Black Hole Event Horizon Area with Charge
An event horizon is a boundary in spacetime beyond which events cannot affect an outside observer.
The event horizon area increases roughly quadratically with the mass and charge.
Formula
![Copy to Clipboard QuantityVariable["A", "Area"] == 4*Pi*(Quantity[1, "GravitationalConstant"/"SpeedOfLight"^2]*QuantityVariable["M", "Mass"] + Sqrt[Quantity[1, "GravitationalConstant"^2/"SpeedOfLight"^4]*QuantityVariable["M", "Mass"]^2 + Quantity[-1/(4*Pi), "GravitationalConstant"/("ElectricConstant"*"SpeedOfLight"^4)]*QuantityVariable["Q", "ElectricCharge"]^2])^2](https://www.wolframcloud.com/objects/resourcesystem/marketplacestorage/resources/975/97519ea4-4964-44e5-bd5e-adfa35bcf290/Webpage/FormulaImage.png)
| symbol | description | physical quantity |
|---|---|---|
| A | event horizon area | "Area" |
| M | mass | "Mass" |
| Q | electric charge | "ElectricCharge" |
Forms
Examples
Get the resource:
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| Out[1]= | ![]() |
Get the formula:
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Use some values:
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![FormulaData[
ResourceObject[
"Black Hole Event Horizon Area with Charge"], {QuantityVariable[
"A","Area"] -> Quantity[1.`*^11, ("Meters")^2]}]](images/975/97519ea4-4964-44e5-bd5e-adfa35bcf290-io-3-i.en.gif)
