2021年6月7日 · This also illustrates why a black hole of a given mass, say mass m, saturates the entropy bound (called the "Bekenstein bound" after Jacob Bekenstein, who first discovered it) for an object of that mass: because a black hole of mass m could have been made from any object (or combination of objects) with that total mass; we know nothing about ...

2011年12月4日 · In summary, the conversation discusses an equation presented by Stephen Hawking to calculate the temperature of a black hole, and the correct values for the variables used in the equation. The correct equation is T = {h c^3 \over 16\pi^2 GMk}, and after plugging in the values for the mass of the sun and the speed of light, the temperature is ...

2014年9月22日 · I don't have a formula for a small black hole to answer the second question exactly, but for a large black hole, you can ignore tidal forces and approximate the black hole by the Rindler metric of a uniformly accelerating observer. With this approximation, the horizon is always located at the Rindler horizon, a distance of ##\frac{c^2}{a}## .

2009年1月7日 · The event horizon of a black hole, which divides "inside" from "outside", is the Schwarzschild radius of R = 2GM/c^2. And the formula really only seems to work for a choice of R that's larger than 2GM/c^2 (i.e. for a radius that puts you 'outside' the black hole)--if you plug in a value of R smaller than that, you get an imaginary number!

2017年6月14日 · FAQ: Understanding Black Hole Equations Conceptually What is a black hole equation? A black hole equation is a mathematical formula that describes the properties and behavior of black holes, which are regions in space where the gravitational pull is so strong that nothing, including light, can escape.

2015年8月19日 · Say we have three people:* h = hovering observer* s = spaceship pilot circling the black hole* o = free-falling observer who is instantaneously at rest relative to hLet* ##a^s## = proper acceleration of s* ##a^h## = proper acceleration of h* ##a_o^s## = three-acceleration of s as measured by o* ##a_o^h## = three-acceleration of h as measured by ...

2015年9月30日 · It is true that, in the case of a black hole that forms by gravitational collapse of a massive object like a star, the horizon of the hole first forms at the center ##r = 0##, and “grows” in radius until it reaches ##r = 2M##, at which point it intersects the surface of the collapsing matter falling inward; after that, it stays at ##r = 2M ...

2017年3月27日 · According to Einstein's Theory of General Relativity, the time distortion near a black hole is calculated with the following formula: T^2 = t^2 / 1 - ( Rs / r ), where: T= Observer A time, far away from the black hole t = Observer B close to the black hole r = Distance between the black hole and Observer B Rs= Schwarzschild Radius

2018年6月9日 · Interpretation of the known QPO data by dint of a signal modulation from the hot spots in the accreting plasma reveals the Kerr metric rotation parameter, a=0.65 ± 0.05, and mass, M=(4.2 ± 0.2)10⁶ M[itex]_⊙[/itex], of the supermassive black hole in the Galactic center.

2014年11月13日 · But for a rotating black hole the event horizon is not actually at the Schwarzschild radius--p. 28 mentions that Boyer-Lindquist coordinates, the Kerr black hole's event horizon would be located at [itex]r = m + \sqrt{m^2 - a^2}[/itex], which reduces to the Schwarzschild radius r=2m only if a=0 (meaning the angular momentum J is 0), and is ...