The periodic table of the elements, one way to describe the properties of matter.
Click on image for full size
L.Gardiner/Windows to the Universe

Starting Points for Science

Some ideas are used in many, many places throughout science. We have grouped these "starting points for science" into three clusters: space, time, and matter.

"Space" is the word we use for everything beyond Earth. However, "space" is also the way we refer to location and the distance between objects. We live in a world with three dimensions, so coordinate systems that describe locations and distances are an important tool for describing space. The many units we use for measuring distance are an important part of our notion of space. Our modern view of the Universe, based on Einstein's General Theory of Relativity, includes the idea that space is curved.

Time is a second key idea. Many of our measures of time, such as days, months, and years, are based on astronomical phenomena. Armed with the concepts of space and time, we can specify the "where" and the "when" in our observations of the world around us.

Out third cornerstone concept is matter, the "stuff" without which the Universe would be a lonely place. We specify the amount of matter in an object in terms of the object's mass. There are four basic forms that matter can take on: solid, liquid, gas or plasma. Matter can be classified and grouped, as is done with the chemical elements in the periodic table. Matter and energy can be transformed into one another, as expressed in Einstein's famous equation relating the two: E = mc2.

Last modified September 11, 2008 by Randy Russell.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

What is mass?

Would it be more difficult to pull an elephant or a mouse? If you pulled each animal with the same amount of force, the elephant would respond less to pulling, even if he didnít pull back at all. Thatís...more


Solid is one of the four common states of matter. The three others are gas, liquid, and plasma. There are also some other exotic states of matter that have been discovered in recent years. Unlike liquids...more

The Plasma State

Plasma is known as the fourth state of matter. The other three states are solid, liquid and gas.In most cases, matter on Earth has electrons that orbit around the atom's nucleus. The negatively charged...more

Element (Chemical Element)

An element (also called a "chemical element") is a substance made up entirely of atoms having the same atomic number; that is, all of the atoms have the same number of protons. Hydrogen, helium, oxygen,...more

The Periodic Table of the Elements

Everything you see around you is made of tiny particles called atoms. There are many different types of atoms, each with a special combination of protons , neutrons and electrons . These different types...more

Tools for Math and Science

Some ideas are used throughout the sciences. They are "tools" that can help us solve puzzles in different fields of science. These "tools" include units of measurement, mathematical formulas, and graphs....more

Starting Points for Science

Some ideas are used in many, many places throughout science. We have grouped these "starting points for science" into three clusters: space, time, and matter. "Space" is the word we use for everything...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA