Near-infrared all-sky survey observing in J, H, and K bands, providing a unique view of galaxies because infrared penetrates dust better than optical light. Used to study galaxy clustering and large-scale structure.

Pressure waves in the early universe's plasma that created characteristic patterns of temperature fluctuations in the CMB. These waves were frozen in when the universe cooled enough for atoms to form, leaving a series of peaks and troughs visible in the CMB power spectrum.

Anti-de Sitter/Conformal Field Theory correspondence. A mathematically proven duality discovered by Juan Maldacena showing that gravitational physics in certain curved spacetimes is exactly equivalent to quantum field theory on the boundary of that spacetime. Provides the strongest mathematical evidence that spacetime can emerge from quantum information processing.

The length of the shortest computer program that can generate a given output. Measures the compressibility of information, distinguishing truly random sequences (incompressible) from apparently complex but actually simple patterns (highly compressible).

A measure of rotational motion conserved in the absence of external torques. In quantum mechanics, angular momentum is quantized and appears in discrete steps. Explains why collapsing gas clouds spin faster as they contract and why quantum particles have intrinsic spin.

The point on a sphere directly opposite another point, separated by 180 degrees. Relevant to galaxy spin asymmetry analysis, where the asymmetry axis identified by Shamir sits at the antipodal location to the CMB hemispherical asymmetry axis.

Ground-based telescope located at 5,190 metres elevation in Chile that observes the CMB with high resolution, providing independent measurements to cross-check satellite data with different systematic errors.

In dynamical systems, a set of states toward which a system evolves over time regardless of starting conditions. Strange attractors characterize chaotic systems and have fractal geometric structure, as found in pulsar spin-down dynamics.

A colloquial term for the unexpected alignment of the CMB's quadrupole and octopole moments, pointing toward similar sky coordinates. Challenges the cosmological principle and currently lacks an explanation within the standard cosmological model.

Regular periodic density variations in the distribution of visible matter, arising from the same acoustic waves that created CMB temperature fluctuations. Provide a standard ruler for measuring cosmic distances and expansion rates across cosmic history, with a characteristic scale of approximately 150 Mpc.

A statistical measure comparing the evidence for two competing hypotheses. A Bayes factor of 0.0041 for cosmological isotropy means the isotropic hypothesis is approximately 250 times less likely than an anisotropic model, given the data.

An upper limit on the entropy and information content of a physical system enclosed in a given volume with a given total energy. Implies that the information content of any physical region is finite and determined by its boundary area and energy, forming one foundation of the holographic principle.

The entropy of a black hole, proportional to the area of its event horizon rather than its volume. Represents the maximum information content of any region of space and provides the foundation for the holographic principle.

A mathematical proof by physicist John Stewart Bell (1964) demonstrating that no theory based on local hidden variables can reproduce all predictions of quantum mechanics. Experimental tests have consistently confirmed quantum mechanics, ruling out local realism.

The operating regime in quantum error correction where physical error rates are low enough that adding more qubits improves protection exponentially. Google's Willow chip achieved this milestone in December 2024, demonstrating that larger quantum systems can be more accurate rather than less.

A geometric phase acquired by a quantum system undergoing cyclic evolution in parameter space. Depends only on the geometry of the path, not the speed of evolution, making holonomic quantum gates that exploit it robust against certain timing and amplitude errors.

The production of light atomic nuclei (primarily hydrogen, helium, and lithium) during the first few minutes after the Big Bang. The precise ratios of these elements depend critically on the strength of the strong nuclear force; small deviations would produce a universe composed almost entirely of one element.

The apparent contradiction between quantum mechanics, which requires information to be conserved, and the behavior of black holes, from which Hawking radiation appears to carry no specific information about infalling matter. Significant theoretical progress was made in 2019 using quantum extremal surfaces to reproduce the Page curve.

The geometric representation of all possible states of a single qubit. Every quantum state, including all superpositions, corresponds to a point on the surface of a unit sphere. Quantum gate operations are rotations on this sphere.

