Sponsors of A Century of Physics Timeline Wallchart
The following organizations sponsored the Timeline Wallchart:

	Lucent Technologies
	National Science Foundation
	United States Department of Energy
	United Parcel Service

Following the story-lines in A Century of Physics
The story of physics in the 20th century unfolds like a splendid tapestry teeming with people, ideas, and things. In order to find patterns in this tangle, it helps to pick out five color-coded story-lines that stretch like broad, horizontal ribbons from beginning to end.

		tells the story of the quest to understand the universe of galaxies and stars embedded in spacetime. Its dimensions are incomprehensible distances, such as the 1022 meters that separate us from our neighboring Andromeda Galaxy.
		Closer at hand, the Human scale refers to the more familiar distances from the global to the microscopic that are immediately accessible to our senses.
		In the foreground, the Atomic scale focuses on the submicroscopic world of atoms and quarks - down to the unimaginable 10-15 meter radius of a proton.
The Cosmic, Human, and Atomic scales correspond to separate branches of physics. Up until 1900, classical physics dealt mostly with phenomena on the human scale, but for a description of the cosmic and atomic realms, new mathematical languages had to be developed. The three story-lines remained fairly distinct until the 1960s, when they finally began to converge in a synthesis that represents one of the great triumphs of modern physics.
		illustrates how physics is related to biology and medicine.
		traces the application of scientific discoveries to devices and techniques that help to shape everyday life.

The references to Art woven into the bottom border serve as reminders that science is but one of many different perspectives on the world.

As physics probes beyond the human scale of comprehensible dimensions, it encounters progressively larger and smaller numbers. In cosmic and atomic physics, numbers with ten, twenty, or even forty digits, either before or after the decimal point, are common. In order to avoid the awkwardness and tedium of writing out such monstrosities, and to reduce the chance of error, scientists -- and this timeline - employ the elegant, compact Exponential Notation. Here are a few examples:

1 000 000 000 000 = 10¹² a trillion (in American usage)
1 000 000 000 = 10⁹ a billion (in American usage)
1 000 000 = 10⁶ a million
1 000 = 10³ a thousand
1 = 10⁰ one
0.001 = 10^-3 a thousandth
0.000 001 = 10^-6 a millionth
0.000 000 001 = 10^-9 a billionth (in American usage)
0.000 000 000 001 = 10^-12 a trillionth (in American usage)