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Sensei

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Everything posted by Sensei

  1. Sensei

    Aliens

    Alien does not even have to be alive organism. It could be machine created by aliens and sent to cosmos to explore and bring data back. Humanoidal ("alienoidal"), or not indistinguishable from computer, device or even entire spaceship being one large computer. Humans did it already. Exploration of solar system is done just by remotely controlled or automatic computers with very small control from the Earth (~3 to ~23 minutes delay between Earth and Mars to receive data in one direction, double it for both action and reaction with view). Experience tells that the best are small, movable, independent units ("drones"), in large quantity (thousands), without one central unit controlling everything. Because if central unit is damaged, the whole mission will fail.
  2. Having no mass is shortcut of having no rest-mass. It means that object have rest-frame of reference. https://en.wikipedia.org/wiki/Rest_frame Objects with rest-frame can change their frame of reference by acceleration in specified direction. Two or more objects in the same frame of reference appear motionless to each other.
  3. Mirrors are made of matter with reflective properties. Reflectivity of material changes with temperature. e.g. metals are reflective at small temperatures, and lose this property as temperature increases. If you successfully manage to trap photons from any light emitting source in a box and they will be bouncing from walls back and forth, part of their energy will be absorbed by mirrors and their temperature will increase. With increase of temperature they will start losing more and more reflectivity and more photons will be absorbed. Perfect mirrors would end up melting entire device sooner or later. Photons with higher energy than visible light will create quantum effects, such as photoelectric effect at lower energies, ionization at higher energy of UVs and x-rays, pair-production and photodisintegration by gamma photons..
  4. Data structures exist even outside of computer science. Take for example the real paper book and analyze what is needed to store the all its data. Each page has page number. It is integer primitive data type, starting from 1. Each page has contents. Usually text. It is string data type (in some languages primitive data type, in other e.g. C/C++ object). So to store single page, you can make data structure like below: struct Page { int Page_Number; string Contents; }; Now we have to put pages inside of book structure. We can do it using array of pages (structure inside of structure). Or we can store just pointer (address) to the first page element. Or we can use array/list OOP objects with template class.. struct Book { string Title; string Author; string Description; int Page_Count; // total number of pages in the book struct Page Pages[ 100 ]; }; In C/C++ we can store pages as dynamically allocated array, and store just pointer to the first Page: struct Page *Pages; or dynamically allocated each Page alone: struct Page **Pages; or struct Page *Pages[]; or we can create static array with predefined quantity: struct Page Pages[ 100 ]; (less recommended because you can't exceed maximum predefined quantity, but requiring less work from programmer for allocation and freeing memory). The best (for programmer) in C++ (or other OOP language) will be something like: array<Page> Pages; or array<Page *> Pages; It is special template class. https://en.cppreference.com/w/cpp/language/templates We can go further with this example. Expand book by list of chapters. Index of keywords etc. etc. Shelf/library of books. With index of authors, index of titles. The simplest algorithm of searching for keyword will have to go through the all books in the library one by one (iteration) and check every page of a book (yet another iteration), and search for sub-string inside of page.Contents and print which book, at which page, at which row of a page has keyword we're interested in. ps. Imagine book without page numbers, without chapters, without indexes. Imagine library without books on shelves sorted in alphabetical order. It would be complete disorder. Searching for any kind of data would be tremendously complicated and tiresome.
  5. Why? Change doctor It is easy.. If you have decimal e.g. 1111 factors will be 101 and 11. If it is e.g. 111111 factors will be 1001 and 111. And so on. You just have to answer question if number of decimal ones is dividable and has factors by itself. 91 is not prime. It is dividable by 7 and 13. 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 1111111 is dividable by 1111111.
  6. ..but OP nowhere said it is sequence of binary ones..
  7. Google can convert different kinds of units for you: https://www.google.com/search?q=230+cu+ft
  8. Unfortunately they are not one-to-one translations and English version is usually the richest in knowledge..
  9. Are you familiar with word "ecliptic"? https://en.wikipedia.org/wiki/Ecliptic https://en.wikipedia.org/wiki/Ecliptic_coordinate_system
  10. Purpose of scientific documentary TV show is to awaken of interest of person who has none or little knowledge in a field it is about. Promotion of science and knowledge among a wider audience, who would not be otherwise reached. Doing it in a boring way will have exactly reverse effect than intended (which many primary and secondary school teachers do).. The desire to know is the natural state of mind of every newborn living being. To understand entire environment and world around. Competent teacher stimulates and wisely expands this state of mind. A bad teacher (e.g. the most likely one who ruined his or her career in the field, and finished up "on exile" in school as teacher) can ruin this state..
