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10-Misellaneous
Why the Traffic
Lights are always in the same order - Red, Yellow or Orange, and Green
Firstly, if they were in different orders then people may mistakenly think a
particular color is for different purpose, when it is really for a different
purpose. Secondly, colorblind people need to rely on the order being constant.
If someone cannot distinguish a red light from a yellow light, then he has to
just go by what order they are in. For an example, on some intersections have
one single light, either flashing red or yellow. If a colorblind person is
driving through one of these and he is not familiar with the intersection
he has to really slow down and look very hard to distinguish whether it is
red or yellow. In fact these lights are not very safe. Even if they are
horizontally laid down, then also these lights are in the same order - Red ->
Yellow or Orange -> Green.
Why Do We Not Find Year of Publishing on Old Books in Arabic Numerals?
Because the world did not have any figure to represent Zero. They used
only Roman numerals and Roman Numerals used only English letters to denote
numbers. They did not have any provision to represent Zero with a separate
figure - see below the Roman Numerals --
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Arabic Numerals in Roman Numerals |
Arabic Numerals in Roman Numerals |
1 = I
2 = II
3 = III
4 = IV
5 = V
6 = VI |
1 = I
5 = V
10 = X
50 = L
100 = C
500 = D
1,000 = M |
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These letters could be written in
small letters also, such as i, v, x, l etc |
When the zero has
been known (thanks to India) then only Arabic numerals started being used
with efficiency. Roman numbering system was in use in Europe till 13th
Century AD.
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