It may be Independence Day, but there's nothing revolutionary about the way your 4th of July fireworks are made.

Fireworks have been built from a mix of explosive powder, chemicals, and glue for ages. The earliest fireworks shows date back more than a thousand years. 

But not all fireworks are built the same. You can't get a bright red firework to light up with the same elements inside as a blue or white one. That's because the color of a firework explosion depends on what kinds of elements are inside, from common metals to rarer minerals and even some salts.

Pyrotechnicians call these bursts of colored light "stars," and they're made of a mixture of fuel, oxidizer (to help fuel burn), color-producing elements (like aluminum or copper), and a binder (glue) packed inside a shell. That all gets fired high into the air before a time-delayed fuse spits fire onto the stars and they take off. 

California-based pyrotechnician and electrical engineer Mike Tockstein, who's prepping the Los Angeles Coliseum for a 4th of July show, told Business Insider that it takes days of pounding, digging, wiring, and "well over 10,000 pounds of equipment" to set up.

Before you peer up into the sky this Independence Day, take a look at some of the common elements that are making your celebration possible. 

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Yellow fireworks are made from an element you might associate with the color white: Sodium.

You may think sodium belongs in your salt shaker. But burning-hot sodium produces a bright yellow explosion that's perfect for lighting up the sky.

Red fireworks come from a common element called strontium.

Strontium was used in the glass screens of a lot of old color TV sets, because it helped block x-rays from hitting us. The element has a yellowish color, but it burns red hot.

Green fireworks are a result of barium salts exploding in the sky.

Most green fireworks are made from barium nitrate, which is toxic to inhale, so it's not used for much else, though it can be an ingredient in grenades. 

• Two chemists have found a way to make sunscreen work better. 
• The treatment boosts the body's ability to deflect ultraviolet rays which cause sunburns and cellular DNA damage. 
• The molecule created is a simplified version of melanin, a biological pigment that can absorb and dissipate UV light, with customizable properties that allow researchers to make it into an effective sun-protection supplement.
• The hope is that sunscreen-makers can use ingredients are more naturally-derived, while offering greater UV-A and UV-B protection. 

Sunscreens nowadays just aren't cutting it. With summer temperatures heating up, slathering on SPF 50 sometimes won't even guarantee protection from the sun's rays. 

More and more beach-goers are also looking for sunscreen that has for more naturally-derived active ingredients over chemical ones like oxybenzone, which was also recently banned in Hawaii.

"There's an obvious need to improve current sun protection, a need for higher SPF, broader protection than what the current sunscreens offer," said Ayala Lampel, a chemist at the City University of New York.

With fellow chemist Rein Ulijn, Lampel sought to create a better, nature-inspired sunscreen.

The product they created is a bio-inspired material called "Peptide Pigments" that can be used as supplemental UV boosters. They can increase the SPF and broad spectrum of existing UV-filtering active ingredients like zinc oxide or titanium dioxide. That way, sunscreen companies could use smaller amounts of these active ingredients without  losing any strength. 

Targeting melanin

What started as an academic project at the Advanced Science Research Center at the Graduate Center of CUNY to create melanin-like peptide molecules turned into a commercial pursuit shortly after the chemists' results were published in the journal Science in June 2017.

To get to a better sunscreen, the researchers turned to biology.

This led them to melanin, a biological pigment that absorbs and disperses UV light across the skin, forming a barrier that protects the skin from UV damage in humans. It's also responsible for summer tans and the color of skin and hair. 

"It's a bit of a miracle material in some ways in terms of its protective ability and its aesthetic function and the fact that it's seen in all living organisms," Ulijn said. But often, it's poorly understood and difficult to produce in the lab, he said.

How it works

What chemists have tried to do in the past is produce melanin by starting with tyrosine, an amino acid precursor, then oxidizing it. Tyrosine is a building block for proteins and other polypeptide materials like melanin. The oxidation reaction works like the browning of apples or bananas or avocados, in which melanin is also the culprit.

Upon oxidation, tyrosine becomes very reactive. And if you have a group of tyrosines colliding together, you end up with "a mess," as Ulijn calls it. Most lab-produced melanin end up as black, dirt-like polymers that cannot be dispersed or incorporated into existing cosmetic products. Imagine applying a foundation speckled with dirt onto your face. 

What Ulijn and Lampel tried to do was yield a more favorable material from the melanin formation process in the lab by imitating how melanin forms in nature.

