23강 물리, 화학, 생명과학, 지구과학
Gateway 혼돈 현상이 나타나는 조건
____ good example of 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 that ____ visits, and in what order.
If the pendulum is released ____ 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 is ____
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.
____ systems are generated by iteration, though not all iteration leads to chaos.
In order to produce chaos, the iteration ____ to be within what is called a nonlinear system.
Nor are all nonlinear systems chaotic: to become so they need to be pushed ____ a 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 one important ____ to note about momentum.
Since motion is relative, ____ relative velocities are relevant.
In fact, ____ you think about 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 ____ true story 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 ____ same as the velocity of his plane.
This can happen, because a bullet slows down to such a velocity toward the end of its flight path due to ____ action of air drag.
Since only relative velocity matters, the momentum of the bullet was negligible ____ far as the pilot was concerned.
Thus, he would have had little problem in ____ the bullet.
Exercises 2 Hipparchus의 업적
Hipparchus of Nicaea ____ the 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 the moon using an astronomical model devised by ____ of Perga.
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 ____ 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 ____ idea of the eccentric, which Ptolemy of Alexandria would expand upon.
Exercises 3 미생물의 광범위한 존재
Living things are not confined to the familiar temperate realm of land, water, and sunlight inhabited by ____ and plant-eating animals.
They can be found in the darkest depths of the ocean, in hot volcanic mud, in pools ____ 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 unfamiliar, not only because they are inaccessible, but also because they are ____ microscopic.
In more homely habitats, too, most organisms are too small for us to see without ____ 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 ____ 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 ____ is not grossly distorted by our biased perspective as large animals living on dry land.