Briefly discuss the Hubble constant
What will be an ideal response?
The Hubble constant is a measure of the rate of expansion of the Universe-the average value of the apparent velocity of recession divided by distance-about 73 km/s/Mpc. The distance to a galaxy can be found by dividing its apparent velocity of recession by the Hubble constant. Edwin Hubble's original measurement of H was too large because of errors in his measurements of the distances to galaxies. Later astronomers have struggled to measure this important constant. The most precise measurements of the Hubble constant, made using the Hubble, Spitzer, and WMAP space telescopes yield a value for H of about 73 km/s/Mpc with an uncertainty of about 3 percent. This means that a galaxy at a distance of 1 Mpc from the Milky Way is receding from us at a rate of 73 km/s, a galaxy 2 Mpc away is receding at 146 km/s, and so on.
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Conversion of Units: The peak of Mt. Everest, at 10,900 m, is the highest point above sea level in the world. What is its elevation in miles? (1.00 m = 3.281 ft)
A. 17.6 mi B. 0.630 mi C. 6.77 mi D. 6.20 mi E. 67.1 mi
What is Hubble's law?
A) The longer the time period between peaks in brightness, the greater the luminosity of the Cepheid variable star. B) The recession velocity of a galaxy is directly proportional to its distance from us. C) The recession velocity of a galaxy is inversely proportional to its distance from us. D) The faster a spiral galaxy's rotation speed, the more luminous it is. E) The faster a spiral galaxy's rotation speed, the less luminous it is.
2.36 × 108 is equal to _____
A) 23,600,000 B) 236,000,000 C) 2,360,000,000 D) 23,600,000,000
A ____________ will be obtained from an observed star's spectrum that has been shifted towards shorter wavelengths as the star is moving ________ us
Fill in the blank(s) with correct word