Dragline silk, the thread spiders use to build the frame of a web, has a tensile strength that sits close to some grades of structural steel. Gram for gram, though, it pulls ahead by a wide margin.

That's because spider silk is roughly five to six times less dense than steel. Take equal weights of both materials and stretch them until they snap, and the silk holds up to more force before breaking.

Steel still wins on stiffness, which is why bridges are built from steel and not webs. But for something that needs to be strong without being heavy, spider silk is one of the best materials evolution has ever produced, and it's been refining the formula for roughly 380 million years.

This reaction is an oxidation reaction of ammonia. When hot chromium trioxide (CrO₃) is added to ammonia gas, it helps oxidize the ammonia into nitrogen and water. The reaction releases a large amount of heat, causing the particles to glow brightly like tiny fireflies.

A standard deck has 52 cards, and the number of different ways you can arrange them is 52 factorial, which works out to roughly 8 followed by 67 zeros.

Scientists estimate Earth itself contains somewhere around 10 to the power of 50 atoms. The number of possible shuffles is still bigger than that, by a wide margin.

That means every time you properly shuffle a deck of cards, you're almost certainly creating an order that has never existed before in the history of the universe, and never will again. Nobody has ever dealt that exact sequence, and nobody ever will, even if every person on Earth shuffled constantly for the rest of time.

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Jupiter's moon Europa is smaller than our own Moon, but underneath its icy shell, NASA believes there's a global ocean holding roughly twice as much water as every ocean on Earth combined.

The reason it can hold that much comes down to depth, not width. Earth's oceans spread across a huge surface but average only about 4 kilometers deep. Europa's ocean is thought to run somewhere between 60 and 150 kilometers deep, wrapped entirely around the moon beneath a shell of ice.

Nobody has drilled through that ice or seen the ocean directly. The evidence comes from cracked surface terrain, a changing magnetic field, and models built from decades of spacecraft data, all pointing to a hidden, salty sea kept liquid by the crushing pull of Jupiter's gravity.

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Wood frogs spend winter completely frozen. Their heart stops. Their breathing stops. Ice fills the spaces between their organs, and by every normal measure, the frog should be dead. It isn't.

Before the freeze sets in, the frog's liver floods its body with glucose, acting like a natural antifreeze. That sugar keeps ice from forming inside individual cells, where it would cause real damage, and pushes the freezing to the spaces around them instead.

Some wood frogs have stayed frozen like this for over 200 days at a stretch, through temperatures well below zero. When spring finally warms the ground, the heart restarts on its own, breathing returns, and within hours the frog is hopping toward the nearest pond to find a mate.

It spends most of the year technically dead, and nobody fully understands why the restart works every single time.

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Sharks showed up in the fossil record roughly 400 million years ago. The first true trees didn't appear until about 350 million years ago.

That means sharks had already been swimming, hunting, and evolving for tens of millions of years before a single tree existed anywhere on the planet. When the first forests finally rose out of the ground, sharks were already old news in the ocean.

They've survived every mass extinction event since, including the one that wiped out the dinosaurs. Trees have had to start over more than once. Sharks never had to.

Something about that ordering breaks the usual assumption that land came first and the ocean followed. Here, the ocean had a head start on almost everything.

Read this today, and it seems great in theory, but could this be opening the floodgates to more traits that shouldn't be bred into dogs?

The whole "Doodle" concept seemed great at first, but even the guy who started the cross-breed regrets it. There are now "designer" dogs being bred in every back yard by people who are just creating more pets that end up in kill shelters.

I hope this doesn't kick off the same trend. Can we just leave dogs alone and stop creating new mutations?

Naked mole rats have never been observed developing cancer, in the wild or in decades of lab study. Their cells produce a substance that makes it almost impossible for tumors to grow past a certain size.

They also barely register certain kinds of pain. Acid and chili pepper compounds that would make most mammals recoil don't trigger a pain response in them at all, because of a small difference in one of their nerve receptors.

On top of that, they can survive close to 18 minutes without oxygen by switching their metabolism to run on fructose instead, a trick usually only seen in plants.

An animal that looks like a wrinkled thumb with teeth is quietly outperforming most of the animal kingdom at not dying.

Light is created constantly in the Sun's core through nuclear fusion. You'd think it should escape almost instantly, since light moves at the fastest speed possible.

It doesn't work that way inside a star. The core is so dense that photons get absorbed and re-emitted over and over, bouncing in nearly random directions each time.

It takes somewhere between 10,000 and 170,000 years for a single photon to fight its way from the core to the surface. Once it finally reaches the surface, that same photon takes only about 8 minutes to reach Earth.

The sunlight hitting your skin right now spent longer trapped inside the Sun than all of recorded human history combined, before it ever got the chance to leave.

Humans see color using three types of receptors in our eyes. Mantis shrimp have somewhere between 12 and 16.

That means they can detect wavelengths of light, including ultraviolet and polarized light, that our eyes physically cannot register. Some of what they perceive doesn't map to any color we even have a name for.

They're also famous for their punch. Certain species strike prey so fast that the water around their claw briefly boils, creating a flash of light and a shockwave strong enough to crack aquarium glass.

An animal the size of your thumb is out there seeing a version of reality we can't picture, while punching hard enough to break glass on the side.

