Near-infrared all-sky survey observing in J, H, and K bands, providing unique view of galaxies because infrared penetrates dust better than optical light.

Sound waves in the early universe's plasma that created pressure variations before atoms formed. These froze into the CMB as characteristic patterns at specific angular scales, like ripples frozen on a pond's surface.

A mathematical equivalence discovered by Maldacena between gravitational theories in Anti-de Sitter space and conformal field theories on the boundary. Proves that spacetime and gravity can emerge from quantum information systems.

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, analogous to linear momentum for straight-line motion. Angular momentum is conserved in isolated systems, explaining why rotating objects continue to rotate and why collapsing systems spin faster. Think of a figure skater spinning faster when pulling in their arms.

The point on a sphere directly opposite another point, separated by 180 degrees. If one point is at coordinates (l, b), its antipode is at (l + 180°, -b).

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

In dynamical systems theory, a set of states toward which a system evolves over time regardless of initial conditions. Strange attractors characterize chaotic systems and have fractal geometric structure.

A colloquial term for the unexpected alignment of the CMB's quadrupole and octopole moments. Called "evil" because it challenges the cosmological principle and points toward specific cosmic structures.

A statistical measure comparing the evidence for two competing hypotheses. A Bayes factor of 0.0041 indicates that the first hypothesis is 250 times less likely than the second, given the data (1/0.0041 ≈ 250).

In quantum error correction, this regime occurs when adding more qubits reduces overall error rates rather than accumulating errors. Demonstrated by Google's Willow chip, this represents a critical milestone for fault-tolerant quantum computing.

The production of light atomic nuclei (hydrogen, helium, lithium) during the first few minutes after the Big Bang. The ratios of these elements depend sensitively on the strength of the strong nuclear force.

A region of spacetime where gravity is so strong that nothing, including light, can escape once it crosses the event horizon. Formed when massive stars collapse or through other mechanisms in the early universe.

The problem that black holes appear to destroy information when they evaporate via Hawking radiation, violating quantum mechanics' requirement that information is conserved. Resolving this paradox is a significant goal of quantum gravity research.

The characteristic frequency distribution of thermal radiation, determined solely by temperature according to Planck's law. The CMB follows a nearly perfect blackbody spectrum at 2.725 Kelvin, making it the most perfect blackbody ever observed in nature.

A geometric representation of a qubit's quantum state as a point on the surface of a sphere. The north and south poles represent the states |0⟩ and |1⟩, while other points represent different superposition states. This visualization helps quantum physicists understand and manipulate quantum information.

A view from relativity where past, present, and future all exist equally as a four-dimensional spacetime structure. Time doesn't flow; all moments exist simultaneously, and temporal experience emerges from how consciousness samples this structure.

Technologies that enable direct communication between brain activity and external devices, typically by recording neural signals and translating them into control commands. BCIs allow paralyzed individuals to control robotic limbs or cursors.

Forces that depend only on distance from a central point and point directly toward or away from that point. Gravity and electrostatic forces are central forces, leading to spherically symmetric solutions in quantum mechanics. The Sun's gravitational pull on Earth is a central force.

The maximum rate at which information can be reliably transmitted through a communication channel under given constraints. This is a fundamental concept in information theory, established by Claude Shannon, which defines the theoretical limit of error-free communication.

Deterministic behavior that appears random due to extreme sensitivity to initial conditions. Small differences in starting states lead to exponentially diverging trajectories, yet the system follows precise mathematical rules.

The largest-scale pattern in the cosmic microwave background, caused by Earth's motion through space at about 370 km/s toward the constellation Leo. Creates a hot spot in our direction of motion and a cold spot in the opposite direction.

A mathematical representation showing how temperature variations in the CMB correlate at different angular scales. The vertical axis shows correlation strength; horizontal axis shows angular scale characterized by the multipole moment ℓ.

The maintenance of quantum properties, particularly superposition, in a quantum system. Loss of coherence (decoherence) causes quantum systems to behave classically.

