250 Fun Facts
250 Random Facts: Geography, Science, Language, Oceans & Culture
Science Facts
Water expands when it freezes, which is why ice floats instead of sinking.
Under certain conditions, hot water can freeze faster than cold water. This puzzle is called the Mpemba effect, and scientists still debate exactly why it happens.
A bolt of lightning can heat the air around it to about 30,000°C, roughly five times hotter than the surface of the Sun.
Sound travels about four times faster through water than through air.
Old church windows are often thicker at the bottom, but not because glass slowly flows. They were simply made unevenly and installed thick side down.
Diamonds and the graphite in pencils are made of exactly the same element: carbon. Only the way the atoms are arranged is different.
Helium was discovered on the Sun in 1868, years before it was found on Earth. Its name comes from "helios," the Greek word for Sun.
Oxygen is the most common element in Earth's crust.
Gold is so easy to shape that a single gram can be hammered into a thin sheet about one square metre in size.
The periodic table now has 118 known elements
When Russian chemist Dmitri Mendeleev arranged the elements into a table in 1869, he left gaps for elements that hadn't been discovered yet and even predicted their properties. Many of those predictions later turned out to be correct, and today the table is complete up to element 118.
A rainbow is actually a full circle. From the ground, we usually only see the top half as an arc.
Bananas are very slightly radioactive because they contain potassium, but you'd need to eat an impossible number for it to matter.
Light travels at about 300,000 kilometres per second.
In one second, light could travel around the Earth about seven and a half times.
Absolute zero, the coldest possible temperature, is -273.15°C.
Mercury is the only metal that is liquid at normal room temperature.
The metal gallium melts at about 30°C, so it can turn to liquid in the palm of your hand.
The centre of the Earth is around 5,000°C, about as hot as the surface of the Sun.
Around 90% of the world's earthquakes happen along the Pacific "Ring of Fire."
Water can boil and freeze at the same time
At a very specific temperature and pressure, called the triple point, water can exist as a solid, liquid and gas all at once. For water, this happens at just above 0°C and at a pressure far lower than what we experience on Earth's surface.
Kevlar, the strong material used in bulletproof vests, was invented by chemist Stephanie Kwolek in 1965.
Velcro was inspired by the sticky burrs that clung to a Swiss engineer's dog after a walk.
The microwave oven was invented after engineer Percy Spencer noticed a chocolate bar melting in his pocket while he worked near radar equipment.
Penicillin, the first widely used antibiotic, was discovered by accident by Alexander Fleming in 1928.
X-rays were discovered by German physicist Wilhelm Röntgen in 1895.
ARPANET, the network that grew into the internet, sent its first message in 1969.
The first text message, sent in 1992, simply said "Merry Christmas."
The QWERTY keyboard layout was designed for typewriters in the 1870s.
Super glue was discovered by accident while scientists were trying to make clear plastic for gun sights.
India celebrates National Science Day because of a discovery about light
On 28 February 1928, physicist C. V. Raman announced the discovery of the Raman effect, which shows how light changes when it scatters off molecules. The discovery earned him the Nobel Prize, and India celebrates National Science Day every year on 28 February in his honour.
Dry ice is frozen carbon dioxide. It doesn't melt into a liquid; it turns straight into gas.
A single fluffy cumulus cloud can weigh around 500 tonnes, about as much as 80 elephants.
Every natural snowflake has six sides.
Raindrops aren't shaped like teardrops. Small ones are round, and larger ones are flattened, a bit like a burger bun.
Thunder is the sound of air expanding very rapidly after being heated by lightning.
You can estimate how far away lightning is by counting the seconds until the thunder. Every three seconds is roughly one kilometre.
Earth's magnetic north and south poles have swapped places many times. The last flip happened around 780,000 years ago.
Stainless steel resists rust because it contains chromium, which forms a thin protective layer on the surface.
In the 1800s, aluminium was so hard to produce that it was more valuable than gold.
Louis Pasteur made milk safer to drink
In the 1860s, French scientist Louis Pasteur discovered that gently heating drinks like wine and milk killed harmful germs without ruining their taste. This process, called pasteurisation, is still used around the world today and has saved countless lives.
The earthy smell after rain has a name: petrichor.
Some metals, like sodium and potassium, react so strongly with water that they can burst into flames.
Tungsten has the highest melting point of any metal, at around 3,422°C.
Trees can share nutrients and send chemical signals to each other through underground networks of fungi.
Some species of bamboo can grow almost a metre in a single day.
A Venus flytrap counts. It snaps shut only if an insect touches its trigger hairs twice, and starts digesting after more touches.
Young sunflowers follow the Sun across the sky, but mature sunflowers usually stay facing east.
Some plants, like the "touch-me-not" Mimosa pudica, fold their leaves within seconds when touched.
The bladderwort, a small water plant, has one of the fastest movements in the plant world. Its tiny traps suck in prey in less than a millisecond.
Jagadish Chandra Bose proved that plants respond to their surroundings
Indian scientist Jagadish Chandra Bose invented an instrument called the crescograph, which could measure tiny movements in growing plants. His experiments showed that plants react to things like light, heat and touch. He was also a pioneer in radio and microwave research in the 1890s.
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