Dinner With a Black Hole
Suppose you are seated at the dinner table, about one meter from the table's centre. The hostess surprises you by placing a primordial Black Hole on the table. The Universe is thought to contain billions and billions of these tiny holes. They were formed from tiny quantum fluctuations grown large by the rapid expansion of the Universe. Typical mass of a primordial Black Hole is about 10^11 kg.
This Black Hole with the mass of Diamond Head, would have a Schwarzhild radius of:
The 10^11 kg hole has a diameter of just 10^(-16) meters, less than the size of a proton!
Sitting at the table, the gravitational acceleration you would feel is given by:
Where G is Newton's gravitational constant, M is Mass of the Black Hole and r is your distance.
This is easy to calculate. G = 6.67 x 10^(-11), M is 10^11 kg and r = 1 meter. The acceleration you would feel is just 6.67 m/sec^2, barely 2/3 that of Earth's gravity! If you braced yourself against the table, you would not fall into the Black Hole.
Suppose that you were suicidal and reached for the Black Hole. As soon as you touched the event horizon, a portion of your finger would be converted into radiation according to E=mc^2. If your fingertip weighs 1 gram, the radiation released would be 9 x 10^13 Joules, equivalent to a small nuclear explosion! The rest of you would be blown sky high, easily exceeding the Black Hole's tiny escape velocity. Your charred remains would never bother the Black Hole again.
As for the table, a small amount would be swallowed by the Black Hole, releasing enough radiation to keep the everything else away. The immediate vicinity would become a swirling mass of charged particles. If enough charged mass orbited the Black Hole, iot would generate a magnetic field like that of Earth.
Sitting to dinner with a Black Hole, a person could not be swallowed even if he wanted to. The Black Hole would create radiation and possibly a magnetic field, just like Earth's centre. As we eat dinner tonight, we have reason to consider a Hole in the Earth.
Labels: black holes