A proposed tabletop quantum gravity experiment in which two small masses are placed in quantum spatial superpositions and allowed to interact only through gravity. If the masses become entangled, this proves gravity must be quantum mechanical, implying spacetime geometry is subject to quantum information-theoretic constraints. Multiple laboratory groups are actively working toward implementation.

A quantum gravity approach proposing that spacetime is fundamentally discrete, consisting of a partially ordered set of spacetime points connected by causal relationships. Maintains spacetime as foundational rather than emergent.

The Cabibbo-Kobayashi-Maskawa matrix in particle physics that specifies the probabilities with which quarks of one type transform into quarks of another type through weak force interactions. Its structure, with large diagonal elements and small off-diagonal elements, ensures that quark transformations are regulated rather than random.

The comprehensive mapping of all neural connections within a nervous system, producing a detailed wiring diagram called a connectome. The only complete connectome currently available is that of the roundworm C. elegans, with 302 neurons.

The oldest light in the universe, emitted approximately 380,000 years after the Big Bang when the universe cooled enough for hydrogen atoms to form. Carries imprinted information about the early universe's structure and conditions, analyzed across multiple frequency bands by WMAP and Planck satellites.

A fundamental statistical limitation arising from the fact that only one universe is observable. For the largest angular scales in the CMB, each multipole moment has only a limited number of independent measurements, creating irreducible uncertainty that cannot be reduced by better instruments.

The foundational assumption in modern cosmology that the universe is isotropic (statistically the same in all directions) and homogeneous (uniform in density on large scales). Multiple independent observations have found evidence of directional asymmetries that challenge this principle at various significance levels.

The process by which quantum superpositions lose their quantum properties through interaction with the environment. When a quantum system interacts with surrounding particles, its coherence distributes across enormous numbers of environmental degrees of freedom. Explains why large objects do not exhibit obvious quantum behavior.

A quantum control technique that suppresses decoherence by applying rapid sequences of precisely timed pulses to a quantum system, causing the system-environment coupling to average to zero over time. Achieves coherence time improvements of 10 to 100 times across multiple quantum platforms.

One of the four fundamental forces, governing interactions between electrically charged particles through the exchange of photons. The framework maps this to the information transmission function: propagating information at light speed across cosmic distances. The fine-structure constant α ≈ 1/137 sets its coupling strength.

A measure of how strongly two quantum subsystems are entangled, quantifying the information shared between them. In holographic physics, entanglement entropy is proportional to the area of geometric surfaces in the corresponding gravitational spacetime, connecting quantum information directly to geometry.

The proposal by Erik Verlinde (2010) that gravity is not a fundamental force but an entropic force arising from statistical tendencies of information-carrying systems to maximize entropy. Represents mainstream theoretical physics exploration of gravity's information-theoretic origins.

A measure of the number of microscopic configurations a physical system could have while appearing the same at the macroscopic level. In information theory, entropy measures the average information per message. Landauer's principle unifies the thermodynamic and information-theoretic meanings: erasing information increases thermodynamic entropy.

The 2013 proposal by Maldacena and Susskind that Einstein-Rosen bridges (wormholes) and Einstein-Podolsky-Rosen quantum entanglement are two descriptions of the same phenomenon. If correct, what we call spatial distance might be another way of describing information correlation patterns.

The boundary of a black hole beyond which nothing, including light, can escape to the outside universe. Events inside the event horizon are causally disconnected from the exterior. The apparent contradiction between this isolation and quantum mechanical unitarity is the source of the information paradox.

A quantum computing architecture in which errors in physical qubits are detected and corrected faster than they accumulate, allowing computations of arbitrary length to be performed with arbitrarily low error probability. Requires operating below the error correction threshold.

A dimensionless physical constant approximately equal to 1/137.036, characterizing the strength of electromagnetic interaction between charged particles. Appears across atomic spectra, chemical bonding, and quantum electrodynamics. Its specific value has no accepted theoretical derivation.

