The article discusses three main telescope types: refractors (best for bright objects, portable), reflectors (best for faint objects, larger apertures), and catadioptrics (compromise between aperture ...

Simply put, a black hole is a region of space-time where gravity is so strong that nothing can escape from it. This includes light, which travels at the cosmic speed limit of 186,000 miles per second.

Sir Francis Graham-Smith in 2007: he carried out much important work on pulsars - Science Photo Library Sir Francis Graham-Smith, the former Astronomer Royal, who has died aged 102, was a pioneer of ...