Instead of using tyrosine as a precursor, Lampel and Ulijn pre-organized it into a short peptide. These peptides consist of organized amino acids and give the molecule more favorable chemical properties. When the tyrosines react, instead of everything happening all at once, it's now more ordered.

The end result was a product that was simpler than melanin, but retained the same overall properties including broad spectrum sun protection against UV-A and UV-B rays as well as blue light like those emitted from electronic devices. By hacking biology, Lampel and Ulijn were able to make the molecules more customizable. They can tune the color of the molecules to match it to different foundation shades as well as the UV absorption by changing the sequence of the peptides. 

Lampel and Ulijn designed the product to easily dissolve into existing cosmetic products. That way, it has a non-oily texture, and doesn't leave behind white streaks. To start, the product is intended to work alongside existing sunscreen products, but Lampel and Ulijn want to see if they can completely replace current sunscreens one day.

For the past five months, the researchers have been working to ensure that the product is consistently reproducible. Now, they're seeking out a corporate partner to collaborate with testing out safety and efficacy. They're also looking for seed money to hire a CEO and a small research and development team.

With everything on track, Lampel says that they're expected to complete human testing in the next year for a first generation product, and hope to bring the product to market in 18 to 24 months.

SEE ALSO: Here’s why certain sunscreens are so dangerous for coral that Hawaii plans to ban them — and what you should use instead

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Inhaling helium and talking like Daffy Duck is a classic party trick. But not many know how helium works. Helium is much lighter than air, so sound waves move much faster through the gas. This amplifies the higher frequencies in your voice. The gas sulfur hexafluoride works in the opposite way. The following is a transcript of the video.

It’s a classic party trick- suck down a balloon and you’ll sound like Daffy Duck every time. But helium isn’t the only gas that’ll change the way you talk. So what’s going on here?

Your voice is as unique as your fingerprint. Janice didn’t inhale a balloon full of helium. That’s just her “normal” voice. So, let's take a look at how that's even possible. The sound of your voice starts in your voice box, or larynx. It’s a two-inch piece of cartilage at the top of your throat. In the box are two stretchy strands of tissue, your vocal cords. Which vibrate against each other at a specific frequency when you talk.

Women generally have thinner, shorter, tighter vocal cords than men. So, their vocal cords vibrate faster which generates a higher pitched voice. That sound is called the fundamental frequency of your voice. On its own it just sounds like a simple buzzing. But when it reaches your vocal tract, the sound waves start bouncing around. Those reflections interfere with each other. Which creates a mix of other frequencies, that you can detect with a spectrogram. So even though your voice starts out as one frequency, it ends up as a mix of multiple ones.

And that's where helium comes into play. Helium is lighter than air. Which means sound moves faster through helium than through air – nearly 3 times faster, in fact. So the sound waves bounce around faster in your vocal tract, which amplifies the higher frequencies in your voice. It's sort of like how speeding up your voice makes it sound higher.

But hold on a sec. These people aren't inhaling helium. They're sucking down sulfur hexafluoride, which is six times heavier than air. So sound waves move slower through it, which amplifies the lower frequencies in your voice. But here's the fascinating thing. The pitch of your voice hasn't changed when you inhale either gas, because your vocal cords move at the same rate no matter what gas you're breathing. So your fundamental frequency stays, well fundamental.

Regardless of whether you want to sound like Daffy Duck or James Earl Jones, keep in mind that inhaling anything but air can be dangerous. Especially when the gas is denser than air, because it will sink to the bottom of your lungs. And you may have to get it out like this. What questions do you have about the human body? Let us know in the comments and thanks for watching.

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I think most of you reading this right now are aware that gold is unlike any other metal, certainly any other element.

It doesn’t play by the same rules as iron or tin or aluminum, and its value has nothing to do with its utility—or lack thereof. People valued the yellow metal for its beauty and malleability eons before they knew of its usefulness in conducting electricity or its chemical inertness.

That gold is so chemically “boring,” though, is one of the main reasons why it’s so highly valued, even today.

This is the conclusion of Andrea Sella, distinguished professor of chemistry at University College London. In 2013, Sella spoke with Justin Rowlatt of the BBC World Service, walking him through all 118 elements of the periodic table.

Gold, according to Sella, is the best possible candidate for a currency of any value.

As he points out, we can automatically eliminate whole swaths of the periodic table for various reasons. We can cross out gases, halogens, and liquids such as helium, fluorine and mercury. No one wants to carry around vials of a colorless gas or, in the case of mercury and bromine, a poisonous substance.

