Concept explainers
Surviving the Plunge. The tidal forces near a black hole with a mass similar to that of a star would tear a person apart before that person could fall through the event horizon. Black hole researchers have pointed out that a fanciful “black hole life preserver" could help counteract those tidal forces. The life preserver would need to have a mass similar to that of an asteroid and would need to be shaped like a flattened hoop and placed around the person’s waist. In what direction would the gravitational force from the hoop pull on the person's head? In what direction would it pull on the person's feet? Based on your answers, explain in general terms how the gravitational forces from the “life preserver" would help to counteract the black hole’s tidal forces.
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Essential Cosmic Perspective (Looseleaf) - With Access
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- The next step in deciding whether the object in Exercise 25.25 is a black hole is to estimate the density of this mass. Assume that all of the mass is spread uniformly throughout a sphere with a radius of 20 lighthours. What is the density in kg/km3? (Remember that the volume of a sphere is given by V=43R3 .) Explain why the density might be even higher than the value you have calculated. How does this density compare with that of the Sun or other objects we have talked about in this book?arrow_forwardAs a person approaches the Schwarzschild radius fo a black hole, outside observers see all the processes of that person (their clocks, their heart rate, etc.) slowing down, and coming to a halst as they reach the Schwarzschild radius. (The person falling into the black hole sees their own processes unaffected.) But the speed of light is the same everywhere for all observers. What does this say about space as you approach the black hole?arrow_forward1. Let’s say we have a black hole with a mass 10 times that of the Sun (the Sun’s mass is 2 x 1030kg so the mass of the black hole is then 2 x1031 kg) Using the definitions for G and c what Schwarzschild radius of this black hole be? g=6.67 x 10-11 m3 kg-1 s-2 c=3 x 108 m s-1arrow_forward
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