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 EM Waves, Charge, and Propagation
Name: Sankar K.
Status: educator
Age: 30s
Location: N/A
Country: N/A
Date: 7/17/2003

In many books it is said that a light wave consists electric and magnetic field perpendicular to each other. But light has no charge. How does this electric field exist when light is in vacuum? Why is the electric field in the EM wave not disturbed or deflected in the presence of external electric field? I feel that, the electric field not propagating. I suggest that it is the energy developed by the electric magnetic fields at the location source is propagating.


Two things can produce electric effects, an electric charge and a changing magnetic field. Two things can produce magnetic effects, a moving electric charge and a changing electric field. A vibrating electric charge produces changing electric fields and changing magnetic fields. The changing electric field then produces a changing magnetic field and the changing magnetic field produces a changing electric field. These changing fields continue driving each other along, giving energy back and forth to each other until reaching an electric charge. At that point, the field may or may not give its energy to the charge, causing the new charge to vibrate. This is vision.

Dr. Ken Mellendorf
Physics Professor
Illinois Central College

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