Two men wrote papers in the 1970s. Their names are Michael Hart and Frank Tipler. They said alien life does not exist. They had a simple idea. If aliens were real, they would have time to grow. They could build smart machines. These machines could travel across space. They could make copies of themselves.
We see no such machines on Earth. The men concluded that humans are alone. This idea became known as Fermi's Paradox. A professor named David Kipping wrote a new paper. He works at Columbia University. He made a new version of the old idea.
He calls it the Cosmological Hart-Tipler Conjecture. His model uses a simple equation. It looks at how life begins. It looks at how life spreads. It looks at the very long time involved. It also looks at the growing universe. Kipping posted his work online. His findings show a worrying truth. Advanced alien life may not exist anywhere.
Sources: phys.org
The words in bold are from the article.
| 1. wrote | a. foreign life |
| 2. aliens | b. devices |
| 3. machines | c. duplicates |
| 4. travel | d. space |
| 5. copies | e. move |
| 6. alone | f. created |
| 7. professor | g. teacher |
| 8. university | h. results |
| 9. universe | i. single |
| 10. findings | j. college |
1.f 2.a 3.b 4.e 5.c 6.i 7.g 8.j 9.d 10.h