Black Hole FAQs: Frequently Asked Questions
Text written and copyrighted by Robert J. Nemiroff in 1995 who is solely
responsible for its content.
beginner, understandable to those who are curious
and have little or no science background,
intermediate, understandable to those who
are curious and have some science background,
advancedintended for black hole afficandos who may
be taking a college course in astrophysics, and lastly
for current topics of research interest in black hole
theory. Please don't "challenge" me with more black hole questions or
theories of your
own. Although I would like to answer those that I can, in reality
I just don't have time to answer them all. Rather, please call you local
university - quite probably there is a physicist or astrophysicist
who can help you. Alternatively, you might consider posing your question
to the internet news groups sci.astro or sci.physics.
What is a black hole?
A black hole is the darkest, densest object ever hypothesized. A black hole
has such strong gravity not even light can escape - causing it to appear
Will a black hole some day destroy the earth?
No. There are no black holes near enough to the earth, or even the solar
system, to cause any harm. The Sun will never become a black hole.
What does it look like to go near a black hole?
If the sun turned into a black hole, would it suck in the earth?
What does it mean that black holes "evaporate?"
Have black holes really been proven to exist?
What are astrophysical examples of black holes?
How can I get a job studying black holes?
If I went near a black hole, would it rip me apart?
If I dropped something into a black hole, would I see it fall in?
What is an event horizon of a black hole?
What is a photon sphere of a black hole?
What does "spacetime" mean?
What is the physical mechanism that generates the gravity of a black
Could I ever pass the event horizon of a black hole?
Could our whole universe really be one big black hole?
How can one measure distance to a black hole if one can't go too near
it and come back?
If I dropped something into a black hole, could I go back and get it
If I held something near a black hole, would it heat up or cool down?
What is the apparant angular size of a black hole?