1323 facts
Yaks have a thick three-layered coat that traps body heat inside. This insulation is so efficient that the outer fur stays cold enough for snow to remain frozen on the animal's bac...
The pink color comes from colostrum, the nutrient-rich milk produced immediately after birth. This thick milk is high in fat and protein to help calves survive freezing mountain te...
Stars form inside massive clouds of gas and dust. Gravity pulls these cold materials together until they collapse and heat up. When the core reaches 15 million degrees Celsius, nuc...
Located 2,500 light-years away, the Ring Nebula formed when a Sun-like star ran out of fuel and shed its outer layers. At its center sits a white dwarf, the cooling core of the ori...
Extreme magnetic fields around neutron stars polarize the vacuum of space. This forces light to split and travel along different paths based on its orientation. In 2016, astronomer...
The universe has no 'outside' or edge. Instead, the fabric of space between galaxies is constantly stretching. This makes distant galaxies move farther apart, similar to dots on an...
Interstellar space contains about one hydrogen atom per cubic centimeter. At 90% the speed of light, a ship would collide with billions of these atoms every second. These high-ener...
During the Apollo 15 mission, astronaut David Scott dropped a heavy hammer and a light feather at the same time. Since the Moon has no atmosphere to create air resistance, both obj...
Completed in 1945, the ENIAC occupied 1,800 square feet and used nearly 18,000 vacuum tubes. These glass tubes were bulky, generated extreme heat, and failed almost daily. The 1947...
Boiling happens when water's vapor pressure equals the surrounding air pressure. In a vacuum, the pressure is so low that water molecules can escape into a gas without being heated...
The void between galaxies is nearly a perfect vacuum. For comparison, the air on Earth is quintillions of times denser, containing about 25 quintillion molecules in that same small...
Dark energy is a mysterious force that acts as the opposite of gravity. While gravity pulls matter together, dark energy pushes space apart. Because this energy is a property of sp...
Freezer burn happens when water in food evaporates through a process called sublimation. This leaves food dry, tough, and tasteless. Vacuum sealing removes the air and creates a ti...
Marshmallows contain tiny air bubbles trapped in a sugary structure. At sea level, these bubbles are compressed by 14.7 pounds per square inch of atmospheric pressure. When placed...
Sound is a mechanical wave that moves by vibrating atoms or molecules in air, water, or solids. Because space is a vacuum with no particles to vibrate, it remains completely silent...
Electron microscopes use high-speed electrons instead of light to create images. Because electrons are so light, colliding with even a single air molecule would knock them off cour...
Through a process called Hawking radiation, black holes slowly lose mass by emitting subatomic particles. Over trillions of years, even the most massive black holes will shrink and...
While a typical region this size should hold 2,000 galaxies, astronomers have found only about 60 inside this void. If the Milky Way were at its center, we wouldn't have discovered...
A vacuum is empty space with no pressure, so it cannot pull or 'suck' anything. Instead, the pressurized air inside a spacecraft exerts force in all directions. If the hull breache...
On Earth, air moves heat away through convection. In the vacuum of space, this is impossible. Spacecraft must instead release heat as infrared radiation. Engineers use specialized...
On Earth, air resistance slows down light objects like feathers. In a vacuum, there is no air to provide resistance, so gravity pulls all objects toward the ground at the same rate...
The speed of light is roughly 299,792 kilometers per second in empty space. When light enters materials like water or glass, it interacts with atoms and slows down. It travels at 7...
Scientist Otto von Guericke joined two copper bowls and pumped the air out from inside. The external air pressure was so strong that it clamped the pieces together with massive for...
Astronauts notice a distinct, smoky odor on their suits and tools after returning from spacewalks. This scent is caused by high-energy particles and organic molecules that cling to...
The Higgs field gives particles mass, but it might not be in its most stable state. If it shifts to a lower energy level, a bubble of destruction would expand at light speed, insta...
