Page 135 - PowerPoint Presentation

OPTIĈKE POJAVE PRI ZALASKU SUNCA

OPTICAL PHENOMENA AT SUNSET

Autor: TEODORA RISTOSKI Učenica VIII razreda OŠ ”Karađorđe”, Beograd

Mentor: ALEKSANDRA DIMID, dipl.fizičar Fizički fakultet Beograd

REZIME

Sunčeva svetlost predstavlja mešavinu svetlosti svih boja. Atmosfera sadrži mnoge čestice zraka, prašine,
vodene pare i nečistode. Kada svetlost prolazi kroz atmosferu, spomenute čestice rasipaju različite boje.
Pri zalasku sunca do našeg oka stiže svetlost sa najvedim talasnim dužinama (crvena i žuta) pošto se takva
svetlost najmanje rasejava. Da bi objasnili rasejanje svetlosti izveli smo Tindalov eksperiment u cilju
otkrivanja zavisnosti propuštene svetlosti i njenog rasejanja u odnosu na talasnu dužinu. Propuštanjem
svetlosti kroz koloidni sistem (mleko i destilovana voda), dolazi do rasejanja svetlosti u svim pravcima na
koloidnim česticama. Što je koloidni sistem gušdi, vede je rasejanje svetlosti. Ovde se primeduje da
svetlosni zraci kradih talasnih dužina bivaju bolje rasejani, pa boja rasejanog svetla dobija plave nijanse.
Najviše se rasejavaju talasi kratkih talasnih dužina. Rezultati su prikazani kroz sumiranje i interpretaciju
prethodnih saznanja i zaključaka do kojih se došlo istraživanjem.

Ključne reči: Rasejanje, refleksija, zalazak Sunca

SUMMARY

Sunlight is the mixture of light of all colors. Atmosphere contains numerous particles of air, dust, aerated
water and impurities. When light penetrates the atmosphere, the mentioned particles scatter different
colors. At Sunset, the light that reaches our eye has the highest wavelength (red and yellow), since this
type of light disseminates the least. The Tyndall experiment was conducted in order to explain light
dissemination: the goal is to reveal the connection between transmitted light and light dissemination in
relation to wavelengths. When light passes through a colloidal system (milk and distilled water), the light
dissipates in all directions on colloidal particles. The more dense a system, the greater light dissipation.
The experiment revealed that light rays having shorter wavelengths are better dissipated, which means
that the color of the dissipated light gets bluish shades. The waves with short wavelengths dissipate the
most. The presented results are based on the summary and interpretation of the acquired knowledge
and conclusions provided by this research.

Key words: Scattering, Reflection, Sunset