Black holes
The most unusual of the space terrain. A Black Hole, also known as a singularity or a hypermass, is an incredibly dense former solar body. It is so dense that its gravity can actually pull back light. Thus the term Black Hole.
Black Holes do one thing, but they do it very well: anything that gets close to a Black Hole is attracted to the singularity. The closer you get to the Black Hole, the more powerful the attraction.
If a ship gets too close to a Black Hole, it will be destroyed. Black Holes affect seeking weapons as well. The area of space around a Black Hole is stressed and can have a negative effect on other systems.
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Laws of black hole dynamics
- First law of black hole dynamics:
For interactions between black holes and normal matter, the conservation laws of mass-energy, electric charge, linear momentum, and angular momentum, hold. This is analogous to the first law of thermodynamics.
- Second law of black hole dynamics:
With black-hole interactions, or interactions between black holes and normal matter, the sum of the surface areas of all black holes involved can never decrease. This is analogous to the second law of thermodynamics, with the surface areas of the black holes being a measure of the entropy of the system.
Types of black holes
There are three types of black holes, classified by their size.
Stellar black holes
The most common type of black holes, stellar black holes are formed when a supermassive star collapses and contracts into an infinitely dense object, varying in size between the core of the sun and a small planet. The object is so dense that the escape velocity required to leave its surface is higher than the speed of light, making it impossible to escape once a vessel has entered the Event Horizon. Theoretically, one could escape by using an FTL propulsion system, however the conditions in the Event Horizon are such that normal laws of physics no longer apply. Therefore it is not likely that FTL drives function correctly.
Supermassive black holes
Supermassive black holes likely exist in the centers of most galaxies, including our own galaxy, the Milky Way. They can have a mass equivalent to billions of suns, and it has been estimated the Universe contains around 300 million of them.
In the outer parts of galaxies there are vast distances between stars. However, in the central region of galaxies, stars are packed very closely together. Because everything in the central region is tightly packed to start with, a black hole in the center of a galaxy can become more and more massive as stars orbiting the event horizon can ultimately be captured by gravitational attraction and add their mass to the black hole. By measuring the velocity of stars orbiting close to the center of a galaxy, we can infer the presence of a supermassive black hole and calculate its mass.
Perpendicular to the accretion disk of a supermassive black hole, there are sometimes two jets of hot gas. These jets can be millions of light years in length. They are probably caused by the interaction of gas particles with strong, rotating magnetic fields surrounding the black hole.
Interestingly, the X-ray luminosity of massive black holes seems to have diminished with time, and along a remarkably consistent gradient. The brightness of active galactic nuclei (AGN) dims along a steady scale according to distances and times from the present. In other words, whatever energies supermassive black holes exhibit tend to fall within a surprisingly narrow range, depending on when they appeared in the history of the Universe. This phenomenon has been called the "anti-hierarchy" - the rule is, the higher the X-ray luminosity of a supermassive black hole, the higher its red shift tends to be, meaning it governs a galactic center farther away from the Milky Way and older in the history of the Universe.
Miniature black holes
Miniature black holes were formed shortly after the "Big Bang," which is thought to have started the Universe about 15 billion years ago. Very early in the life of the Universe the rapid expansion of some matter compressed slower-moving matter enough to contract into black holes.
Black hole survival tips
Of course, the first rule of black holes is: don't fly into them. If, however, you should for some reason come close to such a body, you would be well advised to take into consideration some basic survival tips.
Firstly, bring strong radiation shielding. The accretion disks of black holes can be extremely hot, with immensely heavy x-ray and gamma radiation. Also, lots of photons will be zipping around the inside edge of the event horizon, never quite able to escape, but ready to blind you. Bring some strong sunglasses.
It is important to note regular space flight physics go out the window in proximity and inside a black hole. Once inside the photon sphere (1.5 times the radius of the event horizon), because spacetime gets so warped there that the faster you orbit, the stronger the centrifugal force you feel pushing you towards the event horizon, not away as you'd expect in flat spacetime.
If despite your best attempts you fall into the event horizon of a black hole, tough luck. You will survive for only a finite amount of time. If you fall straight down into a stellar black hole, you'll last a fraction of a second. For a supermassive black hole, you might last a few hours.
Due to the tremendous tidal forces, an unlucky victim will suffer spaghettification, where differences in gravity from your head to your feet stretch you out. Also, lethal levels of radiation will still exist inside the event horizon. But let's not worry about that for now. You're trying to maximize survival time.
Since you've got a spaceship capable of zipping around from star to star, you've got a powerful engine, capable of affecting your rate of descent. Point down towards the singularity and you'll fall faster, point away and you'll fall more slowly. Keep in mind that you're inside a black hole, flying a spaceship capable of traveling near the speed of light, so theories of relativity come into play.
And it's how you use your acceleration that defines how much personal time you'll have left.
In a moment of panic, you may point your rocket outwards and fire it at full thrust, keeping the engine running until you arrive at the central singularity. However, in the convoluted space-time within the event horizon, such a strategy actually hastens your demise, and you'll actually end up experiencing less time overall. So, what are you to do? The solution is identifying an acceleration "sweet-spot" that gives you the maximal survival time. All you have to do, once across the event horizon, is fire your rocket for a fixed amount of time, and then turn it off and enjoy the rest of the fall.
But how long should you fire your rocket for? This is a simple calculation involving the mass of the black hole, how powerful your rocket is, and how fast you crossed the event horizon. Consider a race to the centre between a free faller and a rocketeer. Suppose they cross the event horizon together holding hands. As they cross, they start identical stop watches. One falls inwards, while the other accelerates towards the centre for a little, then swings their rocket round and decelerates such that the free faller and the rocketeer meet and clasp hands again just before hitting the singularity. A check on their stop watches would reveal that the free faller would experience the most personal time in the trip. This is related to one of the basic results of relativity - people in freefall experience the maximum proper time.
So now you know. Even after you've fallen into the black hole's event horizon, there are things you can do to lengthen your harrowing journey so that you get to experience more time.
