Convert Mach (20°C, 1 atm) (Ma (20°C)) to Speed of Light (c) instantly.
About these units
Mach (20°C, 1 atm) (Ma (20°C))
At 20°C and 1 atmosphere, the speed of sound in air is about 343 m/s, making Mach 1 = 343 m/s under those conditions. Mach numbers classify aerodynamic regimes: Mach 0.3–0.8 (Subsonic), Mach 0.8–1.2 (Transonic), Mach 1–5 (Supersonic), Mach 5+ (Hypersonic). Temperature influences Mach speed significantly; colder air slows sound, while warmer air increases its speed. Aircraft design, jet engines, wind tunnels, aerospace testing, and atmospheric re-entry physics all rely heavily on Mach numbers referenced to standard conditions.
Speed of Light (c)
The speed of light in a vacuum, denoted c, is exactly 299,792,458 m/s, one of the most fundamental constants of physics. Light speed defines the structure of spacetime, the upper limit for classical information transfer, and the basis for relativity. Time dilation, length contraction, and mass-energy equivalence (E = mc²) all arise from the invariance of c. In astronomy, the speed of light is used to define light-years, measure cosmic distances, and synchronize observations across telescopes. In communication technology, optical networks rely on light-speed propagation through fiber, albeit slightly slower than in vacuum. c is not just a speed—it is a cornerstone of the physical universe.