Common sense of life｜6 scientific cold knowledge!

Scientific knowledge is not static. With development of science, new laws are constantly being discovered, and old knowledge has to be rewritten or even discarded.

As we grow or age, golden rules we were taught in old school may not work.

For example, before Pasteur discovered microorganisms in 19th century, physicians did not wash their hands before delivering babies to mothers. Dr. Semmelweis, who suggested washing hands before surgery, aroused widespread suspicion in scientific community at time, and some were even offended by his suggestion...

In just a few decades, many old ideas in science have been updated. Here are 6 outdated knowledge.

Before: Pluto is a planet.

Now: Pluto is not a planet.

The past. Diamonds are hardest thing in world.

Now: Superhard cubic boron nitride with nanotwins is hardest substance in world.

Past: The Egyptian pyramids were built by slaves.

Now: The Egyptian pyramids were built by indentured Egyptian workers.

Before: a piece of paper could not be stacked more than 7 times.

Currently: The record for folding a sheet of paper is 13 times.

In past: there are 3 realms of beings (in some places they say 5 realms).

Now: Creatures can have 8 worlds.

Past: The Great Wall of China is only man-made structure visible from space.