Core
Core is a layer-1 blockchain platform launched in 2023 that integrates Bitcoin's proof-of-work security with delegated proof-of-stake mechanisms via its proprietary Satoshi Plus consensus model, enabling scalable smart contract execution and Bitcoin-secured decentralized finance (DeFi) applications.[1][2] Designed to address the blockchain trilemma of security, scalability, and decentralization, Core allows Bitcoin holders to stake their BTC non-custodially for network validation and yield generation, bridging Bitcoin's liquidity with Ethereum Virtual Machine (EVM)-compatible programmability without requiring asset wrapping or sidechains.[3][4] Its native token, CORE, facilitates governance, transaction fees, and staking rewards, with the protocol emphasizing non-inflationary economics and peer-to-peer incentives to miners and delegators.[5][6] The platform's defining innovation lies in its dual-consensus approach, where Bitcoin miners provide external security through a non-Turing complete chain while internal DPoS validators handle high-throughput transactions, reportedly achieving over 2,000 transactions per second in testing.[1][2] Core has garnered attention for pioneering Bitcoin DeFi primitives, such as lending protocols and liquidity pools backed by staked BTC, attracting institutional interest through partnerships with staking providers like Kiln.[7] Early adoption milestones include the Ignition airdrop event distributing CORE tokens to Bitcoin holders and the launch of Core Academy for developer education, fostering ecosystem growth amid volatile crypto markets.[1] While praised for enhancing Bitcoin's utility without compromising its core principles, Core faces scrutiny over centralization risks in DPoS delegation and competition from established EVM chains, though empirical network data shows robust decentralization metrics with thousands of active validators.[3][4]Science and technology
Geology, geophysics, and astrophysics
The Earth's core comprises the innermost layers of the planet, divided into a solid inner core and a surrounding liquid outer core, both primarily composed of iron alloyed with nickel and lighter elements such as sulfur, oxygen, and silicon.[8] The inner core is a dense sphere with a radius of approximately 1,220 kilometers, formed under immense pressure exceeding 3.6 million atmospheres and temperatures around 5,000–6,000 Kelvin, conditions that solidify iron despite the heat.[9] The outer core, extending from the inner core boundary at about 5,150 kilometers depth to the core-mantle boundary at roughly 2,900 kilometers from the surface, is about 2,200 kilometers thick and exists in a molten state due to lower pressure and convection driven by compositional gradients and residual heat from planetary accretion and radiogenic decay.[10] Geological models indicate the core accounts for about 32% of Earth's total mass and 16% of its volume, with the inner core alone contributing around 1.7% of the mass, influencing planetary differentiation where heavier metals sank during the magma ocean phase early in Earth's history.[11] Geophysical investigations, primarily through analysis of seismic waves from earthquakes, provide the primary evidence for the core's structure and dynamics. P-waves (compressional) and S-waves (shear) propagate differently: S-waves do not traverse the liquid outer core, creating a shadow zone detectable since the early 20th century, while the inner core's solidity was confirmed by Danish seismologist Inge Lehmann in 1936 via reflections of P-waves at the inner-outer core boundary.[12] Recent seismic studies using repeating earthquakes and array processing have revealed anisotropies in the inner core, with iron crystals aligned in columnar structures that vary hemispherically, potentially due to differential growth rates influenced by mantle convection.[13] The outer core's fluid motion sustains Earth's geodynamo, generating the magnetic field through self-sustaining convection and the Coriolis effect, with field reversals recorded in paleomagnetic data occurring irregularly over geological timescales, the last full reversal about 780,000 years ago.[14] As of 2025, satellite gravimetry and seismic tomography indicate dynamic changes, including a recent slowdown and potential reversal in inner core rotation relative to the mantle, alongside shape irregularities at the inner core boundary, suggesting ongoing solidification and partial melting influenced by thermal and compositional heterogeneities.[15][16] Astrophysical models contextualize Earth's core within planetary formation theories, emphasizing core accretion as a key mechanism where dense metallic cores form rapidly in protoplanetary disks via pebble accretion and planetesimal collisions, enabling gas envelope capture for gas giants but yielding terrestrial iron cores like Earth's through subsequent magma ocean segregation.