{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","id":"38270854-596f-4a26-8183-db8c968c6020","uuid":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","normalized_title":"编码隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","isbns":["9787121181184","0123456789","6044921875","3039331000","0000000000","0000000000000"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":438,"navigation_url":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020","title_url":"https://workshop.closeclaw.top/ai/title/%E7%BC%96%E7%A0%81%20%E9%9A%90%E5%8C%BF%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E8%BD%AF%E7%A1%AC%E4%BB%B6%E8%83%8C%E5%90%8E%E7%9A%84%E8%AF%AD%E8%A8%80","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/38270854-596f-4a26-8183-db8c968c6020","page_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/page","search_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/search"},"page":{"printed_page":37,"pdf_page":53,"physical_index":53,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"a0d543dd8507cf008a5a3eb81c671367396b1c7600082af98657fe627f26d168"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"你或许还真的很想看到电子从埋在你家后院的8英尺长的铜柱进入地下，然后飞速通过大地到达埋在你朋友家后院的铜柱的情景。\n\n然而每时每刻地球都在充当着全世界成千上万条电路的导线，想到这些，你可能会感到迷茫：电子怎么知道它要去什么地方？其实它们不知道。换一种描述地球的模式或许更恰当些。\n\n没错，地球是一个巨大的导体，但是我们也可以把它看做是电子的来源和储藏库。地球之于电子就恰如海洋之于水滴。地球是一个近乎无尽的电子之源，同时也是一个无比庞大的电子池。\n\n不过地球还是有一定的电阻的。所以当我们使用1.5伏干电池和小灯泡时，不能通过接地来节约我们所需的线路开支。对于低电压电池而言，地球的电阻实在是太高了。\n\n你可能注意到，前面两幅图中所画的电池，其负极都接地了，如下图所示。\n\n以后，我将不再画这个图例了。我将用大写字母“V”（表示电压）来代替它。因此单向的灯泡电报系统的电路示意图就变成了如下这个样子。\n\n字母V是电压的意思，但是它也有吸尘器的意思。我们把V想象成一个电子吸尘器，然后把地面想象成电子的海洋。电子吸尘器通过电路把电子从地下拉出来，让它们沿设计好的线路开始工作（例如点亮灯泡）。\n\n5 绕过拐角的通信\n\n37","previous_page":36,"next_page":38}