Matter appears organized on distinct levels in physical existence.

Scale in science

The visual metaphor drawn as if the levels of material existence were a staircase suggest to us that the universe is arranged in discrete and separate layers; where the organization and function on one layer does not necessarily hold true for the adjacent layers. Although all of the layers are interconnected such that cells or species are comprised of elements and quarks, the difference in sizes across these dozen steps, poses a problem for measuring the relative size of living things, molecules and atoms. Taking the measure of the cosmos becomes a daunting task without some uniform means of expressing the size of objects.

Sizes differ in nature, but biology, chemistry, physics and geology share a common measure:

Uniform measure:

Measures are sometimes referred to as a "metric."

Two definitions are possible for metric, as it

1. generally refers to any unit of measure, implying a consistent means of determining a mathematical or quantifiable relation among pairs of points, or amounts of something.
2. The more restricted definition is specific to the measure of meter in a poem or the agreed upon units of measure in the European metric system . The metric system is a decimal based accounting concept of a standard unit called the meter (about a yard, or three and three tenth's feet long).

Metric implies the act of taking the dimensions and extent of something by assigning numbers in a consistent manner to something under scrutiny. In the above diagram size is being accounted for with respect to a ruler on which the marks or demarcations are in exponential relation to one in respect to the decimal system. This means, when moving to the left the size increases from one to ten to one hundread and to one thousand: 1, 10, 100, 1000.

This use of the decimal and logarithmic scales allows enormously small and very large object to be compared with the amplitude and frequency or size and duration of electromagnetic waves. All three sciences, physics, chemistry and biology share this quantifiable scale in order to interprest the magnitude, variation and function of things in the surrounding world.

The steps, in the initial diagram, can thus be measured with respect to the size of objects found on the steps along the stairs that are used metaphorically to envision how nature is organized on multiple levels of size. The right side of the scale is used to show how small something is in relation to say a period ( . ) which is the equivalent of 1/100th of a meter. Smaller than a period the scale accounts for things whch exist that are no larger than one trillionth of a meter in extent (femtometre on the scale below.).

In the example above it is clear that for using this metric, the material world we perceive can be measured and in doing so it all comes down to a matter of size.