1) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

2) The Battle of Waterloo in 1815 marked the final defeat of Napoleon Bonaparte and the end of his reign as Emperor of France.

3) The concept of human rights advocates for the basic rights and freedoms to which all individuals are entitled, regardless of their nationality, ethnicity, religion, or other characteristics.

4) The word "yesterday" contains three vowels: E, A, and A.