As we all know, scientific theories are just that, theories about an idea that has yet to be proven or disproved. However, if we take a look back into our history, we will see that a lot of crazy theories used to be accepted as true despite having very little empirical evidence to back them up. For example, people used to believe that the traits of a woman’s ex could be transferred to the children she had, by birth, by another man. Of course, now, we know that this is not true. Here are some more scientific theories that used to be believed as true.
1. Spontaneous Generation of Living Organisms
The belief that living organisms were created from non-living matter, such as maggots coming from spoiled meat, was a scientific theory born out of the Roman era. It came about as a result of keen observation, as people always found that maggots appeared in conjunction with spoiled meat, while mice always appeared where there bread and cheese. This came to be known as spontaneous generation, which was eventually disproved in 1858 by Louis Pasteur.
2. A Dangerous Vapor Caused Disease
Back in the Middle Ages, doctors believed that a dangerous vapor, referred to as Miasma, was responsible for the diseases that people came down with. This is how Malaria was named, as “mala” means bad and “aria” means air in Italian. Beyond this, people believed that the Great Plague of London was also caused by bad air which is why you see pictures of people wearing masks around that time. The cause of the bad air? Decaying substances and creatures. However, modern science tells us that diseases are caused by micro-organisms like bacteria.
3. The Earth Was Believed to be Hollow
Although never accepted by most scientists within the scientific sphere of research, some people did believe that the Earth was hollow. This theory was proposed by Edmund Halley in 1692 after he discovered that the Earth’s magnetic field often changed. He believed that this was possible because the Earth had more than one of these magnetic fields. This led him to postulate that the world had four spheres, with Earth being the largest and the one we can see with our eyes.
4. The Four Humors of People
It was once believed that individuals had four humors, blood, phlegm, black bile, and yellow bile, and these were associated with the four elements of the Earth, air, earth, water, and fire. These were also linked to one of the four seasons, and if an individual had an abundance of one of these humor during one of the seasons, this is what led to health ailments. For example, blood was plentiful in the springtime, which would cause problems if you had too much as all four humors needed to be balanced out. Doctors would use things like exercise, certain foods and medicine, hot irons, laxatives, and even in extreme cases, the draining of excess humor. This theory ended up being disproved back in the 1800s.
5. Sperm and Eggs Contained Tiny Humans
Back in the 17th and 18thcenturies, it was believed that the human egg and sperm, when fertilized properly, contained a miniature human that would grow in the womb. This belief came about as scientists claimed that they found small “winged creatures” in embryos. The theory was called preformationism and it extended to animals and insects as well. However, when we developed powerful microscopes, we found that the eggs did not contain tiny humans and instead they undergo a process called epigenesis.