Mcleod0

The discs were photographed to produced animated movies that allow a viewer to travel up and down the skeleton,and into the flesh,and through the bones,and the veins,perhaps I should have suggested you don't watch this during dinner,my bad.In classrooms today, the camera,now present in just about every phone and computer,allows the youngest scientists to observe the world around them,to document it,and to share their findings online.Whether it's the change of seasons or the growth of the germinating seed,cameras are allowing us to see a beautiful worldthrough new eyes.

Mathematicians have used photos to look at where in the twists and turns of a whip the crack sound comes when the whip is breaking the sound barrier.Meteorologists and environmental scientists show the growth of major hurricanes and the recession over the years of many of the world's glaciers.Slow-motion film or high-speed photography have shown us the beating of a hummingbird's wings and the course of a bullet through its target.In one project, cadavers,that's dead bodies,were frozen and sliced into thousands of wafer-thin discs.

Since then, photography has found its way into all aspects of math and science.It enhances our understanding of a world we thought we could already see,but it's one which we really need help to see a little better.It's not always a matter of the world moving by too quickly for our eyes to process.Sometimes cameras can help us see matter or movements that are too small for the naked eye.Botanists use multiple photographs to show the life cycle of plants and how flowers turn over the course of a few hours to follow the sun in what is called phototropism,growing towards the light.

But, there are things that,despite looking really hard,we still can't quite see.For example, you can watch a horse galloping,but your eyes can't keep up with its fast-moving hooves enough to figure out whether all four feet are ever off the ground simultaneously.For these types of questions, we need cameras.About 150 years ago,the photographer Eadweard Muybridge used one to solve the galloping horse mystery.Using careful photography,Muybridge proved that at certain points as it gallops,a horse really is flying."Look, ma! No hooves!"

The human eye is one of the most powerful machines on the planet.It's like a 500 megapixel camera that can run in bright light,in near darkness,and even under water, though not real well.It communicates to our brains so much about the world.Our eyes are how we find partners,how we understand the people around us,how we read,and how we watch game shows on TV where people get knocked into cold water by padded wrecking balls.Yup, the human eye is pretty neat,and we're lucky enough to have two of them.

That chemical was involved in manufacturing Teflon.As for John Gotti,in 1992, the Mob boss was finally convicted of five counts of murder,among other charges.That prompted the head of the FBI office in New York City to announce,"The Teflon is gone.The don is covered in Velcro,and all the charges stuck."

People used to also think that accidentally consuming PTFE that flaked off a scratched pan was bad for you,but the current consensus is that it's harmless.Because PTFE doesn't interact with other chemicals very well,it isn't thought to break down inside your body.Whether it's safe to manufacture Teflon is another story.DuPont and its spin-off company Chemours now face lawsuits worth millions of dollars.They've been accused of polluting the environment for decades and exposing employees and local communities to health risks associated with a toxic chemical called PFOA.

You might wonder if it's safe to cook in a PTFE-coated pan.The answer is yes, if you're careful.PTFE is stable at moderate temperatures,like you'd use to cook eggs or fish,but above 500 degrees Fahrenheit,it starts to degrade,and heating it further releases fumes that can make you feel sick.An empty pan can reach 500 degrees fast over high heat,but most kitchens are ventilated well enough to dissipate the fumes.

The pan is sprayed with liquid PTFE and heated to around 800 degrees Fahrenheit.The layers then solidify into a smooth, slick coating.When you later cook eggs in this PTFE-coated pan,the extra tight carbon-fluorine bonds just ignore the water and fat and protein molecules in the eggs.Without those interactions,the food just slides around without sticking.

Even the famously adhesive feet of geckos usually can't get a grip.But wait!If PTFE doesn't stick to anything,how can it be so firmly attached to something like a pan?One method involves sandblasting the pan or etching it with chemicals to make it rough.Then, a special primer is applied,which acts like glue.Its exact composition is a trade secret guarded by each manufacturer.

