1) The speed of a sneeze can reach up to 100 miles per hour (160 kilometers per hour).

2) 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.

3) The word "triangle" contains four vowels: I, A, E, and E.

4) The first successful human heart transplant was performed by Dr. Christiaan Barnard in 1967.