« previous next »

Author Question: A standard candle is A) a 7-cm-long wax candle. B) another name for a main-sequence star. C) ... (Read 223 times)

maegan_martin

  • Hero Member
  • *****
  • Posts: 532
on: Jul 27, 2018
A standard candle is
 
  A) a 7-cm-long wax candle.
  B) another name for a main-sequence star.
  C) another name for a barred-spiral galaxy.
  D) a light source of known luminosity.

Question 2

Briefly summarize current knowledge about the term Np in the equation Number of Civilizations = Np  flife  fcivilization  fnow.
 
  What will be an ideal response?


potomatos

  • Sr. Member
  • ****
  • Posts: 338
Reply #1 on: Jul 27, 2018
Answer to Question 1

D

Answer to Question 2

We have evidence now for more than a dozen planets around other stars, and evidence for protoplanetary disks around many more stars. Although we cannot yet give a precise value to Np, it now seems likely that it is quite largeperhaps as large as the number of stars in the Milky Way Galaxy.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

The people with the highest levels of LDL are Mexican American males and non-Hispanic black females.

Did you know?

There are 20 feet of blood vessels in each square inch of human skin.

Did you know?

According to the Migraine Research Foundation, migraines are the third most prevalent illness in the world. Women are most affected (18%), followed by children of both sexes (10%), and men (6%).

Did you know?

For pediatric patients, intravenous fluids are the most commonly cited products involved in medication errors that are reported to the USP.

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.

The main events of mitosis and meiosis The main events of mitosis and meiosis
Standard Medical Record and Types of Reports Found in Record Standard Medical Record and Types of Reports Found in Record
Identify the Main Term Identify the Main Term
Annotation of a DNA sequence containing part of the human beta globin gene Annotation of a DNA sequence containing part of the human beta globin gene
Main mechanism of carbon dioxide transport and exchange. A lesser amount of CO2 travels to the lungs Main mechanism of carbon dioxide transport and exchange. A lesser amount of CO2 travels to the lungs
Cladogram Based On DNA Sequence Cladogram Based On DNA Sequence
Video: The Lac Operon in E. Coli

For a complete list of videos, visit our video library