Firewalls

What do firewalls do?

At an abstract level, you can think of a firewall as a filter, or an intermediary between your device and the Internet (you could also think of it as a traffic officer). What a firewall does very generally is decide whether or not certain information from the internet should be allowed to enter your device, and then respectively grants or prohibits entrance to that information.

How does a firewall work - a basic model.

When information "knocks" on a device's firewall,  the firewall "questions" it to determine if it belongs to any of the following categories:

1. "traffic sent in response to a request of the computer (solicited traffic)" (1) or 
2. "unsolicited traffic that has been specified as allowed (excepted traffic)". (1)

If it does not belong to either category, i.e., if it has not been sent as a response to a request of the device and has also not been specifically permitted by the user, then the firewall denies entrance to the information.

References:
(1) https://technet.microsoft.com/en-us/network/bb545423.aspx
(2) https://www.microsoft.com/en-us/safety/pc-security/firewalls-whatis.aspx
(3) https://www.paloaltonetworks.com/documentation/glossary/what-is-a-firewall

Image References:
(a)https://www.microsoft.com/en-us/safety/pc-security/firewalls-whatis.aspx

Understanding PAC-Man

Back in the day, PAC-Man used to be one of the most-played games in the world! Game-play was pretty simple and straightforward - try to eat all the dots and fruit as fast as you can and without being eaten by a ghost. Everyone knew the rules, and people of all ages could play it.

Everyone also knew how the ghosts behaved more or less - they roamed around until they figured out your approximate location, and then started actively chasing you. How did they know however how to do that?

According to Chad Birch, "Each of the ghosts is programmed with an individual “personality”, a different algorithm it uses to determine its method of moving through the maze", but there is also a logic that all ghosts share (1).

More specifically, each ghost has what is called a 'target tile', which it tries to reach, and arriving to which is the basis for the ghost's behavior. "All of the ghosts use identical methods to travel towards their targets, but the different ghost personalities come about due to the individual way each ghost has of selecting its target tile." (1)


 References:

1. http://gameinternals.com/post/2072558330/understanding-pac-man-ghost-behavior

Image References:

1. https://www.google.com/search?q=pac+man&newwindow=1&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiI6_eQraLQAhUJ7mMKHT4BBmcQ_AUICCgB#imgrc=ukfIYq6AlYNIJM%3A

The emmersion of virtual reality (VR) in video games

Earlier today a friend of mine was showing me the reactions of professional video-game testers to VR video-games, and I was thinking about how awesome VR is as a concept, but also how dangerous and detrimental it could be to society.

What is VR?
"Virtual reality is a computer-generated environment that lets you experience a different reality. A VR headset fits around your head and over your eyes, and visually separates you from whatever space you're physically occupying. Images are fed to your eyes from two small lenses. Through VR you can virtually hike the Grand Canyon, tour the Louvre, experience a movie as if you are part of it, and immerse yourself in a video game without leaving your couch." [1]

When was it first conceived?
Starting in the 1950's, experts of all sorts of disciplines have talked about or alluded to the idea of virtual reality. "The first references to the concept of virtual reality came from science fiction. Stanley G. Weinbaum's 1935 short story "Pygmalion's Spectacles" describes a goggle-based virtual reality system with holographic recording of fictional experiences, including smell and touch." [2]
People from areas like theater, literature, and computer science have found interest in this and, one of the very first applications of it was in 1968, when "Ivan Sutherland, with the help of his student Bob Sproull, created what is widely considered to be the first virtual reality and augmented reality (AR) head-mounted display (HMD) system"[2] 



References:
[1] https://www.cnet.com/special-reports/vr101/
[2] https://en.wikipedia.org/wiki/Virtual_reality

Image Sources:
[3] https://www.google.com/search?q=virtual+reality&biw=2144&bih=1051&noj=1&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiO-rmO5pDQAhUEQiYKHYcGCfsQ_AUICygE&dpr=0.9#imgrc=COd8Rc2BkzorGM%3A