Convert Speed of Light (c) to Cosmic Velocity - Second (v₂) instantly.
About these units
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.
Cosmic Velocity - Second (v₂)
The second cosmic velocity is the escape velocity, the speed required to completely overcome a planet's gravitational attraction without further propulsion. For Earth, this speed is about 11.2 km/s. It is higher than v₁ because escaping gravity requires exceeding orbital balance entirely, not merely achieving stable free fall. Escape velocity underlies missions to the Moon, other planets, and deep space probes. Reaching v₂ allows spacecraft to travel along trajectories that leave Earth's gravitational well permanently unless acted on by external forces. This value symbolizes humanity's ability to break free from its home world—a critical milestone in exploration.