Suppose We Observe a Source of X- Rays That Varies

question 9

Multiple Choice

Suppose we observe a source of X- rays that varies substantially in brightness over a period of a few days. What can we conclude?

• A)The X- ray source must have a strong, rapidly varying magnetic field.
• B)The X- ray source is a quasar.
• C)The X- ray source contains a black hole with an accretion disk.
• D)The X- ray source is no more than a few light- days in diameter.

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Definitions:

Gene

A genetic element that is passed from parent to child, believed to influence specific traits in the child.

Gate-Control Theory

A theory proposing that pain is not solely a result of physical injury but rather its perception is controlled by a neurological "gate" in the spinal cord.

Pain Signals

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Nervous System

The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.