[17] Comparative planetology highlights variations: Mercury's disproportionately large core (about 85% of its radius) suggests mantle stripping by giant impacts, while Venus and Mars exhibit weaker dynamos indicative of smaller or solidified cores, inferred from remnant magnetism in meteorites and orbital magnetometry.[18] For Earth, recent simulations incorporating carbon as a nucleating agent demonstrate its critical role in initiating inner core crystallization around 1–2 billion years ago, lowering the melting point and enabling the geodynamo's stability, without which the core might remain fully molten, altering habitability via absent magnetic shielding.[19][20] These models, validated against seismic and neutrino oscillation data from experiments like KamLAND, underscore causal links between core energetics—latent heat from freezing, compositional buoyancy, and secular cooling—and surface observables like plate tectonics and atmospheric retention.[21]Biology and anatomy
Biology is the scientific discipline that studies living organisms, their structure, function, growth, origin, evolution, and distribution. Central to biology is the cell theory, established in the mid-19th century, which asserts that all organisms are composed of one or more cells, the cell is the basic unit of life, and all cells arise from pre-existing cells via division.[22] This principle, derived from microscopic observations by scientists including Matthias Schleiden and Theodor Schwann, underpins understanding of life's organization from unicellular prokaryotes to multicellular eukaryotes. Cells contain organelles like the nucleus (in eukaryotes) housing DNA, mitochondria for energy production, and ribosomes for protein synthesis, enabling metabolic processes essential for life.[23] Genetics forms another core pillar, with deoxyribonucleic acid (DNA) serving as the molecule storing hereditary information. DNA's double-helix structure, confirmed in 1953 by James Watson and Francis Crick using X-ray crystallography data from Rosalind Franklin, consists of nucleotide base pairs (adenine-thymine, guanine-cytosine) that replicate semi-conservatively and transcribe into RNA for protein coding via the central dogma.[24] This mechanism explains inheritance, variation, and adaptation, with genes on chromosomes regulating traits; for instance, humans possess approximately 20,000-25,000 protein-coding genes across 23 chromosome pairs. Mutations and recombination introduce variability, fueling evolutionary change.[25] The theory of evolution by natural selection, articulated by Charles Darwin in On the Origin of Species (1859), posits that species descend from common ancestors through differential survival and reproduction of variants better suited to environments. Evidence includes transitional fossils (e.g., Archaeopteryx linking reptiles and birds), homologous structures across taxa (e.g., vertebrate forelimbs), genetic similarities (e.g., 98-99% DNA homology between humans and chimpanzees), and observed microevolution (e.g., antibiotic resistance in bacteria).[26] Natural selection acts on heritable traits, with empirical data from long-term studies like Darwin's Galápagos finches showing beak adaptations to food sources over generations.[27] Anatomy examines the physical organization of organisms, from macroscopic organs to microscopic tissues. In humans, anatomy reveals a hierarchical structure: tissues (epithelial, connective, muscle, nervous) form organs, which integrate into systems for coordinated function. Key systems include:- Skeletal system: 206 bones providing support, protection, and mineral storage; calcium phosphate composition yields compressive strength up to 20,000 N in long bones.[28]
- Muscular system: Over 600 muscles enabling movement; skeletal muscles attach via tendons, generating force through actin-myosin interactions.
- Nervous system: Brain (1.4 kg, ~86 billion neurons) and spinal cord processing signals at up to 120 m/s; central and peripheral divisions regulate homeostasis.
- Circulatory system: Heart pumping 5-6 L/min blood through 100,000 km vessels; red blood cells (erythrocytes) transport oxygen via hemoglobin.
- Respiratory system: Lungs with 300 million alveoli facilitating gas exchange; tidal volume averages 500 mL per breath.
- Digestive system: Tract from mouth to anus breaking down food; enzymes like amylase initiate carbohydrate hydrolysis.
- Endocrine system: Glands (e.g., thyroid, adrenals) secreting hormones like insulin for glucose regulation.
- Urinary system: Kidneys filtering 180 L/day plasma, reabsorbing 99% water.
- Reproductive system: Dimorphic, with males producing ~100-200 million sperm daily via testes and females ovulating one egg monthly via ovaries.
- Integumentary system: Skin (16% body weight) as barrier, with dermis collagen providing tensile strength.
- Lymphatic/immune system: Nodes and vessels returning fluid; lymphocytes targeting pathogens via antigen recognition.[29][30]