Questions for ‘Newfound gravitational waves may be from the biggest black holes in the universe’ 

An illustration of a pulsar.

Dead stars called pulsars (illustrated) emit beams of radio waves. As pulsars spin, their beams of radio waves sweep past Earth like clockwork. Gravitational waves from supermassive black-hole pairs (upper left) are thought to ripple the fabric of spacetime, subtly altering the pulsars’ timing.

Aurore Simonnet/Sonoma State University, NANOGrav

To accompany ‘Newfound gravitational waves may be from the biggest black holes in the universe 


Before Reading:

  1. What is gravity? Since we can’t see gravity, how do we know it exists?
  2. What is a black hole? Is our sun likely to turn into a black hole at the end of its life? Do a quick internet search to find out. Then explain why or why not.
  3. Many years ago, people believed that Earth was the center of our solar system. Problem was, that belief made the night sky a confusing sight for those people. The things they saw just didn’t make sense. For example, sometimes, the planets would seem to stop in the sky, then trek backward. But why? Then, in the late 1500s, astronomers realized they had it all wrong. The sun was at the center. The Earth and all the other planets orbited the sun. With that discovery, all the other observations suddenly made total sense. What incorrect assumption did those early people make about how the universe works? What does this story tell us about how assumptions might keep us from fully understanding our universe?

During Reading:

  1. What are gravitational waves? What causes them?
  2. What do astronomers believe is the trigger of the newfound gravitational waves? 
  3. How might the collision of two galaxies lead to the formation of gravitational waves?
  4. What do these new findings suggest about the behavior of black holes?
  5. What are pulsars? What do pulsars and lighthouses have in common?
  6. How do gravitational waves affect a pulsar’s “ticks”? What can scientists detect using this effect?
  7. For how many years has NANOGrav watched pulsars? What does NANOGrav stand for?
  8. What does EPTA stand for? Approximately how many years has EPTA watched pulsars?
  9. What might the separate teams that detected the new gravitational waves gain by “joining forces”?
  10. What is another possible explanation for the newfound gravitational waves?

After Reading:

  1. Why were pulsars important in this story? How is the energy given off by pulsars different from that of normal stars? Considering the pulsar’s special ability, what might be another potential use for a pulsar beyond what’s described in this story?
  2. Refer to Question 3 in Before Reading. Imagine we still believed that older model of our solar system. How might that misunderstanding have impacted our achievements in space science? Do you think we would have achieved more, less or the same? Based on your answer, how important do you think it is to keep updating our model of how the galaxies in our universe operate? Explain your answer.