You may be wondering, how can a glacier get so big? Why does it move? These are both good questions. In the winter months, precipitation falls as snow. This solid form of water builds up on the ground as long as the temperatures stay cold enough. As the temperature rises, the snow starts to melt. The frozen water changes state back into a liquid state. Nearer the poles, summer does not last very long. If the summer is long enough and warm enough, all the snow may melt. This is what typically happens now. The earth was a little cooler 12,000 years ago. As a result, during the summer months, that amount of snow did not melt. It may have only been an inch or so of snow that melted. The following winter, snow fell on top of this left-over snow. This next winters snowfall had a head start. Year after year, the snow that did not melt became thicker and thicker. Inch by inch the snow started to build up. Over many years, layer upon layer of snow compacted and turned to ice.

Question: "What climate is needed for glaciers to form."

OPTIONS:
- no
- yes

Answer: "Warm"

Response: no

Tokugawa Takes All: When Hideyoshi died in 1598, he hoped to have his five-year-old son continue his "dynasty," initially under the tutelage of five regents. But one of the regents was Ieyasu Tokugawa, who had been biding his time at Edo for 12 years, nurturing dynastic ambitions of his own. Of the cunning, ruthless triumvirate that came out on top at the end of the country's century of civil war, Tokugawa was without doubt the most patient, the most prudentand most treacherous. He moved quickly to eliminate his strongest rivals, crushing them in 1600 at the great Battle of Sekigahara (near modern Nagoya). During its subsequent two and a half centuries of rule from the new capital established at Edo, the Tokugawa organized a tightly controlled coalition of some 260 daimyo in strategic strongholds throughout the country. The allegiance of this highly privileged and prestigious group was ensured by cementing their ethical principles in the code of bushido, "The way of the warrior": loyalty to one's master, defense of one's status and honor, and fulfillment of all obligations. Loyalty was further enforced by holding the vassals' wives and children hostage in Edo. All roads into Edo, the most famous being the Tokaido Highway, had checkpoints for guns coming in and for wives going out. One of the most effective ways of keeping a tight rein on the country was to cut it off from the outside world, to keep Japan Japanese. At first, Ieyasu Tokugawa was eager to promote foreign trade. He wanted silk and encouraged the Dutch and British as good, nonproselytizing Protestants just interested in trade. But he didn't like the Portuguese and Spanish Catholic missionaries, who he felt were undermining traditional Japanese values. He banned their activities in 1612 and two years later ordered the expulsion of all missionaries and unrepentant Japanese converts. Executions and torture followed. Converts were forced to renounce their faith by trampling crucifixes and effigies of Jesus and Mary. The Catholic Church has counted 3,125 martyrs in Japan from 1597 (beginning under Hideyoshi) to 1660. In 1635 the Japanese were forbidden, on pain of death, to attempt to travel abroad, and Japanese citizens already overseas were prevented from returning, in case they brought back subversive Christian doctrines. Western books were banned, as were Chinese books that mentioned Christianity.

Question: "Who wanted silk and also encouraged the Dutch and British as good, non-proselytizing Protestants just interested in trade?"

OPTIONS:
- no
- yes

Answer: "Ieyasu Tokugawa"

Response: yes

The Golden Heian Era: The geomancers in 794 decided that Heian-kyo (modern Kyoto) would be an auspicious site for the imperial family. It was indeeduntil 1869. Grants of tax-free land over the years had been made to Buddhist temples and members of the court aristocracy. The most powerful families thus carved out for themselves whole regions that were to become the fiefdoms of Japanese feudalism. By the end of the eighth century the clans had created a hierarchy of shiki, or rights, from the highest to the lowest ranks of society. The aristocrat or court patron lent his prestige to a powerful provincial proprietor, who employed a competent estate-manager to oversee smallholders, who in turn worked their farms with dependent laborers. This elaborate structure of interdependent rights and obligations was to serve Japanese society right into the 20th century. Meanwhile, Heian court life blossomed in an effusion of aesthetic expression. Princes and princesses judged the merits of birds, insects, flowers, roots, or seashells. Literary party games held in ornate palace gardens required each guest to compose a small poem as his wine cup floated toward him along a miniature winding channel of water. Expeditions were organized to the best viewing points for the first spring cherry blossoms, and special pavilions were built to watch the rising of the full moon. Every gesture, from the most banal opening of an umbrella to the sublimest act of lovemaking, had its appropriate ceremonial. Conversation often took the form of elegant exchanges of improvised verse. The changing role of Chinese culture in Japanese life was epitomized in the language itself. In the absence of an indigenous alphabet, Japanese scholars had with the greatest difficulty tried to adapt the complex ideograms of monosyllabic Chinese to the essentially polysyllabic Japanese. Thus developed the katakana system used as a vehicle for writing Buddhist names and concepts. After rival Fujiwara factions had been struggling for years to gain control of the imperial throne, they turned to the Taira and Minamoto armies in 1156 to wage the four-year war that heralded the end of the golden age of the Heian court. The Taira, controlling the region along the Inland Sea, defeated the Minamoto armies based in the Kanto province east of the capital.

Question: "Why were the most powerful families able to obtain whole regions for themselves?"

OPTIONS:
- no
- yes

Answer: "Atta's personalities"

Response: no

You may wonder if there are other examples of static discharge. The answer is yes. Lightning is a form of static discharge. It is much more dramatic than what happens between you and the door knocker, but it is the same principle. You can see how it occurs in the following diagram and animation. You have no doubt seen lightning in a rainstorm. What does lighting have to do with static electricity? As it turns out, everything! During a rainstorm, clouds develop regions of different charges. This happens due to the movement of air molecules, water drops, and ice particles. The negative charges are concentrated at the base of the clouds. The positive charges are concentrated at the top. The negative charges repel electrons on the ground below. The ground then becomes positively charged. Over time the differences increase. Eventually the electrons are discharged. This is what we see as lightning. You can watch an awesome slow-motion lightning strike below.

Question: "How is the top of a cloud different from the base of the cloud during a rainstorm?"

OPTIONS:
- no
- yes

Answer: "He negative charges repel electrons on the ground below"

Response:
no