I apologize for the duplication, and I have now merged the identical topics and included the remaining unique topics from the 99-topic list in the appropriate hierarchy.
Physics, Rotational Mechanics, and Geometry
a. Physics, specifically rotational mechanics (1)
i. Rotational Physics and Inertia (1)
ii. Angular Momentum and Object Motion (4)
b. Geometry and angles (5)
i. Euclidean geometry and distance (29)
ii. Geometric Defects and Plane Angles (9)
iii. Geometry of Straight Lines (21)
c. Angular Analysis, Failure Mechanics (4)
d. Interacting Electrons and Atomic Particles (12, 26)
i. Electron Density and Atomic Structure (14)
ii. Cellular Signaling and Protein Receptors (12)
iii. Bound Electron Pairs (60)
iv. Geometric Transformations and Scaling (26)
Emotions, Behavior, and Psychology
a. Psychology and emotions (2)
i. Human evolution and genetics (6)
Human Genetics and Proteins (8)
ii. Human development and adolescence (17)
Human Development and Adolescence (13)
b. Consciousness and subjective experiences (9)
i. Qualia and Conscious Experience (16)
ii. Artificial Intelligence and Consciousness (32)
c. Classical conditioning and learning (11)
i. Classical Conditioning and Learning (10)
ii. Adaptive Biology and Physiology (11)
d. Reasoning and inference (18)
i. Logical Reasoning and Inference (17)
ii. Propositional Logic and Truth (18)
iii. Critical Thinking and Analysis (65)
Technology and Image Processing
a. Image processing and technology (3)
i. Image Processing and Deep Learning (3)
b. Visual perception and optical flow (8)
i. Visual Perception and Motion (6)
c. Digital identifiers and object recognition (22)
i. Digital Object Identifiers (DOI) (28)
ii. Entity Relationships and Domains (23)
d. Image recognition and computer vision (25)
i. Image Recognition and Computer Vision (33)
e. Artificial intelligence and cognitive science (30)
f. Spatial databases and indexing (40)
i. Principal Component Analysis (42)
Feedback Systems and Control
a. Feedback systems and loops (7)
i. Feedback Loops and Time (5)
ii. Systems Stability and Feedback (20)
b. Engineering disciplines and materials analysis (41)
i. Failure Analysis and Engineering (43)
ii. Engineering and Materials Analysis (66)
c. Physiology and environmental biology (10)
d. Fire protection and building components (21)
i. Fire Protection Engineering (34)
e. Causal effects and pressure calculations (39)
i. Causal Factors and Inverse Problems (49)
Computability and Computation
a. Computability and computation theory (24)
i. Computability Theory and Turing Machines (24)
b. Turing degrees and computer science (16, 31)
i. Topological Spaces and Disjoint Unions (31)
c. Formal languages and decision theory (31)
i. Language Theory and Concatenation (15)
ii. Formal Grammars and Languages (79)
Algebraic Relations and Set Theory
a. Set theory and graph theory (13)
i. Graph Theory and Fixed Points (7)
ii. Binary Relations and Set Theory (35)
b. Algebraic structures and mathematical relations (15)
c. Binary relations and orderings (28)
d. Relation, Étale Algebraic Sets and Morphism (14, 29)
i. Algebraic Geometry and Étale Morphisms (19)
e. Power laws and network distribution (38)
i. Power Laws and Network Theory (51)
Chemistry and Chemical Reactions
a. Organic Chemistry and Life (25)
b. Flavin and Nitric Oxide Chemistry (29)
c. Oxidation States and Chemical Bonds (30)
d. Chemical Reactions and Formation (45)
e. Aromatic Compounds and Prime Numbers (40)
f. Peptides and Amino Acids (47)
g. Sodium Silicate and Food Chemistry (71)
Biology, Genetics, and Evolution
a. Connective Tissue and Cell Biology (38)
b. Neurons and Nervous System (59)
c. Plant Cells and Channels (78)
d. Evolutionary Hypothesis of Hearing and Sight (98)
Language, Linguistics, and Communication
a. Semiotics and Communication (80)
b. Linguistics and Pronouns (82)
c. Disambiguation in Language and Context (96)
Philosophy and Metaphysics
a. Metaphysics and Philosophy (54)
b. Scientific Approach to Human Behavior and Psychology (97)
Mathematics and Computational Concepts
a. Manifold Theory and Topology (36)
b. Coordinate Systems and Statistics (52)
c. Scalar and Vector Operations (56)
d. Commutative Algebra and Spectra (70)
e. Fourier Transforms and Signal Processing (87)
f. Adjoint Operators and Hilbert Spaces (88)
g. Root Finding and Algorithms (89)
h. Nonlinear Differential Equations and Independence (99)
Computer Science and Programming
a. Data Compression Techniques (27)
b. Parallel Computing and Graphics (55)
c. Programming Languages and Instructions (61)
d. Vectors, Scalars, and Tensors (63)
e. Error Correction and Coding (64)
f. Recursive Functions and Arithmetic (67)
g. Writing and Program Aggregation (69)
h. PHP Programming (90)
Psychology and Mental Health
a. Anxiety Disorders and Focus (72)
b. Personality Traits and Identity Formation (91)
Miscellaneous Topics
a. Phase Transitions and Thermodynamics (44)
b. Game Theory and Strategy (46)
c. Motor Cortex and Brain Function (50)
d. Solar Interior and Neutrino Models (57)
e. Scientific Laws and Observation (58)
f. Dead Reckoning and Belief (62)
g. Dynamic Equilibrium and Change (85)
h. Knowledge Management and Personal Tools (86)
i. Constants in Physical and Universal Phenomena (93)
j. Contributions of Thomas the Scottish Philosopher and Physicist (94)
k. Classification and Taxonomy in Human Behavior (95)
l. Creating and Organizing Articles in Wikimedia (92)