Exam 21: The Expanding Universe

What would you predict for the recession velocity of a galaxy whose distance (measured with the help of Type Ia supernovae) is 42 Mpc? Note that the Hubble constant has a value of 70 km/s/Mpc.

Where in the universe did the Big Bang take place?

The high temperature and density of the early universe are directly responsible for

If we "reverse" Hubble expansion, we see that the universe should have been very dense in the distant past, and so it must have been ________ than it is today, and we should be able to Observe ________ as a result.

Which three elements were generated during the Big Bang?

Hubble originally estimated the "Hubble constant" to be about 500 km/s/Mpc.What age of the universe would such a number imply?

Redshift z = v_r/c, where v_r is the apparent recessional velocity, and c is the speed of light.Is it possible to observe a redshift greater than 1.0, or lower than=1.0?

The COBE microwave map shown in the figure below seems to indicate that one part of the sky is 0.003 K warmer than the other.What is the cause of such an apparent anisotropy?

If the wavelength of the background radiation peaked at 1 µm at the time of recombination, how old was the universe then compared with its age today?

That "the physical laws and the properties of the universe are the same everywhere and in all directions" is a statement of

An implication of the cosmological principle is that our location in the universe is

If Hubble expansion was due to an explosion throwing galaxies into space, instead of space expanding everywhere, which of the following would be true?

The figure below is the WMAP survey of the cosmic microwave background.Describe at least two important facts about our universe that were determined by analyzing the pattern of this radiation.

What is the meaning of R_U, the scale factor of the universe, and what does its value at a given time tell us about properties of the universe at that time?

The natural abundances of various forms of the elements hydrogen, helium, and lithium are predicted by

Show in graph format how the scaling factor R_U changes with redshift.

The CMB can be regarded as a "wall" beyond which we cannot see light because

If a galaxy has an apparent velocity of 700 km/s, what is its distance if the Hubble constant is 70 km/s/Mpc?

The cosmic microwave background radiation was emitted when the universe had a size about 1/1,000 of today's value.What was the temperature of the microwave background radiation at the epoch of recombination?

What is the significance of the 0.001 percent fluctuations detected in the CMB map by modern satellites like WMAP and Planck, as in the figure shown below?