Omicron (Ο, ο)
Quick Info
- Pronunciation: OM-ih-kron
- English: o
- Common Use: Big O notation
Historical Background
Fifteenth letter of the Greek alphabet, derived from Phoenician letter "ayin", meaning eye. The name literally means "little o" (as opposed to omega, "big o") and reflects its role as the short O sound in ancient Greek.
Scientific Applications
Computer Science
Big O notation
Astronomy
Stellar classification
Mathematics
Order of magnitude
Physics
Solid angle
Chemistry
Orbital notation
Symbol Codes
Unicode
Uppercase
- Code: U+039F
- Hex: Ο
- Decimal: Ο
Lowercase
- Code: U+03BF
- Hex: ο
- Decimal: ο
HTML
Uppercase
Ο
HTML entity for uppercase Omicron
Lowercase
ο
HTML entity for lowercase omicron
LaTeX
Uppercase
\Omicron
LaTeX command for uppercase Omicron
Lowercase
\omicron
LaTeX command for lowercase omicron
Common Usage
Computer Science
Algorithm Analysis
Time complexity notation
Space Complexity
Memory usage bounds
Performance Analysis
Growth rate comparison
Astronomy
Stellar Classification
Hot, blue stars
Spectral Analysis
Temperature classification
Luminosity
Brightness measurement
Mathematics
Asymptotic Analysis
Upper bounds
Function Growth
Order relationships
Complexity Theory
Algorithm efficiency
Common Applications
Algorithm Analysis
Quadratic time complexity
Logarithmic space complexity
Constant time operation
Stellar Classification
O-type star temperature
Luminosity scale
Peak wavelength
Special Applications
Asymptotic Analysis
Big O definition
Complexity hierarchy
Sum property
Astrophysics
O-type star mass
Stellar radius
Luminosity relation
Algorithmic Complexity Classes
Common Time Complexities
Space Complexities
Field Applications
Computer Science
- • Algorithm analysis
- • Performance bounds
- • Resource utilization
- • Complexity theory
Astronomy
- • Stellar classification
- • Spectral analysis
- • Temperature scales
- • Luminosity classes
Mathematics
- • Growth rates
- • Function bounds
- • Series analysis
- • Approximation theory
Writing Guidelines
Both uppercase (Ο) and lowercase (ο) forms are circular, similar to the Latin letter O. In handwriting, be careful to distinguish Omicron from the digit zero (0) and the Latin letter O. The Greek omicron is typically written slightly smaller than the Latin O.
How to Type Omicron
Windows
Alt Code
- Hold Alt
- Type 927 for Ο
- Release Alt
Character Map
- Open Character Map
- Select Greek
- Find and copy Omicron
Unicode
- Hold Alt + X
- Type 039F
- Release Alt + X
macOS
Option Key
- Press Option + o for ο
Character Viewer
- Press Control + Command + Space
- Select Greek
- Click Omicron
Linux
Compose Key
- Press Compose + o + o for ο
Unicode
- Press Ctrl + Shift + U
- Type 03BF
- Press Enter
Frequently Asked Questions
What is the difference between Omicron (Ο) and Latin O?
While they look identical, Omicron and Latin O have different Unicode values and historical origins. In mathematics and computer science, Omicron is specifically used for Big O notation and other technical contexts.
Why is it called "little o"?
The name "omicron" literally means "little o" in Greek, distinguishing it from omega ("big o"). This naming helped differentiate between the two O-like letters in the Greek alphabet.
How is Omicron used in Big O notation?
In computer science, Big O notation (written with Latin O, not Omicron) is used to describe the upper bound of the growth rate of an algorithm. The notation O(n) describes how the algorithm's resource usage grows with input size.
What's the difference between O-type stars and other stellar classifications?
O-type stars are the hottest and most massive of the main sequence stars, with surface temperatures above 30,000 Kelvin. They appear blue in color and are relatively rare in the universe.