You can learn some pretty strange things just by looking at photographs. A rock in the desert might have moved hundreds of feet without anyone touching it. An ordinary-looking piece of bronze could turn out to be part of a 2,000-year-old machine. And somewhere underwater, an octopus is carrying around a shell in case it needs somewhere to hide. None of these things have much in common, which is probably the best part. There’s no particular subject to study here, and you don’t need to remember any of it afterward. But the next time someone mentions a weird animal or an unusual place, you might have something to add. Here are 15 random photos with something interesting behind them.Wikimedia CommonsThe Rocks That Move Across the DesertRocks at California’s Racetrack Playa leave long trails in the dry mud. Scientists discovered that thin sheets of ice, pushed by wind, can move them across the surface.Wikimedia CommonsA 2,000-Year-Old Greek ComputerThese corroded bronze fragments belong to the Antikythera mechanism, an ancient Greek device with interlocking gears used to calculate astronomical cycles and predict eclipses.Wikimedia CommonsAn Octopus With Its Own Portable ShelterThis coconut octopus is hiding inside a shell. The species is known for collecting shells and even carrying coconut halves across the seafloor to use as protection.Wikimedia CommonsA Tree With Rainbow-Colored BarkRainbow eucalyptus trees develop colorful trunks as their outer bark peels away. Newly exposed sections start green, then change color as the bark ages.Wikimedia Commons / John SamuelThe Roman Object Nobody Can ExplainRoman dodecahedrons have twelve faces, circular openings, and small knobs at their corners. Archaeologists have found many examples, but their original purpose remains uncertain.Wikimedia CommonsA Mother Pangolin Curled Into a BallA young Philippine pangolin nudges its mother, who has curled into a protective ball. Pangolins are mammals covered in keratin scales, the same protein found in human fingernails.Wikimedia Commons / Christopher CrouzetThe Lake That Becomes a Giant MirrorA thin layer of water turns Bolivia’s Salar de Uyuni into an enormous natural mirror. The reflected sky can make vehicles appear to be floating above the ground.Wikimedia CommonsA Tiny Animal That Can Survive Extreme ConditionsThis microscopic creature is a tardigrade, sometimes called a water bear. Some species can survive freezing, dehydration, and even exposure to the vacuum of space.Wikimedia Commons / Rod AlldayA Cave With Natural Stone ColumnsFingal’s Cave in Scotland has walls made of tall basalt columns. They formed as ancient lava cooled and contracted, cracking into remarkably regular geometric shapes.English Wikipedia / DevanjediA Bird That Weaves Its Own HouseA baya weaver sits beside its hanging nest, made from strips of grass. Male weavers build these elaborate structures, which females inspect before choosing a mate.Wikimedia Commons / Benjamin GoetzingerThe Crater Nicknamed the Door to HellTurkmenistan’s Darvaza gas crater became famous for its burning natural gas. Photographs taken at night show flames illuminating the enormous hole in the desert.Wikimedia CommonsA Tree That Turned Into StoneThis log in Arizona’s Petrified Forest is actually fossilized wood. Minerals gradually replaced much of its original material, preserving the shape of a tree that lived millions of years ago.Wikimedia Commons / Richard N HorneThe Giant Lily Pads of the AmazonThese enormous floating leaves belong to the Amazon giant water lily. Mature leaves can reach several feet across, with raised edges that make them resemble shallow green trays.Wikimedia CommonsA Lake Covered in Strange CirclesCanada’s Spotted Lake develops colorful circular pools during the dry season. As water evaporates, concentrated minerals create the unusual pattern visible across its surface.Wikimedia CommonsMadagascar’s Avenue of Giant BaobabsThese towering baobabs line a road near Morondava, Madagascar. Their enormous trunks store water, helping the trees survive long dry periods in their native environment.The post 15 Random Photos That Hopefully Help You Learn Something appeared first on Den of Geek.