23강 물리, 화학, 생명과학, 지구과학
Gateway 혼돈 현상이 나타나는 조건
A good example of chaos is the magnetic pendulum sold as ____ executive toy.
It has four magnets arranged in a square at the base and a pendulum that swings back and forth ____ them.
Release the pendulum and note ____ magnets that it visits, and in what order.
If the pendulum is ____ from the 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.
No matter how much care is taken to start the pendulum in the same position, it will visit an entirely different set of points ____ the two occasions.
Chaotic systems are ____ by iteration, though not all iteration leads to chaos.
In order to produce chaos, the ____ has to be within what is called a nonlinear system.
Nor are all nonlinear systems chaotic: to become so they need ____ be pushed beyond a certain point, called a bifurcation.
Before ____ point is reached they may behave in a quite orderly fashion.
Exercises 1 상대 속도와 운동량 개념
____ is one important thing to note about momentum.
Since motion is relative, only relative velocities ____ relevant.
In fact, when you think about it, all velocities are ____
Thus, on the surface of the earth, we always reckon velocity with respect to the ground — the velocity of the earth itself ____ not matter.
There is a true story of a French pilot in World War II who stretched his hand out ____ his small airplane window and caught a bullet.
____ is this possible?
The velocity of the bullet must have been about the ____ as the velocity of his plane.
This can happen, because a bullet ____ 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 negligible as far as the pilot was ____
Thus, he would have had little ____ in 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 ____ geocentric universe of Aristotle.
A noted mathematician, Hipparchus gauged the movement of the sun and ____ moon using an astronomical model devised by Apollonius of Perga.
Hipparchus worked ____ Alexandria and Rhodes; at the latter city, he created a 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 and ____ from the earth.
To account for the orbit of the sun around the earth he developed the idea of ____ 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 hot volcanic mud, in pools beneath the frozen surface of the Antarctic, and ____ kilometers deep in the Earth's crust.
The creatures that live in ____ extreme environments are generally unfamiliar, 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 ____ special equipment: they tend to go unnoticed, unless they cause a disease or rot the timbers of our houses.
____ microorganisms make 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 ____ as large animals living on dry land.