Quantum mechanicsQuantum mechanics, also known as quantum physics, is the fundamental physical theory that describes the behavior of matter and of light; the behaviors it models typically occur at and below the scale of atoms, and have been described as peculiar and mysterious.3 min / Deep Bose–Einstein condensateIn condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero, i.e.3 min / Deep Chaos theoryChaos theory is a branch of mathematics and an interdisciplinary area of scientific study.3 min / Deep Science: EntropyEntropy is a thermodynamic state variable that quantifies the probabilistic distribution of accessible microstates in a system.3 min / Deep Science: EvolutionEvolution is the change in the heritable characteristics of biological populations over successive generations.3 min / Deep Science: GeneticsGenetics is the study of genes, genetic variation, and heredity in organisms.3 min / Deep Science: NeuroscienceNeuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders.3 min / Deep Science: PhotosynthesisPhotosynthesis is a system of biological processes by which photopigment-bearing autotrophic organisms, such as most plants, algae and cyanobacteria, convert light energy—typically from sunlight—into the chemical energy necessary to fuel their metabolism.3 min / Deep Plate tectonicsPlate tectonics (from Latin tectonicus, from Ancient Greek τεκτονικός (tektonikós) 'pertaining to building') is the scientific theory that Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago.3 min / Deep Science: SuperconductivitySuperconductivity is a set of physical properties observed in superconductors: materials where electrical resistance is exactly zero and magnetic fields are expelled from the material.3 min / Deep Olbers' paradoxOlbers' paradox, also known as the dark night paradox or Olbers and Cheseaux's paradox, is a historical argument in astrophysics and physical cosmology that says the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe.3 min / Deep Peto's paradoxPeto's paradox is the observation that, at the species level, the incidence of cancer does not appear to correlate with the number of cells in an organism.3 min / Deep Quantum entanglementQuantum entanglement is the phenomenon in which the quantum state of each particle in a group cannot be described independently of the state of the others, even when the particles are separated by a large distance.3 min / Deep Quantum tunnellingIn physics, quantum tunnelling, barrier penetration, or simply tunnelling is a quantum mechanical phenomenon in which an object such as an electron or atom passes through a potential energy barrier that, according to classical mechanics, should not be passable due to the object not having sufficient energy to pass or surmount the barrier.3 min / Deep Quantum Zeno effectIn quantum mechanics, frequent measurements cause the quantum Zeno effect, a reduction in transitions away from the system's initial state, slowing a system's time evolution.3 min / Deep Science: AerogelAerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure.3 min / Deep Science: AntimatterIn modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter, and can be thought of as matter with reversed charges and parity, or going backward in time (see CPT symmetry).3 min / Deep Belousov–Zhabotinsky reactionA Belousov–Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator.3 min / Deep Boltzmann brainThe Boltzmann brain thought experiment suggests that it is probably more likely for a brain to spontaneously form, complete with a memory of having existed in our universe, rather than for the entire universe to come about in the manner cosmologists think it actually did.3 min / Deep Butterfly effectIn chaos theory, the butterfly effect is the sensitive dependence on initial conditions in which a small change in one state of a deterministic nonlinear system can result in large differences in a later state.3 min / Deep Cotard's syndromeCotard's syndrome, also known as Cotard's delusion or walking corpse syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are deceased, do not exist, are putrefying, or have lost their blood or internal organs.3 min / Deep Dark energyIn physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on its largest scales.3 min / Deep Dark matterIn astronomy and cosmology, dark matter is an invisible and hypothetical form of matter that does not interact with electromagnetic radiation, including light.3 min / Deep Double-slit experimentIn modern physics, the double-slit experiment demonstrates that light and matter can exhibit behavior associated with both classical particles and classical waves.3 min / Deep Science: FerrofluidFerrofluid is a dark coloured liquid that is attracted to the poles of a magnet.3 min / Deep Foucault pendulumThe Foucault pendulum or Foucault's pendulum is a simple device named after French physicist Léon Foucault, conceived as an experiment to demonstrate the Earth's rotation.3 min / Deep Leidenfrost effectThe Leidenfrost effect or film boiling is a physical phenomenon in which a liquid, close to a solid surface of another body that is significantly hotter than the liquid's boiling point, produces an insulating vapor layer that keeps the liquid from boiling rapidly.3 min / Deep Lichtenberg figureA Lichtenberg figure (German: Lichtenberg-Figur), or Lichtenberg dust figure, is a branching electric discharge that sometimes appears on the surface or in the interior of insulating materials.3 min / Deep Maxwell's demonMaxwell's demon is a thought experiment that appears to disprove the second law of thermodynamics.3 min / Deep Mpemba effectThe Mpemba effect is the observation that very hot liquids or colloids (such as ice cream) can freeze more quickly than