25 science facts you never learned in school

On the rare occasion that you swallow a razor blade, don’t fret. The human body is more capable than you think. Acids are ranked on a scale from 0 to 14 – the lower the pH level, the stronger the acid. Human stomach acid is typically 1.0 to 2.0, meaning that it has an impeccably strong pH. In a study, scientists found that the “thickened back of a single-edged blade” dissolved after two hours of immersion in stomach acid.

Yes, really. A cool thing called total internal reflection is applied when pointing a laser beam through a container of water. When light travels through water, it’s slowed by the heavier particles in water, as described here. Thus, the laser beam effectively gets “trapped” in the water.

Ever stopped to think where oxygen comes from? Your first thought may be a rainforest, but marine organisms take the bait. Plankton, seaweed and other photosynthesisers produce over half of the world’s oxygen.

Lost land animals may not be able to find their way home, but sea animals might. According to the U.S. Geological Survey (USGS), “there is evidence that some animals, like sea turtles and salmon, have the ability to sense the Earth’s magnetic field and to use this sense for navigation.”

Your childhood dreams of floating on a weightless cloud may get rained on with this fact: the average cumulus cloud can weigh up to a million pounds. A million pounds! That’s about as heavy as the world’s largest passenger jet.

Before you hop on a plane it’s important to check the weather – here’s what really happens when lightning strikes.

In just one teaspoon of soil, there are more microorganisms than people on the planet, said the U.S. Department of Agriculture. “Millions of species and billions of organisms – bacteria, algae, microscopic insects, earthworms, beetles, ants, mites, fungi and more – represent the greatest concentration of biomass anywhere on the planet.”

These creatures are more dynamic then we think. Rats have the ability to “laugh” when tickled. A National Geographic video demonstrated that rats respond positively to tickling. And they even chase after the researcher’s hand in a playful manner.

NASA experts believe there could be anywhere from 100 billion to 400 billion stars in the Milky Way galaxy, Snopes reports. However, a 2015 paper published in the journal Nature estimated that the number of trees around the world is much higher: 3.04 trillion.

As a gas, oxygen is odourless and colourless. In its liquid and solid forms, however, it looks pale blue. Some science facts are just plain weird.

It’s the letter J. Go ahead and double check. We’ll wait.