To determine the size of a black hole, the key factor to consider is its mass. The amount of mass inside the black hole influences its size, specifically its event horizon, also known as the Schwarzschild radius.
The correct answer is:
- How much mass is inside
Here’s a detailed explanation:
1. Black Hole and Event Horizon: A black hole is an astronomical object with a gravitational pull so strong that nothing, not even light, can escape from it. The event horizon is the boundary surrounding a black hole beyond which nothing can return.
2. Schwarzschild Radius: The size of the event horizon (Schwarzschild radius) of a black hole depends directly on its mass. The formula for the Schwarzschild radius ([tex]\(R_s\)[/tex]) is given by:
[tex]\[
R_s = \frac{2GM}{c^2}
\][/tex]
where [tex]\(G\)[/tex] is the gravitational constant, [tex]\(M\)[/tex] is the mass of the black hole, and [tex]\(c\)[/tex] is the speed of light.
3. Mass Inside: The more massive a black hole, the larger its event horizon. Therefore, the size of a black hole is fundamentally determined by the amount of mass it contains.
4. Other Factors: Options like "How much dark matter it has," "How much light it radiates," and "Its distance to the nearest 7-11" are not relevant to the size of a black hole. While dark matter and radiation can influence other aspects of the universe, they do not directly affect the size of the event horizon of a black hole. Similarly, location factors like proximity to a convenience store are unrelated to astrophysical measurements.
Hence, based on the relationship between mass and event horizon size, we conclude that the size of a black hole is determined by how much mass is inside it. The correct answer is that the size of a black hole is determined by:
- How much mass is inside
