The Economist explains

The Economist explains

Why does Michael Dell want to take his company private?

Why Mr Dell wants to buy his company back again

The Economist explains

Why is the kilogram getting heavier, and what can be done about it?

The kilogram is unique among scientific units in being defined by an artefact, rather than by physical phenomena

The Economist explains

What are Instagram and Twitter fighting about, and why?

Each network is trying to prevent the other from appropriating the valuable data it has amassed from users

A train crash in Argentina

Bad luck or negligence?

A train crash in Buenos Aires kills 49

Technology quarterly

Technology quarterly