23강 물리, 화학, 생명과학, 지구과학
Gateway 혼돈 현상이 나타나는 조건
A good example of chaos is the magnetic pendulum ____ as an executive toy.
It has four magnets ____ in a square at the base and a pendulum that swings back and forth between them.
Release the pendulum and note the magnets that it ____, and in what order.
If the pendulum is released from the same position a second time, the pattern of ____ may at first be the same 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 ____ an entirely different set of points on the two occasions.
Chaotic systems are generated by iteration, though not all ____ leads to chaos.
In order to produce chaos, the iteration has to be within what is ____ a nonlinear system.
Nor are all nonlinear systems chaotic: to become so they need to be pushed beyond a ____ point, called a bifurcation.
____ that point is reached they may behave in a quite orderly fashion.
Exercises 1 상대 속도와 운동량 개념
There is ____ important thing to note about momentum.
Since motion is ____, only relative velocities are relevant.
In fact, when you think about it, all velocities are ____.
Thus, on the surface of the earth, we always reckon velocity with ____ 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 ____ his hand out of his small airplane window and caught a bullet.
____ is 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 such a velocity ____ 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 far as the ____ was concerned.
Thus, he would have had little ____ in catching the bullet.
Exercises 2 Hipparchus의 업적
Hipparchus of Nicaea was the most important astronomer of the Hellenistic Age after Aristarchus of ____.
Unlike ____, Hipparchus believed in the geocentric universe of Aristotle.
A noted mathematician, Hipparchus gauged the movement of the sun and the moon using an astronomical model devised by Apollonius of ____.
Hipparchus worked at Alexandria and Rhodes; at the latter ____, he created a kind of astronomical research center in which he cataloged the stars according to brightness.
He produced a star chart of about ____ 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 ____ of the sun around the earth he developed the idea of the eccentric, which Ptolemy of Alexandria would expand upon.
Exercises 3 미생물의 광범위한 존재
Living ____ are not confined 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, ____ organisms 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 ____ 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 ____ as large animals living on dry land.