Lesson 03
Synchronisation and Coherence
When many repeating systems are connected, each one can influence the others. Under the right conditions, separate phase systems can begin to move together.
This collective alignment is called synchronisation. Coherence measures how closely the individual phases are organised — from widely scattered to almost identical.
Learning objectives
- Understand why independent systems may begin in different phases.
- See how coupling creates collective behaviour.
- Recognise what synchronisation means.
- Interpret what coherence measures.
- Understand why partial synchronisation can occur.
- See why stronger coupling usually creates faster organisation.
Central indicator shows the mean phase direction. Faint lines indicate coupling between neighbouring nodes.
Coherence
15%Mostly disordered
Synchronisation status
Disordered
Live explanation
The phases remain widely distributed around the cycle.
What to notice
- Many systems can organise without a central controller.
- Coupling creates influence between separate phase systems.
- Stronger coupling usually creates faster synchronisation.
- Different natural speeds resist synchronisation.
- Coherence can increase gradually.
- Partial synchronisation is possible.
- A coherent group may recover after a disturbance.
- Synchronisation does not mean the systems become physically identical.
A note on this lesson
This lesson uses a simplified deterministic model of coupled phase systems. It demonstrates synchronisation and coherence as general mathematical behaviours.
Finished this lesson?
Mark it complete to track your progress across the series.