What is so special about the number three (if anything)?

Question

So according to Bob Dorough and De La Soul, "3 is the magic number". However, from a mathamatical point of view, is there a more "magical" number than 3. I am looking mainly for a scientific answer, but humourous ones will also do.

Please state in your answers why you think 3 or whatever number you choose is magical. Ta'!

Loving some of these answers. Some I don't understand (far too technical for my little brain). Amazed (but not suprised) how religion seems to get into all my questions!
Keep them all coming!

Answer 1

Three is the first odd prime number, and the second smallest prime after two. It is both the first Fermat prime (22º + 1) and the first Mersenne prime (22 - 1), as well as the first lucky prime. However, it's the second Sophie Germain prime, the second Mersenne prime exponent, the second factorial prime (2! + 1), the second Lucas prime, the second Stern prime.

Three is the first unique prime due to the properties of its reciprocal.

Three is the second triangular number and it is the only prime triangular number. Three is the only prime which is one less than a perfect square. Any other number which is n2 - 1 for some integer n is not prime, since it is (n - 1)(n + 1). This is true for 3 as well, but in its case one of the factors is 1.

Three non-collinear points determine a plane and a circle.

Three is the fourth Fibonacci number and the third that is unique. In the Perrin sequence, however, 3 is both the zeroth and third Perrin numbers.

Three is the fourth open meandric number.

Vulgar fractions with 3 in the denominator have a single digit repeating sequences in their decimal expansions, (.000..., .333..., .666..., .999...)

A natural number is divisible by three if the sum of its digits in base 10 is divisible by 3. For example, the number 21 is divisible by three (3 times 7) and the sum of its digits is 2 + 1 = 3. Because of this, the reverse of any number that is divisible by three (or indeed, any permutation of its digits) is also divisible by three. For instance, 1368 and its reverse 8631 are both divisible by three (and so are 1386, 3168, 3186, 3618, etc..). See also Divisibility rule.

A triangle is the most durable shape possible, the only "perfect" figure which if all endpoints have hinges will never change its shape unless the sides themselves are bent.

3 is the only integer between e and π.

Three of the five regular polyhedra have triangular faces -- the tetrahedron, the octahedron, and the icosahedron. Also, three of the five regular polyhedra have vertices where three faces meet -- the tetrahedron, the hexahedron (cube), and the dodecahedron. Furthermore, only three different types of polygons comprise the faces of the five regular polyhedra -- the triangle, the quadrilateral, and the pentagon.

There are only three distinct 4×4 panmagic squares.

Only three tetrahedral numbers are also perfect squares.

Answer 2

Well, you've got the Holy Trinity - Father, Son and Holy Spirit.

I think it's an important number in witchcraft (white magic) - like the power of three (and I'm not talking about the Charmed Ones). Apparently, if you do a good deed, you get it back threefold. Mind you - do a bad one you get the same!

Answer 3

There are 5 and 2.
If we have math operation with this 2 number you can solve using the inverse.(5 is the inverse of 2, etc)
ex:
1.265*5= divide 265 with 2 then multiply with 10
answer: 265/2=132.5; then multiply with 10=1325, check it!
2.6985/5= multiply with 2 then divide with 10
ans: 6985*2=13970; then divide with 10=1397, check it!

Answer 4

Seven is quite often given as a 'magic' number.

* Church - seven deadly sins & seven gifts of the Holy Spirit
* Seven days in the week
* Seven planets know to ancients (sun, moon, mercury, venus, mars, jupiter, saturn)
* seven is easiest number to roll with two dice
* magnificent seven :)
* seven seas
* rhymes with heaven

Mathematically though, I don't think seven has any particularly interesting properties ...
* it's 2^0 + 2^1 + 2^2 or 111 in binary
* its a prime
* that's about it :(

Answer 5

don't listen to anyone else but me! number 7 is the most powerful number in manyways! i can even tell you one hundred fairytales with the number 7 in them! in mathemtical view too. saw a showabou this with some math professors a week ago too... why do you think rowling says that on harry potter books? have you read book 6? she did some investigation and used no 7 for a reason.

Answer 6

Yes that is correct, 3 is used to represent the strongest shape which of course is a tri-angle. Also tri-angles can be used to make any other shape, therefore they are the magic shape and 3 is the magic number.

Answer 7

3 is an important and significant number. as in the beginning and through out the bible you can see how important it is, in the Old and in the New Testament.
Our Creator is God the Father, Jesus the Son and the Holy Spirit. Jesus lived for 33 years and then was crucified, dead and buried and in the grave for 3 days, and then God raised Him from the dead. Jesus friend Lazarus was dead 3 days and Jesus raised him from the dead.
We humans are 3 parts, Spirit, Soul and Body. We are a spirit, we have a soul and we live in a body.

Answer 8

3 refers to trinity in medieval times, i don't really remember specifically but i think it refers to sun, god and moon if i'm not wrong

Answer 9

1+1=? it is 3 (your mom and dad give birth to you )

Answer 10

3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510

is a magic number. They rounded it down.

(well it's Pi isn't it.)

copying from wikipedia without posting the source is cheating, elmo.