Simulate a black hole. Set any variable, see how the others change. Supports all standard units.
Blackhole Calculator was created to give flexible (set any variable, in any unit) answers to general questions such as the amount of hawking radiation or lifetime of a blackhole of any mass.
It does not support the complex (and more real-world) cases of charged or spinning blackholes.
Non-charged, non-rotating black holes can be described with a single value, their mass. Blackhole Calculator lets you set derived values (lifetime, radius, etc) and it internally sets the mass which makes that value correct.
The project was intended as a backend for a learning-physics website and the source code for each value would be displayed alongside a more mathematical render of the equation. For simplicity the values are all calculated in relation to mass and for teaching reasons, in a programming idiom.
- http://archive.today/2018.08.10-100540/http://xaonon.dyndns.org/hawking/
- https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator
Viktor Toth uses a different (probably better) formula for blackhole lifetime. This calculator doesn't include their constant factor of 1.8083 because that is based on a more complex understanding of a blackhole than this simple model. I'll revisit this later with many of the other derived fields they support.
Requires Ruby and the gems ruby-units and physics, also benefits from pry or irb.
Create an object representing a blackhole - defaults to expecting mass
bh = Blackhole.new('1e15kg')
=> <Blackhole:0x2e4 (Mass: 1.00E+15 kg, Radius: 1.49E-12 m, Area: 2.77E-23 m^2, Gravity: 3.03E+28 m/s^2, Entropy: 2.65E+46, Energy: 8.99E+31 J, Luminosity: 3.56E+02 W, Lifetime: 8.41E+28 s)>Change the units for a given variable leaving the values unchanged
bh.set_lifetime_units 'y'
=> "y"
bh
=> <Blackhole:0x334 (Mass: 1.00E+15 kg, Radius: 1.49E-12 m, Area: 2.77E-23 m^2, Gravity: 3.03E+28 m/s^2, Entropy: 2.65E+46, Energy: 8.99E+31 J, Luminosity: 3.56E+02 W, Lifetime: 2.67E+21 y)>Set a variable
bh.lifetime = '100 y'
=> "100 y"
bh
=> <Blackhole:0x334 (Mass: 3.35E+08 kg, Radius: 4.97E-19 m, Area: 3.11E-36 m^2, Gravity: 9.04E+34 m/s^2, Entropy: 2.97E+33, Energy: 3.01E+25 J, Luminosity: 3.18E+15 W, Lifetime: 1.00E+02 y)>Change a variable
bh.luminosity *= 10
=> 3.18E+16 W
bh
=> <Blackhole:0x334 (Mass: 1.06E+08 kg, Radius: 1.57E-19 m, Area: 3.11E-37 m^2, Gravity: 2.86E+35 m/s^2, Entropy: 2.97E+32, Energy: 9.51E+24 J, Luminosity: 3.18E+16 W, Lifetime: 3.16E+00 y)>Supports all standard units for setting and displaying
bh.set_mass_units 'ounce'
=> 3.73E+09 oz
bh
=> <Blackhole:0x334 (Mass: 3.73E+09 oz, Radius: 1.57E-19 m, Area: 3.11E-37 m^2, Gravity: 2.86E+35 m/s^2, Entropy: 3.70E+35, Energy: 9.51E+24 J, Luminosity: 3.18E+16 W, Lifetime: 3.16E+00 y)>Catches improper units
bh.set_mass '1.21 GW'
ArgumentError: Improper argument - not mass. Value is powerInitialize with any of the variables by specifying in the constructor
bh = Blackhole.new('1.21 GW', :luminosity)
=> <Blackhole:0x3e8 (Mass: 5.43E+11 kg, Radius: 8.06E-16 m, Area: 8.16E-30 m^2, Gravity: 5.58E+31 m/s^2, Entropy: 7.81E+39, Energy: 4.88E+28 J, Luminosity: 1.21E+00 GW, Lifetime: 1.34E+19 s)>AGPLv2