Techniques for separating cosmic signals from galactic contamination using the different frequency dependencies of various emission mechanisms. Like unmixing different instruments in an audio recording, where each instrument has a characteristic frequency signature that enables isolation.

The tendency to search for, interpret, and recall information in ways that confirm pre-existing beliefs. This cognitive bias can cause us to see patterns in random data or recall coincidences, while overlooking the numerous times predictions didn't come true.

The comprehensive mapping and study of neural connections in the brain, analogous to genomics for genes. Connectomics aims to create complete wiring diagrams of neural networks, showing how billions of neurons connect through trillions of synapses.

The standard interpretation of quantum mechanics developed by Niels Bohr and Werner Heisenberg, treating wave function collapse and measurement as fundamental aspects requiring no deeper explanation. Dominated physics for decades despite interpretational challenges.

A statistical measure quantifying the strength and direction of a linear relationship between two variables, ranging from -1 to +1. A value of r = 0.91 indicates a very strong positive correlation, meaning the two variables increase together in a highly predictable way.

A measure characterizing the dimensionality of an attractor in phase space. Low correlation dimensions indicate the system's behavior, though appearing complex, is actually governed by a small number of variables.

Functional units of neural processing in the cortex, vertical arrangements of neurons that process related information together. These columns show organized spacing patterns involving mathematical relationships.

Thermal radiation left over from the Big Bang, showing the universe as it appeared 380,000 years after the beginning. This is our earliest direct observation of the cosmos and provides crucial information about the universe's early state.

Irreducible statistical uncertainty in CMB measurements arising because we observe only one universe. We can't repeat the measurement with a different cosmic realization or average over multiple universes. Particularly important at large angular scales where we have few independent samples.

A term in Einstein's field equations representing the energy density of empty space. Its observed value is extraordinarily small (about 10-120 in Planck units), creating the worst fine-tuning problem in physics.

The foundational assumption of modern cosmology, stating that the universe is homogeneous (uniform density) and isotropic (looks the same in all directions) on large scales. Enables the application of the same physical laws throughout the cosmos and underlies standard cosmological models.

A number determining the strength of an interaction between particles. The strong force coupling constant alpha_s ≈ 0.1, electromagnetic coupling alpha ≈ 1/137, and other coupling constants define how strongly different forces operate.

A method of testing whether observed patterns are real by checking if they appear consistently across multiple independent frequency measurements. Real signals persist across frequencies; artifacts vary randomly. This is the gold standard in observational cosmology for distinguishing genuine phenomena from instrumental effects.

Hypothetical energy causing the universe's expansion to accelerate rather than slow down. Required by standard cosmology to explain supernova observations showing accelerating expansion, comprising approximately 68% of the universe's total energy content.

Hypothetical matter that doesn't emit or absorb light but reveals itself through gravitational effects. Required by standard cosmology to explain galaxy rotation curves, gravitational lensing, and large-scale structure formation.

The process by which quantum systems lose their quantum properties, such as superposition and entanglement, through interaction with their environment, causing them to behave classically. Major challenge for quantum computing and quantum information processing.

A network of brain regions active when not focused on the external world, involved in self-referential thought, autobiographical memory, and imagining the future. This network activates when your mind wanders or you reflect on yourself.

Descriptive mathematics describes patterns we observe after the fact. Prescriptive mathematics constrains what patterns are possible before observation. The active mathematics hypothesis proposes constants are prescriptive, determining allowed physical configurations.

The twisted ladder structure of DNA molecules, where two complementary strands wind around each other in a spiral. This structure optimizes information storage while allowing the strands to separate for replication.

The mathematical equations of general relativity describing how mass-energy curves spacetime. Written as Gμν = 8πG/c⁴ Tμν, these ten coupled nonlinear partial differential equations determine the spacetime structure.