We can then rule out alkaline earth metals such as magnesium and barium for being too reactive and explosive. Carcinogenic, radioactive elements such as uranium and plutonium are too impractical, as are synthetic elements that exist only momentarily in lab experiments—seaborgium and einsteinium, for example.

That leaves us with the 49 transition and post-transition metals: titanium, nickel, tin, lead, aluminum and more.

But many of these pose problems that should immediately exclude them from consideration as a currency. Most are too hard to smelt (titanium), too flimsy for coinage (aluminum), too corrosive (copper) and/or too plentiful (iron).

We are now left with just eight candidates, the noble metals: platinum, palladium, rhodium, iridium, osmium, ruthenium, silver and gold. These are all attractive as currencies, but except for silver and gold, they’re simply too rare.

So: silver and gold.

What gives gold the edge over silver, however, is—once again—its chemical inertness. Unlike its white cousin, gold doesn’t tarnish. It’s nonreactive to air and water. Add to this its softness, and it easily emerges as the perfect currency. Ancient peoples recognized this, and I don’t think anyone now would have any problem coming to the same conclusion either.

“I view gold as the primary global currency.”

Those are the words of former Fed Chairman Alan Greenspan, speaking to the World Gold Council for the 2017 winter edition of its Gold Investor publication.

“It is the only currency, along with silver, that does not require a counterparty signature. Gold, however, has always been far more valuable per ounce than silver. No one refuses gold as payment to discharge an obligation. Credit instruments and fiat currency depend on the credit worthiness of a counterparty. Gold, along with silver, is one of the only currencies that has an intrinsic value. It has always been that way. No one questions its value, and it has always been a valuable commodity, first coined in Asia Minor in 600 BC.”

Right now, for the first time in human history, world currencies are free-floating, meaning they’re not backed by anything tangible.

It’s largely because of this that world debt has been allowed to soar to astronomical highs in recent years, threatening the stability of the global economy. As we’ve seen in Zimbabwe, Venezuela and elsewhere, a nation’s currency can rapidly lose its value and become worthless. Families and individuals who didn’t have a portion of their wealth stored in a real asset such as gold lost everything.

This is why I always recommend a 10 percent weighting in gold, with 5 percent in physical gold (coins, bars and jewelry) and the other 5 percent in high-quality gold stocks, mutual funds and ETFs.

SEE ALSO: The 'mother of all bubbles' is keeping gold in focus

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NOW WATCH: A diehard Mac user switches to PC

I was cutting my grass when the battery in my iPod died.

Instead of enjoying the distraction of music, my brain switched to its usual nerd mode of thinking about molecules. Within a few passes of cut grass, I was pondering the biggest “Why not?” of my scientific career: Could we discover new drugs and useful agricultural compounds by challenging organisms with clusters of random chemistry?

My background is in molecular biology – the study of DNA, genes and how an organism’s blueprints are decoded and assembled into life. The discipline requires an understanding of how molecular codes are deciphered and turned into functional biology. Anyone in this field is plagued with dreams of dancing molecules, interacting and performing the roles that turn DNA information into our food, the plants in our environment and our families.

Every day in the lab we move genes around. It’s easy. Not meant to generate new products for consumers, moving DNA is used as a research tool that lets us understand how specific genes work. A classic example is the NPR1 gene from the model plant Arabidopsis; it’s a defense gene that confers enhanced tolerance to disease when you drop it into almost any plant’s genome. Manipulating genetic information – in plants, microbes and some animals – is commonplace.

On that half-cut lawn it occurred to me – instead of inserting DNA information we understand, what if we introduced a scrambled mess of random DNA code into a plant or bacterium? Could we identify random bits of genetic information that could give rise to small proteins (called peptides) that change an organism’s physiology or development?

Normally DNA encodes instructions that coordinate the order of the amino acid building blocks in a protein. Each amino acid has specific chemical characteristics. Strung together in a peptide chain, they fold into a protein that provides cellular structure or function, based on the complementary chemistries of its amino acid components.

My hypothesis was that a short, scrambled DNA message could give rise to a novel string of amino acids. This would be a small cluster of discrete chemistry that likely never existed before on the planet. The vast majority of the time it would be meaningless and just become cellular rubbish. But maybe on rare occasion it could do something new and desirable.

To test the hypothesis, our research team used randomized templates to synthesize trillions of random DNA fragments using simple DNA amplification techniques. Each was flanked by the genetic instructions to start and stop production of a peptide inside the plant.

