Black Hole radii
- Thread starter Archduke
- Start date
I would guess as a black hole is a singularity by definition it has no size.
Fly safe o7
Fly safe o7
No. By definition a Black Hole is just where the stress-energy density is sufficient that the gravitational escape velocity is celeritic at the Schwarzchild radius. I thought someone might mention the singularity. Most physicists do not consider Black Holes beyond the horizon, since future geodesic trajec tories all have direction to a singular state. This singularity is a representation of mathematical formalisation inability to predict further. As such, unqualified reference to Black Hole is most often attributed to a Cauchy surface of the event horizon.If the singularity is regarded as as a real, physical singularity ,then, given the actual in-game reference that most such Black Holes are formed by collapsing, degeerate stars, then there is a system where angular momentum is conserved. Therefore the Black Hole is a Kerr hole, and the frame dragging (which is clearly evident in the game visual depiction) therefore pulls the singularity into an extended ring object - which therefore has a non-zero radius.Apologies. line breaks and formatting are never preserved when posting on these boards via this browser.
Last edited:
I don't have any journal data to check, but it might simply be the case of Elite rounding down the displayed number. It does so with other characteristics too: for example, you can see plenty of moons where the game says the semi-major axis is 0.00 AU, but it obviously doesn't use 0. You can get the precise data from the journal, however.
Looks like you're right.That would make sense, the Moon's mean semimajor axis is approximately 384 Mm which makes it some 400th of an AU which would be rounded to zero.I think (might need to check) the radius shown in game for stellar mass objects is given in units where the radius of Sol = 1) The Schwarzchild radius, then, for typical main sequence star densities would be less than 1% When 0.00 there's only 2 decimal places, but when I checked the SMBH Sag A*, the radius is expressed as 15.5477 Which would be somewhere in the region of 11 000 Mm (which is inconsidstent with real estimates of the actiual Sag A*) and therefore most likely the horizon boundary.
Currently writing down your Name in case I have any questions regarding astrophysics...
I agree it's the lack of decimals in the game that makes them "appear" as infinitely small. The biggest black holes in game does indeed have a visible radius. Like Sag A* (15.5 solar radii) and Great Annihilator (0.0008 solar radii).
Rounding errors indeed
Maybe we should petition to get them to adjust the displayed numbers a bit?
Low mass planetoids is having the same "issue", with 0.0000 EM planets.
How about having black hole measurements using Earth as the unit and moons to use, the Moon as units? Maybe even show both in the system view, as a comparison and for "overlapping" objects.
Low mass planetoids is having the same "issue", with 0.0000 EM planets.
How about having black hole measurements using Earth as the unit and moons to use, the Moon as units? Maybe even show both in the system view, as a comparison and for "overlapping" objects.
Last edited:
