A gamma-ray burst accompanies the merger

FAST began its commissioning phase after construction in a karst depression.

The instrument’s great collecting area promised sensitivity to faint radio sources.

First light marked a milestone for the observatory built by Chinese scientific teams.

LIGO and Virgo detected a signal from two merging neutron stars.

The merger was also observed with electromagnetic instruments, launching a coordinated campaign.

The combined observations connected gravitational waves with light from the same distant event.

The article explains how moving plates and engraved scales model the visible sky for particular latitudes.

Users could solve problems involving stars, sunrise, direction, calendars and the hours of prayer.

Metalworking, calligraphy, geometric design and numerical tables were all necessary to produce a reliable instrument.

They expanded astrolabe theory, manufacture and uses before the instrument circulated further through Africa, Asia and Europe.