Regions around an atomic nucleus where electrons are likely to be found. Orbitals have specific shapes determined by quantum mechanics and represent the probability distribution of electron locations. Unlike planetary orbits, electron orbitals are fuzzy probability clouds rather than defined paths.

An intrinsic form of angular momentum carried by electrons and other particles. Despite its name, it's not actual physical spinning but rather a fundamental quantum property with no classical analog. Electrons can have spin "up" or spin "down."

A characteristic or behavior that arises from simpler components interacting according to basic rules, but wasn't present in the components themselves. Temperature emerges from molecular motion; consciousness might emerge from neural activity; spacetime might emerge from information processing.

A measure of quantum entanglement between regions of a system, quantifying how much information is shared across boundaries. Higher entanglement entropy means stronger quantum correlations between regions.

A measure of disorder or randomness in a system. In thermodynamics, entropy always increases in closed systems. In information theory, entropy quantifies uncertainty or information content.

In cosmology, the ratio of a substance's pressure to its energy density, written as w = p/ρ. For dark energy, w = -1 represents a cosmological constant (perfectly constant throughout time), while values that change over time indicate evolving dark energy. The COSMIC Framework predicted w evolves as w(z) = w₀ + wₐ·z/(1+z), where w₀ is the current value and wₐ describes the rate of change.

Proposed by Maldacena and Susskind, this suggests Einstein-Rosen bridges (wormholes, ER) might be equivalent to Einstein-Podolsky-Rosen pairs (quantum entanglement, EPR). If true, spatial connectivity might be another way to describe quantum entanglement.

The boundary of a black hole beyond which nothing can escape. The "point of no return" where escape velocity exceeds the speed of light, making return impossible according to relativity.

A solution that maximizes or minimizes some quantity. In optimization problems, extremal solutions often involve mathematical constants like π, e, or φ because these constants emerge naturally from calculus of variations.

A dimensionless fundamental constant approximately equal to 1/137 that characterizes the strength of electromagnetic interactions. Appears throughout quantum electrodynamics and atomic physics.

A dimensionless constant alpha ≈ 1/137.036 determining the strength of electromagnetic interactions. It appears throughout quantum electrodynamics and atomic physics, governing atomic structure and spectral lines.

Psychological states of complete absorption in an activity, characterized by effortless action, time distortion, and peak performance. Studied extensively by psychologist Mihaly Csikszentmihalyi. Athletes call it "being in the zone."

A geometric structure exhibiting self-similarity across scales. Fractals have non-integer dimensions and can be generated by simple recursive rules, enabling efficient information encoding in natural structures.

Mathematical patterns that exhibit self-similarity across scales, meaning the same structural patterns repeat at different magnifications. Natural examples include coastlines, mountain ranges, branching patterns in trees and blood vessels, and lightning strikes.

A thermodynamic quantity combining internal energy and entropy. Systems naturally evolve to minimize free energy, striking a balance between energy minimization and entropy maximization to determine equilibrium states.

A coordinate system based on the Milky Way's structure, where l represents galactic longitude (0° to 360°) and b represents galactic latitude (-90° to +90°). The galactic center is at (l, b) = (0°, 0°).

The dimming and reddening of starlight caused by dust in the Milky Way. Varies with direction, being strongest toward the galactic plane and minimal at the galactic poles.

Output neurons of the retina that transmit visual information to the brain through the optic nerve. They receive input from photoreceptors through bipolar cells and perform initial processing like edge detection and motion sensitivity.

Einstein's theory of gravitation describes gravity as curvature of spacetime caused by mass and energy. Successfully predicts gravitational phenomena from planetary orbits to gravitational waves and has passed every experimental test to date.

A theory proposing that consciousness arises when information becomes globally available across multiple brain systems, enabling flexible response and report. Information enters consciousness when it's broadcast to many brain areas simultaneously rather than remaining localized.

