Couldn't find element LayerAd

Error finding content

What is a Fluid? - Windows to the Universe

Shop Windows to the Universe

Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.
Ocean waves off the coast of Mexico
Click on image for full size
copyright 2002 University Corporation for Atmospheric Research

What is a Fluid?

When you hear the word Fluid you might think of a liquid like water or juice - something that you can stir up with a spoon. That's right - all liquids are fluids. But did you know that gases like air are fluids too?

If you can stir something up with a spoon or blow it through a straw, it's a fluid. Actually, all liquids and gases are fluids. In space and inside stars there's another kind of fluid called a plasma. Plasma makes up stars.

Most of the universe is made of fluid! All of these things are fluids: oatmeal, jello, milk, blood, rain, the Earth's atmosphere, oceans, giant gas planets like Jupiter, stars like the Sun, and huge clouds of gas and dust in space. Can you think of others?

Last modified November 2, 2005 by Jennifer Bergman.

Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Cool It! Game

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

The Plasma State

Plasma is known as the fourth state of matter. The other three states are solid, liquid and gas.Almost everything is made up of atoms (your dog, your science book, this computer...). The atom has a nucleus...more

Rain

Raindrops form when tiny water droplets collide together in clouds to form bigger ones. When they get too heavy, rain falls out of the clouds. Rain is more than 5mm in diameter. The types of clouds that...more

Solid

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

Mechanics

Mechanics is one of the main branches of physics. Mechanics deals with the motion of physical objects. It also deals with the forces that act on physical objects. How hard do I have to pull a full wagon...more

The Magnetic Field

The force of magnetism causes material to point along the direction the magnetic force points. Here's another picture of how this works. This picture shows where the magnetic poles of the Earth are to...more

Planetary Magnets

The Earth has a dipole magnetic field. This is when magnetic field lines point in a direction out of the South Pole and into the North Pole. Planets can also have quadrupoles (4 poles) and octupoles (8-poles)....more

Eccentricity of an Orbit

Do you think Earth moves around the Sun in a circle? That is almost true, but not quite. The shape of Earth's orbit isn't quite a perfect circle. It is more like a "stretched out" circle or an...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF