The evidence for the Big Bang

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   Timeline with galaxies drawn closer together further back in time. If galaxies are moving apart today, what was the universe like long ago, by Esme's reading?

   • Farther apart and colder
   • Closer together, hotter and denser
   • Exactly the same as today
   • Packed into one spot in empty space

2. Read this first

   Background temperature (NASA, ESA)

   Time	Temperature
   at release	about 3,000 K
   today	about 2.7 K

3. 2.

   The background light was about 3,000 K when released and is about 2.7 K now. By about what factor has space stretched, by Jun's math?

   • About 1,100
   • About 11
   • About 3,003
   • About 0.0009
4. 3.

   Peak = 2,898,000 nm·K ÷ temperature; 2.7 K. Using peak = 2,898,000 nm·K ÷ temperature, where does 2.7 K background light peak, by Kira's math?

   • About 1 km, in radio
   • About 1 nm, in X-rays
   • About 500 nm, in visible light
   • About 1 mm, in the microwaves
5. 4.

   The background was found in 1965 by Penzias and Wilson (NASA). Why was it strong evidence, by Luz's reading?

   • The model predicted a leftover glow, and it was found
   • It was starlight from our galaxy
   • It showed the universe has stopped expanding and is now shrinking
   • It showed galaxies are moving apart
6. 5.

   All-sky map of the background with tiny temperature differences. The background is nearly the same temperature in every direction, with only tiny differences (NASA). What does this suggest, by Milo's reading?

   • It comes from one nearby star
   • The universe began as a blast at one spot in space
   • It shows galaxies' colors
   • The early universe was hot and smooth everywhere
7. 6.

   Four cards, labeled A to D. Which of these would most weaken the Big Bang model if it were found, by Pia's reading?

   • A microwave glow in each direction
   • A scientist calling the model just a theory
   • A star clearly older than 13.8 billion years
   • A galaxy with a large redshift
8. 7.

   All-sky map of the background with tiny temperature differences. Why do the tiny temperature differences in the background matter, by Ren's reading (NASA)?

   • They were seeds that grew into galaxies
   • They show where the explosion happened
   • They are nearby stars
   • They are errors made while drawing the map
9. 8.

   Hydrogen and helium make up nearly all the atoms in the oldest stars, which have very little iron. What does this support, by Tala's reading?

   • The first stars formed from Big Bang gas, before much iron existed
   • The oldest stars formed first, from galaxy collisions
   • Old stars have used up their iron
   • The Big Bang made mostly iron
10. 9.

    If the universe's 13.8 billion years were one 24-hour day, about how many hours ago did the Sun form (4.6 billion years ago), by Zee's math?

    • A few seconds ago
    • About 16 hours ago
    • About 8 hours ago
    • About 4.6 hours ago
11. 10.

    Three evidence lines pointing to one explanation. Three independent lines of evidence all point to the same model. Why does that matter, by Ari's reading?

    • One line would be enough
    • It shows the evidence pieces are the same
    • It means the model is just a guess that has not been tested yet
    • Independent agreement makes the explanation much stronger