英译汉第二篇

　　In the mid-1800s a caterpillar the size of a human finger began spreading across the northeastern U.S. This appearance of the tomato hornworm was followed by terrifying reports of fatal poisonings and aggressive behavior toward people. In July 1869 newspapers across the region posted warnings about the insect, reporting that a girl in Red Creek, N.Y., had been “thrown into spasms, which ended in death”(考试中是has died)after a run-in with the creature. That fall the Syracuse Standard printed an account from one Dr. Fuller, who had collected a particularly enormous specimen. The physician warned that the caterpillar was “as poisonous as a rattlesnake” and said he knew of three deaths linked to its venom.

　　Although the hornworm is a voracious eater that can strip a tomato plant in a matter of days, it is, in fact, harmless to humans. Entomologists had known the insect to be innocuous for decades when Fuller published his dramatic account, and his claims were widely mocked by experts. So why did the rumors persist even though the truth was readily available? People are social learners. We develop most of our beliefs from the testimony of trusted others such as our teachers, parents and friends. This social transmission of knowledge is at the heart of culture and science. But as the tomato hornworm story shows us, our ability has a gaping vulnerability: sometimes the ideas we spread are wrong.

　　Over the past five years the ways in which the social transmission of knowledge can fail us have come into sharp focus. Misinformation shared on social media Web sites has fueled an epidemic of false belief, with widespread misconceptions concerning topics ranging from the prevalence of voter fraud, to whether the Sandy Hook school shooting was staged, to whether vaccines are safe. The same basic mechanisms that spread fear about the tomato hornworm have now intensified—and, in some cases, led to—a profound public mistrust of basic societal institutions.

　　“Misinformation” may seem like a misnomer here. After all, many of today's most damaging false beliefs are initially driven by acts of propaganda and disinformation, which are deliberately deceptive and intended to cause harm. But part of what makes propaganda and disinformation so effective in an age of social media is the fact that people who are exposed to it share it widely among friends and peers who trust them, with no intention of misleading anyone. Social media transforms disinformation into misinformation.

　　Many communication theorists and social scientists(考试中是Many social scientists) have tried to understand how false beliefs persist by modeling the spread of ideas as a contagion. Employing mathematical models involves simulating a simplified representation of human social interactions using a computer algorithm and then studying these simulations to learn something about the real world. In a contagion model, ideas are like viruses that go from mind to mind. You start with a network, which consists of nodes, representing individuals, and edges, which represent social connections. You seed an idea in one “mind” and see how it spreads under various assumptions about when transmission will occur.