  11. They would have to be DESIGNED to work together since the beginning by producer of paint.. Flat, matte or satin paint from definition have little or no gloss.
  12. Your brand new TV, phone, car, house, cloth, etc. etc. are waste (waste-to-be) too... it is just a matter of time.. just wait a couple years, or a couple decades..
  13. But they are easier to maintain by staff. Dust and dirt do not attach to it so easily..
  14. A couple layers of transparent glossy paint on top?
  15. You should do research what China is importing from the world, to be able to answer your question. https://www.google.com/search?q=china+import+from+world e.g. http://www.worldstopexports.com/chinas-top-10-imports/ "Electrical machinery, equipment: US$496.8 billion (24% of total imports) Mineral fuels including oil: $343.6 billion (16.6%) Machinery including computers: $190.3 billion (9.2%) Ores, slag, ash: $163.6 billion (7.9%) Optical, technical, medical apparatus: $98.7 billion (4.8%) Vehicles: $75.1 billion (3.6%) Plastics, plastic articles: $71.6 billion (3.5%) Gems, precious metals: $60.5 billion (2.9%) Organic chemicals: $57.8 billion (2.8%) Copper: $40.8 billion (2%)" They need dollars/euros/gold/whatever valuable, to pay world for the all these goods. Say, if import is X in Y currency, and export is X in Y currency. Y is really meaningless, as entire transfer of money can be replaced by pure exchange of goods.
  16. Ah, a is already premultiplied by y.. so, correctly I should write: b = x - a;
  17. In binary numeral system, to clear the least, or the most significant bits, there can be used bitwise AND operator e.g. in C/C++: a = x & ~( 1 << y - 1 ); and to get reminder there can be used yet another bitwise AND operator e.g. b = x & ( 1 << y - 1 ); In the normal circumstances you (or CPU) would have to do modulo e.g.: a = ( x / y ) * y; and e.g. b = x - a * y; Multiplication and division by arbitrary integer are slower than bitwise operators.
  18. Multiplication or division by 2^x can be replaced by bitwise left shift or bitwise right shift. https://en.wikipedia.org/wiki/Bitwise_operation They are extremely fast, in comparison to regular multiplication or division by arbitrary integer (not to mention floating point).
  19. Angela "opened borders" to help southern European countries to solve problem of illegal immigration, taking part of the ones that arrived to Italy and Greece and other countries. It was movement of solidarity with involved European countries. Flood of migrants, who don't know language, don't have work, don't have money, can disrupt any country, and nationalists or other populist parties can win the next election, promising people fight with immigrants, which won't do any good.. The situation of refugees is even worse in the Middle East. For example Jordan has 10.4 million citizens and 1.3 million refugees from Syria.
  20. You can make chlorine gas from the first molten NaCl (above 801 C) and then electrolized liquid.. but it is dangerous, toxic, inefficient and pricey way to get some HCl and HOCl (they are products of chlorine gas and water). You will need to separate them at the end. Search net for "electrolysis of molten NaCl".
  21. The most obvious way is to print to file in the application which you are using to create text file e.g. Word, WordPad, browser etc. etc. Then just use network public shared location to store these files.. Virtual Printer is software that you download and install on the server machine, which will be pretending true printer for clients. https://en.wikipedia.org/wiki/Virtual_printer https://en.wikipedia.org/wiki/List_of_virtual_printer_software Client machine and client application connects to server machine, thinking it is true printer, but it is virtual printer, which just stores file on disk.
  22. Photons are particles. Matter are particles too. Just different kind. Protons, neutrons, electrons mostly. In the matter conservation law you count the number of Baryons and Leptons (and charges) on the left and right side of the equation and they must match. It is used to properly balance chemical equation, prior and after chemical reaction. The number of Baryons (protons and neutrons together) is almost matching Dalton unit: https://en.wikipedia.org/wiki/Dalton_(unit) e.g. average mass of Carbon is 12.011 u. Baryon number of Carbon C-12 is 12. 6 protons + 6 neutrons. These 0.11 u difference is caused by presence of very little amount of Carbon C-13 and minuscule amount of Carbon C-14. Photon has Lepton, Baryon and charge numbers equal 0. Electron and positron have Baryon number equal 0. Electron has Lepton number +1. Positron has Lepton number -1. Electron has charge -1. Positron has charge +1. Prior annihilation we have electron and positron with leptons +1-1 and charges -1+1. After annihilation we have two gamma photons with the all 0.
  23. @Netra77 Listen Strange (and me) and download text editor for programmers and webmasters. I am recommending ConTEXT. http://www.contexteditor.org/downloads/ It will highlight properties, attributes, tags etc. If they are improperly entered, highlighted is entire text below troublesome area.
  24. No. The proper, modern, CSS-way is to do it inside of CSS file. And you should read and use CSS properties float, clear, overflow for such task. Read post from this morning. And the all links that I gave. There are examples of usage of these CSS properties.
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