A mathematical constant, φ ≈ 1.618, that appears frequently in nature, art, and mathematics. It describes optimal proportions and is evident in the spiral growth patterns of shells, galaxies, and plants. The golden ratio often appears where systems optimize growth or packing efficiency.

Precise measurement of gravitational fields and their variations. Used in geology to map subsurface density variations, in archaeology to detect buried structures, and in fundamental physics research to detect tiny gravitational effects.

The energy stored in an object due to its position in a gravitational field. Objects naturally move toward configurations that minimize this energy, which is why planets and stars are spherical. Think of a ball rolling downhill toward lower gravitational potential energy.

A fundamental quantum gate that creates an equal superposition of states. It rotates a qubit state by a specific angle in Hilbert space, transforming a definite state (0 or 1) into an equal mixture of both. This gate is essential for many quantum algorithms.

The philosophical problem of explaining why and how subjective experiences (qualia) arise from physical processes. Distinguished from the "easy problems" of explaining cognitive functions like memory or attention. The hard problem asks why there's something it's like to be conscious.

Thermal radiation predicted to be emitted by black holes due to quantum effects near the event horizon. Causes black holes to lose mass and eventually evaporate completely over extremely long timescales.

A fundamental limit in quantum mechanics stating that certain pairs of properties, such as position and momentum or energy and time, cannot both be measured with arbitrary precision simultaneously. Not a measurement limitation but a fundamental feature of quantum reality.

A pattern where opposite hemispheres of the sky show systematically different properties. In the CMB, one hemisphere indicates roughly 10% more power in temperature fluctuations than the opposite hemisphere.

An abstract mathematical space used in quantum mechanics where quantum states are represented as vectors. Quantum operations rotate these vectors, and the geometry of Hilbert space determines the possible operations. Despite being abstract, Hilbert space has precise mathematical rules.

The idea that all information in a volume can be encoded on its boundary surface, suggesting that spacetime volume might be redundant with boundary information. Originates from black hole thermodynamics and has profound implications for quantum gravity.

The discrepancy between different measurements of the universe's expansion rate, called the Hubble constant H₀. Early universe measurements from the Cosmic Microwave Background give approximately 67 km/s/Mpc, while local measurements from supernovae give approximately 73 km/s/Mpc.

A period of extremely rapid exponential expansion of the universe immediately after the Big Bang, proposed to explain various cosmological observations including the large-scale homogeneity of the universe and the flatness of space.

A measure of how much information different parts of a system share and coordinate. High information integration means components work together in ways where the whole system processes more information than the sum of its parts operating independently.

Physical transformations of distinguishable states that carry meaning or enable computation. All information processing requires energy (Landauer's principle) and involves changing physical configurations, whether in computer chips, brains, or quantum fields.

The process by which information initially concentrated in specific states spreads throughout a system, becoming increasingly difficult to recover. In quantum systems, this spreading has a maximum rate set by temperature, with black holes achieving the maximum scrambling rate. See Element 20 for detailed theoretical treatment of quantum information scrambling.

A theoretical quantity describing how information content and flow might contribute to spacetime curvature, analogous to how mass-energy curves spacetime in general relativity. Recent theoretical work suggests this might modify Einstein's equations at quantum scales.

A mathematical framework proposing that consciousness corresponds to integrated information, quantified by the measure phi (Φ), which represents how much a system is more than the sum of its parts. Higher phi means more consciousness.

A line or surface connecting points of equal temperature. In CMB analysis, isotherms reveal temperature distribution patterns whose fractal dimensions provide information about cosmic structure.

The property of looking statistically the same in all directions. Perfect isotropy means no preferred directions exist. Statistical isotropy allows random fluctuations but no systematic directional bias.

The physical law stating that erasing information requires minimum energy kT ln(2) per bit and generates heat. Connects information theory to thermodynamics and has been experimentally confirmed at both classical and quantum scales.

The observation that proteins fold into specific three-dimensional structures in milliseconds, despite having astronomically many possible configurations to search through. Random search would require times longer than the universe's age, yet proteins find their correct shape almost instantly.