Heat requires matter to move through conduction or convection. A thermos features a double-walled container with a vacuum in between, meaning there are no particles to carry heat a...
To keep particles from hitting air molecules, the LHC maintains an internal pressure ten times lower than the Moon's atmosphere. Engineers pump out 9,000 cubic meters of air and us...
Atoms are 99.9999999% empty space. If you collapsed this void, the remaining matter from every person on Earth would occupy less than one cubic centimeter. While tiny, this sugar c...
This altitude is called the Armstrong Limit. At this height, the boiling point of water drops to 98.6°F (37°C). Without a pressurized suit, the moisture on your tongue, in your eye...
Known as the Casimir Effect, this phenomenon proves that empty space is actually filled with energy. When plates are nanometers apart, they restrict the energy waves between them....
At the quantum level, a vacuum is actually a 'quantum foam' where virtual particles constantly pop in and out of existence. Due to the Heisenberg Uncertainty Principle, energy leve...
This process, called cold welding, happens because space lacks oxygen. On Earth, metal surfaces react with air to form a thin layer of oxidation that prevents them from sticking. I...
Before LEDs, gas lanterns used mesh pouches called mantles coated in thorium nitrate. When heated by a flame, the thorium glowed with an intense white light. While the radiation wa...
High-energy gamma rays penetrate packaging to destroy the DNA of bacteria and viruses. Because this process uses light energy instead of radioactive particles, the items remain saf...
Early 20th-century manufacturers mistakenly believed radioactivity had healing properties. Doramad toothpaste contained thorium, which was claimed to massage gums and destroy bacte...
Polonium-210 is 250 billion times more toxic than hydrogen cyanide. It emits intense alpha radiation that destroys DNA and vital organs from the inside out. While it cannot penetra...
Most phosphate fertilizers are produced from ancient seabed rocks that absorbed uranium from seawater millions of years ago. When these rocks are processed, radioactive elements ar...
During experiments at Los Alamos in 1945 and 1946, this 6.2-kilogram core accidentally went critical. These incidents released massive radiation bursts and a distinct blue glow. In...
These unique fungi use melanin to convert gamma radiation into chemical energy. This process, called radiosynthesis, works similarly to how plants use sunlight for photosynthesis....
This invisible, odorless gas is produced by decaying uranium in soil and rocks. It enters buildings through foundation cracks and floor drains, reaching toxic levels in enclosed sp...
Because sunlight is too weak for solar panels in deep space, Voyager 1 uses Radioisotope Thermoelectric Generators (RTGs). These devices convert heat from decaying plutonium into e...
Popular from the 1880s to the 1940s, this glass uses uranium dioxide to achieve its distinct yellow-green tint. While slightly radioactive, the uranium is safely trapped inside the...
High-energy cosmic rays transform nitrogen into radioactive carbon-14 in the upper atmosphere. Plants and animals absorb this isotope while they are alive. Once an organism dies, i...
These women painted watch dials and were told to use their lips to sharpen their brushes. This caused them to swallow lethal amounts of radium. Since the body treats radium like ca...
These signs use radioluminescence to remain visible during power outages. Tritium gas is sealed inside phosphor-lined glass tubes. As the tritium decays, it releases electrons that...
At high altitudes, the atmosphere is thinner and provides less protection from cosmic radiation. Flying at 35,000 feet exposes passengers to high-energy particles from space. This...
This radiation comes from isotopes like potassium-40 and carbon-14 found in your tissues. These elements enter your body through the food you eat and the air you breathe. This inte...
While radiation in most European wildlife has decreased since 1986, German wild boars remain highly radioactive. They eat deer truffles, an underground fungus that absorbs cesium-1...
Produced between 1936 and 1943, these vibrant orange-red plates contain up to 14% uranium by weight. While they are popular collectibles, they emit alpha, beta, and gamma radiation...
Earth's internal heat comes from two main sources: leftover energy from its formation 4.5 billion years ago and the constant decay of radioactive elements like uranium and thorium....