In order to gain social worker certification and become eligible to work in the field, individuals must earn at least a Bachelor of Science or Bachelor of Arts. A master's degree in social work is usually required for state licensure as a clinical social worker. Some programs offer training in specialized fields.
View full size image. Johannes Gutenberg is usually cited as the inventor of the printing press. Indeed, the German goldsmith's 15th-century contribution to the technology was revolutionary â enabling the mass production of books and the rapid dissemination of knowledge throughout Europe.efore the invention of the printing press â sometime between 1440 and 1450 â most European texts were printed using xylography, a form of woodblock printing similar to the Chinese method used to print The Diamond Sutra in 868.
He invented the printing press in 1454. Gutenberg did not invent the printing press, the printing press he used was a modified lithography press that already existed. What he invented was movable type, which greatly sped up the process of setting up the press for printing. True Renaissance man Johannes Gutenberg was the first European to use movable-type printing, and he created the mechanical printing press. The mechanical printing press is one of the most important inventions every made.