23강 물리, 화학, 생명과학, 지구과학
Gateway 혼돈 현상이 나타나는 조건
A good example of chaos is the ____ pendulum sold as an executive toy.
It has four magnets arranged in a square at the base and a pendulum that swings ____ and forth between them.
____ the pendulum and note the magnets that it visits, and in what order.
If the pendulum is released from the same position a second time, the pattern of movement may at first be the ____ but soon it will become completely different.
In fact, the pattern of its ____ is chaotic.
No matter how much care is taken to start the pendulum in the same position, it will visit an ____ different set of points on the two occasions.
Chaotic systems are generated by iteration, though not all iteration leads to ____.
In order to ____ chaos, the iteration has to be within what is called a nonlinear system.
Nor are all nonlinear systems ____: to become so they need to be pushed beyond a certain point, called a bifurcation.
Before that ____ is reached they may behave in a quite orderly fashion.
Exercises 1 상대 속도와 운동량 개념
There is one important ____ to note about momentum.
Since motion is relative, ____ relative velocities are relevant.
In fact, when you think ____ it, all velocities are relative.
Thus, on the surface of the earth, we ____ reckon velocity with respect to the ground — the velocity of the earth itself does not matter.
There is a true ____ of a French pilot in World War II who stretched his hand out of his small airplane window and caught a bullet.
How is this ____?
The velocity of the bullet must have been about the same as the velocity of his ____.
This can ____, because a bullet slows down to such a velocity toward the end of its flight path due to the action of air drag.
Since only relative velocity matters, the momentum of the bullet was ____ as far as the pilot was concerned.
Thus, he ____ have had little problem in catching the bullet.
Exercises 2 Hipparchus의 업적
____ of Nicaea was the most important astronomer of the Hellenistic Age after Aristarchus of Samos.
Unlike Aristarchus, Hipparchus ____ in the geocentric universe of Aristotle.
A noted mathematician, Hipparchus gauged the movement of the ____ and the moon using an astronomical model devised by Apollonius of Perga.
Hipparchus worked at Alexandria and Rhodes; at the latter city, he created a kind of astronomical research ____ in which he cataloged the stars according to brightness.
He ____ a star chart of about 850 stars, tracking their movements and relative brightness.
Hipparchus ____ more accurate measurements than Aristarchus did of the distance of the moon and sun from the earth.
To account for the orbit of the sun around the earth he developed the idea of the eccentric, ____ Ptolemy of Alexandria would expand upon.
Exercises 3 미생물의 광범위한 존재
Living things are not ____ to the familiar temperate realm of land, water, and sunlight inhabited by plants and plant-eating animals.
They can be found in the darkest depths of the ocean, in ____ volcanic mud, in pools beneath the frozen surface of the Antarctic, and buried kilometers deep in the Earth's crust.
The creatures that live in these extreme environments are generally ____, not only because they are inaccessible, but also because they are mostly microscopic.
In more homely habitats, too, most organisms are too small for us to see without special equipment: they tend to go unnoticed, unless they cause a ____ or rot the timbers of our houses.
Yet microorganisms ____ up most of the total mass of living matter on our planet.
Only recently, through new methods of molecular analysis and specifically through the analysis of DNA sequences, have we begun to get a picture of life on Earth that is not grossly distorted by our biased perspective as large ____ living on dry land.