10 most difficult light riddlesLight quiz
What is the phenomenon occurring at the rainbow?
reflection, refraction and dispersion
diffraction and refraction
A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
What are the most luminous objects in the universe?
A quasar is an extremely energetic source of radiation powered by accretion disc around galaxy's central supermassive black hole. Quasars were much more common in the early universe, as all known quasars are extremely distant.
In what process sky colors (including blue sky and red sun) are created?
Rayleigh scattering, named after the British physicist Lord Rayleigh (John William Strutt), is an elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the radiation.
What type of plasma is Sun composed of?
none of the above
The Sun is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. Hot plasmas (thermal plasmas) have electrons and the heavy particles at the same temperature, i.e. they are in thermal equilibrium with each other. Cold plasmas (nonthermal plasmas) on the other hand have the ions and neutrals at a much lower temperature, whereas electrons are much "hotter".
How many typical stars can supernova be luminous as?
ten typical stars
one thousand typical stars
one million stars
one hundred billion stars
Supernovae are extremely luminous and often briefly outshine an entire galaxy. No supernova has been observed in the Milky Way since 1604, but they are often observed in distant galaxies.
Which of the following is the worst for eyesight during a sunny day?
wearing sunglasses with UV filter
wearing sunglasses without UV filter
not wearing sunglasses at all
wearing sunglasses inside buildings
Wearing sunglasses without UV filter causes the pupils to dilate and eyes to absorb more UV rays than they normally would without the sunglasses. Hence, it's much better not to wear sunglasses at all, than to wear ones without UV filter.
Which beverage is is fluorescent in UV light?
Tonic water is transparent in daylight. Under ultraviolet light, the quinine makes it fluorescent (pictured), even though it is present in a negligible concentration.