Saturday, March 13, 2010

Top 3 Types of Illusions

Once in a while we come across some random illusion that may or may not make our day. Illusions draw interest and are often a source of fascination.

They temporarily relieve boredom though too much can be mind-numbing as well.

Illusions occur within all of our five physical senses: sight, hearing, taste, smell, and touch. Of the five, visual illusions are the most common, well-known, and well researched.

An illusion is a distortion of the sensory perception, revealing how the brain normally interprets sensory stimulation. At least scientifically, that is how it is defined. But why dwell on the scientific side when you can just let yourself be awed (or bored) for a moment.

Visual Illusion
There are many types of visual illusions including those that are naturally occurring (mirage and rainbow). Showing samples for each will definitely take more than one posting. Instead, I will cite three that I personally find amusing.

Created by well-renowned Belgium-based chalk artist Julian Beever. His works are created using a projection called anamorphosis. Viewed from the correct angle, his pavement drawings spring to life. Or in this case, sinks to the ground.

See more of Julian Beever's work here.

These static wheels, even though stationary, appear to be slowly rotating. This image is not even an animated GIF.

If you focus on one wheel, that wheel stops while the rest apparently keeps on rotating. If you focus on another, the previous wheel begins to rotate.

This illusion has something to do with eye movement.

Magic Eye refers to stereogram images created using a patented process. Magic Eye images may be easier to see if viewed on paper rather than a computer screen. If possible, print this image and follow these instructions.

See more Magic Eye samples here.

Auditory Illusion
My brother introduced me to this one. At first I never paid attention. How can an audio file be that interesting unless it is a full-length version of the "Hello Garci" tape?

Well, this is not a scandal recording. Rather, an ingenious recording created by a group experimenting on how our ear perceives sound.

Listen to this amazing Virtual Haircut illusion by clicking on the vintage radio image on the right. I must warn you though; you NEED an earphone to appreciate this.

Touch Illusion
There exist very few examples of illusions under this category probably due to the fact that touch sensation is slower than that of vision and hearing.

For demonstration purposes, one can try this:

Immerse one hand in cold water, the other in hot water for about a minute or so. Then immediately place both hands in lukewarm water. The "cold" hand will feel that the lukewarm water is hot while the "hot" hand will feel that it is cold.

Thursday, March 4, 2010

OpenDNS vs Google Public DNS

There are many reasons why sometimes you can’t browse the internet. One of these reasons can be that you have a so-called dirty or noisy DSL line. Another probable reason is that your ISP’s name resolver (DNS server) is so busy that it slows down to the point that it does not respond anymore.

This is a very common problem experienced by PLDT DSL subscribers. Globe Broadband users also suffer from this conundrum.

The solution to this problem is to simply change your computer’s DNS server address manually. Either set it to OpenDNS address or to Google Public DNS address. Either one will work and is SO much better than PLDT’s DNS servers.

But which one is better: OpenDNS or Google Public DNS?

OpenDNS has loads of features (e.g.: adult-filtering, anti-phishing, typo-correcting, and many more). Parents will find these very useful as they can configure settings for each of their children’s PCs from virtually any terminal that has internet access. OpenDNS also redirects you to their search portal if you inadvertently entered a non-existing domain name.

On the other hand, Google Public DNS has absolutely nothing what-so-ever feature. And they are committed, according to them, that they will never add a redirector to those non-existing domain names.

Less is More
In my ping test, Google Public DNS appears to be faster than OpenDNS:

  C:\>ping (OpenDNS)
  Reply from bytes=32 time=204ms
  Reply from bytes=32 time=188ms
  Reply from bytes=32 time=210ms
  Reply from bytes=32 time=208ms
    Minimum = 188ms, Maximum = 218ms, Average = 206ms

  C:\>ping (Google Public DNS)
  Reply from bytes=32 time=53ms
  Reply from bytes=32 time=53ms
  Reply from bytes=32 time=54ms
  Reply from bytes=32 time=57ms
    Minimum = 53ms, Maximum = 60ms, Average = 55ms

As you can see from the chart, Google DNS ping response is 75% faster than that of OpenDNS response. Take note that this is just the Ping test. The DNS recursor response is a different category. I only did this Ping test because it’s the easiest way to test their general performance.

PLDT's DNS servers (and most local DNS servers) are very unreliable. OpenDNS has no record of downtime since they have gone public years ago. Google Public DNS has just recently been opened to service. It’s new, simple, and most of all, it’s fast.

Contributed by: Emil Baseleres

Monday, March 1, 2010

Try Before You Buy

Want to try the next generation Windows operating system? Afraid you might get frustrated as most were with the "forced" upgrade to Windows Vista?

Is it really worth your hard-earned bucks or are you better off with whatever you are currently using?

The good news is you can try Windows 7 for 90 days FREE before buying it. You can download the whole Windows 7 trial from the Microsoft website.

The fastest way to download Windows 7 is through BitTorrent protocol, using a BitTorrent compatible client (e.g.: uTorrent, Vuse, BitComet). The ISO image of Windows 7 64-bit is about 3GB while the 32-bit version is about 2.3GB. We are only interested in the 64-bit version of Windows 7 because the 32-bit edition does not offer anything greater than what Windows XP can do. So we will go straight with the 64-bit version which can make use of more memory than any 32-bit version of Windows can.

Untouched ISO Image
What we need is an "untouched" ISO image of Windows 7. Untouched means it was not modified in any way because there are many leaked versions of Windows 7 out there in the BitTorrent communities. Those leaked versions are often pre-activated and at times have malwares within them. Or, even if they do not have any embedded malwares, they are sometimes activated in a wrong way. And we do not want that either, do we?

The untouched ISO image of Windows 7 is one that came originally from the MSDN website. This ISO image is the exact image of the disc you burn to a DVD±R. It is the same exact disc that you can get from any retail store (except that you did not get it from a store).

It is crucial that you check for the authenticity of the ISO image that you have downloaded. The ISO file should be bit-for-bit the same as the one provided by MSDN. This ensures that there are no alterations and no corruptions while downloading the file.

Torrent File
The torrent file for the ISO image can be downloaded here (mirror1 / mirror2 / mirror3). This torrent file is about 16KB. Do not confuse the torrent file for the ISO image. The torrent file is simply the container for the ISO file. You load up the torrent file using your BitTorrent client, and your BitTorrent client will be the one downloading the 3GB ISO image file. Depending on your ISP provider, it might take you hours or even days for your download to complete.

Integrity Check
After the download is completed, you may want to check the integrity of the ISO image file. To do that, you will need an MD5 hash checker. You can either use HashTab or HashCheck. Or any other hash checker you want.

The ISO image file should have an MD5/SHA-1 hash of:
  MD5: F43D22E4FB07BF617D573ACD8785C028
  SHA-1: 326327CC2FF9F05379F5058C41BE6BC5E004BAA7

The file name is not that important. But the extension name should be .iso.

If everything else is checked, that is, the hash checksum of the ISO file you have downloaded is the same as stated above, then we are ready to burn your ISO image as an image disc.

Contributed by: Emil Baseleres