# A Base-10 Delineation By Wavelength

What Do We Understand About Each?

**Please note**: This page began in October 2018. Instead of these standard 21 base-10 levels of delineation, our model would have no less than 202 levels. Our work to understand each of those 202 notations will require years of work before truly becoming robust. Among many projects around the world, we are following the work of scientists at Trinity College Dublin in Ireland.

**Perhaps the most important part of this chart is that color spectrum of lines defining visible light from 320 to 700 nanometers which is within Notation 88. **

**Questions: **What are the missing categories? How would this scale go finer than one picometer (at the top)? A **picometer** is equal to 1×10^{−}^{12} meters, or one trillionth (1,000,000,000,000) of a meter. Taken as a given, we will bump into the limits of physical measurements. That’s OK. What SI values are smaller than one picometer and larger than 100 Megameters (Mn) at the bottom of the chart?

The **megameter** (**Mm**) is a unit of length in the International System of Units (SI) defined as 10^{6} meters using the SI prefix system, however Mn is rarely used. Instead exponential notation is extended using the meter or kilometer. So, 100 Mn in this chart on the left would be 10^{8} meters. The next is gigameter, 10^{9} (billion), then comes terameter, 10^{12} (trillion), or 1,000,000,000,000 m.

The next step up is the petameter, 10^{15} (quadrillion), or 1,000,000,000,000,000 meters. Beyond our sun, Alpha-centari is the closest star to Earth and is 4.366 light-years away which is 41.4 petameters.

The next group is defined by the exameter, 10^{18} (quintillion), or 1,000,000,000,000,000,000 meters. Zettameter (Zm) is the next step out, 1,000,000,000,000,000,000,000 meters (1 with 21 zeroes), Sextillion or 10^{21} meters. There is no star within our little Milky Way galaxy more than a zettameter away. The Andromeda Galaxy is 24 Zm from Earth (visible with an unaided eye).

The yottameter or 10^{24} meters (a septillion) is the current accepted limit of the SI extensions. Randy Bancroft, known on the web as The Metric Maven writes pointedly:

**Going smaller is also important**. Currently the smallest unit of SI measurements is the yoctometer or 10^{-24} or a septillionth of a meter. The problem is our chart goes to the Planck base units of length; and time and within the time units, we are down to the 10^{-44} seconds and within the Planck Length scale we are down to 10^{-35} meters. Ten steps (groups) within the infinitesimal meter lengths will need names. And, twenty steps within the infinitesimal time lengths all need names. Anybody game?

Eventually we will try to integrate this work with the International System of Quantities.

**Internal references**: Our Chart, Time, Clock

**External References**: NIST, The Metric Maven, Electromagnetic Spectrum