Another great thing that people forget about is the refresh rate. Set it as high as your monitor will support-it really helps the eyes.
Okay, I fianlly have to admit it - I've never really known what this means - or at least, it seems fairly obvious, but how would it affect your eyes to have a low refresh rate? :? I also don't really understand dark matter...
I'll try and explain.
Refresh rate is measured in Hertz [Hz], or updates per second. In the context of CRT monitors, a refresh rate of 60Hz would mean the cathode ray tube projects the visual data from the video card sixty times every second onto the viewing screen.
Most individuals' natural vision is "better" than 60Hz, however. ie, their brain interprets the visual signals from the optical nerves faster than sixty times a second. So what this means is, an image on a CRT monitor running at 60Hz will seem 'shaky' or 'wavy' or just 'blurry.' And it'll easily lead to eye strain, as your eyes are forced into overdrive since you're actually noticing the ever-so-quick redrawing taking place on the image in front of you.
Higher refresh rates on CRTs mean the given image is updated more frequently over the course of a second. Eventually the refresh rate overcomes the refresh rate of your brain, the result being the illusion of looking at one solid image, despite the fact it's actually just over 60 rapid-fire images per second.
An analogy is the difference between a flipbook and a movie theatre. Both are the same core concept -- the rapid presentation of slightly changing images produces the illusion of one dynamic image. However, the movie theatre is much better at producing this illusion because it uses many more images over a given timeframe than any flipbook could ever hope to use.
LCD monitors do not have the refresh issue because, as stated above, they actually are solid images. There's no projection taking place -- the liquid crystal pixel cells are induced to take on certain colors, which produces the image on your screen. It's like a rapidly-changing mosaic as opposed to a flipbook. You can prove this to yourself by pressing (gently) on the LCD screen -- the image under your pressure point will become slighly distorted. This can't happen on a CRT, because the image is virtual, as opposed to real.
Oh, and you wanted to know about dark matter.
To understand dark matter, you first have to understand why it has to exist, based on our current understanding of the universe. Massive bodies in our universe -- like, say, a cluster of galaxies -- obviously exert massive amounts of gravitational force. Astrophysicists long ago discovered ways of measuring this force, based on the luminosity (brightness) of the given object and spectrum analysis that determine how far away the object is from us here on earth, etc.
However, there's a massively horrific problem. Say an astrophysicist uses the formulas and data to measure the gravitational pull of, say, one galaxy. He gets his value -- let's be easy and say this value is 4
Then, to check his work, the astrophysicist compares his finding of 4
to the actual amount of gravitational pull the galaxy is emitting, based on how other objects react to the galaxy itself. The result? 100
This is such a catastrophic error that only one of three things is possible:
1.) The formulas and or data were wrong. Extensive testing evetually ruled this option out.
2.) There is a fundamental aspect or form to the universe which we don't yet understand. Entirely possible but incredibly unpopular, since a paradigm shift of this level is either so massive that it's ages away or so critical that it renders hundreds of years of research invalid.
3.) There's something else out there. Something that's making gravitational force ludicrously more powerful than it 'should' be. That
is 'dark matter.'
Why 'dark' matter? Because, quite simply put, it's not 'bright.' It's not luminous. We can't percieve it with our current instrumentation. All our calculations have only involved luminous matter, stuff that can emit or reflect photons.
In short, if you took all the gravitational force in the universe, and set it at 100%, for the time being, we can only see the matter responsible for 4% of it
. The other whopping 96%
is being caused by something we can't yet detect.