Simpler view controlsNEW

• View chooses Graph, Details or Both, preserving your selection, zoom and opened sections.
• Graph → All equally shows the whole map in foreground, with coloured relationships.
• Context + background emphasises the selected context and subdues the rest.
• Context only shows just the selection and its context.
• Selecting an object never changes the Graph choice automatically.

Guided tutorials

• Choose Start guided tutorial below, or select a route under Tools → Tutorials.
• Physics routes explore why mass has rest energy and why moving clocks record less time.
• Each tutorial introduction offers a direct link to open, bookmark or share.
• PhysicsKG operates the live viewer and points out each step; use Back and Next step to follow along.
• Explore from here lets you investigate freely; Resume tutorial restores the guided view.

Start with the map

• The viewer starts with SR-1 selected, modules folded and Graph set to All equally.
• Click a module to read its introduction and connections.
• Use the + in a folded module's top-right corner to reveal its concepts; use the − on an expanded module's boundary to fold it again.
• Use Search to go directly to a concept or module.
• Clicking empty graph space keeps the current selection.

Choose the context

• Context chooses relationships around the selection and filters eligible edges across the whole map.
• Use named contexts such as Prerequisites, Derivation, Foundations, Uses, or Related.
• Choose one hop, two hops, or the complete transitive chain.
• Changing context does not move the graph or fold modules.
• In Derived from or Where this is used, Show in graph applies that section's context and fits it automatically. Full tree follows the complete chain.
• From Details-only, Show in graph opens Both without changing module folding.

Reveal the concepts

• A selected concept inside a folded module appears as a circular concept face within the module.
• Expand context reveals any folded modules containing context concepts.
• Context counts, expansion and fitting remain useful in every Graph mode.

Move and read

• Pan and zoom freely; selection only pans enough to reveal an off-screen item.
• Frame chooses what Fit does: reveal the selection or frame the selection, context or whole displayed graph.
• After Fit context, press Fit++ to bring context concepts closer temporarily, in any Graph mode.
• Open or close individual details sections as you read.
• Pinch or Ctrl/Cmd-wheel over details to magnify its text and graphics without changing the map.
• Preview links and inspect edges without losing the current details.
• Browser Back and Forward retrace selected concepts and modules.
• Next at the foot of each concept follows the reading sequence through SR, MATHS and GR.
• Use a block's speech-bubble +, then choose a paragraph, to add a note; a filled bubble means notes are present.

Personal layout

• Node dragging is off during ordinary browsing.
• Enable Tools → Layouts → Edit personal layout to save moved nodes locally.
• After Fit++, drag context nodes for temporary adjustments; navigating away restores them.

Study

• Practice questions reveal their answers only after an attempt or “I don't know”.
• Automatic questions are marked for you; compare free-text answers and mark yourself.
• Tools → Study tracks attempts and latest results locally, with links back to each question.
• Blue ticks record read content blocks and completed concepts or modules.
• Blue and green graph ticks summarise reading and question completion; one Study option hides both.

Personal data

• Personal layouts, notes, study-question records and blue reading ticks are stored together.
• They remain in this browser by default; authored PhysicsKG content is unaffected.
• Tools → Personal data can download or import a portable archive.
• Optionally sign in with a Google account to synchronise automatically through Google Drive across browsers and devices.
• If authorization expires, local work remains safe and a Sync paused action offers reconnection.
• Privacy and Google Drive data use explains exactly what is stored and transferred.

Content status

Covers Special Relativity and General Relativity.

Manifolds and Coordinates exposition enhanced with motivating example.