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 stars8%novaenovae3%supernovaesupernovae45%quasarsquasars41%Created by: globalquiz.org. Statistics based on 7007 answers in 2 languages »space 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%redred25%blackblack12%Created by: Paweł Kołodziejczyk. Statistics based on 3333 answers in 2 languages »Latin 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 52% ten typical starsten typical stars5%one thousand typical starsone thousand typical stars14%one million starsone million stars27%one hundred billion starsone hundred billion stars52%Created by: globalquiz.org. Statistics based on 7742 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 53% SpriteSprite20%milkmilk14%tonic watertonic water53%pineapple juicepineapple juice12%Created by: Luca Biaggi. Statistics based on 9242 answers in 2 languages »beverages 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 54% blueblue15%greengreen8%yellowyellow20%redred54%Created by: Hà Linh Chi. Statistics based on 13293 answers in 2 languages »optics 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 57% blue-eyed peopleblue-eyed people57%brown-eyed peoplebrown-eyed people14%elderselders1%there is no differencethere is no difference26%Created by: Kantapat Rassamee. Statistics based on 5557 answers in 4 languages »eyes 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 66% light paintinglight painting66%phototypographyphototypography9%overexposureoverexposure10%painting on the lenspainting on the lens13%Created by: globalquiz.org. Statistics based on 12980 answers in 2 languages »photography 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 66% superlighthousesuperlighthouse15%solar power plantsolar power plant66%tent-type greenhousetent-type greenhouse6%a fountain in Dubaia fountain in Dubai11%Created by: globalquiz.org. Statistics based on 9759 answers in 2 languages »electricity 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.average 69% 3 seconds3 seconds16%1 minute1 minute6%8 minutes8 minutes69%1 hour1 hour7%Created by: Hitter smasher. Statistics based on 13554 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 71% thermodynamic free energythermodynamic free energy10%specific heat capacityspecific heat capacity12%speed of lightspeed of light71%Coulomb, unit of the electric chargeCoulomb, unit of the electric charge5%Created by: Paweł Kołodziejczyk. Statistics based on 4633 answers in 2 languages »discoverers riddles » Play technology quiz and see all the questions.