3 is the natural number following 2 and preceding 4.
Some interesting facts about the number Three:
- Three is the first unique prime due to the properties of its reciprocal.
- Vulgar fractions with 3 in the denominator have a single digit repeating sequences in their decimal expansions, (.000…, .333…, .666…)
- Humans perceive white light as the mixture of the three additive primary hues: red, green, and blue.
- Earth is the third planet in its local Solar System.
- In paleontology, trilobites are named as such because their bodies are divided in three longitudinal lobes.
- Three is the atomic number of lithium.
- The three Doshas (weaknesses) and their antidotes are the basis of Ayurvedic medicine in India.
- In Vietnam, there is a superstition that considers it bad luck to take a photo with three people in it; it is professed that the person in the middle will die soon.
- The Rule of Three is an American superstition in which celebrity deaths tend to occur in threes.
- On most telephone keypads, the “3″ key is also associated with the letters “D“, “E“, and “F“.
- Some may use “3″ as an alternate to the letter “E“, often in jest or when using Leetspeak, to denote being experienced in certain technology related fields.
- The tritone, which divides the octave into 3 equally spaced notes (root, tritone, octave).
- Three Mile Island is known for a nuclear accident.
- In bowling, 3 strikes in a row is called a turkey.
- A triathlon consists of three events: swimming, bicycling, and running.
- The game rock-paper-scissors involves three hand shapes. Rock, paper, and scissors.