Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Pseudo Solids
Name: Shaly J.
Status: Student
Age: 15
Location: N/A
Country: N/A
Date: May 2004

What is a pseudo solid?

As far as I can determine, "pseudo solid" has no specific meaning. It is not a real "thing." It is a word that is used by scientists or engineers when they talk to each other and try to understand the way materials really behave.

In science and engineering, especially engineering, it is not possible to know things exactly. Instead, engineers "approximate" what they are studying using a simpler picture. For example, the way fuel burns inside a jet engine, or the way plastic flows when it is melted. These events are difficult to understand because they are really very complicated when you try to measure them very accurately. So engineers try to understand these examples in a simpler manner. If your field of research is about something nearly solid, then you might call it a pseudo solid. For example, some colloid materials (mixtures of solid and liquid, like thick paint) are solid. These mixtures do not flow. Blobs of this material aren't very strong and if you push the blob it will start to flow. Some people call this a pseudo solid because the a solid turns into a liquid.

A paste mixture of starch and water will flow, but if you hit it fast it becomes hard. This is not a pseudo solid. Engineers simply call it a non-Newtonian fluid.

Some people refer to glass or plastic as a "pseudo solid" when they want to say that these materials sometimes have properties that are not perfectly solid.

Bob Erck

Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory