23강 물리, 화학, 생명과학, 지구과학
Gateway 혼돈 현상이 나타나는 조건
A good example ____ chaos is the magnetic pendulum sold as an executive toy.
It has four magnets arranged in ____ square at the base and a pendulum that swings back and forth between them.
Release the pendulum and note the magnets ____ it visits, and in what order.
If the pendulum is released from ____ same position a second time, the pattern of movement may at first be the same but soon it will become completely different.
In fact, the pattern of its movement ____ chaotic.
____ matter how much care is taken to start the pendulum in the same position, it will visit an entirely different set of points on the two occasions.
Chaotic systems are generated by iteration, though not all iteration leads ____ chaos.
In ____ to produce chaos, the iteration has to be within what is called a nonlinear system.
Nor are all nonlinear systems chaotic: to become so they need to be pushed beyond ____ certain point, called a bifurcation.
Before that point is reached ____ may behave in a quite orderly fashion.
Exercises 1 상대 속도와 운동량 개념
There is ____ important thing to note about momentum.
Since motion is relative, only relative ____ are relevant.
In fact, when you think about it, all ____ are relative.
Thus, on the surface of the earth, we always reckon ____ with respect to the ground — the velocity of the earth itself does not matter.
There is a true story of a French pilot in World War II who stretched his hand out of his small airplane window and caught ____ bullet.
How ____ this possible?
The velocity of the bullet must have been about the same as the ____ of his plane.
This can happen, because a bullet slows down to ____ 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 negligible as ____ as the pilot was concerned.
Thus, he would have had little problem ____ catching the bullet.
Exercises 2 Hipparchus의 업적
Hipparchus of Nicaea was ____ most important astronomer of the Hellenistic Age after Aristarchus of Samos.
Unlike Aristarchus, Hipparchus believed in the geocentric universe ____ Aristotle.
A noted mathematician, Hipparchus gauged the movement of the sun and the moon using an ____ model devised by Apollonius of Perga.
Hipparchus worked at Alexandria and Rhodes; at the latter city, he created ____ kind of astronomical research center in which he cataloged the stars according to brightness.
He produced a star ____ of about 850 stars, tracking their movements and relative brightness.
Hipparchus made more accurate measurements than Aristarchus did of the distance of the moon ____ sun from the earth.
To account for the orbit of the sun around the earth he developed the idea of the eccentric, which Ptolemy of Alexandria would expand ____
Exercises 3 미생물의 광범위한 존재
Living things are not confined to the familiar temperate realm of land, water, and ____ inhabited by plants and plant-eating animals.
They can be found in the darkest depths of the ocean, in hot volcanic mud, in pools beneath ____ frozen surface of the Antarctic, and buried kilometers deep in the Earth's crust.
The creatures that live in these extreme environments are generally unfamiliar, not only because they ____ inaccessible, but also because they are mostly microscopic.
In more homely habitats, too, most ____ are too small for us to see without special equipment: they tend to go unnoticed, unless they cause a disease or rot the timbers of our houses.
Yet microorganisms make up most of the total mass of living matter on our ____
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 ____ our biased perspective as large animals living on dry land.