In Current Science, SI is the abbreviation for Système International (d’Unités) International System of Units. The units are:
- Time: seconds (s)
- Space: meters (m)
- Mass: kilograms (kg)
- Temperature: degrees kelvin (K) or °C (Celsius)
- Electrical current: ampere (A)
- Luminosity: candela (l)
- Amount of matter: mole. (See neu mole)
- angle (θ) ° (degree), rad (radian), or rev (revolution), 360° = 2π rad = 1 rev
- cycles (n) cyc (cycles)
- speed of light, 299 792 458 m/s
- one year time in seconds, 31,557,600 s
- light year (distance in meters @ speed of light), 9.46 ×1015 m