陷入混沌

当我还是物理系的学生时，我的大部分时间都用在研究子虚乌有的东西上，诸如无摩擦力的滑轮、无质量的弹簧以及不随高度而变的重力等。科学家们早应意识到，真实的系统与其环境之间存在着一些难于进行实际测量的相互作用，而随着时间的推移这些效应就逐渐积累起来，因此我们知道，理想的解法仅能在一定的时间内描述系统。而我们所不知道的则是这一段时间可能有多短。     

世界末日的忧伤

病毒横行，环境灾难，灰雾蔓延——天文学家Martin Rees爵士预测，人类文明在这种种祸害的围攻之下熬到二十二世纪的机会只有50％。     

Maternal employment, work schedules, and children's body mass index

Previous work has shown that mothers' employment is associated with increases in children's body mass index (BMI), a measure of weight for height. Nonstandard work (working evenings or nights, weekends, or an irregular shift) may also be associated with children's BMI. This article examines the association between maternal work and children's BMI and considers the influence of mothers' nonstandard work schedules. Using data from school-age children (approximately 8 to 12 years) in the NICHD's Study of Early Child Care and Youth Development (N = 990), this study found that an increase in the total time a mother is employed is associated with an increase in her child's BMI; additionally, the association between maternal employment and children's weight is much stronger at 6th grade relative to younger ages. There was no evidence that maternal or home characteristics or children's time use mediated these associations, nor was there any evidence that nonstandard work was associated with children's BMI. Implications for policy and future research are discussed.     

Peer education in the commons: a new approach to reference services

In planning for a new library construction project for the University of Oklahoma-Tulsa, graduate students enrolled in the University of Oklahoma (OU) School of Library and Information Studies collaborated in an innovative effort to develop a commons-based reference service. By first considering a philosophical approach to the need for a commons, blending in the experiences of other libraries that have created similar spaces, and focusing on the workflow issues likely to be encountered by the graduate assistants staffing the commons itself, this planning team developed an uncommon peer-to-peer approach to reference and education services, one focused on the patron as student.     

How many deaf people are there in the United States? Estimates from the Survey of Income and Program Participation

The Survey of Income and Program Participation (SIPP) is one of a few national surveys that regularly collects data identifying the American population of persons with hearing loss or deafness. Estimates from the SIPP indicate that fewer than 1 in 20 Americans are currently deaf or hard of hearing. In round numbers, nearly 10,000,000 persons are hard of hearing and close to 1,000,000 are functionally deaf. More than half of all persons with hearing loss or deafness are 65 years or older and less than 4% are under 18 years of age. However, these findings are limited to those who report difficulty hearing "normal conversation" and do not include the larger population of persons with hearing loss for which only hearing outside the range and circumstances of normal conversation is affected. Policy makers, communications technology manufacturers, health and education service providers, researchers, and advocacy organizations have an interest in these results.     

往来于行星之间的公共汽车

James Oberg和Buzz Aldrin认为，地球与火星之间的重力助推轨道将节约运送人员和设备的成本。     

怎样飞往火星

专职作家George Musser和Mark Alpert介绍了载人飞行任务的诸多设想。