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 284 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!

CAPTAINAMERICA

  • Member
  • Posts: 325
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

Women are two-thirds more likely than men to develop irritable bowel syndrome. This may be attributable to hormonal changes related to their menstrual cycles.

Did you know?

Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.

Did you know?

Patients who cannot swallow may receive nutrition via a parenteral route—usually, a catheter is inserted through the chest into a large vein going into the heart.

Did you know?

To maintain good kidney function, you should drink at least 3 quarts of water daily. Water dilutes urine and helps prevent concentrations of salts and minerals that can lead to kidney stone formation. Chronic dehydration is a major contributor to the development of kidney stones.

Did you know?

As many as 28% of hospitalized patients requiring mechanical ventilators to help them breathe (for more than 48 hours) will develop ventilator-associated pneumonia. Current therapy involves intravenous antibiotics, but new antibiotics that can be inhaled (and more directly treat the infection) are being developed.

Gravitational Lensing of Extremely Distant Galaxies Gravitational Lensing of Extremely Distant Galaxies
Evaluative measures Evaluative measures
Communication as active process Communication as active process
Physical Geography Physical Geography
Spiral Galaxy Messier 83 Spiral Galaxy Messier 83
Nursing Care Plan Process: Client with High Blood Lipid Levels Nursing Care Plan Process: Client with High Blood Lipid Levels
Video: Glucagon (glycogenolysis and gluconeogenesis)

For a complete list of videos, visit our video library