Basic building blocks of digital circuits that perform simple logical operations on binary inputs. Standard gates include AND (output is 1 only if both inputs are 1), OR (output is 1 if either input is 1), and NOT (inverts the input). All computer operations can be reduced to combinations of logic gates.

An approach to quantum gravity attempting to quantize spacetime itself into discrete chunks rather than treating spacetime as smooth. An alternative to string theory with a different mathematical structure and philosophical foundations.

A mathematical quantity characterizing how quickly a system's behavior becomes unpredictable or chaotic. In quantum systems, it measures the information scrambling rate. Black holes have the maximum possible Lyapunov exponent allowed by quantum mechanics.

A unit of distance equal to one million parsecs, or about 3.26 million light-years. Used to measure cosmic distances, the Hubble constant is typically expressed in kilometers per second per megaparsec.

A proposed time-like parameter describing the evolution of the pre-geometric substrate before spacetime emerged. Not the time we experience (which emerged during the phase transition), but a parameter ordering of substrate states.

The frequency spectrum of thermal dust emission. "Modified" because dust grains don't emit as perfect blackbodies due to their composition, structure, and size distribution. The modification typically involves an emissivity index that varies with frequency.

A computational technique that generates many random realizations of a process to estimate statistical properties. Tests whether observed patterns could arise by chance from random processes.

A number characterizing angular scale in the CMB power spectrum. Larger ℓ means smaller angular scales showing finer details. For example, ℓ = 2 corresponds to the largest scale at 180 degrees, while ℓ = 1000 corresponds to about 0.2 degrees.

An information-theoretic measure quantifying how much information two variables share. High mutual information indicates that knowing one variable tells you a lot about the other, suggesting a strong correlation in their information content.

The pattern of connections in a network, independent of specific physical implementation. Network topology describes which nodes connect to which other nodes and includes measures like clustering coefficient, path length, and modularity.

Specific brain states and neural activity patterns that correlate with conscious experiences. These represent measurable physical signatures corresponding to subjective awareness, like which brain regions activate when you see the color red or recall a memory.

The brain's ability to reorganize itself through experience, forming new neural connections and strengthening existing ones. Practicing any skill strengthens the neural circuits supporting that skill through neuroplasticity.

A real number whose infinite decimal expansion contains every possible finite sequence of digits, each appearing with equal frequency. If π is normal (unproven but conjectured), it would contain every possible piece of information encoded somewhere in its digits.

A functional unit in the visual cortex containing neurons selective for all possible stimulus orientations, typically spanning about 1 millimeter. Hypercolumns tile the visual cortex, each processing a small region of visual space with full orientation selectivity.

A property of a set of functions where different functions are orthogonal (their inner product is zero) and each is normalized (its self-inner product is one). Quantum wave functions must be orthonormal for probabilistic interpretation to work correctly.

A theoretical graph showing how information content should evolve during black hole evaporation if quantum mechanics is correct. Shows information initially increasing then decreasing as the black hole evaporates, with all information eventually recovered.

A galaxy's motion relative to the cosmic expansion (Hubble flow). Caused by gravitational attraction toward massive structures. The Milky Way has a peculiar velocity of about 600 km/s toward the "Great Attractor."

A material property describing how magnetic fields interact with the material, measuring how much the material gets magnetized by a magnetic field. Like permittivity, it can vary with frequency due to atomic and molecular resonances in real materials.

A material property describing how electric fields interact with the material, measuring how much the material gets polarized by an electric field. Frequency-dependent permittivity means the material responds differently to different electromagnetic frequencies, as seen in real materials due to atomic resonances.

A quantum gate that adds a phase shift to quantum states without changing their probability amplitudes. Phase information is crucial for quantum interference effects used in quantum algorithms. Think of a phase as the "timing" of a wave.

An abstract space where each possible state of a system corresponds to a point. The system's evolution traces a trajectory through phase space, revealing underlying geometric structure and attractors.

