Technology, science, and inventions enhanced in the twentieth century?

Technology, science and inventions enhanced a lot of fields in the twentieth century, such as:
-medicine and healthcare, including illness prevention
-communication, including worldwide communication and fast communication with friends
-space travel
-science, including social sciences

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.

They went to leyden, holland