Then we used standard genetic engineering techniques to insert a novel DNA sequence into thousands of individual Arabidopsis thaliana plants – and sat back to watch what would happen when the plants turned the random genetic information into little random peptides. We were hoping for cases where specific protein structures might find a connection with biological chemistry and we’d see the result in the plants themselves.

As the plants grew, we were blown away by what we observed.

Some plants were flowering early. Others were small and stunted. Others grew larger leaves. Some were loaded with healthy purple pigments. Still others grew up to a point…then died.

We then retrieved the particular random DNA sequence we’d added to each, a simple feat for a molecular biologist, and inserted the same sequence into new plants. Most of the time the random information affected the new generation of plants in exactly the same way, demonstrating that something was indeed happening related to the added, garbled information. We recently published our results in the journal Plant Physiology.

What is this random information doing inside the cell? The small random molecules generated from the inserted DNA instructions could affect a specific process, just by chance. They could bind a needed nutrient. They might inhibit a key enzyme. They could turn on flowering or protect a plant from freezing. Nobody really knows exactly how until the plants are examined in detail one by one. These new proteins may also be good models to design new useful molecules with similar chemical properties, but that are more durable in the cell. Our goal is to produce a compound that may be applied to crops to change the way plants grow and behave, or perhaps stop the growth of invasive or weedy plants.

The process is like throwing monkey wrenches into a complicated machine. Most of the time they clank around and affect nothing; but once in a long while a wrench catches in some critical gears and brings the machine to a halt. Other times the wrench might short-circuit a wasteful process, allowing the machine to run more efficiently. These peptides are molecular monkey wrenches.

Some of these peptides must interfere with an important biological process because they kill the plant. These findings bring to light new vulnerabilities in plants that researchers could exploit to develop environmentally friendly and nontoxic herbicides. Agriculture currently relies on a few relatively old chemistries, cultivation (using fossil fuels) or human labor to control the weeds that compete with food plants for resources. Good weed control means that valuable fertilizers, water and sunlight go only to the desired plants, rather than weeds. So new herbicide chemistries would be extremely valuable as farmers work to produce food for growing populations.

But why stop at plants? We are using the same approach to discover the next generation of antibiotics. The goal is to identify random information that affects a single species of problematic bacterium. For instance, we could potentially target S. aureus, the antibiotic-resistant bacteria that causes MRSA. We are hunting for new molecules that could destroy MRSA-related bacteria while leaving the rest of the microbiome unaffected. These experiments are underway in our lab.

Randomness may pinpoint undiscovered vulnerabilities or opportunities in plants, bacteria and other organisms. There even may be applications in solving human disease. The future is exciting as we mine the vast collections of new molecules and study how they integrate with biology to produce important desired outcomes.

Several of the molecules we’ve already identified slow plant growth. Future products from this technology might even be applied to make lawns grow more slowly. While others may find this advance helpful, I’ll have to skip using it. Cutting the grass gets my good ideas flowing.

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NOW WATCH: Why the World Cup soccer ball looks so different

• Coffee from a cafe tastes different than home-brewed for a number of reasons: the type of brew, water, grind, and freshness of the bean.
• There are two families of coffee brews and depending on which you use, you need to control temperature and time to extract the best flavors.
• The water's levels of calcium ions and bicarbonate (whether your water is hard or soft) can affect the sourness of the coffee. You can't control your tap water.
• Roasted coffee contains of CO2 and other volatiles which affect flavor — but they decrease over time, so most cafes only use beans four weeks after their roasting date.

Coffee is unique among artisanal beverages in that the brewer plays a significant role in its quality at the point of consumption.

In contrast, drinkers buy draft beer and wine as finished products; their only consumer-controlled variable is the temperature at which you drink them.

Why is it that coffee produced by a barista at a cafe always tastes different than the same beans brewed at home?

It may be down to their years of training, but more likely it's their ability to harness the principles of chemistry and physics. I am a materials chemist by day, and many of the physical considerations I apply to other solids apply here.

The variables of temperature, water chemistry, particle size distribution, ratio of water to coffee, time and, perhaps most importantly, the quality of the green coffee all play crucial roles in producing a tasty cup. It's how we control these variables that allows for that cup to be reproducible.

How strong a cup of joe?

Besides the psychological and environmental contributions to why a barista-prepared cup of coffee tastes so good in the cafe, we need to consider the brew method itself.

