The abstract considers the method of determining latitude by astronomical observations
Therefore, the stars of the second generation should contain more heavy elements. If we proceed from this sign, then our Sun obviously belongs to the stars of the second generation.
Methodical considerations. The average lifespan of stars, which is billions of years, does not make it possible to trace the evolution of a particular star during a more or less significant period of its existence. Even a hundred and a thousand years in the life of a star is a moment in a person’s life. Astronomers are helped by a method of comparison that is already familiar to us.
What cannot be achieved by observing the state of a single star can be accomplished by comparing stars of the same type but of different ages. Such an "age series" seems to replace the states of a single star that follow one another in time.
Most of their lives from the moment when thermonuclear reactions ignite in their bowels and until the moment of "burning out" of hydrogen, ordinary, "normal" stars are in a stable state.
Therefore, the main interest for science are the initial and final stages in their lives, when events unfold quite rapidly – the processes of "birth" and "death" of these cosmic bodies.
Latitude: definition by astronomical observations. Abstract
The abstract considers the method of determining latitude by astronomical observations
The height of the pole of the world above the horizon. Let us turn to Figure 12. We see that the height of the pole of the world above the horizon hр = Р РСN, and the latitude of the place j = РСОR. These two angles (ÐPCN and ÐСОR.) Are equal to each other as angles with mutually perpendicular sides: [OC] ^ [CN], [OR] ^ [CP].
The equality of these angles gives the simplest way to determine the latitude j: the angular distance of the pole of the world from the horizon, equal to the latitude. To determine the latitude of the area, it is enough to measure the height of the pole of the world above the horizon, because:
hp = j.
Daily movement of lights at different latitudes. We now know that as the latitude of the observation site changes, the orientation of the axis of rotation of the celestial sphere relative to the horizon changes. Consider how visible will be the movement of celestial bodies in the North Pole, at the equator and at mid-latitudes of the Earth.
At the pole of the Earth, the pole of the world is at its zenith, and the stars move in circles parallel to the horizon. Here the stars do not come and go, their height above the horizon is constant.
At mid-latitudes, stars rise and set, but there are some that never fall below the horizon. For example, the polar constellations in the latitudes of the USSR never enter. Constellations farther from the North Pole appear briefly above the horizon, and constellations at the South Pole do not descend.
But the further south the observer moves, the more southern constellations he can see. At the Earth’s equator, if the sun did not interfere during the day, in a day you could see the constellations of the entire starry sky.
For the observer at the equator, all stars rise and fall perpendicular to the horizon plane. Each star here passes over the horizon exactly half of its way. The North Pole of the world coincides for the observer with the point of the north, and the South Pole of the world coincides with the point of the south. The axis of the world lies in the plane of the horizon.
The height of the lights in the climax. The pole of the world in the apparent rotation of the sky, which reflects the rotation of the Earth around the axis, occupies a constant position above the horizon at a given latitude. The stars of the day describe above the horizon around the axis of the world circles parallel to the celestial equator. In this case, each luminary crosses the celestial meridian twice a day.
The phenomena of the passage of luminaries through the celestial meridian are called culminations. In the upper culmination, the height of the luminary is maximum, in the lower: – minimum.
Fig. 1. Daily paths of luminaries relative to the horizon for an observer who is: a – at the pole of the Earth; b – in the middle latitudes; in – at the equator.
In the luminary M1, which does not enter at a given latitude f, both culminations are visible (above the horizon), in stars that rise and fall (M1, M2, M3), the lower culmination occurs below the horizon, below the north point. In the M4 luminary, which is far south of the celestial equator, both culminations may be invisible (non-rising luminary).
The moment of the upper culmination of the center of the Sun is called the real noon, and the moment of the lower culmination is called the real north.
Find the relationship between the height h of the luminary M in the upper culmination, its inclination 6 and the latitude j. To do this, use Figure 16, which shows the vertical line ZZ ‘- the axis of the world PP’ and the projection of the celestial equator
We know that the height of the pole of the world above the horizon is equal to the latitude of the area, ie hr = j. Therefore, the angle between the noon line NS and the axis of the world PP ‘is equal to the latitude j, ie РРON = hp = j. It is obvious that the inclination of the plane of the celestial equator to the horizon, which is measured by ÐQOS, will be equal to 90 ° – j, since ÐQOZ. = РРON as angles with mutually perpendicular sides. Then the star M with inclination b, which culminates south of the zenith, has a height in the upper culmination:
h = 90 ° – j + 6 (1).
