This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: When an astronomer measures the redshift to a distant galaxy, exactly what physical process is being ... (Read 228 times)

09madisonrousseau09

  • Hero Member
  • *****
  • Posts: 559
on: Jul 27, 2018
When an astronomer measures the redshift to a distant galaxy, exactly what physical process is being measured?
 
  What will be an ideal response?

Question 2

The spectral classification of stars started with the amount of hydrogen present in their spectra, but a better method now uses the amount of oxygen in the star's spectra.
 
  a. True
  b. False
  Indicate whether the statement is true or false


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

wuly

  • Sr. Member
  • ****
  • Posts: 327
Reply #1 on: Jul 27, 2018
Answer to Question 1

Galaxies are being separated from each other as space-time expands. As it expands, photons travelling through space are stretched so that their wavelength increases. Photons from distant sources spend more time travelling through space and are stretched more. Therefore, when an astronomer measures the redshift to a distant galaxy, he or she is measuring the spectra to their apparent brightness. When a galaxy is moving away from the observer, their spectrum has shifted to longer (red) wavelengths.

Answer to Question 2

False


09madisonrousseau09

  • Member
  • Posts: 559
Reply 2 on: Jul 27, 2018
Gracias!

lcapri7

  • Member
  • Posts: 350
Reply 3 on: Yesterday
Excellent

« previous next »
 

Did you know?

Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

Did you know?

Approximately 70% of expectant mothers report experiencing some symptoms of morning sickness during the first trimester of pregnancy.

Did you know?

More than 20 million Americans cite use of marijuana within the past 30 days, according to the National Survey on Drug Use and Health (NSDUH). More than 8 million admit to using it almost every day.

Did you know?

Famous people who died from poisoning or drug overdose include, Adolf Hitler, Socrates, Juan Ponce de Leon, Marilyn Monroe, Judy Garland, and John Belushi.

Did you know?

Calcitonin is a naturally occurring hormone. In women who are at least 5 years beyond menopause, it slows bone loss and increases spinal bone density.

Physical Geography: The Caribbean Sea Physical Geography: The Caribbean Sea
Physical Geography Physical Geography
The CAMEO entry for chlorine. Useful information includes chemical and physical properties, personal ... The CAMEO entry for chlorine. Useful information includes chemical and physical properties, personal ...
Equipment Used During the Physical Assessment Equipment Used During the Physical Assessment
The respiratory system and the process of gas exchange The respiratory system and the process of gas exchange
Video: Effect of the environment on coat color in the Himalayan rabbit Animation

For a complete list of videos, visit our video library