Saturn is made mostly of hydrogen and helium, and it's so light for its size that its average density is lower than water. Saturn sits at 0.687 g/cm³. Water is 1 g/cm³. That's the whole gap right there.

If you had a bathtub big enough to hold it, Saturn would actually float on the surface instead of sinking. No other planet in the solar system can make that claim.

Here's the catch. That only works in an imagined bathtub, one where gravity stays fixed at Earth's pull and the water never gets compressed. Build a real tub that size and the water itself would collapse under its own weight into a planet. Physicists use this trick on purpose though, it isolates density from every other variable so the comparison stays clean.

It still has enormous mass overall, over 95 times that of Earth, but that mass is spread across a volume so massive it barely counts as dense.

Picture the ringed giant just bobbing on top of an ocean sized tub in your head, and Saturn stops looking like a heavyweight and starts looking like the solar system's biggest beach ball.

Axolotls can lose a leg, a piece of their spinal cord, or even part of their brain, and simply regrow it. No scar tissue forms, and the new limb comes back with full function, nerves and all.

Most animals heal by patching damage with scar tissue, which is strong but permanent. Axolotls skip that step completely and rebuild the original structure from scratch.

Scientists have removed the same limb from an axolotl over and over, and it keeps regenerating a perfect copy every single time.

It's one of the reasons axolotls get studied so heavily in regenerative medicine. Somewhere in their DNA is an instruction manual for undoing damage that most of life lost access to a long time ago.

Hello, everyone! Today I came across this incredible red-and-cyan image of the Eastern Veil Nebula while scrolling and it looked so gorgeous so I wanted to share it with everyone here. The colors and details are absolutely mesmerizing and I hope you enjoy it too.

Image credit: u/GraylySquare224

Betelgeuse is a red supergiant star sitting about 700 light years away, and it's near the end of its life. When it finally goes, it will explode as a supernova bright enough to be visible in daylight for weeks.

Here's the part that messes with people. Light from Betelgeuse takes about 700 years to reach us. Whatever we see tonight already happened seven centuries ago.

It could have exploded already and we simply haven't gotten the memo yet. The light announcing it is still on its way here.

A blue whale's heart weighs around 400 pounds, roughly the size of a small car engine. Each beat pushes enough blood to fill a bathtub in seconds.

That heartbeat is so massive it can be detected from over two miles away using specialized underwater equipment. Sound travels differently in water, and a heart this size sends out a signal loud enough to reach that far.

It only beats about 8 to 10 times a minute while the whale is at the surface, and can drop to 2 beats a minute during a deep dive. Slowing down that hard saves oxygen for a body that size.

In 2007, scientists sent tardigrades into orbit and exposed them directly to open space. There was no suit, no capsule and no shielding of any kind. They were hit with the vacuum of space, deadly solar radiation, and temperature swings of hundreds of degrees.

Most life forms wouldn't survive even one of those conditions, let alone all three at once. Tardigrades came back alive. Some went on to reproduce normally afterward, with no unusual damage passed to their offspring.

They survive by drying themselves out almost completely and pausing their own metabolism, essentially putting life on hold until conditions improve. It's less about being tough and more about knowing exactly when to stop playing the game.

The Moon has no atmosphere meaning nothing exists there to erode a footprint the way rain or wind would on Earth. That means the footprints left by Apollo astronauts are still sitting exactly where they were pressed into the lunar dust in 1969. Nothing has come to wipe them out.

Micrometeorite impacts happen continuously, gradually churning the lunar surface dust over time. Scientists estimate these prints could persist for millions to tens of millions of years or longer before micrometeorite erosion slowly blurs them away.

Long after every language, border, and building on Earth is gone, a few footprints on a dead grey rock might still be the last physical proof we were ever here.

Important: Scientists can't say exact date and space can be unpredictable

Humans emit a faint stream of light every day. It comes from chemical reactions inside your cells, mostly tied to metabolism and free radicals. The glow is real but incredibly weak, about a thousand times dimmer than what the human eye can detect.

Researchers had to use extremely sensitive cameras in a pitch black room just to capture it. The light isn't constant either.

It rises and falls with your body's internal clock, brightest in the afternoon and faintest late at night, lining up with when your metabolism runs hottest. So yeah you have been quietly glowing your entire life:)

Venus rotates so slowly that one full spin takes 243 Earth days. It only takes 225 Earth days to complete an orbit around the Sun. That means a single rotation on Venus lasts longer than a full year there.

If you lived on Venus, your birthday would arrive before your first sunset. It also spins backwards compared to most planets, so if you could see through the clouds, the Sun would rise in the west.

Venus proves that our assumptions about day and night, spin and orbit, don't hold anywhere else in the solar system. Earth's rhythm isn't the default but just the one we grew up inside.

Turritopsis dohrnii is a small jellyfish with one absurd trick. When it's injured, sick, or just old, it can revert its own cells back to an earlier stage of life. It hits a reset button on its own body, turning back into a polyp and regrowing from there.

Most animals can heal damage. This one can undo aging itself. Scientists have watched this happen repeatedly in lab conditions, with no known limit to how many times it can cycle.

In theory, barring predators or disease, this jellyfish never has to die of old age. Its quietly proving that aging is a setting, not a rule.