Disclaimer: For brevity, (and because I myself don’t know the technicalities for a lot of these) the explanations have been kept simple and may not be entirely correct
Electrons are smaller in mass than atoms
Recall that atoms are made of neutrons, protons, and electrons. Neutrons and protons have mass themselves, so electrons must have a smaller mass than the mass of the atom as a whole.
Lasers work by focusing sound waves
Lasers work by bouncing light back and forth between two mirrors, one of which is only partially reflective. The enclosure is made so that the light waves constructively interfere (i.e. they add up and get louder) and then escape through the partially reflective mirror.
Antibiotics kill viruses as well as bacteria
Antibiotics target specific parts of bacteria cells and disrupt their function in some way. Some antibiotics rupture the cell wall while others may inhibit replication. Since viruses are not cells and have completely different ways of replicating, antibiotics don’t have anything to target, so they are ineffective in treating viral infections.
Human beings, as we know them today, developed from earlier species of animals
This is true. A common misconception is that humans evolved from apes. Humans are actually one of the living species of great apes. They evolved alongside orangutans, bonobos, gorillas, and chimpanzees. Fossil evidence suggests that all these share a common ancestor. Figuring out exactly when humans evolved is a tricky question as evolution is a continuous, random, and slow process. In addition, there is only partial information about what really happened.
It is the father’s chromosome that decides whether the baby is a boy or a girl
The X and Y chromosomes are responsible for a child’s sex. Males have both X and Y while females have two X chromosomes. During fertilization, the egg will have an X chromosome from the mother, but the sperm can have either an X or a Y chromosome. When these combine, the result can be XX (female) or XY (male). Therefore, the father’s chromosome is what decides the sex of the baby.
Water boils at lower temperatures at higher altitudes
The reason the glass of water next to you is not spontaneously evaporating is because of atmospheric pressure. Think of the water molecules as trying to escape their liquid state, but being pushed back down by the weight of the Earth’s atmosphere. As you increase your altitude, less air pushes down on you, so there is lower atmospheric pressure. Since the atmosphere isn’t pushing as hard on the water, it takes less energy to get it to boil. If pressure is reduced to near zero, the water will practically instantly boil, even at low temperatures.
A light-year is a unit of time
While it may appear like the light instantly turns on when you flip a switch, light, in fact, does not travel instantaneously. The speed of light is about 300,000 meters per second. It’s extremely fast, but not instant! A light year is defined as the distance that light travels in a year. It’s a useful unit for describing distances in outer space.
The size of the gravitational force the Earth exerts on the Moon is the same as the size of the force the Moon exerts on the Earth
This is a Newton’s third law question. If you don’t recall, Newton’s third law states that a force from object A to object B has a complementary force equal in size and opposite in direction from object B to A. You might then wonder why the moon orbits the Earth, and not the other way around. The Earth is much more massive than the moon, so it is harder to get it to accelerate. Even though the moon pulls with the same force on the Earth, the Earth barely budges. You’ll hear people say that the Earth has much greater inertia than the moon.
Astrology is not at all scientific
We see constellations because of our perspective. It is important to remember that these stars are in 3D space and that the figures they make in the sky are nothing but pretty illusions. There is no evidence in favor of horoscopes or any of astrology.
Oxygen is the most abundant element in the universe
Scientists have ways of determining the chemical makeup of the universe and they’ve observed that hydrogen is the most abundant element. This makes sense because hydrogen is the simplest and lightest element. Heavier elements, like oxygen, are actually made in these massive nuclear furnaces we know as stars through a process called nuclear fusion. As the name implies, two smaller atoms are fused to make larger atoms.
The universe is expanding at an accelerating rate
Edwin Hubble initially observed that distant galaxies were moving away from us. To study this expansion, we have to literally look to the other side of the universe. In the 1990s, some scientists observed very distant supernovae and found that they were moving slower than expected. Since light takes a very long time to travel from these supernovae, scientists found that the universe wasn’t expanding as fast in the past as it is now. Therefore, the universe is not only expanding, but it is expanding at an accelerating rate.
Scientific Literacy 