Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to ascertain the nature of the astronomical objects, rather than their positions or motions in space". Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.
Education is the process of facilitating learning, or the acquisition of knowledge, skills, values, beliefs, and habits. Educational methods include storytelling, discussion, teaching, training, and directed research. Education frequently takes place under the guidance of educators, but learners may also educate themselves. Education can take place in formal or informal settings and any experience that has a formative effect on the way one thinks, feels, or acts may be considered educational. The methodology of teaching is called pedagogy.
We must encourage [each other] once we have grasped the basic points to interconnecting everything else on our own, to use memory to guide our original thinking, and to accept what someone else says as a starting point, a seed to be nourished and grown. For the correct analogy for the mind is not a vessel that needs filling but wood that needs igniting no more and then it motivates one towards originality and instills the desire for truth. Suppose someone were to go and ask his neighbors for fire and find a substantial blaze there, and just stay there continually warming himself: that is no different from someone who goes to someone else to get to some of his rationality, and fails to realize that he ought to ignite his own flame, his own intellect, but is happy to sit entranced by the lecture, and the words trigger only associative thinking and bring, as it were, only a flush to his cheeks and a glow to his limbs; but he has not dispelled or dispersed, in the warm light of philosophy, the internal dank gloom of his mind.
Plutarch, On Listening to Lectures.