The small central region of the retina densely packed with cone photoreceptors that provides the sharpest visual acuity. The visual cortex devotes disproportionately large areas to representing the fovea, a property called cortical magnification.

The shortest path between two points in curved space, generalizing the concept of a straight line to curved geometry. In general relativity, freely falling objects travel along geodesics through curved spacetime. What we experience as gravitational attraction is the curvature of geodesics caused by mass and energy.

Non-neuronal cells in the nervous system providing structural support, insulation, and maintenance for neurons. Although long thought passive, glial cells actively participate in information processing and synapse regulation. They constitute approximately 85% of brain cells, paralleling the dark matter fraction in cosmic structure.

A theory of consciousness proposing that awareness emerges when information becomes globally broadcast across brain networks, making it simultaneously accessible to multiple specialized processing systems. Treats consciousness as a shared workspace where different brain modules can contribute to and access a common information pool.

The mathematical constant approximately equal to 1.618, defined as φ = (1 + √5)/2. Appears in the geometry of pinwheel centers in the visual cortex, in biological growth patterns, and in optimization problems. Shows distinct resonance behavior at 61 GHz in preliminary CMB frequency analysis.

The philosophical problem, articulated by David Chalmers, of explaining why and how physical processes in the brain give rise to subjective experience. Explains the neural correlates of consciousness, but does not address why those states feel like anything at all.

Thermal radiation emitted by black holes due to quantum effects near the event horizon, predicted by Stephen Hawking in 1974. Virtual particle pairs are created near the horizon; one falls in while the other escapes as radiation. The escaping particle carries energy away, causing the black hole to slowly lose mass.

Hypothetical properties that, if they existed, would restore determinism to quantum mechanics by supplying definite values for particle properties before measurement. Bell's theorem proved that no such theory can reproduce quantum mechanical predictions if it also requires causes to propagate no faster than light.

The abstract mathematical space in which quantum states are represented as vectors. Physical operations, measurements, and quantum gates are represented as transformations of these vectors. Its geometry determines what quantum operations are possible.

The principle, developed by 't Hooft and Susskind, stating that all information describing a volume of space can be encoded on its two-dimensional boundary surface. Implies that three-dimensional space may be emergent from a lower-dimensional information substrate.

A quantum logic gate implemented using the geometric (Berry) phase acquired when a quantum system traces a closed loop in parameter space. Robust against certain timing and amplitude errors because it depends only on the geometry of the loop, not on how fast the evolution occurs.

The statistically significant discrepancy between two independent measurements of the Hubble constant: CMB-based measurements yield approximately 67 km/s/Mpc while direct measurements from nearby supernovae yield approximately 73 km/s/Mpc. The ~9% disagreement may reflect efficiency-regime differences predicted by the information-first framework.

The failure to perceive stimuli that are fully visible but outside the focus of attention. Demonstrates that conscious visual experience is determined not by what enters the retina but by what attention selects for processing, supporting the active construction model of perception.

The new term in PEG theory's extension of Einstein's field equations. Quantifies how much information is being processed at each point in spacetime, analogous to how the stress-energy tensor Tμν quantifies mass-energy density. In most conditions proportional to Tμν; in extreme conditions they may differ measurably.

A theory of consciousness developed by Giulio Tononi proposing that consciousness corresponds to integrated information, quantified as phi (Φ). A system is conscious to the degree that its parts generate more information as a whole than they do independently.

A technique for combining CMB observations at multiple frequencies to minimize contamination from galactic foregrounds. Exploits the fact that the CMB has the same blackbody spectrum at all frequencies while foreground emission has different spectral shapes.

A theoretical result showing that black hole information is preserved during Hawking evaporation through contributions from disconnected spacetime regions called islands. Correctly reproduces the Page curve, demonstrating that geometric spacetime structures actively participate in information preservation.

The physical law proved by Rolf Landauer (1961) and experimentally confirmed, stating that erasing one bit of information necessarily dissipates at least kT ln(2) energy as heat. Establishes that information is not abstract but has direct physical energy consequences, linking information processing to thermodynamics.

