Physics Lab AR vs Enigma Simulator

Are you a curious student eager to explore deeper into the physics world? Are you a science enthusiast who wants to share your ideas with others? Are you an adventurer bounded by textbook instructions and budget limits? Are you a romantic dreaming of having your own customized galaxy? Are you a teacher who wants to use fun and interactive demonstrations in your physics lessons? Learn science by doing experiments in your virtual lab with Physics Lab. With our new AR mode, you can even bring your experiments to life! In Physics Lab, you can play with various circuit components, build your own 3D electric circuits, and see how they work in real time. With 100+ circuit components to choose from (and more coming soon), the possibilities are endless. Plus, all of our experiments are backed by science and calculated with precise numbers, so you can learn and have fun at the same time. Physics Lab is not only for students, but for teachers too! Use it to demonstrate experiments in class, and help your students learn and explore in a new way. And because it's virtual, you don't have to worry about expensive lab equipment or safety concerns. Explore with freedom - Pick from 100+ circuit components (more coming!) - Drag them from the toolbox to the virtual desk and connect them the way you like - All experiment results are backed by science and calculated in precise numbers - Design your own galaxy or load from our solar system - Electromagnetic experiments with field line visualization Better than real life - Set properties of circuit components to different figures and observe changes of behavior and stats in real time - One-click to turn what you have built into an editable circuit diagram and vice versa - No expenses on lab equipments, no worry about safety issues A lab for everyone - Teachers have been using Physics Lab to demonstrate experiments and assist teaching in class - Students, in primary or high schools, can learn science and explore freely anywhere, anytime - Kids or not, curious minds now have their own virtual lab to learn knowledge by doing experiments Whether you're a teacher, student, or just someone who loves learning about physics, Physics Lab has something for everyone. Connect with us and let us know what you think, and check out our subscription options to access even more experiments and components. We can't wait to see what you create! Email: turtlesim@u.northwestern.edu =========================== Concerning Component Subscription During your subscription period, you will have access to all paid components for free, including future ones. 1) Subscription periods are one month long and will be charged to your iTunes Account at the time of purchase. 2) Your subscription is linked to your Physics Lab account. 3) You will be charged for renewals 24 hours before the end of the current period, and will be notified of the cost. 4) You can manage your subscriptions at any time in your Account Settings. 5) By purchasing a subscription, you are agreeing to our Terms of Use and Privacy Policy. Terms of Use: https://static.turtlesim.com/products/Term-Of-Use.txt Privacy Policy: https://static.turtlesim.com/products/Privacy-Policy.txt

Enigma密码机 在密码学史中，恩尼格玛密码机（德语：Enigma，又译哑谜机，或“谜”式密码机）是一种用于加密与解密文件的密码机。 确切地说，恩尼格玛是一系列相似的转子机械加解密机器的统称，它包括了许多不同的型号，为密码学对称加密算法的流加密。 键盘一共有26个键，键盘排列和广为使用的计算机键盘基本一样，只不过为了使通讯尽量地短和难以破译，空格、数字和标点符号都被取消，而只有字母键。 键盘上方就是显示器，这可不是意义上的屏幕显示器，只不过是标示了同样字母的26个小灯泡，当键盘上的某个键被按下时， 和这个字母被加密后的密文字母所对应的小灯泡就亮了起来，就是这样一种近乎原始的“显示”。 在显示器的上方是三个直径6厘米的转子，它们的主要部分隐藏在面板下，转子才是“恩尼格玛”密码机最核心关键的部分。 如果转子的作用仅仅是把一个字母换成另一个字母，那就是密码学中所说的“简单替换密码”,这就是“恩尼格玛”难以被破译的关键所在，这不是一种简单替换密码。 同一个字母在明文的不同位置时，可以被不同的字母替换，而密文中不同位置的同一个字母，又可以代表明文中的不同字母，字母频率分析法在这里丝毫无用武之地了。 这种加密方式在密码学上被称为“复式替换密码”。 使用“恩尼格玛”通讯时，发信人首先要调节三个转子的方向（而这个转子的初始方向就是密匙，是收发双方必须预先约定好的）， 然后依次键入明文，并把显示器上灯泡闪亮的字母依次记下来，最后把记录下的闪亮字母按照顺序用正常的电报方式发送出去。 收信方收到电文后，只要也使用一台“恩尼格玛”，按照原来的约定，把转子的方向调整到和发信方相同的初始方向上，然后依次键入收到的密文， 显示器上自动闪亮的字母就是明文了。加密和解密的过程完全一样，这就是反射器的作用，同时反射器的一个副作用就是一个字母永远也不会被加密成它自己， 因为反射器中一个字母总是被连接到另一个不同的字母。 而除了转子方向和排列位置，“恩尼格玛”还有一道保障安全的关卡，在键盘和第一个转子之间有块连接板。 通过这块连接板可以用一根连线把某个字母和另一个字母连接起来，这样这个字母的信号在进入转子之前就会转变为另一个字母的信号。 这种连线最多可以有六根（后期的“恩尼格玛”甚至达到十根连线），这样就可以使6对字母的信号两两互换，其他没有插上连线的字母则保持不变。 ——当然连接板上的连线状况也是收发双方预先约定好的。 就这样转子的初始方向、转子之间的相互位置以及连接板的连线状况就组成了“恩尼格玛”三道牢不可破的保密防线， 其中连接板是一个简单替换密码系统，而不停转动的转子，虽然数量不多，但却是点睛之笔，使整个系统变成了复式替换系统。 连接板虽然只是简单替换却能使可能性数目大大增加，在转子的复式作用下进一步加强了保密性。