director of the Harvard Black Hole Initiative. I predict that the next-generation EHT (ngEHT)
will generate data at the blackhole event horizon from which to credibly infer or observe the
properties of physical dynamics inside a black hole. The result? A revolution. The laws of nature
will never be the same. An intuition: the ngEHT gives the wavefunction objective status.
Observable effects of the wavefunction show it to be a physical object in a singularity from
which to infer the mechanisms of the initial singularity.
We live in a world of paradox. The probability of an entangled initial singularity emerging from
a quantum state expanding to a classical state suggests to me initial conditions in which an
objectively real wavefunction physically acts upon each state at the effect of the EPR paradox. If
measurements disentangle quantum systems such as the wavefunction, fundamental physical
theory will have to change.
Will wavefunction initial conditions always be hidden between the lines of the Book of Nature?
Will revolutionary instrumentation rewrite the chapter of hidden conditions? Quantum theory
makes epistemic claims on the origins of the universe and our consciousness of it. Are our lives
fundamentally determined by initial conditions? Are we as creative agents predestined by the
conditions of our birth, our histories and our cultures? Is free will consistent with what’s beneath
quantum mechanics and our perception of physical reality? Open questions such as these will
shape the future of philosophical and theological discourse on origins, causation and
consciousness.
To conclude I raise the question of social construction in theoretical and experimental science. I
have introduced to you an inquiring group of physicists devoted to resolving conflicts in the
community by investing in cooperation and collaboration. But social history shows how
influential groups with a fixed agenda can force conformity to wrongthink.
Original thinkers from Aristotle to Spinoza to Turing have suffered deeply for differing from
fashionable groupthink. In contemporary culture groups can easily ignore or abuse unfashionable
ideas ahead of the curve. Think of Virginia Woolf, John Bell, Hugh Everett, uncountable
off-the-charts students too concerned about securing jobs to challenge groupthink as wrong as
Luther was to prooftext the Book of Joshua against confirmed laws of planetary motion.
We stand at the precipice of a revolution in contemporary physics because of highly organized
collaborations and exquisite new instrumentation. Let us listen to all voices emerging from their
courageous work of turning physics and philosophy upside down in all directions.