Bending Light: The Optics Challenge

What this quiz asks

• Short-sighted people need glasses with which kind of lens?
• In ordinary glass, light travels at only about two-thirds of its speed in a vacuum.
• When a fainter second rainbow appears above the main one, how are its colours arranged?
• What lets an optical fibre guide light around bends without it escaping through the sides?
• Polarised sunglasses are especially good at cutting out what?
• Can the gravity of a massive object such as the Sun bend the path of starlight passing close to it?
• Select ALL of these that are forms of electromagnetic radiation.
• In which unit is the focusing power of a spectacle lens usually given?
• The 'water' of a mirage on a hot road is caused by light reflecting off a thin layer of water vapour.
• In 1800 William Herschel put a thermometer just beyond the red end of a spectrum and found which invisible radiation?
• Which English scientist's two-slit experiment in the early 1800s showed light making interference patterns, like waves?
• The first working laser, built by Theodore Maiman in 1960, used a crystal of which gemstone?
• A main rainbow forms a circle around the point directly opposite the Sun. What is the circle's radius, in degrees?
• Which Danish astronomer made the first estimate of the speed of light in 1676, by timing eclipses of Jupiter's moon Io?
• Augustin Fresnel's ringed lens, far thinner and lighter than a solid one, was first put to use in 1823 in what?
• Order these materials by how strongly they bend light (their refractive index), from weakest to strongest.
• Which scholar, working in Cairo in the 11th century, wrote the Book of Optics, arguing that we see because light enters the eye?
• Select ALL of these colours that a single wavelength of light can produce.
• What is the eerie blue glow in the water around a working nuclear reactor core called?
• In 1849, who made the first measurement of the speed of light on Earth, using a spinning toothed wheel and a distant mirror?