Convert Planck Length (ℓₚ) to Ken (ken) instantly.
About these units
Planck Length (ℓₚ)
The Planck length, approximately 1.616 × 10⁻³⁵ meters, is perhaps the most conceptually profound unit in physics. It represents the scale at which classical notions of space and time cease to exist and quantum gravity effects dominate. Below this length, it is believed that spacetime becomes "foamy," subject to fluctuations predicted by quantum field theory and speculative models such as string theory. The Planck length is derived from fundamental constants: the speed of light, Planck's constant, and Newton's gravitational constant. These constants combine to yield a natural scale where both quantum mechanics and general relativity must merge into a unified theory. No experiment has ever probed distances anywhere near the Planck scale — it is many orders of magnitude smaller than even the size of protons — but it plays a crucial role in theoretical cosmology, black hole physics, and models of the early universe. The Planck length stands as a symbol of the limits of physical measurement and the frontier of fundamental physics.
Ken (ken)
The ken is a traditional Japanese unit of length, typically about 1.8 meters, though historically it ranged from 1.6 to 1.9 meters depending on the era and region. The ken is deeply tied to traditional Japanese architecture, especially temple and shrine construction. In classic building design, the ken measured the spacing between pillars in wooden structures. Because Japanese architecture emphasizes modularity and harmonious proportions, the ken allowed builders to create spaces that were both structurally efficient and aesthetically consistent. Many tatami room layouts are also derived from ken-based proportions. Beyond architecture, the ken carried symbolic importance in religious and cultural contexts. Temples were often laid out using ken multiples, reinforcing a sense of order, symmetry, and sacred geometry. Even though modern Japan uses the metric system, the ken persists in the restoration and preservation of historical buildings.