The incredible properties of PTFE come from its molecular structure.It's a polymer,meaning it's made of long chains of repeating units of atoms strung together.A PTFE chain has a backbone of carbon atoms,each of which is attached to two fluorines.The fluorine atoms surround the carbon like armor,spiraling around the chain,and the bond between carbon and fluorine is incredibly tight.Like a couple that ignores everyone except each other,carbon and fluorine interact so strongly that the normal, intermolecular forces that help substances stick to each other don't stand a chance.

Teflon's properties make it perfect when you need something slippery,chemical resistant,or waterproof,which means it has a lot of applications.It can be found all over the place,as a coating on raincoats,industrial ball bearings,artificial joints,circuit boards,and even the Rocky Mountains-themed roof of the Denver International Airport.

Teflon is a brand name for polytetrafluoroethylene,or PTFE.It was stumbled upon accidentally in 1938 by a 27-year-old American chemist named Roy Plunkett while he was trying to develop a non-toxic refrigerant fluid for DuPont,a chemicals company.The strange, white substance that formed inside his lab canister was chemically inert,meaning it wouldn't react with other substances.It also had an extremely low coefficient of friction,making other materials slide right off it.

Nothing stuck to Mafia boss John Gotti who evaded justice for years by bribing and threatening jurors and witnesses.That earned him the name the Teflon Don after one of the slipperiest materials on Earth.Teflon was in the spacesuits the Apollo crew wore for the moon landing,in pipes and valves used in the Manhattan Project,and maybe in your kitchen as the nonstick coating on frying pans and cookie sheets.So what is this slippery solid,and why doesn't anything stick to it?

Cotton with these qualities has diverse uses—from soft textiles to the U.S. dollar bill,which is 75% cotton.The next crucial stage of the cotton fiber’s growth 00:02:56,058 --> 00:02:59,347 begins as it thickens its secondary cell wall by depositing large quantities of cellulose into the secondary layer.Cellulose goes on to make up over 90% of the fiber’s weight.The more cellulose that gets deposited,the denser that secondary layer becomes—and this determines the strength of the final fiber.

In ideal growing conditions—with the right temperature, water, fertilizer, pest control, and light—a cotton fiber can grow up to 3.6 centimeters long with only a 25 micrometer width.Long, fine fibers can wrap around one another better than shorter, less fine fibers,which means those long, fine fibers make stronger threads that hang together better as fabric.

This new growth also reinforces the cell wall by going against the grain of the existing wall.The strengthened wall is more rigid, restricting further growth.That means if the fiber remodels its walls too early,it will be short,and ultimately make rough, weak fabrics.But if cell wall strengthening begins too late,the wall won’t be sturdy enough—producing fibers that are too weak to hold fabrics together well.

That cell has multiple layers of cell wall.After a few days, the sides of the first layer,called the primary cell wall,stiffen, pushing cell growth in one direction and causing the fiber to elongate.The fiber elongates quickly for about 16 days.Then it begins the next stage: strengthening the cell wall.It does this by making more of the carbohydrate cellulose.Cellulose will make up 34% of the cell wall at this stage and swiftly increases.

These seemingly contradictory features—strength and flexibility, softness and durability—have their roots in the intricate biology These fibers begin life deep within a cotton flower,on the surface of a seed.As many as 16,000 fibers will festoon a single seed,bulging from the seed’s surface like miniature water balloons.Each cotton fiber, no matter how large it grows,is made of just one cell.

Centuries ago, the Inca developed ingenuous suits of armor that could flex with the blows of sharp spears and maces,protecting warriors from even the fiercest physical attacks.These hardy structures were made not from iron or steel,but rather something unexpectedly soft: cotton.These thickly woven, layered quilts of cotton could distribute the energy from a blow across a large surface area,shielding warriors without restricting their mobility.

This stage is essential for developing long-lasting material for the likes of, say, a t-shirt.The garment’s capacity to withstand years of washing and wear is largely determined by the density of that secondary cell wall.On the other hand,its softness is strongly influenced by the length of the fiber,established with the remodeling of the primary wall layer.Finally, after about 50 days, the fiber is fully grown.