Why Do Stars in the Disk of a Spiral Galaxy

question 38

Multiple Choice

Why do stars in the disk of a spiral galaxy orbit in roughly the same direction, in the same plane in space?

• A) It is pure coincidence; the stars just happen to be going in the same direction.
• B) The gas that formed the stars was shaped as a giant, rotating disk.
• C) Collisions between the stars caused their motions to organize into a general, spinning disk direction.
• D) After the stars formed, gravity pulled the stars down into a plane in space, all orbiting a supermassive black hole.

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Definitions:

Timing Bias

A form of cognitive bias where an individual's decisions or perceptions are influenced by the timing of information or events.

Base Rate Neglect

The tendency to ignore information about general principles in favor of very specific but vivid information.

Bonferroni Inequalities

Statistical safeguards used to reduce the chances of making incorrect inferences when multiple hypothesis tests are being performed simultaneously.

False Discovery Rate

A statistical method used to estimate the proportion of false positives among a set of identified positives, often applied in multiple hypothesis testing.