Uploaded November 2020 | Updated September 2026, 1 hour ago
The ancient Greeks believed that there were four elements that everything was made up of earth, water, air, and fire. This theory was suggested around 450 BC and was the foundation of philosophy, science, and medicine for two thousand years. It was a simple theory based purely on the observation of the world at that time. But unfortunately, it failed to provide any measurable evidence and so had to be reevaluated. It was not until the 5th century BC when Leucippus of Miletus developed the theory of atomism. He believed that everything in the universe is made up of tiny indivisible blocks called atoms. After centuries of scientific research, scientists can confirm that an atom is indeed the smallest particle of an element that has the same chemical properties as the original element. However, it turns out that atoms can be broken down further into many other subatomic particles. Furthermore, all the matter that is made up of atoms in the universe only amounts to about 5% of all the stuff that there is. So, what makes up the rest of 95% of our universe? Currently, scientists call this the dark universe, made up of dark matter and dark energy. No one really knows what dark matter and dark energy are or how they work. But there are many clues in the universe that point to their existence and may shed some light on what they might be. Let us take a closer look at exactly how we know the existence of dark matter and dark energy. But for this video we will only focus on dark matter and what we know about it so far.
The ancient Greeks believed that there were four elements that everything was made up of earth, water, air, and fire. This theory was suggested around 450 BC and was the foundation of philosophy, science, and medicine for two thousand years. It was a simple theory based purely on the observation of the world at that time. But unfortunately, it failed to provide any measurable evidence and so had to be reevaluated. It was not until the 5th century BC when Leucippus of Miletus developed the theory of atomism. He believed that everything in the universe is made up of tiny indivisible blocks called atoms. After centuries of scientific research, scientists can confirm that an atom is indeed the smallest particle of an element that has the same chemical properties as the original element. However, it turns out that atoms can be broken down further into many other subatomic particles. Furthermore, all the matter that is made up of atoms in the universe only amounts to about 5% of all the stuff that there is. So, what makes up the rest of 95% of our universe? Currently, scientists call this the dark universe, made up of dark matter and dark energy. No one really knows what dark matter and dark energy are or how they work. But there are many clues in the universe that point to their existence and may shed some light on what they might be. Let us take a closer look at exactly how we know the existence of dark matter and dark energy. But for this video we will only focus on dark matter and what we know about it so far.
