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 Information on phone lines
Name: N/A
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: N/A


Question:
How does information travel across phone lines?



Replies:
As electrical signals, since they are electrical wires! Actually, the method used is being changed from "analog" to "digital" - you may have heard some of the long distance companies advertising, as are some of the cellular phone companies now, about how they use clear, sharp digital rather than analog. The old way was easier for voice-style communication because you just convert the analog sound waves of the voice directly into the analog signals of the telephone. A modem converts digital computer signals into analog telephone signals, for example, which seems an unnecessary step (you could just send the digital message directly as is done on ethernet's and other local area networks between computers).

Arthur Smith



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 (help@newton.dep.anl.gov), or at Argonne's Educational Programs

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

Argonne National Laboratory