Big O Notation vs Quantum Atlas

Big O Notation is an independent study app for learning, reviewing, and practicing algorithm complexity. It is built for students, self-taught developers, coding interview candidates, and anyone who wants clearer intuition for time and space complexity. Study across Fundamentals, Practical Skills, Common Pitfalls, and Advanced Concepts with 160 focused questions. Every question includes an explanation so you can understand why an answer is right and where your reasoning went off track. Features: - FSRS spaced-repetition intervals for smarter review - Weak-point heatmap to spot topics that need attention - Daily challenge for steady practice - Mock exams for timed review - Offline practice - No login required Practice offline, no login required. Independent study app for Big O Notation practice. Not affiliated with, endorsed by, or sponsored by any company, certification body, exam operator, or vendor. All trademarks belong to their respective owners.

Quantum Atlas is a beautiful, pocket-sized reference for the building blocks of reality. From the seventeen particles of the Standard Model to the ideas behind quantum mechanics, field theory, electrodynamics, and the strong force — it turns dense physics into something you can actually explore. And play with. A PERIODIC TABLE FOR PARTICLES Browse all 17 quarks, leptons, and bosons of the Standard Model in a clean, tappable table. Each particle card lays out mass, charge, spin, the forces it feels, its antiparticle, the year and team that discovered it, how it decays, and a plain-English explanation of the role it plays in the universe. No textbook required. LEARN THE CONCEPTS A deck of 12 concept cards covers wavefunctions, superposition, entanglement, spin, uncertainty, tunneling, the photoelectric effect, decoherence, gauge symmetry, vacuum fluctuations, and more — each one designed to be read in a minute and remembered for longer. INTERACTIVE LAB — 22 SIMULATIONS YOU CAN TOUCH Don't just read about physics. Play with it. Every simulation is a real, working experiment that you steer with your finger. The new flagships: • Hydrogen Spectrum — drag an electron between energy levels and watch the photon fall onto its exact wavelength • CHSH Game — a coordination game where classical strategies cap at 75% and entanglement breaks the ceiling at 85.4% The classics: • Double-slit, Mach–Zehnder interferometer, Quantum tunneling • Wave packet spreading, the Uncertainty principle • Spin measurement, Sequential Stern–Gerlach, Bell test • Bloch sphere, Two-state Rabi cycles, Quantum gates playground • Decoherence, Particle in a box, Harmonic oscillator • Photoelectric effect, Blackbody radiation • Atom builder, Orbital shapes • Particle decay tree, Feynman diagram builder GO DEEPER Four theory atlases — 34 entries in all — collect the key results and intuition for each domain: • Quantum Mechanics — wavefunctions, measurement, uncertainty, the foundations • Quantum Field Theory — fields, particles as excitations, virtual processes • Quantum Electrodynamics — photons, vertices, the running of the coupling • Quantum Chromodynamics — quarks, gluons, confinement, asymptotic freedom The Decay Explorer follows 11 unstable particles through their full chains of products, weighted by real measured branching ratios. Run it once and you get one outcome; run it again and you get a different one — exactly like the real universe. The Spectra Explorer renders the real emission lines of 98 elements at their true wavelengths, grouped by periodic-table family — every fingerprint that astronomers actually use to identify atoms across the galaxy. WHO IT'S FOR • Physics students who want to feel concepts, not just read them • Science teachers who need a visual aid that actually demonstrates • Engineers and developers brushing up on quantum • Anyone who has ever wanted to ask "but how does it actually work?" OFFLINE AND PRIVATE No accounts. No ads. No tracking. No analytics. Everything works offline, and nothing about your usage ever leaves your device. SIMPLE, ONE-TIME UNLOCK The Standard Model, the Concepts deck, and the Quantum Mechanics atlas are free, forever. Unlock everything else — the Lab's 22 simulations, the three remaining theory atlases (QFT, QED, QCD), the Decay Explorer, and the Spectra Explorer — with a single one-time purchase. Family Sharing supported. Designed with a premium dark interface, hand-built for iPhone and iPad.