We humans seem to like drinks that contain coffee constituents (organic acids, Maillard products, esters and heterocycles, to name a few) at 1.2-1.5% by mass (as in filter coffee), and also favor drinks containing 8-10% by mass (as in espresso). Concentrations outside of these ranges are challenging to execute. There are a limited number of technologies that achieve 8-10% concentrations, the espresso machine being the most familiar.

There are many ways, though, to achieve a drink containing 1.2-1.5% coffee. A pour-over, Turkish, Arabic, Aeropress, French press, siphon or batch brew (that is, regular drip) apparatus — each produces coffee that tastes good around these concentrations. These brew methods also boast an advantage over their espresso counterpart: They are cheap. An espresso machine can produce a beverage of this concentration: the Americano, which is just an espresso shot diluted with water to the concentration of filter coffee.

All of these methods result in roughly the same amount of coffee in the cup. So why can they taste so different?

When coffee meets water

There are two families of brewing device within the low-concentration methods — those that fully immerse the coffee in the brew water, and those that flow the water through the coffee bed.

From a physical perspective, the major difference is that the temperature of the coffee particulates is higher in the full immersion system.

The slowest part of coffee extraction is not the rate at which compounds dissolve from the particulate surface. Rather, it's the speed at which coffee flavor moves through the solid particle to the water-coffee interface, and this speed is increased with temperature.

A higher particulate temperature means that more of the tasty compounds trapped within the coffee particulates will be extracted.

But higher temperature also lets more of the unwanted compounds dissolve in the water, too. The Specialty Coffee Association presents a flavor wheel to help us talk about these flavors — from green/vegetative or papery/musty through to brown sugar or dried fruit.

Pour-overs and other flow-through systems are more complex. Unlike full immersion methods where time is controlled, flow-through brew times depend on the grind size since the grounds control the flow rate.

The water-to-coffee ratio matters, too, in the brew time. Simply grinding more fine to increase extraction invariably changes the brew time, as the water seeps more slowly through finer grounds.

One can increase the water-to-coffee ratio by using less coffee, but as the mass of coffee is reduced, the brew time also decreases. Optimization of filter coffee brewing is hence multidimensional and more tricky than full immersion methods.

Other variables to try to control

Even if you can optimize your brew method and apparatus to precisely mimic your favorite barista, there is still a near-certain chance that your home brew will taste different from the cafe's. There are three subtleties that have tremendous impact on the coffee quality: water chemistry, particle size distribution produced by the grinder and coffee freshness.

First, water chemistry: Given coffee is an acidic beverage, the acidity of your brew water can have a big effect.

Brew water containing low levels of both calcium ions and bicarbonate (HCO₃⁻) — that is, soft water — will result in a highly acidic cup, sometimes described as sour. Brew water containing high levels of HCO₃⁻ — typically, hard water — will produce a chalky cup, as the bicarbonate has neutralized most of the flavorsome acids in the coffee.

Ideally we want to brew coffee with water containing chemistry somewhere in the middle. But there's a good chance you don't know the bicarbonate concentration in your own tap water, and a small change makes a big difference. To taste the impact, try brewing coffee with Evian — one of the highest bicarbonate concentration bottled waters, at 360 mg/L.

The particle size distribution your grinder produces is critical, too.

Every coffee enthusiast will rightly tell you that blade grinders are disfavored because they produce a seemingly random particle size distribution; there can be both powder and essentially whole coffee beans coexisting. The alternative, a burr grinder, features two pieces of metal with teeth that cut the coffee into progressively smaller pieces. They allow ground particulates through an aperture only once they are small enough.

There is contention over how to optimize grind settings when using a burr grinder, though. One school of thought supports grinding the coffee as fine as possible to maximize the surface area, which lets you extract the most delicious flavors in higher concentrations.

The rival school advocates grinding as coarse as possible to minimize the production of fine particles that impart negative flavors. Perhaps the most useful advice here is to determine what you like best based on your taste preference.

Finally, the freshness of the coffee itself is crucial. Roasted coffee contains a significant amount of CO₂ and other volatiles trapped within the solid coffee matrix: Over time these gaseous organic molecules will escape the bean. Fewer volatiles means a less flavorful cup of coffee. Most cafes will not serve coffee more than four weeks out from the roast date, emphasizing the importance of using freshly roasted beans.

One can mitigate the rate of staling by cooling the coffee (as described by the Arrhenius equation). While you shouldn't chill your coffee in an open vessel (unless you want fish finger brews), storing coffee in an airtight container in the freezer will significantly prolong freshness.

