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Alexey Abrikosov, jr . Institute of Theoretical and Experimental Physics, Moscow, Russia Andrei Varlamov COHERENTIA, CNR

Winter Alpine Physics. Alexey Abrikosov, jr . Institute of Theoretical and Experimental Physics, Moscow, Russia Andrei Varlamov COHERENTIA, CNR-INFM, Rome, Italy. Speed scales. 0 50 100 150 200 250 km/h. 248 . 1 km/hr!.

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Alexey Abrikosov, jr . Institute of Theoretical and Experimental Physics, Moscow, Russia Andrei Varlamov COHERENTIA, CNR

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  1. Winter Alpine Physics Alexey Abrikosov, jr. Institute of Theoretical and Experimental Physics, Moscow, Russia Andrei Varlamov COHERENTIA, CNR-INFM, Rome, Italy

  2. Speed scales 0 50 100 150 200 250 km/h

  3. 248.1 km/hr! Harry Egger,Austria, 1999. Speed skiing Monte Rosa glacier underMatterhorn; Maximum gradient— 62°

  4. LesArcs, France Speed skiing tracks

  5. Harry Egger Physics

  6. Free Fall Free fall from 1000 m

  7. Wind tunnel

  8. Physical factors in speed skiing • Gravity and angle • Air drag • Friction

  9. Bobsleigh & Luge The sport of bobsleigh began at the end of 19th century when the Swiss attached a steering mechanism to a toboggan. In 1897, the world's first bobsleigh club was founded in St. Moritz, Switzerland. Eugenio Monti (Italy) won 11 world championships (1957–1968 );

  10. Nagano, 1998, 4-man event Sigulda bob & luge track Track and speed

  11. Addends of victory Push Ride Win!

  12. Inertial frame Noninertial frame Centripetal versus centrifugal

  13. New! New! Physical factors in bobsleigh • Initial impulse • Gravity • Air drag • Friction • Optimal trajectory

  14. Luge speed record 139.4 km/h Tony Benshoof

  15. A B The problem of optimal trajectory • What is the fastest way from A to B? • Is the straight way faster?

  16. Galileo’s hypothesis — the circular arc? Brachistochrone What is the path of quickest descent from A to B? The minimal time problem

  17. Mechanics —Maupertuis’ minimal action principle Optics — Fermat's minimal time principle Other minimum principles Brachistochrone— minimal time problem

  18. Cycloid Johann Bernoulli, 1697

  19. Alpine Skiing

  20. Special Slalom

  21. History of skiing • Cave drawing from Eastern Russia.(between 7000 and 5000 B.C.)

  22. The bindings were made of twisted willow from birch-roots. Telemark skis. Sondre Norheim(Telemark County, Norway, XIX century) • New skis were shorter (about 2 m 40 cm) than other skis used at that time.

  23. Fridtjof Nansen Norwegian arctic explorer, zoologist and statesman; Nobel Peace Prize 1922. 12 times national champion in skiing; World record for one-mile skating. The first to cross the mid-Greenland ice cap on skis (1888). 1890— book On Skis Over Greenland

  24. Nansen Gallery

  25. Telemark turn

  26. stem (faster) wedge (slow) parallel turn — Christiania Basics of alpine skiing

  27. Shiro Shimizu wedge stem Christiania Ski robots

  28. Skidding Work against friction A is proportional to swept area S

  29. No skidding • Easy to flex • Hard to twist • New geometry Hourglass contour widetip narrowwaist flared tail sidecut Carving revolution of 1990-ies

  30. Grenoble, 1968 K.Schranz, Austria J.Heuga, USA G.Perillat, France Optimal trajectory

  31. Main propelling force — Skiing without friction center of mass skis With and without friction

  32. Swing and parametric resonace

  33. center of mass skis Carving and acceleration

  34. Center of mass in motion

  35. center of mass skis Cross-country versus Alpine Cross country Alpine

  36. swing center of mass center of mass center of mass Cross country Cross country skis skis feet Alpine Alpine Acceleration

  37. What it looks like Ivica Kostelic, World Championin slalom, 2003

  38. Energy conservation Altitude loss and speed gain

  39. Acceleration (extension) Deceleration (flexion) Speed control • Passive — skidding and carving; • Active — flexion–extension.

  40. a — acceleration; V — velocity; s — distance; Bad (pastime) skier Good (sportive) skier = Energy pumping –

  41. New! winners; loosers Physical factors in alpine skiing • Gravity • Air drag (downhill, GS, SuperG) • Friction (skidding and carving) • Optimal trajectory (slalom) • Flexion-extension (slalom, GS)

  42. Anton Sailer Jean-Claude Killy Gallery of Alpine Glory - I

  43. Gustavo Thoeni Ingemar Stenmark Gallery of Alpine Glory - II

  44. Alexander Zhirov Alberto Tomba Gallery of Alpine Glory - III

  45. 1948 1972 Acknowledgements Yuriy Preobrajenskiy

  46. Skiing is not the bliss but a perfect substitute

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