The evidence for the Big Bang

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Table, Evidence for the Big Bang (NASA, ESA), with columns Observation, What it shows

   Galaxy redshifts grow with distance, space is expanding; microwave background at about 2.7 K, a hot, dense early universe; mostly hydrogen and helium, a little lithium, early element-making.

2. 1.

   Match each observation to what it supports. Which pairing is right, by Bo's reading?

   • Elements: expansion; redshifts: element-making
   • Redshifts: hot start; background: expansion
   • Background: starlight; redshifts: galaxy color
   • Redshifts: expansion; background: hot start; elements: early element-making
3. 2.

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

4. Background temperature (NASA, ESA)

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

5. 3.

   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
6. 4.

   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 500 nm, in visible light
   • About 1 mm, in the microwaves
   • About 1 km, in radio
   • About 1 nm, in X-rays
7. 5.

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

   • It was starlight from our galaxy
   • It showed the universe has stopped expanding and is now shrinking
   • It showed galaxies are moving apart
   • The model predicted a leftover glow, and it was found
8. 6.

   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?

   • The universe began as a blast at one spot in space
   • The early universe was hot and smooth everywhere
   • It comes from one nearby star
   • It shows galaxies' colors
9. 7.

   As the universe expands, what happens to the background's temperature over time, by Noah's reading?

   • It stays at 3,000 K
   • It keeps rising
   • It keeps falling
   • It jumps up and down each year
10. 8.

    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 galaxy with a large redshift
    • A scientist calling the model just a theory
    • A microwave glow in each direction
    • A star clearly older than 13.8 billion years
11. 9.

    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 are nearby stars
    • They are errors made while drawing the map
    • They show where the explosion happened
12. 10.

    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?

    • About 4.6 hours ago
    • A few seconds ago
    • About 8 hours ago
    • About 16 hours ago