There is a ‘flash of light’ that can be measured throughout the universe as cosmic microwave background radiation. Where did it come from?

Question

There is a  ‘flash of light’ that can be measured throughout the universe as cosmic microwave background radiation. Where did it come from?

BlackTom AI · Accepted Answer

Question restated: There is a ‘flash of light’ that can be measured throughout the universe as cosmic microwave background radiation. Where did it come from?

Option 1: 'From the earliest formed stars' — This is incorrect. The CMB is not light from individual stars or their radiation; stars formed long after the CMB's origin and their light would be absorbed or redshifted by later cosmic history. The CMB is a relic signal from an earlier epoch, not from stellar radiation as such.

Option 2: 'From an original explosion referred to as the ‘big bang’' — This is a common simplified description, but it’s not precise enough to identify the physical origin of the CMB. The Big Bang describes the overall origin of the universe, but the CMB specifically arises from the era of recombination when the universe became transparent. Saying it comes from a Big Bang explosion misses the key process of photon decoupling.

Option 3: 'From the transparency which resulted when plasma condensed into neutral atoms' — This statement captures the essential physics. In the early universe, photons were constantly scattered by free electrons in a hot plasma. When electrons combined with protons to form neutral hydrogen (recombination), the Universe became optically transparent and photons could travel freely. Those photons are the CMB we observe today, redshifted to microwave wavelengths.

Option 4: 'From the release of energy as the early universe cooled' — While cooling of the universe accompanies many processes, the CMB specifically corresponds to when photons last scattered off matter during recombination, not a generic release of energy from cooling. This description omits the critical detail of photon decoupling and the resulting propagation of photons through a now transparent medium.

Summary of key idea: The cosmic microwave background is the afterglow of the early universe when a hot plasma became neutral and transparent, allowing photons to travel freely. The remaining options either attribute the CMB to later stellar sources, overly broad Big Bang terminology, or a general cooling narrative without pinpointing the photon decoupling event.

My LMS Subjects Quiz Topic 1: The Big Bang

There is a ‘flash of light’ that can be measured throughout the universe as cosmic microwave background radiation. Where did it come from?

查看解析

登录即可查看完整答案

类似问题

The 3 degree Kelvin background radiation is most probably

The Cosmic Microwave Background radiation consists of photons that were released from their constant interactions with matter at a time coincident to another important event. Which one of the following events coincided with the formation of the CMB?

The cosmic microwave background radiation comes from

Why is the cosmic microwave background radiation so cool?

Which of the statements is true about the cosmic microwave background?

The fact that the Microwave Background Radiation has almost exactly the same spectrum in all directions in the sky is evidence that the Universe is:

Astronomers have found the cosmic microwave background (CMB) radiation. What is the nature of this radiation?

What is so important about the lumps we see in the Cosmic Microwave Background Radiation?

更多留学生实用工具

考试浏览器助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单