The 20th century is known as the century of inventions because of numerous biggest and notable inventions took place in those 100 years. This world has not seen so many inventions in the whole history than alone in the past century.
Several inventions from past have been refined by the scientists and can be seen in much better modern shape now.
After watching this video, you might think it as a clip of sci-fi movie but in-fact this a toy motor wheel for kids from 1920.
You can notice its modern shape nowadays.