An abrupt change in a system's properties when conditions cross a critical threshold. Examples include water freezing into ice or a superconductor becoming resistanceless. The framework proposes that spacetime emerged through a phase transition in an information substrate.

Quantized vibrations in crystal lattices, representing collective oscillations of atoms around their equilibrium positions. Each crystal structure has characteristic phonon frequencies at which vibrations are enhanced, much like a bell has characteristic resonant frequencies.

Quantized vibrations in crystal lattices, representing particle-like excitations of collective atomic vibrations. Crystals have characteristic frequencies where vibrations are enhanced, similar to how a bell has characteristic resonant frequencies that determine its tone.

Light-sensitive cells in the retina (rods and cones) that convert photons into electrical signals. Rods operate in low light, while cones enable color vision and high-acuity detection in bright conditions.

The arrangement of leaves, flowers, or seeds on a plant stem. Many plants exhibit Fibonacci spiral patterns in phyllotaxis, optimizing light exposure through arrangements related to the golden ratio.

The smallest meaningful length scale in physics, approximately 10⁻³⁵ meters. Below this scale, quantum effects make spacetime geometry uncertain and classical concepts of distance break down.

European Space Agency satellite that mapped the CMB from 2009-2013 with higher resolution and more frequency bands than WMAP, currently providing the most detailed CMB measurements available and the foundation for modern cosmology.

The scale, approximately 10⁻³⁵ meters and 10⁻⁴³ seconds, where quantum gravitational effects become comparable to other physical effects. This is where quantum mechanics and general relativity must both be considered simultaneously, and where spacetime itself might exhibit quantum properties. The Planck length emerges naturally from combining three fundamental constants: Planck's constant (quantum mechanics), the gravitational constant (gravity), and the speed of light (relativity). Remarkably, the holographic principle reveals that each Planck area corresponds to approximately one bit of information, establishing a fundamental connection between information content and geometric structure at the deepest level of physical reality.

Mathematical relationships where one quantity varies as a power of another. In networks, this often means that the number of nodes with k connections is proportional to k(-γ) for some exponent γ, creating a "fat tail" distribution with rare but highly connected hubs.

A frequency dependence where emission varies as a power of frequency, written as fα where α is the spectral index. Synchrotron radiation from cosmic rays spiraling in magnetic fields follows power-law spectra with negative spectral indices.

A rapidly rotating neutron star emitting beams of electromagnetic radiation. Pulsars function as cosmic clocks but exhibit subtle timing variations revealing complex internal dynamics.

The subjective, qualitative aspects of conscious experiences (the "what it's like" to experience something), such as the redness of red or the painfulness of pain. Qualia represent the hard problem because we don't know why physical processes generate subjective feelings.

The property of quantum systems to exist in superposition states, maintaining definite phase relationships between quantum states. Coherence is fragile and destroyed by environmental interaction (decoherence), limiting quantum computers and quantum phenomena in warm, noisy environments.

The quantum field theory of electromagnetism, describing how light and matter interact. QED is the most precisely tested theory in physics, with predictions matching experiments to better than one part in a billion.

A quantum phenomenon where particles become correlated such that measuring one instantly affects the others, regardless of distance. Entanglement forms the basis of quantum information theory and enables phenomena that are impossible in classical physics.

A field pervading all space where particles appear as localized excitations. Modern physics describes all fundamental particles as quantum field excitations rather than point objects.

The theoretical framework combining quantum mechanics with special relativity, treating particles as excitations of underlying quantum fields permeating all of spacetime. This is the foundation of the Standard Model of particle physics.

Operations that transform quantum states in quantum computers. Unlike classical gates, quantum gates can create superposition and entanglement and must be reversible (preserve information). Quantum gates perform rotations in abstract quantum state space.

The theory governing behavior at atomic and subatomic scales, where particles exhibit wave properties and exist in superposition until measured. Fundamentally probabilistic rather than deterministic.

