Center of the universe

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/center-of-the-universe

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the dominant historical model?Ptolemaic geocentric model, with Earth at the center
2. What is the observational evidence for expansion?Hubble's Law: Galaxies recede with velocities proportional to their distance (cosmic redshift)
3. Why do scientists say the universe has no center?Scientists say there is no center because the Big Bang happened everywhere at the same time and space expands the same everywhere. This makes every point look like the center.
4. How does the balloon analogy explain that there is no center?The balloon analogy shows that as the balloon inflates, every point on its surface moves away from every other point. There is no special spot in the middle of the surface.

Geocentric Model: A cosmological model with Earth as the unmoving center of the universe.
Heliocentric Model: A cosmological model with the Sun at the center of the solar system.
Cosmological Redshift: The stretching of light wavelengths due to the expansion of spacetime between the source and observer.
Homogeneous Universe: A universe that is the same everywhere in terms of matter and energy distribution.