Omega (Ω, ω)
Quick Info
- Pronunciation: oh-MAY-guh
- English: ō
- Common Use: Ohm (resistance)
Historical Background
Twenty-fourth and last letter of the Greek alphabet, derived from Phoenician letter "ayin", meaning eye. The name literally means "great o" (as opposed to omicron, "little o"). The symbol Ω has become particularly significant in electrical engineering as the unit of electrical resistance, while ω is widely used in physics and mathematics to represent angular frequency.
Scientific Applications
Physics
Angular velocity
Electronics
Electrical resistance
Mathematics
Solid angle
Astronomy
Density parameter
Complex Analysis
Domain boundary
Symbol Codes
Unicode
Uppercase
- Code: U+03A9
- Hex: Ω
- Decimal: Ω
Lowercase
- Code: U+03C9
- Hex: ω
- Decimal: ω
HTML
Uppercase
Ω
HTML entity for uppercase Omega
Lowercase
ω
HTML entity for lowercase omega
LaTeX
Uppercase
\Omega
LaTeX command for uppercase Omega
Lowercase
\omega
LaTeX command for lowercase omega
Common Usage
Physics
Angular Motion
Angular velocity in rotational dynamics
Wave Theory
Angular frequency in oscillations
Quantum Mechanics
Solid angle calculations
Electronics
Circuit Analysis
Electrical resistance measurement
Impedance
Complex resistance
Power Systems
Load resistance
Cosmology
Density Parameters
Universe composition
Dark Energy
Energy density
Matter Distribution
Mass density ratios
Common Applications
Rotational Motion
Angular frequency
Angular acceleration
Angular momentum
Electrical Engineering
Ohm's law
Complex impedance
Power dissipation
Special Applications
Cosmology
Density parameters
Total density
Hubble parameter
Wave Mechanics
Angular frequency
Photon energy
Wave function
Physical Applications
Electronics
- • Circuit analysis
- • Power calculations
- • Impedance matching
- • Resistance measurement
Mechanics
- • Rotational dynamics
- • Gyroscopic motion
- • Harmonic oscillation
- • Angular momentum
Cosmology
- • Universe density
- • Dark energy
- • Matter distribution
- • Expansion rate
Theoretical Applications
Complex Analysis
Residue theorem
Laplace equation
Domain boundary
Quantum Mechanics
Transition frequency
Expected frequency
Energy eigenvalue
Electrical Applications
DC Circuits
Series resistance
Parallel resistance
Power law
AC Circuits
Impedance magnitude
Inductive reactance
Capacitive reactance
Writing Guidelines
Uppercase resembles a horseshoe (Ω), lowercase looks like a rounded w (ω). In handwriting, ensure the lowercase ω is clearly distinguished from the Latin w and the Greek nu (ν). The uppercase Ω should have a clear base line and symmetrical curves.
How to Type Omega
Windows
Alt Code
- Hold Alt
- Type 937 for Ω or 969 for ω
- Release Alt
Character Map
- Open Character Map
- Select Greek
- Find and copy Omega
Unicode
- Hold Alt + X
- Type 03A9 for Ω or 03C9 for ω
- Release Alt + X
macOS
Option Key
- Press Option + z for Ω
- Press Option + w for ω
Character Viewer
- Press Control + Command + Space
- Select Greek
- Click Omega
Linux
Compose Key
- Press Compose + w + w for ω
Unicode
- Press Ctrl + Shift + U
- Type 03C9
- Press Enter
Frequently Asked Questions
What is the difference between Omega (Ω) and Omicron (Ο)?
While both represent "o" sounds, Omega (meaning "great o") and Omicron (meaning "little o") were used to distinguish between long and short "o" sounds in ancient Greek. In modern usage, Ω represents electrical resistance and ω represents angular frequency.
Why is Omega used for electrical resistance?
The symbol Ω was chosen to represent the unit of electrical resistance (ohm) in honor of Georg Simon Ohm, who discovered the relationship between voltage and current. The choice of Omega may have been influenced by its association with completion or finality.
How is omega used in physics?
In physics, ω (lowercase omega) typically represents angular velocity or angular frequency in rotational motion and wave phenomena. It's related to linear frequency f by the equation ω = 2πf.
What's the difference between ω and v for velocity?
While both represent types of velocity, ω specifically represents angular velocity (rotation rate) measured in radians per second, while v represents linear velocity measured in distance per time.