As I wrote in my previous post, gravity is a very interesting topic. In fact, this is especially true when the more intriguing factors are taken into consideration, such as Black Holes. Did you know, perchance, that it is possible that the universe is, in fact, a black hole? I don’t suppose. With a radius of 15 billion light years, this is equivalent to the radius needed for an object of the mass of the universe to have a gravity requiring an escape velocity greater than the speed of light. The interesting point here is that black holes don’t have to be this massive. If one were to compress the mass of Earth into the size of a golf ball, it would have a gravity strong enough to be considered a black hole. Unfortunately, most of the black holes we can “view” are collapsed stars that had such large masses that they collapsed even after becoming a neutron star.
Though we might not notice it, gravity plays a large part in many science fiction stories and movies. In science fiction space ships, it appears that characters can walk around as if there is a gravity similar to that on Earth. There are two possibilities for this to happen. One is that the spaceship could be spinning. A spaceship with a 200 meter radius would have to spin at a rate of 44 m/s. This is the equivalent of making one full rotation every 40 seconds. The other option, in the case that the spaceship isn’t spinning, is that it is being accelerated with a force equivalent to that of Earth’s gravity (1 g, or 10 m/s/s). If a spaceship accelerated like this, it would travel 1/2 of a light year in one year. This is a huge distance.
Among many other interesting facts that I learned, these were perhaps the most interesting. Perhaps, if I get enough feedback, I shall write a bit more.