Ramifications of a Black Hole in Charted Space
- Thread starter ovka
- Start date
A black hole would really have no meaningful effect unless you were very close to it. If you were to instantaneously replace Earth's Sun with a black hole of the same mass, there would be no real change to the solar system gravitationally *. It is only when you get close to the Event Horizon that you start having significant and weird relativistic effects. Of course, if you do not know of the existence of an interstellar black-hole, it could mess with your Jump-navigation plot, precipitate you out of J-Space at 100dia from the Black Hole instead of your intended destination, and/or cause GM-house-rule specific problems with J-Space and/or jump-drives in general. But with gravitics and the associated gravitometer-sensors that would be a spin-off of that technology, gravitational anomalies ought to be easier to detect than they are to us today, even at long (or interstellar) range, I would imagine.
* - Obviously, the lack of stellar radiation would turn the Earth into a dark and frozen iceball, but that is a different issue.
EDIT: Of course, it might make a difference to the historical evolution of the star systems surrounding the black-hole system, as the supernova that created it historically may have sterilized all native life that any of the surrounding systems might have had.
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Oh snap... What's the actual diameter of a black hole? Since there are disagreements about the use of gravitational forces, you might pop out way closer than you think.
For a non-rotating (Schwarzschild) black hole:
RSchwarzschild = 2GM/c2
For a solar-mass black-hole, about 3 km. Meaning 100 diameters would be about 600km. A lot closer than I would want to be. Of course a real black hole would be at least 2-4 solar masses, and I would house rule as a GM that the 100 diameter limit is an astrogators approximation for normal stellar and planetary bodies, and not necessarily applicable to neutron stars or black holes.
EDIT: Rotating (Kerr) Black holes have other interesting properties:
Kerr Black Hole:
https://en.wikipedia.org/wiki/Rotating_black_hole
Ergosphere:
https://en.wikipedia.org/wiki/Ergosphere
Well, for one, it's really dark.
G. Kashkanun Anderson
SOC-13
From the data, it should be safe to assume that the Shadowsand primary is a pretty quiescent black hole. They need material to feed from in order to produce the deadly radiation (X-ray bursts, most notably) they're known for, and as a solitary primary, it has no close companion to leech material from. The only other listed source for material would be the Shadowsand Belt itself, and since it's inhabited, I would call it a certainty that it's far enough away from the primary to avoid losing material to it; I don't think even Traveller characters have the iridium balls it would take to try and beltstrike a black hole accretion disk.
The supernova event itself would have had a disastrous effect on any worlds orbiting the systems near enough to it; but it would have had to have happened in the extremely recent past for the worlds currently around it to be the ones affected. Stellar remnants from core collapse supernovae tend to be moving extremely rapidly through their stellar neighborhood -- the asymmetry of such events makes them the epitome of Newton's Third Law in action -- and they will have traveled a very long ways from their origin point within just a few hundred thousand years.
The fact that it has planets orbiting it indicates that it most likely is several million years old. The most likely reason for a planet to exist around a black hole would be as objects re-accreted from material left over after the blast, and this would take a while. Everything in the system, including the belt, should be unusually high in heavy elements as well, which I assume is still of some decent value to miners in the Far Future. There's also a better than average chance that they are carbon planets -- assuming we can eventually prove that such worlds actually exist beyond theory.
I think it's pretty nifty too.
The Wiki has some data beyond the UWP:
External Link: [http://wiki.travellerrpg.com/Shadowsand_(world)) Shadowsand]
Shalom,
Maksim-Smelchak.
According to Hawking combined pairs trapped in the black hole are torn apart at a certain distance where their momentum and the black hole's pull balance out. His conclusion is that this is the cause of Hawking radiation of black holes, and that this will eventually cause the black hole to evaporate, dying in a massive explosion.
To the best of my knowledge, there is no formula to predict such an event.
I'm also assuming the worlds present get their sunlight from the accretion disk. I would imagine that would look very strange to any PCs and NPCs; a band of light instead of a single bright fiery ball.
To the best of my knowledge, there is no formula to predict such an event.
I'm also assuming the worlds present get their sunlight from the accretion disk. I would imagine that would look very strange to any PCs and NPCs; a band of light instead of a single bright fiery ball.
G. Kashkanun Anderson
SOC-13
Black holes of stellar mass don't detonate; they evaporate to the point where they ultimately become mini black holes that then detonate, and when they do, the explosion itself is probably unremarkable by galactic standards.
The evaporation of stellar black holes is an epochs-long process. Singularities a couple of solar masses in size should take many billions of years to evaporate via Hawking radiation, and the very largest ones will take a googol years to do it. Don't wait up.
There's no indication that there's anything to accrete from here, so pitch blackness is all anyone should see in the general direction of that black hole. You wouldn't want to be around if it were to start accreting anything anyway. Accreting black holes are lethal sources of gamma rays and X-ray emissions.
Depends on what part of the disk you're talking about. By the time you get to the event horizon you're pretty much off the charts, temperature-wise. But the problem, as I mentioned above, is that an accreting black hole is going to be firing off X-ray bursts at everyone in the general vicinity like paparazzi going to town at the Oscars. I don't think you want to even be in the same star system when that kind of thing is going on.
so, it depends on where and when?
recently there was talk of all the mineral wealth that would be accessible once the polar ice caps melted, and nations were lining up to claim arctic territory. I suppose there could be an adventure about a black hole accretion disk that was going quiescent for a while, opening up vast new mining opportunities in the outer rim ....
