10 most difficult light riddles A list of light related questions that are most often answered incorrectly Technology quiz 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 41% supergiant starssupergiant stars7%novaenovae3%supernovaesupernovae46%quasarsquasars41%Created by: globalquiz.org. Statistics based on 12205 answers in 2 languages »universe 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 46% whitewhite46%blueblue15%redred24%blackblack12%Created by: Paweł Kołodziejczyk. Statistics based on 6478 answers in 2 languages »climate 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 11457 answers in 2 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 51% SpriteSprite22%milkmilk13%tonic watertonic water51%pineapple juicepineapple juice12%Created by: Luca Biaggi. Statistics based on 13512 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 difference28%Created by: Kantapat Rassamee. Statistics based on 8616 answers in 4 languages »eyes riddles » The rainbow is violet on the inside of its arc. What color is it on the outside?Red. Visible light spans from red to violet. It is easy to remember, since wavelengths just outside the visible range are called infrared and ultraviolet.hard 55% blueblue15%greengreen9%yellowyellow19%redred55%Created by: Hà Linh Chi. Statistics based on 19988 answers in 2 languages »optics riddles » What kind of building is that?Solar power plant. In The PS10 Solar Power Plant, 624 movable mirrors concentrate the sun's rays to the top of a 115 meter (377 ft) high, tower where a steam turbine is located. The plant is located near Seville, Spain.average 65% superlighthousesuperlighthouse15%solar power plantsolar power plant65%tent-type greenhousetent-type greenhouse7%a fountain in Dubaia fountain in Dubai12%Created by: globalquiz.org. Statistics based on 14494 answers in 3 languages »electricity riddles » What photographic technique was used to create this photo?Light painting. The photo was taken with long exposure. For the first 15 seconds, the author hold still with lights on, to achieve the light in background. Later, he switched off the light and wrote his name with light in his hand. He used his nose as a reference point so he could close the "O" letter - which explains the flare at this position.average 67% light paintinglight painting67%phototypographyphototypography8%overexposureoverexposure9%painting on the lenspainting on the lens14%Created by: globalquiz.org. Statistics based on 24323 answers in 2 languages »photography riddles » How long does it take the sunlight to reach the Earth?8 minutes. The distance from Earth to the Moon is 1.2 light seconds. The distance to the nearest star (Proxima Centauri) is 5.46 years.easy 71% 3 seconds3 seconds15%1 minute1 minute6%8 minutes8 minutes71%1 hour1 hour6%Created by: Hitter smasher. Statistics based on 21043 answers in 2 languages »Sun riddles » What is "c" in E=mc^2?Speed of light. In words, energy equals mass multiplied by the speed of light squared.easy 72% thermodynamic free energythermodynamic free energy9%specific heat capacityspecific heat capacity12%speed of lightspeed of light72%Coulomb, unit of the electric chargeCoulomb, unit of the electric charge5%Created by: Paweł Kołodziejczyk. Statistics based on 8602 answers in 2 languages »discoverers riddles » Play technology quiz and see all the questions.