Unit-explicit scientific calculator
Search a formula, enter the plasma state, and inspect the calculation, units, scope, and source in one place.
Type to search formula names, canonical symbols, parameters, and common aliases.
Try a broader search term or choose another category.
JSON record includes canonical inputs and outputs, formula provenance, display units, and active applicability warnings.
Meanings, units, and conventions used by this calculator.
| Symbol | Name and physical definition | Role here | Unit and convention |
|---|
Reproducible visualisation
The plots use the same equations as the calculators, evaluated at each sampled point. Physical applicability remains limited by the assumptions of each model.
Choose a preset or enter the fixed state used by both plotting tools.
Ordering diagram
Logarithmic markers compare standard frequencies and spatial scales for the reference state. Their ordering may change with the selected plasma environment.
Controlled parameter sweep
Vary one input while all other state variables remain fixed. Up to three quantities from the same physical family share a common axis and unit.
These plots contain no smoothing, fitting, or interpolated physics. Curves connect direct evaluations of the implemented equations only for readability. A visually smooth trend does not establish model validity, identify a wave mode, or replace uncertainty analysis. Exported files record the displayed values and fixed state.
Development research workflow · WI_H1_SWE only
Import a prepared local Wind CSV and its matching JSON sidecar, inspect exclusions and assumptions, then calculate the four supported proton quantities. Files stay in this browser until you download them.
The optional evidence file enables only the density-fit component of proton inertial-length uncertainty when it matches the accepted CDF identity. It does not establish full measurement error.
Choose local files to begin.
fit_flag=10 only; rejected rows never enter a formula.Scale proximity or ordering alone does not identify a physical mode. The figure uses only proton inertial length and perpendicular proton gyroradius in metres.
Download analysis.json for complete local replay. Companion files provide editable numbers, the figure, and a fact-only Methods draft. Uploaded rows are never placed in the page URL.
Worked examples
These examples use illustrative parameter sets to show how the core quantities fit together. They are not reconstructions of specific published events.
Open a state in the calculator, then review every input against the interval, instrument cadence, coordinate system, and species definition used in your analysis.
Scientific evidence
Reference comparisons, analytical relations, units, and applicability limits provide different kinds of support. Software consistency and source identity are checked separately; neither establishes that a physical model applies to a particular observation.
Additional implementation, regression, and provenance checks are documented in the formula audit and public test suite. They detect software changes but do not independently validate a physical model.
Selected numerical comparisons at stated reference inputs are shown below. The formula audit and public tests retain the complete evidence record, methods, and limitations.
Reference values and unit conversions have independent anchors. Analytical relations test stated identities; applicability checks exercise specific implemented boundaries. Fixed regression cases and execution checks detect unintended software changes, but are not independent scientific benchmarks. These checks do not establish model applicability beyond the exercised boundaries or turn reduced formulas, empirical fits, or simplified instability criteria into general kinetic solvers.
Symbols and units
Definitions, units, species meanings, and conventions used throughout Alfvenica.
Unit display
Unit choices change how values are displayed; the calculated physical quantities remain the same.
Symbols and meanings
Search symbols, names, and common aliases.
| Symbol | Name and physical definition | SI and display units | Species and convention |
|---|
About the project
Alfvenica is an independent, open-source browser toolkit that brings commonly used space- and astrophysical-plasma calculations together with their units, assumptions, interpretation, and sources. It is intended for researchers, educators, and learners who want to inspect the model behind a number rather than use a black-box result.
I began developing Alfvenica while working with spacecraft observations and kinetic-Alfvén-wave problems. Repeatedly checking units, conventions, assumptions, and limiting cases was often as important as obtaining the numerical result. The toolkit grew from that practical need.
Alfvenica combines a searchable calculator, physical interpretation, controlled plotting, illustrative plasma states, explicit model assumptions, primary references, and an in-browser validation report. It supports first-pass estimates, teaching, consistency checks, and transparent methods—not automated wave identification.
Calculations and plots run locally with explicit unit conventions; input values are not transmitted. Space, SI display, and CGS-oriented mixed choices change how results are shown; the mixed mode is not a complete Gaussian/esu/emu implementation and retains electrical resistivity and conductivity in SI. Each calculator states its assumptions and references.
Constants cite CODATA 2022, standard coefficient targets cite the 2023 NRL Plasma Formulary, and model-specific entries retain literature references and stated conditions. In-browser checks include independently anchored coefficient comparisons and a unit conversion, alongside analytical, applicability, and numerical consistency checks. Development scaling tests and software integrity checks are documented separately in Validation and the formula audit.
Single-ion, scalar-temperature, fluid, reduced two-fluid, bi-Maxwellian, and frozen-flow assumptions appear in several tools. Characteristic scales are usually ordering scales, not sharp universal boundaries. Alfvenica does not replace kinetic dispersion solvers, instrument pipelines, event context, or uncertainty analysis.
ChatGPT and Anthropic Claude assisted with software development, documentation, testing, and technical consistency checks. All AI-assisted outputs incorporated into Alfvenica were reviewed and verified by the author against the source code, scientific references, and numerical tests, as applicable.
Alfvenica is under continuing development. Scientific corrections, independent benchmarks, documentation improvements, code contributions, feedback, and genuine research collaboration are welcome. Report a scientific issue or read the contribution guide.
Chettri, M. K. (2026). Alfvenica: Interactive Space Plasma Toolkit (Version 2.0.0) [Computer software]. https://github.com/mkchettri8/alfvenica