In such a way he is incorrect to imagine that the Sun every day appears accurately on the point cardinal East and if it puts in the West. This will only occur in the equinoxes, that is, in two occasions during the year. The way as books describes the methods of localization of the points cardinals in the truth allows that the pupil only finds the region approach where if he locates each one of them. It fits to the professor to leave clear to the pupil this situation. Some books still affirm that a method sufficiently practical to meet the point South cardinal is to use itself the constellation of the Southern Cross as reference. However, such constellation nor always will be visible in position shown for the didactic book or, many times, not even will be visible, therefore she will be very next to the horizon or below to the same, depending on the latitude where if it finds the observer. Shades to the noon Some didactic books affirm that to the noon the shade of an object if would only concentrate below of it, since the Sun would be accurately in the zenith. (BOCZKO, 1998).
Such information, however, is not accurately correct, since for places contained between the tropics the situation can occur, in the maximum, 2 days per year. In if treating to places on the tropics, it will occur in only one occasion during the year, (in the solstice of the corresponding summer). In the high latitudes never the shade will be observed in the vertical line to the noon (by the way, in schedule none). The best information that the didactic books would have to give to this respect would be that the shade of the object, to the noon, is shortest throughout the day. Stars ' ' pontudas' ' Comumente the didactic books represent the stars as being astros endowed with ' ' pontas' ' in several directions. One is about plus a situation where an image can harm the data understanding concept, therefore in the reality the stars are astros spherical and the such ' ' pontas' ' are only twinkles created for the fact of the light to estelar to cross the atmosphere of the Land. Comparison of brightness between planets and stars Exists little difference between a planet and a star when seen from the Land, being both shining astros, with the difference that this possesss proper light and that one it reflects only it. In such a way, it is difficult to the layperson in Astronomy to identify the planets in the sky.
In an attempt to nullify doubts regarding as to proceed, some didactic books present the idea of that it stops differentiating planets of stars is enough to make a comparison enters the brightness of both. This method is correct until certain point, therefore the planet presents, normally, brightness firmer than of a star, scintillating less than this. However, the method is not of all safe, therefore depending on the conditions atmospheric, the planets will reveal with so rocking brightness how much of a star. Moreover, in case that the planet if finds next very to the horizon, its light will have to cross one
| September 6th, 2020 | Posted in News |