Fang Liu

A black hole is like a perfect vault: everything that falls in disappears without a trace. But in the 1970s, Jacob Bekenstein and Stephen Hawking discovered that the horizon carries an indelible "sticker" — entropy (a measure of hidden information about swallowed matter).

The railway's electrical network is like an orchestra: trains are musicians whose systems respond differently to current. When their 'electric voices' fall out of tune, disorder arises — a cacophony that can escalate into dangerous voltage rocking.

A huge pool of clear liquid is hidden deep underground. Inside, there is nothing but a pristine 'broth' that flashes with faint light when an invisible particle flies through. This is the JUNO detector—20,000 tons of liquid scintillator built to hunt for neutrinos. The main enemy of such a hunt is not darkness but its own noise.