The ability of quantum systems to exist in multiple states simultaneously until measured. A qubit can be both 0 and 1 at the same time, with specific probability amplitudes determining measurement outcomes.

Temporary changes in energy occurring even in "empty" space due to Heisenberg's uncertainty principle. Virtual particles constantly appear and disappear in the quantum vacuum, producing measurable effects such as the Casimir force.

Mathematical descriptions of quantum systems that encode all possible information about a particle's state. The square of the wave function gives the probability of finding the particle at different locations. Wave functions can interfere with themselves, creating quantum phenomena.

The phenomenon that quarks are never observed in isolation but always bound together in groups (hadrons). The strong nuclear force increases with distance, preventing quarks from separating, unlike other forces that weaken with distance.

The quantum analog of a classical bit. While a classical bit is either 0 or 1, a qubit can exist in a superposition of both states simultaneously until measured. Qubits are the basic units of quantum computation and can be implemented using various physical systems.

A theoretical form of dark energy that changes over time, as opposed to the cosmological constant, which remains perfectly constant. The name comes from the ancient concept of a "fifth element" beyond earth, water, air, and fire. DESI's measurements provide evidence for quintessence-like behavior in dark energy.

The stretching of light wavelengths as space expands, causing light from distant objects to shift toward the red end of the spectrum. Used to measure cosmic distances and the expansion rate; the farther away an object, the more its light is redshifted.

The stretching of light wavelengths as space expands, causing distant objects to appear redder. A higher redshift means a greater distance and an earlier cosmic time. Redshift z = 1 means the universe was half its current size.

Apparent distortions in galaxy positions arising because redshift measures both cosmological expansion and galaxy peculiar velocities. "Fingers of God" pointing toward us and "pancaking" perpendicular to our line of sight are characteristic patterns.

A fundamental constant of quantum mechanics equal to h/2π, where h is Planck's constant. Appears in equations involving angular momentum and quantum state transitions, with a value approximately 1.055 × 10⁻³⁴ joule-seconds.

The organized projection of visual space from the retina to the visual cortex, where adjacent points in the visual field map to adjacent points in cortical tissue. Your visual cortex contains a spatial map of the visual world.

Properties of systems that remain unchanged under rotation. A sphere has perfect rotational symmetry because it looks the same from any angle. Many physical laws exhibit rotational symmetry, meaning they remain unchanged regardless of orientation in space.

A phenomenon in quantum field theory where the effective strength of fundamental interactions varies with energy scale. The fine structure constant α, which governs electromagnetic interactions, increases slightly at higher energies due to vacuum polarization effects from virtual particle pairs.

Networks where connection distribution follows a power law, meaning most nodes have few connections but a few "hubs" have many connections. The internet, citation networks, and many biological networks are scale-free, which provides robustness against random failures.

Patterns that look similar at different scales of observation. Fractals are perfect examples where zooming in reveals the same pattern repeating at finer scales. Coastlines, mountain ranges, and river networks exhibit scale-invariant structure in nature.

Major optical telescope survey that has mapped millions of galaxies in the northern hemisphere, revolutionizing our understanding of large-scale structure and providing crucial data for testing cosmological models.

Systematic biases in observational data arising from how objects are selected for study. Survey boundaries, brightness limits, and detection thresholds can create apparent patterns not present in the underlying population.

A measure of statistical significance representing standard deviations from the expected value. A 3σ result means the probability of the observation occurring by chance is about 0.3%, while 5σ (the physics discovery threshold) means about 0.00006% probability. The DESI dark energy measurement at 3.9σ indicates very strong evidence for evolving dark energy.

A point where mathematical quantities become infinite in general relativity's equations. Black hole centers and the Big Bang beginning are predicted to contain singularities, though many physicists believe quantum gravity will resolve these infinities.

