2026年机经42

Let's talk about the French artist Edgar Degas. Even if you don't recognize them right away, you've likely seen his paintings of dancers. Edgar Degas is known for his depictions of ballet scenes— um, graceful dancers stretching or practicing. He was born in 1834, and many consider him a key figure in French Impressionism. Now, Impressionist artists were concerned with using bright colors, and the effects of light. They focused on capturing, well, impressions of a scene or a moment—people in boats, at a picnic. Very often, they painted outside and created beautiful landscape paintings. But Degas rejected the label of Impressionist for himself and his art. For one thing, he actually hated the idea of painting in the open air. He preferred the controlled environment of his studio, and he painted indoor scenes like Ballet Studio. Not landscapes. Degas saw himself as a realist. Realist art shows everyday people and things, but not in an idealized way. Unpleasant even. So, like the ballet dancers, he might be waiting around backstage, not often performing. Their faces might show that they're tired or uncomfortable. Later, Degas took up photography. He liked the sharpness of photographs, which isn't an Impressionist quality. As much as people might have liked to have seen his photos, I know I would have. He only shared them with people closest to him, and it's a bummer that less than 50 of them are still in existence.

For your group assignment next week, I've asked you to document your individual contributions. Some of you asked me why. The reason isn't only that I want to give everyone a fair grade. The main reason is actually rooted in psychology. In the late 1800s, a French agricultural engineer named Max Ringelmann conducted a simple experiment. He asked people to pull on a rope, first alone and then in groups. What he found was surprising: when people pulled in groups, the total force was less than the sum of individual efforts when pulling alone. In other words, people weren't pulling their weight when others were involved. This effect is called social loafing. Its existence was confirmed in later research. In a study in the late 1970s, researchers asked participants to cheer as loudly as they could, both alone and in groups. And individuals in groups made less noise per person than when cheering alone. But here's the good news: social loafing often has a solution. In a study in the 1990s, participants were asked to brainstorm uses for a common object, like a brick, under two situations. In one situation, participants worked in groups but were told their ideas would be individually identified and evaluated. In another situation, ideas were pooled anonymously. The results: when people knew their contributions would be linked to them personally, they generated higher quality responses. This shows that accountability and visibility can significantly decrease loafing. So basically, documenting your individual work for your upcoming group assignment will likely improve your overall project results.

Have you ever thought of termites as architects? It might sound a bit far-fetched, but these tiny insects do construct some of the most impressive structures in the animal kingdom—massive mounds with complex ventilation systems that function as natural air conditioning. These mounds, sometimes towering over 3 meters high, can be found in the savannas of Africa and Australia. Now, you might be wondering, how do termites, with their small size and limited resources, build such marvels? Well, it's all about teamwork and their incredible use of natural principles. Termite mounds are not just heaps of dirt; they are intricately designed with a network of tunnels and chimneys that manage airflow. By exploiting the temperature differences between the inside and outside of the mound, these structures regulate heat and moisture, essentially working as natural air conditioners. The ventilation system allows fresh air to flow in and out, maintaining a stable environment inside, crucial for the survival of its inhabitants. But there's a twist. These mounds also have a downside. During heavy rains, the structures can be prone to collapse, a significant issue for the colony. Yet, termites have adapted by rebuilding quickly, demonstrating resilience. By observing these industrious creatures, architects and engineers have been inspired to develop sustainable building designs for humans. The termite mounds exhibit how nature's design principles can be harnessed to create energy-efficient structures. It's a fascinating blend of biology and architecture, where the humble termite stands as a pioneer in sustainable living.

You may be familiar with Roman numerals, where the capital letter I means 1, the letter X means 10, etc. They were used in Europe until around the 16th century, when they were gradually replaced by Arabic numerals we use today. We typically say Arabic numerals, but it would be more precise to call them Hindu Arabic numerals, or Indo-Arabic numerals. While Arab mathematicians did bring this numeral system to Europe, it actually originated in India. So, what do Arabic numerals offer that Roman numerals do not? For one thing, Arabic numerals are a place-value system. Place-value means that a symbol's value changes depending on its place within a number. Consider the number 5. In 50, or 5-0, it is in the tens place, whereas in 500, or 5-0-0, it is in the hundreds place. In that sense, one of the symbols is worth more than the other. In the Roman system, however, a symbol's value doesn't change. This is why Arabic numerals are generally more efficient for handling large numbers. The Arabic system also introduced the idea of zero. We might not think about it much today, but it was a big breakthrough back then. Without the concept of zero, there'd be no advanced mathematics. Zero became widely accepted in Europe around the 15th century, but we have evidence of its use in India way back in the 9th century. It appeared on a stone tablet. A stone tablet in a temple in India.