The conditions in the early universe at the time matter became decoupled from radiation were (in terms of age t, peak background wavelength $\lambda$, and equivalent temperature T) A) t = 2 * 10¹¹ years, $\lambda$ = 1 mm, microwaves, T = 3 K B) The universe was never radiation-dominated since matter has always dominated by generating the gravitational field into which the universe has expanded. C) t = 3 minutes, $\lambda$ = 0.3 $\mu$m, near UV, T = 10⁷K D) t = 380,000 years, $\lambda$ = 1 $\mu$m, infrared, T = 3000 K

Question

Quizplus · Accepted Answer

The correct conditions for when matter became decoupled from radiation in the early universe are at about 380,000 years after the Big Bang, with a peak background wavelength in the infrared range (~1 micrometer) and an equivalent temperature of about 3000 K. This period marks the recombination era when the universe cooled enough for electrons to combine with protons, forming neutral hydrogen and allowing photons to travel freely.

The Conditions in the Early Universe at the Time Matter λ\lambdaλ

The Conditions in the Early Universe at the Time Matter $\lambda$