c.curionodeThe Turing Archive

2013 · Computer systems

Keeping time without a shared clock

Distributed systems need rules for ordering events and agreeing on state.

2013Turing Award
Keeping time without a shared clock: Distributed systems need rules for ordering events and agreeing on state.
Original AI-generated infographic by Curionode. Read the text version below for the full explanation.
Read the poster text
  1. Order

    Track causal relationships.

  2. Replicate

    Maintain state on several machines.

  3. Agree

    Coordinate a consistent sequence of actions.

These ideas help systems coordinate across delays, failures and independent machines.

Logical ordering is not physical time, and agreement guarantees depend on the assumed communication and failure model.

01 · The idea

In everyday language

Leslie Lamport developed foundations of distributed and concurrent computing. Logical clocks capture a useful ordering of events even when machines do not share a perfectly synchronised clock. His wider contributions include replicated state machines, consistency, safety and liveness: concepts for specifying what a distributed system must and must not do.

Why it matters

These ideas help systems coordinate across delays, failures and independent machines.

02 · The people

Who brought the idea to life?

Illustrated portrait of Leslie Lamport

Leslie Lamport

Leslie Lamport developed foundations for reasoning about distributed systems, where different machines act without a single shared clock or perfectly reliable communication. His work includes logical clocks, consensus, fault tolerance, and formal specification. At Microsoft Research he continued developing tools for describing and checking systems before implementation. His ideas explain how coordinated behavior can be achieved despite delays and failures, and where fundamental limits remain.

Read the biography ↗

03 · Read further

From the original sources

Original explanations based on the official award record. The subject label is an editorial navigation aid.

  1. Official ACM profile: Leslie Lamport ↗amturing.acm.org
  2. Heidelberg Laureate Forum: Leslie Lamport ↗www.heidelberg-laureate-forum.org