By Jessica Reynolds,Â Guest Blogger
Even with what scientists currently know about black holes, much is still a mystery. Scientists are constantly refining what they know. For example, until recently scientists believed they would only ever find one black hole per star cluster. In Oct. 2012, however, scientists found two small, twin black holes at the center of a cluster. Despite what we donâ€™t know about black holes, though, there are some things weâ€™re quite sure about.
Black Hole Basics
Black holes produce an intense gravitational pull. So strong, in fact, that black holes even bend light toward themselves. And the farther to the center you get to the black hole, the more gravitational pull it has. This gravitational pull is caused by pushing a lot of mass into a very small place. This happens when a very large star collapses in on itself, pushing its mass close together and increasing gravitational pull. How big does a star need to be to become a black hole? To give you an idea: Our sun is too small.
You canâ€™t â€œseeâ€ black hole. Instead, black holes are tracked by what you canâ€™t see. More on this in the section below.
Things start to get odd at the horizon, or edge, of a black hole. From a distance, the horizon appears static. This is because light can still escape from the black hole at the edge of the horizon (without crossing over the horizon). If you were to ever cross over into a black hole, however, the horizon would appear to move away from you at the speed of light.
A black holeâ€™s size is relative, especially when talking about size in terms of mass. Theoretically, you can create a black hole out of any amount of mass as long as you compress it into a small enough space. In terms of size in width and length: Scientists just arenâ€™t sure. No theory currently exists about how small or big a black hole can actually be.
More Information on Black Hole Basics
Tracking Black Holes
As I said, scientists canâ€™t actually see black holes. Generally, scientists see objects from the light those objects give off, but black holes donâ€™t give off any light (because it canâ€™t escape). So instead of seeing a black hole itself, scientists track the effects of a black hole.
For example, scientists recently found a star â€œwhippingâ€ around the center of the Milky Way galaxy. Although scientists canâ€™t see the black hole, they see this star (titled SO-102) making a complete revolution every 11.5 years around seemingly nothing. It is this â€œnothingnessâ€ that scientists call a black hole.
The fact that scientists canâ€™t â€œseeâ€ black holes today isnâ€™t stopping them from trying. According to a January 2012 Forbes article, scientists are trying to feed data from multiple telescopes into a supercomputer in hopes of capturing the first image of a black hole. If successful, scientists will be able to test Einsteinâ€™s Theory of Relatively. And the discovery of SO-102 could give them the opportunity theyâ€™ve been waiting for.
These are indeed exciting times for black holes. In addition to the current events talked about above, Cambridge scientists are studying some newly-discovered and growing supermassive black holes and scientists in Britain have been funded to create an artificial black hole in the lab.
Unfortunately, hobbiests and citizen scientists will have a hard time being part of the action. The best we can do at the moment is to follow the projects mentioned here. We can only hope that, at some point, scientists will gain enough insight to allow citizen scientists to see â€“ and study â€“ the black hole themselves.
About the Author
Jessica Reynolds loves design, art, photography and science. She brings all these talents to the table by writing for Poster Session, a division of MegaPrint.