Within Which Time Frame from the Initial Big Bang Do

question 169

Multiple Choice

Within which time frame from the initial Big Bang do cosmologists believe all four fundamental forces of nature were united into a single force?

• A) t = 0 to 10⁶ years, when radiation dominated the universe
• B) t = 0 to 1 s, when photons interchanged freely with electron-positron pairs
• C) t = 0 to 10^-35 s, when the strong nuclear force "froze out" of the universe
• D) t = 0 to 10^-43 s, the Planck time, when gravity "froze out" of the universe