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Why We Need An Open Wireless Movement | Electronic Frontier Foundation
- referred from http://identi.ca/notice/72145242 - post by Graham Perrin
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When people turn on WEP or WPA encryption for their networks deliberately, there are two common reasons: a desire to prevent their neighbors from "free riding" on their connections; and a fear that unencrypted WiFi is a security or privacy risk. Both of those reasons have a degree of legitimacy, but neither of them changes the fact that we would be better off if there were more open networks. Also, both of these problems could be solved without password locking our networks. What we need, instead, is to develop and deploy better WiFi protocols.
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Information sharing interferes with 'wisdom of crowds': study
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Social influence effect: Social influence diminishes group diversity without diminishing the collective error. Typical examples of experimental sessions for three information conditions, displaying five individual responses. Image (c) PNAS, doi: 10.1073/pnas.1008636108
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Disbelieving Free Will Makes Brain Less Free | Wired Science | Wired.com
- The latest findings extend the effects of disbelieving to a more basic physical level. Whether there’s a relationship between free will, motor activity and more complex behaviors is yet to be determined, but “abstract belief systems might have a much more fundamental effect than previously thought,” wrote the researchers.
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Turning Information Into Energy - IEEE Spectrum
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However, Lal believes that it could be possible to build simple feedback systems into micro- or nanomechanical devices. In that case, such systems could become a ready source of onboard energy and more. Lal says that feedback to counteract Brownian motion could squelch the vibration-induced noise that plagues sensors or efficiently guide nanoparticles through nanoscale pores and channels where Brownian motion would otherwise randomize the flow.
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科技日报2010年11月16日头版有篇名为《科学家首次将信息转化为能量》的文章，文中介绍了日本的一项研究，研究人员在实验室中让一个纳米小球沿电场制造的“阶梯”向上爬动，爬上一层后利用电场能量在那层阶梯上加一堵墙，使之落不下来，该小球就会越爬越高，从而势能也越来越大。与上一个人造分子机器类似，这同样也是一个熵减过程实验，其主要贡献是纳米尺度上的精密控制新技术。编辑如实地反映了这个研究，但“验证了约150年前英国物理学家詹姆斯•克拉克•麦克斯韦提出的“麦克斯韦妖”这一设想”这个说法却是个误解，而且文章末尾由这个实验联想到了对能量守衡和转化定律的挑战，这显然也是误读。“孤立系统”是热力学第二定律的熵增原理必不可少的条件，而这两项研究借助的系统都不是孤立系统，而是与外界有能量交换的开放系统，不同之外在于前者使用的是光能，而后者使用的是电能。研究结论不仅不是对热力学第二定律的挑战，恰恰相反，它们是对该定律的验证，若把他们实验室的电闸拉了，什么也不会发生。
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这是“麦克斯韦妖”第一次在实验中实现。1871年，麦克斯韦提出了“麦克斯韦妖”设想：一个绝热容器被分成相等的两格，中间是由一种机制控制的一扇活板门，容器中的空气分子做无规则热运动时会撞击门，门则可以选择性地将速度较快的分子（温度较高）放入其中一格，将速度较慢的分子（温度较低）放入另一格，这样，两格的温度就会一高一低。麦克斯韦认为，整个过程中使用的能量就是“分子是热的还是冷的”这一信息。
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2011年5月30日星期一
SocialPipeline 05/30/2011 (p.m.)
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