Scientific

A rainbow is an optical illusion, not a physical object, formed by sunlight reflecting and refracting through water droplets. Its perceived location changes with your perspective, moving as you move.

The human body contains trillions of cells, each with about 2 meters of DNA tightly packed. If all the DNA from a single human were uncoiled, it would stretch from the Earth to the Sun and back over 600 times.

About 335 million years ago, Earth's landmasses were joined in a giant continent. Over millions of years, plate tectonics caused Pangaea to break apart, slowly drifting to form the continents we know today.

Two entangled particles, even when separated by vast distances, remain connected such that measuring the property of one instantaneously influences the other. Einstein called this "spooky action at a distance."

The olfactory bulb, which processes smells, is directly connected to the amygdala (emotion) and hippocampus (memory) parts of the brain. This bypasses the thalamus, explaining why smells trigger vivid memories.

This "cosmic microwave background" (CMB) is the oldest light in the universe, a leftover from the Big Bang when the universe was only about 380,000 years old. It's evidence supporting the Big Bang theory.

Scientists estimate the temperature of Earth's solid iron-nickel inner core to be around 5,200 degrees Celsius (9,392 degrees Fahrenheit). This extreme heat is a remnant from the planet's formation and ongoing radioactive decay.

Light travels fastest in a vacuum (about 299,792 kilometers per second). When it passes through denser mediums like water or glass, it interacts with the atoms, causing it to slow down temporarily.

The hydrochloric acid in your stomach has a pH between 1.0 and 2.0, making it incredibly corrosive. Thankfully, your stomach lining regenerates rapidly, preventing it from dissolving itself.

While diamonds are exceptionally hard, materials like Wurtzite Boron Nitride and Lonsdaleite have been theoretically or experimentally shown to be harder. These are rare and don't occur naturally in large quantities.