The observation that proteins fold into their functional three-dimensional shapes in milliseconds, despite the astronomically large number of possible configurations they could adopt. Named after Cyrus Levinthal, who showed random search through all configurations would take longer than the age of the universe.

The philosophical position that physical properties exist independently of measurement (realism) and that events at one location cannot instantaneously influence events elsewhere (locality). Bell's theorem and subsequent experiments have shown quantum mechanics is incompatible with local realism.

A fault-tolerant qubit encoded in the collective quantum state of many physical qubits, protected by quantum error correction codes. Unlike physical qubits, a logical qubit maintained below the error correction threshold can preserve quantum information for arbitrarily long times.

Any computational operation in which the input state cannot be uniquely recovered from the output state. Deletion, rounding, and memory erasure are all logically irreversible. Landauer's principle requires these operations to dissipate at least kT ln(2) energy per bit.

A theoretical framework for quantum gravity proposing that spacetime is quantized at the Planck scale, consisting of discrete quantum units of space. Represents an alternative to string theory approaches to quantum gravity.

A quantity measuring the rate at which nearby trajectories diverge in a dynamical system. In quantum systems, the Lyapunov exponent quantifies the rate of quantum scrambling. The fundamental bound λ ≤ 2πk_BT/ℏ was proved by Maldacena, Shenker, and Stanford in 2016; black holes saturate this bound exactly.

A parameter describing the angular scale of CMB temperature fluctuations. Low ℓ values correspond to large angular scales while high ℓ values correspond to fine angular detail. The CMB power spectrum plots fluctuation amplitude against ℓ, revealing characteristic acoustic peaks.

The fundamental quantum mechanical theorem proving that it is impossible to create an identical copy of an arbitrary unknown quantum state. Prevents naive application of classical error correction strategies to quantum systems. Quantum error correction circumvents it by encoding information in entangled states rather than copies.

A real number whose digit expansion is statistically uniform in every base, such that every possible finite sequence of digits appears with the expected frequency. Most real numbers are normal, but proving any specific number such as π or e is normal remains an open problem in mathematics.

A mathematical framework for finding the best way to manipulate a dynamical system to achieve a desired outcome while minimizing a cost function. Applied to quantum systems, it finds precise electromagnetic pulse shapes that implement quantum gates with maximum fidelity and minimum time.

A quantum correlation function measuring how much quantum operators become entangled under time evolution. Quantifies the degree of quantum scrambling: when OTOCs decay from their initial value, local quantum information has spread into global entanglement.

Don Page's theoretical prediction for how the entanglement entropy of Hawking radiation should evolve over the lifetime of an evaporating black hole if quantum mechanics is unitary. The entropy first rises, then falls after the Page time, reaching zero when the black hole fully evaporates, indicating information is preserved.

The moment roughly halfway through a black hole's evaporation when entanglement entropy of emitted Hawking radiation reaches its maximum and begins decreasing. After the Page time, subtle correlations between radiation particles begin encoding the original information about infalling matter.

The framework's proposal that gravity emerges from information organization patterns in spacetime rather than being a fundamental force. Extends Einstein's field equations by adding an information density tensor Iμν alongside the standard stress-energy tensor Tμν.

The fundamental unit of length in quantum gravity, approximately 1.616 × 10⁻³⁵ metres, below which quantum gravitational effects dominate. Each Planck area corresponds to approximately one bit of information according to the holographic principle.

A framework for neural information processing in which the brain continuously generates predictions about incoming sensory data and transmits primarily prediction errors rather than raw signals. Explains how the brain constructs rich visual experience from highly compressed input, and why visual illusions persist even when explicitly identified.

A phenomenon in which two or more particles share a quantum state such that measuring one instantly determines correlated properties of the other, regardless of distance. Recent work suggests entanglement may be the mechanism by which spacetime geometry is created.