colder ones, for similar volumes and surrounding conditions.3 min / Deep Science: NeutrinoA neutrino ( new-TREE-noh; denoted by the Greek letter ν) is an elementary particle that interacts via the weak interaction and gravity.3 min / Deep Pioneer anomalyThe Pioneer anomaly, or Pioneer effect, was the observed deviation from predicted accelerations of the Pioneer 10 and Pioneer 11 spacecraft after they passed about 20 astronomical units (3×109 km; 2×109 mi) on their trajectories out of the Solar System.3 min / Deep Rogue waveRogue waves (also known as freak waves, monster waves, or killer waves) are large and unpredictable surface waves that can be extremely dangerous to ships and isolated structures such as lighthouses.3 min / Deep Roko's basiliskRoko's basilisk is a thought experiment which states that there could be an artificial superintelligence in the future that, while otherwise benevolent, would punish anyone who knew of its potential existence but did not directly contribute to its advancement or development, in order to encourage that advancement.3 min / Deep Schrödinger's catIn quantum mechanics, Schrödinger's cat is a thought experiment concerning quantum superposition.3 min / Deep Science: SonoluminescenceSonoluminescence is luminescence induced by sound waves, such as in the emission of light from imploding bubbles in a liquid when excited by sound.3 min / Deep Strange matterStrange matter (or strange quark matter) is quark matter containing strange quarks.3 min / Deep Science: SuperfluiditySuperfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy.3 min / Deep Time crystalIn condensed matter physics, a time crystal is a quantum system of particles whose lowest-energy state is one in which the particles are in repetitive motion.3 min / Deep Science: TriboluminescenceTriboluminescence is a phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed (see tribology).3 min / Deep Schrodinger's catA thought experiment about quantum measurement became science's most famous imaginary pet.8 min / Easy Double-slit experimentLight and matter behave in ways that challenge everyday intuition.10 min / Medium Uncertainty principleA core quantum idea limits what can be known about paired properties.10 min / Medium Maxwell's demonA tiny imaginary gatekeeper probes the relationship between information and entropy.9 min / Medium Foucault pendulumA swinging pendulum makes Earth's rotation visible inside a room.7 min / Easy Lichtenberg figureBranching electrical scars reveal hidden paths of discharge through matter.7 min / Easy Belousov-Zhabotinsky reactionA chemical reaction creates pulsing colors and self-organizing patterns.8 min / Medium Mpemba effectA counterintuitive freezing puzzle asks when hot water can freeze faster than cold.7 min / Easy FerrofluidMagnetic liquid forms spikes and sculptural patterns under a magnetic field.6 min / Easy SuperfluidityMatter cooled near absolute zero flows in deeply strange ways.9 min / Medium AerogelAn ultralight solid looks like frozen smoke and insulates remarkably well.6 min / Easy Strange matterA hypothetical state of matter raises unnerving questions about dense stars.8 min / Medium Butterfly effectTiny initial changes can cascade into enormous differences in complex systems.7 min / Easy Rogue waveOnce dismissed as sailor lore, huge sudden waves became a measured ocean hazard.8 min / Easy Pioneer anomalyTiny deviations in spacecraft motion prompted years of investigation.8 min / Medium AntimatterMatter's mirror counterpart is real, rare, and central to big cosmic questions.9 min / Medium NeutrinoGhostly particles pass through ordinary matter almost without noticing it.9 min / Medium Dark matterInvisible mass shapes galaxies while resisting direct detection.10 min / Medium Dark energyA name for the unknown driver behind the universe's accelerating expansion.10 min / Medium Rare-earth hypothesisA skeptical answer to why complex life might be uncommon in the universe.9 min / Medium VantablackA material famous for absorbing almost all visible light.6 min / Easy SuperconductivitySome materials lose electrical resistance under special conditions.9 min / Medium Roko's basiliskA thought experiment about decision theory, futurism, and online myth-making.8 min / Medium Boltzmann brainA thought experiment asks whether a lone conscious observer could arise from random fluctuations in a vast universe.9 min / Medium Vacuum catastropheQuantum field theory and observed cosmic energy disagree by an almost incomprehensibly large amount.9 min / Deep Time crystalA phase of matter repeats in time rather than space and challenges ordinary ideas about equilibrium.9 min / Medium SonoluminescenceTiny bubbles driven by sound can collapse and release flashes of light in liquid.8 min / Medium TriboluminescenceCrushing, scratching, or pulling certain materials apart can produce visible light.7 min / Easy Leidenfrost effectA liquid can skate on its own vapor when it touches a surface far hotter than its boiling point.7 min / Easy HeLaCells taken from Henrietta Lacks became the first widely used immortal human cell line.9 min / Medium CRISPRA microbial defense mechanism became a precise and consequential tool for editing genes.10 min / Medium Split-brainStudies of people with a divided corpus callosum revealed surprising separations within conscious processing.9 min / Medium BlindsightSome people with cortical blindness can respond to visual information they do not consciously see.8 min / Medium Cotard's syndromeA rare delusion can make a person believe they are dead, do not exist, or have lost their organs.8 min / Medium SynesthesiaStimulation of one sense can automatically produce an experience in another, such as colors linked to sounds.8 min / Easy