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 What is the significance of permittivity of free space?
Name: Unknown
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993

What is the physical significance of the constant known as the permittivity of free space?

It is basically the scale factor between the unit of force and the unit of charge. There are actual electric and magnetic unit systems in which there is no such factor (since it would be 1). For most of our experiences we insist on measuring charge in coulombs and measuring forces (or electric fields) in Newtons (Newtons per coulomb). The coefficient that we need to make it come out right is related to the permittivity of free space. The words probably go back to the days when we thought there was an ether in space. You can also think about it as the way space effects the forces between two charges. In this way it become s a property of space.

Sam Bowen

Click here to return to the Physics 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