Saved on this device

Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Engineering

Why Fail-Safe Design Uses Both Redundancy and Diversity

Quick fact

In aerospace, the Boeing 777 uses triple-redundant fly-by-wire systems with three different processor architectures and two different software languages to protect against both hardware and software common-mode failures.

Why this is interesting

Imagine a plane with two identical engines, both made by the same manufacturer with the same design. If they fail for the same reason, you have no engine left. How do engineers guard against that scenario?