How did Edwin Hubble measure the distance to the Andromeda Galaxy?
A) He measured its parallax.
B) He applied the period-luminosity relation to Cepheid variables.
C) He deduced it from its redshift.
D) He used white dwarf supernovae.
Question 2
What use are 21 cm radio waves to Galactic astronomers?
A) They cut through the dusty cocoons to let us watch star birth.
B) We can reflect them off the core of the Galaxy.
C) Their Doppler shifts let us map the motions and locations of gas in the spiral arms.
D) They bounce off stars like our Sun to let us precisely measure their distances.
E) They pick up the cool, dark matter much better than can optical telescopes.
A method to measure the lateral movement of membrane proteins.
Using Parallax to Determine Distance
Andromeda (M31)
Major trunk lines carrying long-distance traffic crisscrossed the area east of the Mississippi. The
A typical peak-and-hold fuel-injector waveform. Most fuel injectors that measure less than 6 ohms ...
The relationship between recombination frequency and physical distance between genes