Megaparsec
A megaparsec (Mpc) is a unit of distance used in astronomy to measure vast stretches across the universe. One megaparsec equals one million parsecs, or about 3.26 million light-years (1 Mpc ≈ 3.086 × 10¹⁹ kilometers). This unit is commonly used when discussing the distances between galaxies, galaxy clusters, or large-scale structures of the universe. Because the universe is so massive, astronomers need units like megaparsecs to express distances that are too large for even light-years to handle efficiently. The megaparsec is essential in cosmology and is often used when describing the scale of the observable universe.
Planck Length
The Planck length is the smallest meaningful unit of length in physics, representing a fundamental scale at which classical ideas about gravity and space-time break down and quantum effects dominate.
It is defined as approximately 1.616 × 10⁻³⁵ meters.
The Planck length is derived from fundamental constants: the speed of light, Planck’s constant, and the gravitational constant.
It sets a theoretical limit below which the very concepts of space and distance may lose conventional meaning.
Used mainly in theories of quantum gravity and string theory.
Key facts:
1 Planck length ≈ 1.616 × 10⁻³⁵ m
Smallest scale in quantum physics and cosmology
Represents a scale where quantum effects of gravity become significant
The Planck length is crucial for understanding the fabric of the universe at its most fundamental level.
No conversions available for length.