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Guia visualA seed that twists its way into soil
How can a grass seed move itself? Cooke describes a cultivated grass whose long awn responds to moisture. 🌱 Moisture loosens the lower twisted awn. As it untwists, it turns the feathery upper part. 💧 Then the awn dries and twis…
Vídeo curtWhy Easier Gears Turn Less
Why does an easier bicycle gear turn the wheel less uphill? The chain links the front chainring to a rear sprocket, carrying crank motion to the wheel. Divide front teeth by rear teeth: the ratio gives wheel turns per crank revol…
The Strait of Messina’s Shifting Sea
Loudon called the sight the Fata Morgana, placing it in the Bay of Reggio, in Sicily’s Strait of Messina. Loudon said the sea could seem like magic glass, reflecting multiplied castles, towers, avenues, plains, herds, and flocks.…
The Bear’s Unsuccessful Escape
In A Hundred Anecdotes of Animals, a captured bear cub, tethered by the neck to a whaler, swam to an ice floe and tried to get free. At a crack in the ice, it let the rope fall into the opening, lowered its body into the crack, a…
VisualA Green Day on the Hillside
Tactile grass and glossy leaves catch the light in a quiet green landscape. A gentle breeze seems to move across the rolling hills. /media/aiimages/813c8eaa-0ae3-44a8-9608-5f7d4e4a9ec5.png
Vídeo curtThe Waterfall Hidden Beneath the Ocean
Between Greenland and Iceland, cold water spills through the Denmark Strait. But this isn’t water falling through air. It’s a current flowing through other water. Cold water is denser than the warmer water around it. So gravity d…
How Ronald Reagan swore in Alan Greenspan as Fed chair
[02:19] Reagan Explains How the Fed Defeated Runaway Inflation [06:26] Economics Is More Than Numbers: Reagan's Tribute to Greenspan [07:06] George H.W. Bush Swears In Fed Chairman Alan Greenspan [09:59] Alan Greenspan's Hilariou…
How Civil War soldiers turned rain gear into board games
[01:10.000] Civil War Soldiers Hid Board Games on Rain Blankets [01:55.200] How to Play Chuck-a-luck: The 19th Century Dice Game [04:25.250] The Big Payout in Civil War Chuck-a-luck
How a 1961 USIA film portrayed divided Berlin
[01:39] Why Berlin Kept a Ruined Church in Its City Center [02:08] When Soviet and American Soldiers Celebrated Victory Together [03:14.000] How Allied Agreements Divided Postwar Berlin [05:38.400] How a 1961 USIA Film Portrayed…
How four men conquered North America's highest peak in 1913
[01:07.600] Climbing Denali Before Modern Airplanes Existed [01:54] Disaster After Disaster on the First Denali Ascent [03:41] The Unlikely Crew That Conquered Denali [04:18.000] The 21-Year-Old Who Made Mountaineering History
Elite skiers and Ivy League soldiers in the Italian Alps
[04:42.000] The Olympic Skiers Who Fought in WWII [07:55] Dropping a Mortar Round Down the German HQ Chimney [10:10] The Overlooked Cost of Combat Patrols [10:46] What Veterans Told Recruits About the Front Line [14:50] Why One S…
The unsung frontline history of American combat nurses
[02:30] George Washington's Two-Dollar Nurses [05:40] 57,000 Nurses Answer the Call in WWII [07:26] The Angels of Anzio Treated Even Their Attackers [08:52] When Combat Nurses Walked in Beauty [10:54] Field Hospitals Where Tents…
Christmas on the front lines of the Korean War
[01:43] Frontline soldiers sing carols around a fire [04:06.000] Singing for peace across the battlefield [06:29] A frontline jeep driver sends love back home [09:26] Major General McGarr Delivers a Korean War Christmas Address […
How park rangers make traditional homemade flour tortillas
[02:26] The Baker's Trick for Perfect Tortilla Portions [02:39] How to Roll Tortillas Like an Abuela [03:52] The 30-Second Rule for Cooking Tortillas [04:49] How Different Cultures Created Flour Tortillas
Edgar Allan Poe's The Raven read at Ford's Theatre
[00:14] The Haunting Opening of The Raven [02:52] The Stately Raven Steps Inside [06:40] Will He Ever See Lenore in the Afterlife? [07:06] Take Thy Beak From Out My Heart
Honoring John Philip Sousa at Congressional Cemetery
[01:51] Marine Band Tribute at John Philip Sousa's Grave [05:39.500] Marine Band Performs at Sousa's Gravesite [07:33] Remembering America's Most Iconic Military Musician [09:48.000] The Time John Philip Sousa Almost Ran Away to…
Vídeo curtMake This Dot Disappear
Close your left eye. Keep your right eye on the cross. Keep looking at the cross while slowly moving your phone closer and farther. At one distance, the dot should disappear. Pause here to try it. At the back of each eye, a nerve…
Army salvage divers tackle underwater rodeo training
[00:11] US Army Deep Sea Divers Emergency Briefing [01:21] Salvage Divers Descend on Umbilical Lines [05:38.800] Climbing a Pier Ladder in Diving Gear