team of russia
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Team of RussiaTeam of RussiaPresented by Nikita Shanin
Problem №17 «Vikings»:According to a legend, Vikings were able to navigate in an ocean even during overcast (dull) weather using tourmaline crystals. Study how it is possible to navigate using a polarizing material. What is the accuracy of the method?
Plan of solution
Problem analysis
Theory research
Checking of the model in practice
Method’s accuracy estimation
Physical model of the phenomenon
Conclusion
Nikita Shanin IYPT 2011 2
Polarization of light wave
– unpolarized wave
– plane-polarized (linearly polarized) wave
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Polarization methods
Initial wave
Final wave
Filter
transmission plane of linear polarizer
Oscillation’s direction
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1
2
Polarization methods
Initial wave
Scattering medium
Plane-polarized wave
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Dipole radiation
Physical model
To identity the circle, which passes though a point of sun and arbitrary point:1. To analyze the arbitrary point using filter and to find the darkest filter position2. Perpendicular to oscillation plane shows the required circle
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HSB model
Hue – vary from 0° up to 360°
Saturation –, vary from 0 up to 100
Brightness – vary from 0 up to 100
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Conclusion
It’s impossible to navigate according this method during overcast weather
Error of sun position detection amounts to about 27 degrees
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Reference
Мякишев. Физика: Оптика 10-11 кл. 4-еизд. М:Дрофа, 2002; 480с.
Viking navigation hypothesis under foggy and cloudy skies requires more light (physorg.com, February 27,2007), www.physorg.com/pdf91798327.pdf
Leif K. Karlsen: Secrets of the Viking navigators (nordskip.com), http://www.nordskip.com/vkarlsen.html
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