A surface in spacetime that minimizes a combination of area and entanglement entropy, generalizing the Ryu-Takayanagi formula. Using quantum extremal surfaces in calculations of black hole entropy reproduces the Page curve, the key breakthrough of 2019 progress on the information paradox.

In quantum field theory, the fundamental entities are fields that have a value at every point in spacetime. Particles are not independent objects but excitations (ripples) in these fields. The electron field, electromagnetic field, and others extend throughout all of space.

The theoretical framework combining quantum mechanics and special relativity, treating fundamental particles as excitations of underlying quantum fields. The Standard Model of particle physics is a quantum field theory.

The quantum computing equivalent of a classical logic gate. Performs operations on qubits by rotating their state vectors in Hilbert space. Unlike classical gates, quantum gates must be reversible (mathematically unitary), connecting directly to information-preservation.

The fundamental physical theory governing behavior at atomic and subatomic scales. Introduces superposition, entanglement, and wave functions, replacing classical pictures of particles with definite properties with probability amplitudes.

The author's theoretical framework proposing that spacetime might function as an information storage substrate at the Planck scale, with discrete geometric configurations encoding quantum information. An original theoretical speculation building on established results in holography and black hole thermodynamics. No experimental validation currently exists.

The process by which information initially localized in a small part of a quantum system spreads throughout the entire system through quantum entanglement, becoming encoded in global correlations. Scrambled information is conserved by quantum unitarity but practically inaccessible without measuring all parts simultaneously.

The quantum mechanical property by which a system exists in multiple states simultaneously, with each state having an associated probability amplitude. A qubit in superposition simultaneously represents both 0 and 1, enabling quantum computers to explore many computational paths at once.

The principle in quantum mechanics stating that quantum evolution preserves total probability and is information-conserving. Mathematically, unitary evolution means the operator's inverse equals its conjugate transpose. Unitarity is equivalent to information conservation: no physical process can destroy quantum information, only scramble it.

The phenomenon whereby quarks are never found in isolation but always bound in groups. The strong nuclear force grows stronger as quarks are pulled apart, making separation energetically impossible. The coupling constant governing this force must take its precise observed value for stable atomic nuclei to exist.

The fundamental unit of quantum information, analogous to a classical bit but capable of existing in superposition states. A qubit's complete state is represented as a point on the Bloch sphere. Physically implemented using two-level quantum systems such as electron spins, photon polarizations, or superconducting circuits.

Einstein's two physical theories: special relativity (1905), establishing that space and time are relative to the observer's reference frame, and general relativity (1915), describing gravity as spacetime curvature caused by mass-energy. Both revealed that the most fundamental properties — mass, length, time — are relational rather than intrinsic.

A rapid, ballistic eye movement that shifts gaze from one fixation point to another. Humans make approximately three saccades per second. During each saccade, visual processing is suppressed (saccadic suppression), preventing perception of motion blur that would otherwise result from the rapid image movement.

A quantum mechanical model of N fermions with all-to-all random interactions, every particle interacting with every other with randomly chosen interaction strengths. The SYK model is maximally chaotic, saturating the scrambling bound with a Lyapunov exponent equal to the maximum allowed value, making it a tractable theoretical stand-in for studying how black holes process information.

A statistical distribution where probability follows a power law. Scale-free distributions appear in many natural networks, including the internet, biological metabolic networks, and both neural and cosmic web networks. Characterized by highly connected hub nodes and the absence of a characteristic scale.

A network type combining high local clustering (neighbors of a node tend to be connected to each other) with short average path lengths between any two nodes. Found in neural connectivity, social networks, and the cosmic web. Optimizes both local and global information processing efficiency.

In general relativity, the phenomenon by which mass and energy cause the geometric structure of spacetime to curve. Objects in curved spacetime follow geodesics, the straightest possible paths through the curved geometry. Spacetime curvature propagates as gravitational waves when mass-energy distributions change dynamically.

