## A simple solution to Eight Queens Problem

I play chess occasionally but I don’t know what happened and made me remember this problem. The 8-Queens problem goes like this. You have an empty chessboard and you have to place eight queens on it in a way that no two queens can attack each other. This simply means that each row, column or diagonal has only one queen. It is a well known problem and it is used in Artificial Intelligence courses. The eight queens is the real example for the generalized problem, the n-queens on a nxn chessboard. There are solutions when n equals to 1 or be greater than 3. This problem is also known as the eight queens puzzle and it was proposed in 1848 by Max Bezzel.

## Learn about ACTA

If you don’t know anything about Anti-Counterfeiting Trade Agreement (ACTA) then you should watch at least this video. It doesn’t matter why you are using internet or you think that it doesn’t affect you, it does. It appears that SOPA and PIPA were just distractions to the real enemy of the internet, ACTA. They have created ACTA in the name of intellectual property rights and to create international standards to protect them. ACTA gives access to everything you do or say over the internet, everything. They will have access in everything that you send and receive over the internet even you emails and chats. And they do this to check if anything you send or receive has to do with intellectual property rights.

## Father exposes online predators

People nowadays use the best tool to hunt and find victims, the Internet. This includes thieves, pedophiles and all sort of bad people you can think of. Several months ago I read about a thief that was searching facebook to find who are away from home in order to break into their houses. People, without thinking the consequences, tell to everybody who is using facebook that they will be on another country via status updates. They might also have in their profile where they live or that can be easily found from all the other info in their profile. If you tell someone that you are not home for days then you make it very easy to come and rob you. This is just an example and there are many more.

## How users can destroy internet companies

There are many companies that their operations, and most of their profit, are based on the Internet. Some of those Internet companies earn most of their money by advertising products and other companies. Examples of such Internet companies are Facebook and Google. Users have the power to destroy any Internet company they want. Most probably you can not do such thing alone but a large group or movement like Anonymous might can. This article is written because I found it interesting and I don’t support any actions that will intentionally harm a company. I will describe two methods that can hurt advertisers and ad-serving companies and websites, if done massively, advertisement blocking and intentional advertisement clicking.

## Ultra PDF Merger v1.3.10 has been released

Ultra PDF Merger is a freeware PDF utility that joins your PDF files, or part of them, together. It is a windows application and it runs on both 32bit and 64bit systems. Ultra PDF Merger is portable which means you don’t have to install anything, just download it, extract its content and run it. In this way you can put it in your USB drive and use it anywhere. There are two changes in this version. The most important is that you can choose the pages you want to merge by choosing the starting and the ending page. The second change is that the check for two or more files has been removed. You now have the option to “merge” only one file.

## Black Holes

Stars like humans and everything else die. When a huge star dies (supernova explosion) it does not disappear completely but a dense core remains. If the mass of that remaining core is at least three times more than the mass of our sun, gravity is the winner force, star collapses and a black hole is born. There are billions black holes in the universe and it is believed that they can be divided into two categories. “Stellar mass” black holes which are 10-25 as massive as the Sun and “Supermassive” black holes which are millions of times as massive as the sun. If the small ones have so strong gravitational field, then I can only imagine how strong is the gravitational field of the big ones, which are millions of times as massive as the small ones.

## Facebook – Adding “friends” is dangerous

Facebook has announced that hackers login to Facebook hacked accounts 600.000 times (not all of them successfully) in 24 hours. So far we had to worry only for our password, to be different from our other accounts (email, other websites), to be strong and don’t be hacked (Trojans, Keyloggers). Facebook added a new feature to regain your account if it is hijacked and it is called “Trusted Friends”. You can select three to five friends that will get a code and if you enter those codes you will get access to your account. You might think that this is a good thing and that you will get access to your hijacked account but this is the one side of the coin. You might also think, if this feature was created to help you then how is it possible to have another side?

## Hackers love hacking Facebook accounts

According to Facebook, 600.000 logins every 24 hours are hackers that gain access to victims’ accounts. Once a hacker gains access to an account he can see all private information stored on victim’s account including photos and emails. He can add friends, send private messages and write on the wall. Usually, hackers post links on the victim’s wall to product and services that will give them profit if someone clicks and/or buy them. If the 600.000 hacks are unique every day (which are not most probably) in about 4 years everyone’s account will be hacked.

## Ultra PDF Merger v1.0 – Bind your PDF files together

Few months ago I had some reports (PDF files) that I wanted to bind them into one. I had a utility that until that time was merging my files successfully, I don’t want to name it here. Those reports seemed to have some characters that the utility could not read and it was failing. I have searched the internet and I have found several PDF binders, mergers and joiners but the ones I tried didn’t meet my needs, so I have decided to create one. The result of this story is the Ultra PDF Merger. It succeed when others have failed.

## How to create a WordPress Child Theme

What is a WordPress child theme? Child theme is a WordPress theme but you don’t have to create it from scratch, you use another theme as a base called parent theme and you modify its functionality, layout and styling. You don’t have to be a code guru to create a child theme, in fact you don’t need to know PHP at all. Why should I use child theme? You have found a theme that you like but it needs some additions or modifications to make it meet your needs.