Why do we have everything in seven?,like seven days in a week, seven vocals in an octave, seven colors rainbow

Answer 1

About seven days a week:

.......3AD, Constantine embraced a new religion, Christianity, which he turned into the state religion of Rome. Intending to launch a reordering of politics and religion, he also sought to reorder time by transforming the Julian calendar into the official calendar of the church. The essential structure of the calendar remained the same, but the details changed. The new calendar introduced a new set of holidays and festivals, including, in AD 321, the designation of Sunday as a state-sanctioned day of rest and worship. This officially established the seven-day week for the first time in the Roman Empire, and eventually this seven-day week was adopted throughout the world.......no one know why.....maybe it's because 6 work days and 1 rest day is optimal for employers and employees......(Microsoft ® Encarta ® 2006)

About seven vocals in an octave:

Well, It's called OCTAVE, not HEPTAVE, right?
It's just a matter of harmony. When you go up 1 octave, the frequency doubles. They then found a convenient way to arrange the other notes, and it came up with seven.
It is not necessary seven. In Vietnam, we have another ethnic "octave" with only 5 vocals, and it sounds rather well.

About seven colors of a rainbow: It's really not seven, physically. It's only seven literary. I think they saw the rainbows as seven colors after the 7-day-weeks had been adopted.

Why, you have 10 fingers, don't you?

Answer 2

There are eight vocals in an octave - you have to count "do" twice. They call it an octave for a reason. There are actually infinite colours in the rainbow, just seven DISTINCT ones. "Red" is what we assign to a group of millions of wavelengths.

As for days in a week, well yes that's seven and I'm not sure why.

Answer 3

Offhand, I'd say because it's the average number of distinct items that a human can hold in short-term memory. This makes seven the largest number N for which most humans would find it easy to memorize a list of N items. That's why we have seven days in a week, seven digits in an american telephone number (assuming a local call), seven deadly sins, 007, and so forth.

Answer 4

Do you have 7 fingers?
Do we use base 7 in math class?
Are there 7 types of fruit?

You are generalizing, I'm sorry, but your question is basically pointless...but I do appreciate the "2 points" notice, not 7 points.

ps: there is no sport that I know of that scores by 7's...but I could be wrong!!

Answer 5

Hell-if I know , but I guarantee that the rainbow colors came first

Answer 6

In 'The Twelfth Planet' the earth is viewed as the 7th planet (counting IN from Pluto) encountered by our extraterrestrial forebears.

http://www.sitchin.com/

Answer 7

Why have you stopped with three examples; atleast you should give seven such examples.