Across
- 2. The opposite of the Big Bang
- 3. An invisible, undetected substance
- 8. It keeps planets in orbit and causes objects to fall
- 9. a huge collection of gas, dust, and stars
- 10. Heat death of the universe
Down
- 1. any physical substance that has mass
- 4. Rate The speed of change increases continuously
- 5. Opposite or against something
- 6. The totality of space and matter
- 7. Something that is difficult to understand, unexplained, or kept secret