10 most difficult light riddles A list of light related questions that are most often answered incorrectly Light quiz 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. very hard 33% iridescenceiridescence11%Rayleigh scatteringRayleigh scattering33%miragemirage12%atmospheric refractionatmospheric refraction42%Created by: Ninjai. Statistics based on 5329 answers in 3 languages »optical illusions riddles » How far away did the lightning strike if it took 3 seconds to hear the thunder?Approx. 1 km. Sound travels through air at 331.2 meters per second, so after 3 seconds it would travel approximately 1 kilometer.very hard 33% approx. 0.3 kmapprox. 0.3 km10%approx. 1 kmapprox. 1 km33%approx. 3 kmapprox. 3 km43%approx. 9 kmapprox. 9 km12%Created by: Ninjai. Statistics based on 748 answers in 2 languages »weather riddles » What type of plasma is Sun composed of?Hot. 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".hard 40% coldcold10%hothot40%ultracoldultracold20%none of the abovenone of the above27%Created by: Ninjai. Statistics based on 4580 answers in 2 languages »Sun riddles » What are the most luminous objects in the universe?Quasars. 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.hard 42% supergiant starssupergiant stars7%novaenovae3%supernovaesupernovae46%quasarsquasars42%Created by: globalquiz.org. Statistics based on 12893 answers in 3 languages »time riddles » What is the unit of measure of the luminous flux in the SI system?Lumen. The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total quantity of visible light emitted by a source hard 45% LuxLux22%LumenLumen45%CandelaCandela26%IlluminanceIlluminance6%Created by: Tschuka. Statistics based on 977 answers in 2 languages »physics riddles » Which color has the greatest albedo?White. Albedo in Latin is simply "whiteness". It is the reflecting power of a surface - the ratio of reflected radiation from the surface to incident radiation upon it.hard 47% whitewhite47%blueblue15%redred24%blackblack12%Created by: Paweł Kołodziejczyk. Statistics based on 7010 answers in 4 languages »Latin riddles » Which of the following is the worst for eyesight during a sunny day?Wearing sunglasses without UV filter. Wearing sunglasses witout 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.hard 47% wearing sunglasses with UV filterwearing sunglasses with UV filter3%wearing sunglasses without UV filterwearing sunglasses without UV filter47%not wearing sunglasses at allnot wearing sunglasses at all35%wearing sunglasses inside buildingswearing sunglasses inside buildings12%Created by: Ninjai. Statistics based on 10985 answers in 2 languages »optics riddles » How many typical stars can supernova be luminous as?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.hard 51% ten typical starsten typical stars5%one thousand typical starsone thousand typical stars14%one million starsone million stars28%one hundred billion starsone hundred billion stars51%Created by: globalquiz.org. Statistics based on 12009 answers in 3 languages »stars riddles » 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.hard 52% SpriteSprite22%milkmilk13%tonic watertonic water52%pineapple juicepineapple juice12%Created by: Luca Biaggi. Statistics based on 14091 answers in 2 languages »beverages riddles » Who should you expect to show stronger red-eye effect?Blue-eyed people. The iris plays no role in the effect, but the blue-eyed people have relatively low melanin in the fundus as well. Therefore, they show a much stronger red-eye effect, as the light passing fundus is not absorbed by melanin. The role of melanin in red-eye effect is nicely demonstrated in case of heterochromia (one eye blue, one brown): typically, only the blue eye displays the effect.hard 54% blue-eyed peopleblue-eyed people54%brown-eyed peoplebrown-eyed people16%elderselders1%there is no differencethere is no difference27%Created by: Kantapat Rassamee. Statistics based on 9123 answers in 5 languages »eyes riddles » Play light quiz and see all the questions.