Mathematical functions defined on the surface of a sphere that arise in any problem with spherical symmetry. Describe the angular dependence of quantum wave functions and appear wherever physics involves rotational symmetry. π appears in their normalization as a mathematical necessity, not a convenience.

A graph-based mathematical structure used in loop quantum gravity to represent quantum states of the gravitational field. Nodes represent quanta of volume; edges represent quanta of area. Spin networks suggest spacetime geometry emerges from discrete combinatorial structures.

The theoretical framework describing all known fundamental particles and three of the four fundamental forces: electromagnetism, the weak nuclear force, and the strong nuclear force. Accounts for all observed particle interactions with extraordinary precision but does not incorporate gravity.

A fractal geometric structure in phase space toward which a chaotic dynamical system evolves over time. Unlike simple fixed points or limit cycles, strange attractors have fractal dimension between integers. Pulsar spin-down dynamics exhibit correlation dimensions around 2.06, consistent with a strange attractor of roughly 2 to 3 dimensions.

The quantum mechanical property whereby a system can exist in a combination of multiple states simultaneously, with definite probabilities for each outcome when measured. A qubit in superposition is genuinely both 0 and 1 until measurement forces a definite outcome.

A quantum error correction code that arranges physical qubits on a two-dimensional lattice, with data qubits storing quantum information and ancilla qubits measuring parity checks between neighbors. Errors appear as chains across the lattice; syndrome measurements detect these without measuring the quantum information directly. Basis for Google's Willow chip.

The ability of synapses, the connections between neurons, to strengthen or weaken over time in response to changes in activity levels. Widely considered the primary cellular mechanism of learning and memory. Long-term potentiation and long-term depression are well-studied forms.

Electromagnetic radiation emitted by charged particles accelerating through magnetic fields at relativistic speeds. The dominant foreground contamination at CMB frequencies below approximately 40 GHz, originating primarily from electrons spiraling through the Milky Way's magnetic field.

In quantum error correction, a measurement that reveals the presence and location of errors without measuring, and thereby collapsing, the quantum information being protected. Extracts classical information about error patterns by measuring parity relationships between qubits rather than the qubit values themselves.

The process by which a quantum system evolving under its own dynamics reaches thermal equilibrium, with all local observables indistinguishable from those of a thermal state. Deeply connected to scrambling: a system thermalizes when information about the initial state has been scrambled into global correlations inaccessible to local measurements.

The critical physical error rate below which quantum error correction improves with scale. Surface codes have a threshold of approximately 1%. Below this threshold, the exponential advantage of redundancy outweighs the linear increase in errors with qubit count, enabling exponential error suppression.

A statistical measure of galaxy clustering quantifying the excess probability of finding a galaxy at distance r from another galaxy, compared to a random distribution. Positive values indicate clustering; negative values indicate underdense voids. Central tool for testing the cosmological principle.

The fundamental quantum mechanics requirement that the total probability of all possible outcomes of any quantum process equals one, and that quantum evolution is information-preserving. Equivalent to information conservation: no physical process can destroy quantum information, only redistribute it.

The energy of empty space, driving the observed accelerating expansion of the universe. The cosmological constant Λ represents this energy in Einstein's equations and must be fine-tuned to approximately 1 part in 10¹²⁰ for the universe to permit structure formation. DESI results (2025) suggest this energy evolves over time, consistent with an information-processing substrate interpretation.

The mathematical object in quantum mechanics encoding all information about a quantum system's state. Its evolution over time involves circular functions and rotational dynamics. Measurement appears to resolve the wave function to one of its possible outcomes according to the probabilities encoded in its amplitudes.

The process by which a quantum system in superposition transitions to a definite classical state upon measurement. The Copenhagen interpretation treats this as a physical collapse; relational quantum mechanics reinterprets it as the establishment of a relationship between two physical systems with no privileged role for conscious observers.

A mathematical technique for analyzing signals by decomposing them into components at different scales and positions. In the visual cortex, neurons tuned to different spatial frequencies implement a wavelet-like representation that is information-theoretically optimal for natural images.