Top 5 Myths Debunked by Science
🔍 Introduction
Many things we believe sound true because we hear them again and again. People repeat these ideas at school, at home, on TV, and on the internet. Over time, they start to feel like facts.
In this lesson, we are going to explore five very common myths that many people believe are true. We will read, analyze, and question these ideas using science and logic.
By the end of the lesson, you will be able to separate facts from myths and think more critically about what you hear every day.
🔥 WARM-UP
Before we start, let’s think together.
- Have you ever believed something that later turned out to be false?
- Why do you think people repeat myths so often?
- Do you usually check information or just accept it?
Now, read the myths below and ask yourself:
👉 Did I believe this before?
🧠 1) Myth: Humans Only Use 10% of Their Brain
Many people believe that humans use only 10% of their brain and that the rest is “sleeping” or unused. This myth sounds exciting because it suggests we could become super intelligent.
Science shows that this is not true. Brain scans prove that we use almost all parts of our brain every day, even when we are resting or sleeping. Different areas work together all the time.
If we really used only 10%, most of our brain would shut down, and we would not survive. Our brain is always active — just in different ways.
💬 Reflection Questions
- Why do you think this myth is so popular?
- Do movies and books help spread this idea?
⚡ 2) Myth: Lightning Never Strikes the Same Place Twice
People often say that lightning never hits the same place twice. This idea makes lightning sound random and harmless in some areas.
In reality, lightning hits the same place many times, especially tall buildings. For example, skyscrapers and towers receive lightning strikes over and over again.
Lightning usually follows the easiest path, and tall objects make that path shorter. That’s why buildings are designed to protect themselves.
💬 Reflection Questions
- Why is this myth dangerous?
- How does science help keep people safe?
🥶 3) Myth: Cold Weather Causes Colds
Many people think that cold weather makes you sick. When temperatures drop, people immediately connect cold air with colds.
Science explains that colds are caused by viruses, not temperature. Cold weather does not create viruses. However, people stay indoors more during winter, which makes viruses spread more easily.
So the cold itself is not the problem — human behavior plays a big role.
💬 Reflection Questions
- Why do people still believe this myth?
- How could better information change habits?
🐟 4) Myth: Goldfish Have a 3-Second Memory
It is very common to hear that goldfish forget everything after three seconds. This myth makes goldfish seem simple and unintelligent.
Studies show that goldfish can remember things for weeks or even months. They can learn, recognize people, and follow routines.
This myth exists because people often underestimate animals and their abilities.
💬 Reflection Questions
- Why do we underestimate animals?
- What does this myth say about how humans see intelligence?
🚀 5) Myth: Space Is Completely Silent
Movies often show space as totally silent. Explosions happen, but there is no sound at all.
It is true that sound does not travel in empty space. However, space is not completely empty. There are particles, waves, and vibrations that scientists can detect and convert into sound.
So space is not “silent” — it is just very different from what we hear on Earth.
💬 Reflection Questions
- How do movies shape our beliefs?
- Should entertainment always be realistic?
✍️ WRITING TASK
Now it’s your turn to reflect and express your ideas.
Choose ONE myth and write a short text answering these questions:
- Which myth did you believe before?
- Why did you think it was true?
- What surprised you the most after learning the truth?
- Do you think this myth will continue in the future? Why?
📌 Try to write 8–10 lines.
When I was young, a myth that I thought was true was the myth that if I ate mango with milk, I would instantly die. I thought it was true because my parents and friends said that if you ate this combination, you would die, and because of this, I never ate this combination. But when I discovered, I felt very sad, because this myth was a part of my life, and that’s why I felt sad. I think that this myth will not continue, because at these days, the parents don’t talk about any Brazilian myths for the kids, and I don’t like this, because this myth is almost a Brazilian culture and every Brazilian has to hear about this myth. And because of this, I chose this myth.
In my childhood, I believed in a lot of myths. For me, the most interesting one was that a lightning never strikes the same place twice. I thought that this myth was true because it is very difficult for a lightning to strike the same place twice. Everybody thinks that lightnings are totally random, but it is not true.
But after I learned that was true I became very sad because it was part of my life. The explanation of this is that the lightning always strikes the easiest path. I don’t think that this myth will continue in future because, in the future, there will be a lot of ways to prove that a lightning never strikes the same place twice.
That is why in my childhood I thought that a lightning never strikes the same place twice.
The myth that I chose, is the myth of the lightning. I never believed in this myth, because I always knew that the lightnings choose the easiest place. Lightings always follow the easiest path. In other words lightings usually strike tall places like trees, posts and buildings.
This myth could kill a person, because when you see a lighting striking one place, and you stay in this place thinking that the lightning will not strike again, you can die. The people usually do this under a tree, which can be fatal.
When I was young, I used to believe that we use only 10% of the brain. It was so funny, because when I heard it at first, I thought that if we used 100% of the brain, we would be able to fly. Other myth that I used to believe is that if I ate mango and milk, I would die. I believed this because my friends said that it was true. When I discovered that it is false, my world fell apart.
One of the myths that I still believe is the myth that when we stay in a cold place, we would feel sick. I say this because this happened with me, my dad used to tell me, when I was a kid, that this was false, but I still can’t believe it.