This topic contains a solution. Click here to go to the answer

Author Question: Briefly explain why radiation was trapped for 300,000 years during the era of nuclei, and why the ... (Read 53 times)

anjilletteb

  • Hero Member
  • *****
  • Posts: 569
Briefly explain why radiation was trapped for 300,000 years during the era of nuclei, and why the cosmic background radiation broke free at the end of this era.
 
  What will be an ideal response?

Question 2

The most likely way we could terraform Mars would involve
 
  A) adding greenhouse gases to the atmosphere
  B) moving the planet closer to the Sun
  C) restarting Martian volcanoes
  D) firing projectiles into the polar caps



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

AaaA

  • Sr. Member
  • ****
  • Posts: 339
Answer to Question 1

During the era of nuclei, the universe consisted of a hot plasma of hydrogen nuclei, helium nuclei, and free electrons. Throughout this era, photons bounced rapidly from one electron to the next, just as they do deep inside the Sun today, never managing to travel far between collisions. If a nucleus managed to capture an electron to form a neutral atom, one of the photons quickly ionized it. This era came to an end when the expanding universe had cooled down to about 3,000 K. At this temperature, the hydrogen and helium nuclei were able to capture electrons and form stable, neutral atoms for the first time. With electrons bound into atoms, the photons began to stream freely across the universe.

Answer to Question 2

A





 

Did you know?

The National Institutes of Health have supported research into acupuncture. This has shown that acupuncture significantly reduced pain associated with osteoarthritis of the knee, when used as a complement to conventional therapies.

Did you know?

Eat fiber! A diet high in fiber can help lower cholesterol levels by as much as 10%.

Did you know?

Limit intake of red meat and dairy products made with whole milk. Choose skim milk, low-fat or fat-free dairy products. Limit fried food. Use healthy oils when cooking.

Did you know?

It is important to read food labels and choose foods with low cholesterol and saturated trans fat. You should limit saturated fat to no higher than 6% of daily calories.

Did you know?

Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.

For a complete list of videos, visit our video library