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 Clarificatoin of Black Hole Radiation
Name: N/A
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: 1991 

How come the radiation Hawking describes is unidentifiable? Is the matter that slowly appears just outside the event horizon from within the hole, or are these particle pairs being created arbitrarily?

Yes, of course, anything that is "radiated from" a black hole must come from outside of the event horizon. As far as the last part of your question is concerned, my dictionary gives "random" as one definition of the word "arbitrary". When you study quantum mechanics you will learn that single events, like the radiation of a quantum of light by an atom, are nearly always random.

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