Izvleček
V prispevku opišem učni dejavnosti, povezani z nam najbližjo zvezdo – Soncem. Pri prvi učenci ponovijo poskus, ki ga je leta 1800 izvedel znameniti britanski astronom William Herschel, pri čemer je po naključju odkril infrardečo svetlobo. Učenci se ob tem poskusu naučijo, da je Sončeva svetloba, ki ji pogosto pravimo vidna oziroma bela svetloba, v resnici sestavljena iz mešanice barv. Izvejo tudi, da obstaja očem nevidna, infrardeča svetloba in da ta veliko učinkoviteje greje predmete, na primer termometre, kot bela svetloba. Pri drugi dejavnosti učenci izdelajo kamero obskuro, ki jo uporabijo za opazovanje Sončevih peg. Te pege narišejo na bel papir ter primerjajo risbe, ki jih naredijo v obdobju več dni ali tednov. Naučijo se, da Sončeve pege navidezno spreminjajo svojo lego na Sončevem disku, s tem pa ponovijo odkritje velikega znanstvenika Galilea Galileja, namreč, da se Sonce vrti. Če je opazovanj dovolj, učenci lahko celo ocenijo vrtilno dobo Sonca.
Abstract
Two Experiments with Sun
The author describes two experiments related to our closest star, the Sun. As part of the first activity, students replicate an experiment by the famous British astronomer William Herschel in 1800, when he serendipitously discovered infrared light. Through this activity, students learn that sunlight, which we often call visible or white light, consists of all possible colours. They become aware of the existence of infrared light, which is invisible to the eye but much more efficient at heating objects, such as thermometers, than white light. As part of the second activity, students construct a camera obscura to observe sunspots. They draw these spots on a piece of white paper and compare their drawings over a period of several days or weeks. By noticing that sunspots seem to change their position on the Sun‘s disk, they can confirm the great scientist Galileo Galilei‘s discovery that the Sun rotates. With enough observations, students can even estimate the rotation period of the Sun.