5 Science Myths People Still Believe

Which organisms first colonized land and is glass really a liquid? Scientific knowledge is constantly updated, but some ideas prove incredibly persistent. They circulate for decades in textbooks and online articles, shaping our worldview. Let’s debunk five common misconceptions that scientists have long disproven.

1. Nothing Can Move Faster Than Light

Since Einstein’s time, people have been confident: the speed of light in a vacuum (about 300,000 km/s) is the ultimate speed limit in the Universe. And this is an absolute truth, but with an important caveat: it holds true specifically for motion in a vacuum, for instance, in outer space.

Light slows down when passing through any medium: water, glass, or even air. In water, its speed drops by about a third.

Moreover, physicists have learned to create conditions where light is almost brought to a halt. For example, by passing it through a cloud of ultra-cold atoms, where the speed of light can drop to just a few meters per second. In such a medium, many particles can outrun photons.

2. Sputnik 1 Was the First Man-Made Object in Space

The first Soviet satellite, launched on October 4, 1957, was the first object placed into Earth’s orbit. However, humanity conquered space itself (the conventional boundary of 100 km above Earth) earlier.

Back in 1944–1945, German V-2 ballistic rockets reached altitudes of over 180 km during combat launches. Their flight was suborbital: the rockets traveled into space but immediately fell back along a parabolic trajectory, without completing a revolution around the planet.

Thus, Sputnik 1’s primacy lies precisely in achieving the first cosmic velocity and entering orbit. But it was not the first artificial object to reach space.

3. Glass is a Very Slow-Flowing Liquid

A common myth states: in ancient buildings, the glass at the bottom of windows is thicker because it has “flowed” over centuries under gravity. This is a mistake. Glass at normal temperatures is an amorphous solid; it lacks a crystalline lattice, but it cannot flow.

The irregularities in ancient windows are explained by the old manufacturing technique — the crown glass method. Artisans would blow a large bubble, which was then cut and flattened into a sheet. This resulted in sheets of varying thickness with characteristic optical distortions. Installing such glass with the thicker, heavier edge at the bottom was logical and safe, creating the illusion of “flowing.”

4. Fish Were the First Animals to Come Onto Land

The classic evolutionary picture of a lobe-finned fish crawling onto shore to give rise to all land vertebrates misses important context. This happened about 370 million years ago when land was no longer a lifeless desert.

It had been colonized hundreds of millions of years earlier by bacteria, fungi, lichens, and then plants. Following them, even before the first “walking” fish appeared, invertebrates were already thriving on land: ancestors of millipedes, spiders, and insects. So the first vertebrate colonists emerged not onto a barren shore but into an already established, albeit primitive, ecosystem.

5. Humans Only Use 10% of Their Brain

This is perhaps the most persistent myth about our bodies. In reality, a person uses their brain’s potential 100%, just not all at once.

The brain is a highly efficient and energy-intensive organ that cannot afford to have 90% of its mass idle. Modern scanning methods show that even during sleep or rest, a significant number of brain regions are active. Each of its parts has a specialization: some areas are responsible for language, others for movement, memory, emotions, or processing visual signals. A simple task, like raising a hand, activates neural circuits in the motor cortex, basal ganglia, and cerebellum. Damage to even a small, seemingly “unused” area due to a stroke or injury almost always leads to a specific deficit — loss of speech, face recognition, or planning ability — proving its importance.

Where did this legend come from? The roots of the myth likely trace back to the early 20th century. Possibly, its source was a misinterpretation of psychologist William James’s words about people using only part of their mental potential. Another version is a misinterpretation of the work of neurobiologists who, in the 1930s, discovered that only about 10% of brain cells are active neurons, while the rest are auxiliary glial cells (they provide support and nutrition to neurons but are also critically important).

To avoid such mistakes, it is important to read research correctly and keep up with new discoveries.