Convert Light Year (ly) to Electron Radius (re) instantly.
About these units
Light Year (ly)
A light year is the distance that light travels in a vacuum in one Julian year, equal to approximately 9.4607 × 10¹⁵ meters. Despite its name, it is a unit of distance, not time. The light year arose from the need to express vast astronomical separations using a concept familiar to laypeople: the finite speed of light. By linking distance to time, it becomes easier to comprehend that observing distant stars is also an act of looking back in time. The light year is especially useful when describing the locations of nearby stars, nebulae, and star-forming regions. For example, Proxima Centauri lies roughly 4.24 light years away. Because light moves at about 300,000 km/s, even the nearest galactic objects are many trillions of kilometers distant, making ordinary units impractical. One of the light year's greatest strengths is how vividly it illustrates the immensity of space. When astronomers say a galaxy is millions of light years away, they convey not only a vast spatial separation but also the staggering temporal depth of the universe. The light year therefore plays a dual role as both a scientific measurement and an educational tool that grounds cosmic distances in a memorable framework.
Electron Radius (re)
The classical electron radius, approximately 2.818 × 10⁻¹⁵ meters, is a theoretical value derived from classical electromagnetic theory rather than an actual measured size. It represents the radius a charged sphere would need to have in order for its electrostatic self-energy to equal the electron's rest energy. Although electrons are now understood to be point-like or extremely small compared to this radius, the classical electron radius remains useful in scattering theory, especially in calculations involving Thomson scattering — the elastic scattering of electromagnetic radiation by free electrons. Thus, while not a physical dimension of the electron, the classical radius serves as a meaningful parameter in specific areas of physics and retains importance in radiation modeling and plasma physics.