A "black hole" is defined as a region of space where gravity is so great that it prevents anything, including light, from escaping. Einstein's theory of general relativity predicts that a sufficiently compact mass will deform a point in space to form a black hole. Surrounding a black hole is a mathematically generated surface called the "event horizon" that marks the point of no return. A black hole absorbs all light that reaches the event horizon.

Large black holes are expected to form when very massive stars collapse at the end of their life cycle. However, such an end to a star's life may just be the beginning of a black hole's existence. Once formed, it can continue to grow by absorbing mass from its surroundings and merging with other black holes.

In fact, supermassive black holes containing millions of solar masses may form. Astronomers generally believe that supermassive black holes exist in the centers of most galaxies.

While we cannot see a black hole, its existence can be inferred through its interaction with surrounding matter and light and with electromagnetic radiation. For example, matter falling onto a black hole can form an accretion disk heated by friction, and thus forming some of the brightest objects in the universe. If there are stars orbiting a black hole, their orbits infer its mass and location.

This technique has been used to identify numerous black hole candidates. In fact, we now know that the core of our Milky Way galaxy contains a supermassive black hole with a mass of about 4.3 million suns.

Recently, particle physicists have been wondering if it may be possible to create small black holes in the laboratory. Let's speculate for a moment and assume this to be possible. How might we use artificial black holes for the good and enjoyment of humanity?

Here are a few ideas that we ran across in our search for future technologies and applications. Start with the potential for some new extreme sports. Imagine skating on the rim of the event horizon of a black hole. You would be the greatest extreme sports athlete ever.

Unfortunately, the gravity of the black hole would quickly prove to be too much for a human, and we can imagine what would happen next.

Communities lucky enough to have a small black hole could enjoy free and permanent removal of all local waste. Of course, you need a catapult capable of launching waste into the black hole in order to keep workers safely from away from the quantum crush.

Instead of expensive drilling and mining equipment, companies can explore clean cut, deep cavities created by the small black holes.

Of course, there are many more possible applications, but we have a favorite. Imagine a portable small black hole device that had a mass of only a few hundred kilograms. Further imagine this device could be pointed in any desired direction.

Then, it could create negative thrust by absorbing mass from the surroundings. Further imagine that this device could expel the absorbed mass along the same line of thrust.

The net effect would be a high thrust device that needed no propellant and could run indefinitely. This would be perfect for space travel. The only remaining question is: "What are the laws of physics needed to make this work?" Got any ideas?