At About What Time After the Big Bang Did the Universe

question 148

Multiple Choice

At about what time after the Big Bang did the universe pass through the transition from being radiation-dominated to being matter-dominated?

• A) at the Planck time, 10^-43 s
• B) about 15 billion years, as stars began to form
• C) 500,000 years
• D) 30,000 years

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Definitions:

Variable

An element, feature, or factor that is likely to vary or change; it can be quantitative or qualitative in experiments and mathematical models.

Mathematical Convention

Established, standardized practices or rules that are followed within mathematical reasoning and calculations.

Independent Variable

The variable causing a change in some other (dependent) variable.

Unemployment Rate

The percentage of the labor force unemployed at any time.