It depends upon the density of the star field behind it. But generally at any safe distance, the black hole (and the lensing effect) would be so small as to be invisible.
The large black hole at the center of the milky way uses it's magnetic field to rip stars apart, and we have X-RAY band images of it doing this and the stream of gas reaching across half a light year, the bigger they are the larger the danger space.
Barred galaxy images show the black hole in the centers forcing stars into a common angular speed thus forming the bar, and they only get the spiral past a set point this indicates an even larger black hole than that of the milky way's. Our bar is still very small.
Barred galaxy images show the black hole in the centers forcing stars into a common angular speed thus forming the bar, and they only get the spiral past a set point this indicates an even larger black hole than that of the milky way's. Our bar is still very small.
G. Kashkanun Anderson; Hawking states in "A Brief History of Time" that black holes die in a titanic explosion.
I personally have issue with that since a black hole formed from a collapsing star in the first place. If it's shedding material via Hawking radiation, then eventually it'll wither away. Unless, and this is a big if, the radiation brings said black hole back down to the mass of a star, and forces a reignition through compression, at which point you get a star again that may or may not collapse on itself.
As you can tell I'm not very well read on black holes other than various documentaries. And this discussion does call into question the viability of a block hole serving as the central mass for a system.
p.s. everything I've heard about suggests that black hole accretion disks are "equatorial", and that the radiation bursts happen laterally at the poles. If that's the case, then how does that kind of black hole cause an issue with a colonized planet?
I personally have issue with that since a black hole formed from a collapsing star in the first place. If it's shedding material via Hawking radiation, then eventually it'll wither away. Unless, and this is a big if, the radiation brings said black hole back down to the mass of a star, and forces a reignition through compression, at which point you get a star again that may or may not collapse on itself.
As you can tell I'm not very well read on black holes other than various documentaries. And this discussion does call into question the viability of a block hole serving as the central mass for a system.
p.s. everything I've heard about suggests that black hole accretion disks are "equatorial", and that the radiation bursts happen laterally at the poles. If that's the case, then how does that kind of black hole cause an issue with a colonized planet?
Some of them generate x-rays that we can spot from across our galaxy, or for the big black holes, at the hearts of distant galaxies.
So wear your SPF 4 Billion.
If this black hole still has a planet around it, obviously it's not as powerful - but since any large chunk of matter could cause a local flareup, it's not a planet I'd want to visit, and I don't envy the job of the local tourist board.
Most of the radiation goes out along the poles. But most isn't all, and depending upon how much matter there is in the accretion disk, the remaining amount may be enough to fry the planet and everything on it. Or it may be enough to supply some interesting auroras.
In addition to the UV, X-rays and gamma radiation coming off the accretion disk (based upon the interaction of the matter as it swirls to it's doom), there is a fair amount of particle radiation as well, as a small fraction of the component atoms are also ejected at random angles into space. Again somewhere between negligible and world destroying.
No. A Stellar-Mass Black Hole is the mass of a star (or more properly, the mass of the former stellar core). A black hole does not gain mass when it forms - it is no more massive than the original stellar core that formed it. The issue is not the mass, it is the density. Consider classical Newtonian gravity (g = GM/r2). Gravitational Field strength drops off as an inverse square as distance from the center of gravitation increases. As r --> 0, g --> ∞ * . And as g increases, so does the escape velocity.
* - For a normal body such as a planet or star, the inverse square law applies up until you reach the planetary (or stellar) surface, after which (as you move into the body of the planet or star) the gravity decreases linearly until you reach the center, where the gravity is zero. So if you keep mass constant, as you compress that mass of a star or planet into a smaller and smaller volume, the gravity at its surface gets larger and larger, despite the mass not changing. A ball-point pen could theoretically be compressed into a black hole, and would be no more massive than the original pen, but the size of its event horizon would be infinitesimal, and the former pen would then be a point mass of infinite density at its center.
So at some distance (called the Schwarzschild Radius, RS = 2GM/c2), an object placed at this distance RS from the center of gravitation will have an escape velocity equal to the speed of light. Less than this radius, and the escape velocity exceeds the speed of light. Once a star (or actually any object) is compressed within this radius, it can never escape or reemerge from this spherical volume, since to do so would require a super-luminal velocity. Which means that once an object is compressed within this radius, it is on an unavoidable collapse to a point singularity of infinite density at the center of gravitation. The mass may still be finite, but the density becomes infinite.
So even if the black hole loses mass over time via Hawking Radiation, that mass is still infinitely compressed to a point at the center of an Event Horizon that decreases in surface area (and radius) in proportion to the amount of mass lost. But the star will never re-emerge.
kilemall
SOC-14 5K
Well, there is that Microgame, Black Hole, a mini-BH/asteroid setup with missiles zooming around hitting you in the backside-
https://boardgamegeek.com/image/69416/black-hole
https://misternizz.wordpress.com/2014/08/29/an-ancient-black-hole-replay-metagaming-tbf/
And, a naval battle with the defender intentionally setting his back to a black hole....
https://www.youtube.com/watch?v=oT34czUh5mY
https://boardgamegeek.com/image/69416/black-hole
https://misternizz.wordpress.com/2014/08/29/an-ancient-black-hole-replay-metagaming-tbf/
And, a naval battle with the defender intentionally setting his back to a black hole....
https://www.youtube.com/watch?v=oT34czUh5mY