From this formula it is seen that the latitude can be determined by measuring the height of any luminary with a known inclination in the upper culmination. It should be borne in mind that when the luminary at the time of culmination is south of the equator, its inclination is negative.
The need for astronomical knowledge. Abstract
When studying cosmic phenomena, astronomers think primarily of the Earth. This is especially true of studies of other planets in the solar system that allow us to better understand our own space home.
It is often said that science does not give us credible knowledge about the world, that its conclusions do not seem to be trusted.
In this regard, we will consider the question related to the probability of those scientific data about the universe, which are one of the most important elements of the modern scientific picture of the world. These data also play a primary role in https://123helpme.me/write-my-lab-report/ shaping the worldview of man: because the worldview, as we already know – this is the attitude of man to the world, awareness of his place in it. This example is particularly illustrative also because, at first glance, of all the knowledge that science has, the knowledge of space objects and space processes is the least reliable.
In fact, almost all astronomical data are obtained by studying the various radiations that come to us from space, analyzing and interpreting the information that nature itself puts into them. But such indirect research is a rather difficult task. Between the physical process that takes place in space, and the conclusions of scientists who observe this process from Earth, there is a chain of many links. And at transition from each of them to the next these or those errors, inaccuracies and incorrect conclusions are possible. And it is not possible to check something directly as it is done, say, in physics or chemistry.
In addition, the astronomer often observes not the phenomenon itself, but only the change that this distant cosmic phenomenon causes in a device that registers, say, the deviation of an arrow or blackening of a photographic plate, or a curved line drawn on a tape recorder. And on the basis of these changes, he must, based on a certain model, draw conclusions about the nature of the phenomenon under study. However, the relationship between the readings of astronomical instruments and the nature of a cosmic process may not be clear. The same figures can be, in general, caused by completely different phenomena occurring in the universe.
Therefore, when interpreting the results of certain astronomical observations, there is often the possibility of different explanations of the same facts, and hence different conclusions about their nature.
Doesn’t all this mean that conclusions based on astronomical research cannot be trusted? And the question is broader: are remote research able to provide reliable information about the world around us?
To get answers to these questions, you need to be able to verify the data obtained. In recent years, thanks to the rapid development of rocket and space technology and the successful development of outer space, this opportunity has finally appeared.
"Space astronomy" was born before our eyes: with the help of spacecraft, measuring and television equipment is delivered directly to the areas of nearby celestial bodies and to their surface. The data obtained as a result of such research make it possible to compare the knowledge about the planets of the solar system, carefully accumulated by many generations of astronomers, with the new "space information".
Of course, space research methods make it possible to obtain more additional information than terrestrial astronomy, especially about the details of various phenomena in the world of planets. But in general, as it turned out, they not only did not refute the general system of ideas about the solar system, formed on the basis of astronomical research, but, on the contrary, confirmed its validity. This is an extremely important fact, the significance of which goes far beyond the actual planetary astronomy. He suggests that, despite the remote nature, astronomical research gives us credible knowledge about the universe.
It should also be noted that there is no fundamental difference between the process of scientific cognition of space objects and the process of cognition in other natural sciences, say, in the physics of elementary particles.
And in physics there is much inaccessible to our direct intervention – in general, any science at a certain stage of its development has its "limits of direct availability." But in these sciences, as well as in astronomy, such limits are successfully overcome.
However, in addition to the social roots of religion, there are also epistemological, associated with the process of knowing the world by man. Difficulties of the research process, the presence of unresolved scientific problems, the inability to cover a single theory of all the infinite variety of world phenomena, the discovery of unexpected facts that do not fit into the usual ideas and require their substantial revision, all these circumstances in the absence of consistent dialectical-materialist approach to the process knowledge of the world around us can be a source of idealistic and religious ideas.