Podcast
Questions and Answers
What was the major drawback of Kelvin and Helmholtz's suggestion that the Sun stayed hot thanks to gravitational contraction?
What was the major drawback of Kelvin and Helmholtz's suggestion that the Sun stayed hot thanks to gravitational contraction?
- It predicted that the Sun would shrink noticeably as we watched it, and the Sun appears to be stable in size.
- It was proposed before Einstein's theory of general relativity and was therefore incorrect.
- It predicted that Earth would also shrink, which would make it impossible to have stable geology on our planet.
- It predicted that the Sun could last only about 25 million years, which is far less than the age of Earth. (correct)
When is/was gravitational contraction an important energy-generation mechanism for the Sun?
When is/was gravitational contraction an important energy-generation mechanism for the Sun?
- right after the Sun began fusing hydrogen in its core (correct)
- when the Sun transports radiation through the convection zone
- only during solar minimum
- only during solar maximum
What do we mean when we say that the Sun is in gravitational equilibrium?
What do we mean when we say that the Sun is in gravitational equilibrium?
- The Sun maintains a steady temperature.
- The hydrogen gas in the Sun is balanced so that it never rises upward or falls downward. (correct)
- This is another way of stating that the Sun generates energy by nuclear fusion.
- It predicted that Earth would also shrink, which would make it impossible to have stable geology on our planet.
What was one of the major drawbacks of the suggestion that the Sun stayed hot thanks to gravitational contraction?
What was one of the major drawbacks of the suggestion that the Sun stayed hot thanks to gravitational contraction?
What two forces are balanced in gravitational equilibrium within the Sun?
What two forces are balanced in gravitational equilibrium within the Sun?
What is the average temperature of the surface of the Sun?
What is the average temperature of the surface of the Sun?
Which is closest to the temperature of the core of the Sun?
Which is closest to the temperature of the core of the Sun?
From the center outward, which of the following lists the 'layers' of the Sun in the correct order?
From the center outward, which of the following lists the 'layers' of the Sun in the correct order?
Which layer of the Sun do we normally see?
Which layer of the Sun do we normally see?
Based on its surface temperature of 5,800 K, what color are most of the photons that leave the Sun's surface?
Based on its surface temperature of 5,800 K, what color are most of the photons that leave the Sun's surface?
