{"group":"life","pic":"living/pics/flying-pedal.webp","question":"Can you fly on Mars?","answer":"Like a bird, under glass. In the great dome's thick air you pedal a plane like a bike and lift off over the orchard. Outside, long-winged tour planes carry you over the Grand Canyon of Mars at sunrise.","play":{"label":"Walk Arcadia City","href":"play/"},"lift":{"title":"The same wing, three skies","line":"Lift comes from air pushing on a wing. Pick a sky and see how much lift the same wing gets, against the weight it has to hold up.","lift":"Lift","weight":"Weight","skies":[{"id":"earth","name":"Earth","text":"Thick air and full weight: lift and weight balance, so the plane flies."},{"id":"mars","name":"Mars, outside","text":"The air gives only {fl_lift_pct}% of the lift. To fly, the wing would need about {fl_wing_x} times the area, so the tour planes fly fast on very long wings."},{"id":"dome","name":"The great dome","text":"The dome's air is {fl_dome_pct}% as dense as Earth's, and you weigh {g_pct}%: plenty of lift to pedal into the sky."}]},"dome_title":"The great dome","dome":[{"icon":"wave","title":"A roof of water","text":"About {roof} m of water between two skins of glass keeps the radiation out and the light soft and rippling."},{"icon":"air","title":"Air like home","text":"The dome holds the city's own air, {fl_dome_pct}% as dense as Earth's: thick enough for a wing."},{"icon":"plane","title":"Pedal planes","text":"Long wings of clear film on a carbon frame. You pedal like on a bike and the propeller pulls you up."},{"icon":"leaf","title":"A runway through the orchard","text":"A long strip of grass between the fruit trees, for gentle take-offs and soft landings."}],"power":{"title":"A third of the effort","line":"A pedal plane like the Gossamer Albatross needs about {earth_w} W to stay up on Earth. In the dome it needs about {fly_w} W: {easier_x} times less, because you weigh less and the air still holds you.","earth":"On Earth","dome":"In the dome","w":"W"},"canyon":{"title":"The Grand Canyon of Mars, to scale","line":"The tour planes fly over a canyon {canyon_x} times as deep as Arizona's: deep enough to hide Everest with {canyon_room_m} m to spare.","mars":"Grand Canyon of Mars","gc":"Grand Canyon, Arizona","everest":"Everest","scale":"Depths drawn to scale"},"earth_mars":{"earth":{"head":"Thick air holds you up"},"mars":{"head":"The air is almost empty"},"pics":{"earth":"living/pics/em-flying-earth.webp","mars":"living/pics/em-flying-mars.webp"},"rows":[{"label":"The air","icon":"air","earth":"Thick enough for wings, kites and gliders.","mars":"Only {fl_lift_pct}% as dense as Earth's."},{"label":"Your weight","icon":"walk","earth":"Your full weight to hold up.","mars":"{g_pct}% of it."},{"label":"The great canyon","icon":"globe","earth":"The Grand Canyon is {fl_gc_km} km deep.","mars":"The Grand Canyon of Mars is {valles_km} km deep: {canyon_x} times as deep."}]},"pin":[0.52,0.33],"scene":{"pic":"living/pics/scene-flying.webp","look":"05-17","shot":"orchard","focus":"50% 50%","spots":[{"at":[0.5,0.07]},{"at":[0.75,0.3]},{"at":[0.33,0.43]},{"at":[0.25,0.76]}]},"proof":{"pic":"living/people/flying-proof.webp","place":"Kill Devil Hills, North Carolina","when":"{fl_wright_date}","head":"Wing cloth that flew on two worlds","credit":"Photo: John T. Daniels (public domain)"},"fact":"The Wright brothers' first flight lasted {fl_wright_s} seconds. {fl_wright_gap} years later, a scrap of its wing cloth flew again, tucked under Ingenuity's solar panel, on Mars.","quiz":[{"q":"How dense is the air outside on Mars, compared with Earth's?","a":["About {fl_lift_pct}%","About half","About the same"],"why":"Mars's air is only {fl_lift_pct}% as dense as Earth's, so a wing gets almost no grip on it.","more":"Ingenuity drew about {ing_w} W in flight, all of it from six small batteries charged by its solar panel.","cite":"02-01 F-04, 03-03 F-18","from":"problem","fig":0,"icon":"air"},{"q":"What powers the planes in the great dome?","a":["The pilot, pedalling like on a bike","A small rocket","Rotors, like a helicopter"],"why":"The dome's thick air and the pilot's lighter weight make muscle power enough.","more":"In 1979 an amateur cyclist, Bryan Allen, pedalled the Gossamer Albatross all the way across the English Channel.","cite":"05-17 LV-06, F-01","from":"fix","fig":2,"icon":"plane"},{"q":"How much less pedalling does a plane need in the dome than on Earth?","a":["About {easier_x} times less","The same","Twice as much"],"why":"You weigh {g_pct}% as much and the air is still thick, so the power falls to about a third.","more":"The Grand Canyon of Mars runs about {valles_l_km} km, long enough to stretch from California to New York.","cite":"05-17 LV-06, 02-01 F-51","from":"why","fig":0,"icon":"bolt"}],"notes":[{"beat":"fix","text":"Before the great dome rises, Arcadia flies over the Grand Canyon of Mars in pressurised tour planes with long, slender wings.","cite":"05-17 LV-06, LV-08"}],"everyday":{"title":"A flying day","items":[{"time":"06:40","head":"Over the rim at first light","text":"The tour plane glides along the canyon rim in the half dark, everyone at the windows, waiting for the Sun.","tag":"{canyon_x} times Arizona's depth","pic":"living/pics/flying-canyon.webp","pos":"60% 50%"},{"time":"07:00","head":"Sunrise over the canyon","text":"The Sun climbs over the rim in its cold blue glow, and fog lies in the canyon floor below.","tag":"{valles_km} km deep","pic":"living/pics/em-flying-mars.webp","pos":"50% 45%"},{"time":"15:00","head":"Pedalling over the orchard","text":"Back home, a lazy loop above the fruit trees, waving at friends on the path.","tag":"{fly_w} W of pedalling","pic":"living/pics/scene-flying.webp","pos":"33% 45%"}]},"living":"On rest sols the great dome hums with wings. You climb into a pedal plane at the end of the runway, pedal hard for a few seconds and lift off over the orchard, slow enough to wave at friends below. Once in a lifetime you fly out at dawn and watch the Sun light the walls of the Grand Canyon of Mars.","from":"From the great dome","later":{"pics":{"city":"living/pics/flying-canyon.webp","far":"living/pics/flying-pedal.webp"},"city":{"tag":"Canyon flights","text":"Pressurised tour planes with long wings fly over the Grand Canyon of Mars at sunrise."},"far":{"tag":"Pedal planes","text":"In the great dome's thick air, anyone can pedal a plane into the sky."}}}