A teaching tape for SR-02, magnet and conductor descriptions
magnet and conductor
Teaching tape that compares the magnet-rest and conductor-rest descriptions at 10 m/s and at 0.6c.
Open SR-02 with these settings
Where it starts
| Setting | Value |
|---|---|
| Relative speed (speed) | 10 |
| Uniform magnetic field B (magneticField) | 1 |
| Segment length (segmentLength) | 0.1 |
What it changes, and what to expect
Set Relative speed (speed) to 20 changes what the run starts from
Walking pace, where the two descriptions agree
At this speed it makes no observable difference which body you call the one at rest: whether you say the moving magnet produces an electric field or the moving conductor's charges feel a force, the current you would measure is the same. Einstein's first paragraph is about that agreement being an embarrassment for the theory rather than a comfort, because the two accounts describe one phenomenon with two different mechanisms. Raise the speed in the next step and the two accounts stop matching.
Set Relative speed (speed) to 179875474.8 changes what the run starts from
The two descriptions at 0.6c, where they no longer agree
At 0.6c the two electromotive forces differ by the factor 1.25.
These are the values the tape's author recorded, not a result this page computed. Nothing here runs the instrument. Open SR-02 with these settings: the link opens it with them already in place. Compare what it gives you with what is recorded here. The settings travel in the link and the laboratory reads them as it loads, so without JavaScript it opens at its worked example instead.
What these numbers were recorded under
| Identity | Recorded as |
|---|---|
| Model | magnet-conductor-host version 1 |
| Seed | 0 |
| Random-stream semantics | version 1 |