Network properties where most nodes connect to nearby neighbors, but occasional long-range connections dramatically reduce the average path length between any two nodes. This architecture enables both local efficiency and global connectivity.

Ground-based telescope at the Amundsen-Scott South Pole Station observing the CMB at millimeter wavelengths, providing another independent dataset with different systematic errors than satellites due to different location and instrumentation.

A graph showing how much radiation an object emits at different frequencies. Each physical process, including CMB, dust, and synchrotron, has a characteristic SED that acts like a fingerprint, enabling their separation through multi-frequency observations.

Mathematical functions that describe patterns on the surface of a sphere. In quantum mechanics, they represent the angular parts of electron orbital wave functions and appear in solutions to many physics problems with spherical symmetry. These functions are to spheres what sine waves are to circles.

In loop quantum gravity, a mathematical structure describing the quantum state of spacetime geometry. Nodes represent chunks of volume and links represent adjacent regions.

An attractor with fractal structure characterizing chaotic dynamics. Though trajectories never repeat, they remain confined to the attractor's fractal geometry, creating bounded yet non-periodic motion.

A mathematical object in general relativity describing the density and flow of energy and momentum in spacetime. The source term in Einstein's equations tells spacetime how to curve based on what matter and energy are present.

A theoretical framework attempting to describe all particles and forces as vibrations of tiny one-dimensional strings. Requires extra dimensions beyond the familiar three of space and one of time, and makes few testable predictions with current technology.

The force that binds quarks together into protons and neutrons, and binds protons and neutrons together into atomic nuclei. It's the strongest of the four fundamental forces, but it operates only at subatomic distances.

A fundamental quantum property where a system exists in multiple states simultaneously until measured. A qubit in superposition is both 0 and 1 at the same time, with specific probability amplitudes for each. Measurement forces the system to "choose" one state.

A concept introduced by Carl Jung describing meaningful coincidences that appear causally unrelated but seem too significant to be random chance. The framework suggests these might occasionally reflect non-local information detection, though this requires careful investigation.

Electromagnetic radiation emitted by charged particles moving through magnetic fields at relativistic speeds (near the speed of light). In our galaxy, synchrotron radiation from cosmic rays contaminates CMB measurements, especially at low frequencies below 30 GHz.

Tiny variations, about 1 part in 100,000, in the CMB's intensity across the sky. These reveal how matter was distributed in the early universe and seed all later structure formation including galaxies, clusters, and the cosmic web.

A statistical measure quantifying how galaxy clustering deviates from a random distribution. Measures the excess probability of finding a galaxy pair separated by distance r compared to what a random distribution would predict.

A prediction of classical physics that hot objects should emit infinite energy at high frequencies, which contradicted observations. Resolved by Planck's quantum hypothesis that energy comes in discrete packets, launching the quantum revolution.

Transformations in quantum mechanics that preserve total probability and can be thought of as rotations in abstract quantum state space. All quantum gates implement unitary rotations. The "unitary" property ensures information is preserved during transformation.

In quantum field theory, particles can briefly appear and disappear from the vacuum if they exist for times shorter than allowed by Heisenberg's uncertainty principle. Higher frequency photons carry more energy, enabling them to create heavier virtual particle-antiparticle pairs that contribute to quantum vacuum fluctuations.

The region of the cerebral cortex that processes visual information, located primarily in the occipital lobe. Primary visual cortex (V1) receives direct input from the retina and performs initial processing, while higher visual areas extract increasingly complex features.

The quantum property where entities exhibit both wave-like and particle-like behavior depending on how they're observed. Light acts as waves in interference experiments but as particles in the photoelectric effect.

Space-based mid-infrared survey mapping the entire sky, particularly effective at detecting dust and cool objects invisible at shorter wavelengths.

Wilkinson Microwave Anisotropy Probe, a NASA satellite that mapped the CMB from 2001-2010 across five frequency bands from 23 to 94 GHz, providing high-precision measurements of cosmic parameters that revolutionized cosmology.