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Sharpen Your General Knowledge
Shamim Ansary:
Can Cats See In the Dark and Do Cats Have Night Vision In Complete Darkness?
But even with their powerful night vision, cats cannot see in complete darkness.
No animal can see in the dark without at least a little light, however, cats have a distinct advantage on us in the dark.
For one thing, their pupils can expand three times wider than ours can.
Also, they have a layer of crystalline material behind their retinas that reflects light back out, giving their eyes a second chance to pick up images.
This layer, called the tapetum lucidum, is also the reason that cats’ eyes shine eerily at night when they catch a glint of light.
Unfortunately, what cats gain in night vision they lose in daytime sharpness.
While their eyes are perfectly suited to picking up movement, their overall vision is blurry, so much so that if something stops moving, the cat is likely to lose track of it.
Which is why you sometimes see cats watching television, but almost never catch them reading a book.
rumman:
Thanks Mr. Ansary for your productive post. There are many things that we are not yet aware in this world. However, we should have knowledge on these interesting things.
Shamim Ansary:
Why Is a Newspaper Called a “Gazetteâ€, What Does It Mean, and Where Did the Word Come From?
In 59 B.C. Julius Caesar introduced the first handwritten daily newspapers, which were posted in prominent locations around Rome.
However, it wasn’t until long after Gutenberg’s printing press was invented that news became an industry.
During the mid-sixteenth century, citizens of Venice paid to hear public readings of the news.
The price for these readings was a small copper Italian coin called a gazetta, which gave us the word gazette for a newspaper.
Shamim Ansary:
Why Does Salt Melt Snow and Ice?
When you put salt on ice or snow, it begins to melt. This is because the salt lowers the freezing point of water. The more salt added, the more it melts.
As the salt dissolves, it creates heat, melting more water and dissolving more salt. That’s why towns plow roads to clear them of snow and then put salt on them to melt the remaining ice and keep it from freezing up again.
Fresh, unsalted water starts to freeze at 32 degrees F., but water with even a small amount of salt in it won’t begin to freeze until the temperature drops to 28 degrees F.
Unfortunately, salted sidewalks and streets can be harmful to your pet’s feet. If you walk them in an area that has been salted, be sure to wash their feet afterward.
Shamim Ansary:
How Does a Chameleon Change Colors?
Chameleons are lizards known for their ability to change colors. But contrary to popular belief, the chameleon does not change its color to match its background. It changes as a result of its mood, the temperature, or light conditions.
Most chameleons have brown or green as their main color, but they can turn to an off-white, yellow, or light green. When they are cold, their color is lighter than when they are warm.
The chameleon’s skin has several layers, with different color pigment cells in each layer. The inner layer has black pigment cells. The chameleon’s nerves control the expansion and contraction of the color cells. When the black cells either move closer to or farther from the skin surface, they blend with, blot out, or intensify other cells. This causes the chameleon’s color to change.
The chameleon’s tongue, which always hits its prey, can be extended more than twice the length of the chameleon’s body!
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