Libraries around the world still keep old books hundreds of years old. But will we be able to read today’s digital (数字的) books in hundreds of years? Librarians are worried. Even now, we can’t open some files (文件) from 20 or 25 years ago. Will our digital works be lost in a digital black hole? Will we face the loss of valuable information?

Technology is changing fast. Old ways of keeping information are gone now, or they are no longer supported by new technology. For example, many people used floppy discs (软盘) to save files years ago, but today few machines can open them. Also, millions of songs and music pieces were saved on tapes or CDs, but now most old music players no longer work. Another problem is that websites often change or close down, and all the information on them can fall into the digital black hole.

Books, however, are quite easy to keep. We don’t need special tools or technology to read them. If you keep them in a dry and safe place, they will stay safe for a long time. Li Shizhen’s great medical book Ben Cao Gang Mu came out in 1593. Amazingly, three copies from the first printing still survive today. That’s not bad for a book more than 400 years old.

Today, to some researchers, printed books remain a safe way to keep information. In 2014, a professional group began to raise money to print a famous online encyclopedia into 1,000 books. This would make sure that even if digital technology fails, the knowledge can still be kept.

For now, when it comes to storing information, printed copies seem to be the safest choice. However, future technology might develop and provide new ways to solve the problem of the digital black hole. Time will tell.