So don't feel bad that your carefully brewed cup of coffee at home never stacks up to what you buy at the cafe.

There are a lot of variables — scientific and otherwise — that must be wrangled to produce a single superlative cup. Take comfort that most of these variables are not optimized by some mathematical algorithm, but rather by somebody's tongue. What's most important is that your coffee tastes good to you… brew after brew.

SEE ALSO: A California medical school just got $200 million to invest in 'energy healing,' 'mineral infusions' and other alternative medicines — and doctors aren't happy

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Three researchers who developed a way to see the basic molecules of life in three dimensions won the 2017 Nobel Prize in chemistry, the Royal Swedish Academy of Sciences announced on Wednesday.

Jacques Dubochet of Switzerland’s University of Lausanne, Joachim Frank of Columbia University in New York City, and Richard Henderson of the MRC Laboratory of Molecular Biology in England were honored “for developing cryo-electron microscopy for the high-resolution structure determination of biomolecules in solution,” said Göran Hansson, secretary general of the Royal Swedish Academy of Sciences, in announcing the prize in Stockholm.

Basically, cryo-EM lets biologists see what they’re studying, from the surface of the Zika virus to human enzymes involved in disease. And that has big implications for drug development: Seeing the shape of a molecule involved in cancer, for instance, can give scientists clues about the kind of molecule they need to create to disrupt the disease. The prize is therefore another example of the chemistry Nobel honoring research that is squarely within biology.

“This discovery is like the Google Earth for molecules in that it takes us down to the fine detail of atoms within proteins,” Allison Campbell, president of the American Chemical Society, said. “A picture truly is worth a thousand words, and the laureates’ discoveries are invaluable to our understanding of life and the development of new therapeutics.”

“I think this is a very exciting choice,” Jeremy Berg, editor-in-chief of Science and former director of the National Institute for General Medical Sciences at the National Institutes of Health, told STAT.

Cryo-EM “is truly revolutionizing biochemistry, particularly over the past five years,” Berg said. Many of the structures it has revealed, often at an atomic level, “are those of greatest interest to biologists, but have been difficult to reveal by other means,” he said, including “ion channels central to the function of the nervous system and the machinery for splicing RNA, essential for effective gene expression.”

The three laureates worked independently, but their discoveries about how to prepare biological samples to have their picture taken, how to take the picture without destroying the sample, and how to turn the initial fuzzy image into something sharp converged to make cryo-EM today’s go-to imaging technology.

Older microscopic techniques couldn’t generate images of life’s molecular machines; the cutting-edge technique of yore, electron microscopy, seemed to work only for seeing dead objects, since the electron beam destroys living things. But Frank, who said on Wednesday that he “didn’t mind” receiving the early-morning call from Stockholm, developed a way to take the fuzzy 2-D images from electron microscopes and turn them into a sharp 3-D picture, the first step toward cryo-EM.

Ordinary electron microscopy makes biomolecules, which contain water, collapse. But in the 1970s Dubochet showed that adding water to electron microscopy in a certain way that prevented that. He cooled water so rapidly that it became a sort of solid liquid (more like glass than ice), forming a sort of cage around the biological sample. That cage helped the biomolecules keep their shape during the imaging.

(Dubochet is known not only for his discoveries but also for having one of science’s more unusual official CVs, which starts with being “conceived by optimistic parents” in October 1941 and includes “being the first official dyslexic in the canton of Vaud” in 1955.)

Henderson showed that it is possible to freeze biomolecules “mid-movement,” the Nobel committee said, generating a three-dimensional image of a protein down to the atomic level. His breakthrough came in 1990, when he used cryo-EM to reveal the 3-D structure of a bacterial protein called bacteriorhodopsin. That demonstration of what cryo-EM could achieve was “decisive for both the basic understanding of life’s chemistry and for the development of pharmaceuticals,” the committee said.

In the new millennium, cryo-EM became the go-to technology for seeing the molecules of life, capturing everything from proteins that cause antibiotic resistance to the surface of the Zika virus to receptors in human cells that sense the spiciness molecule in chili peppers. And biologists hope that by actually seeing what their drugs have to target, they might develop more effective medications more quickly: a study last year, for instance, showed the atomic-level structure of an enzyme that, if disrupted, might fight cancer.

The three scientists will receive the Nobel Medal, Nobel Diploma, and a document confirming the Nobel Prize amount (9 million Swedish krona, about $1.1 million) from King Carl XVI Gustaf of Sweden at the annual Nobel ceremony in Stockholm on Dec. 10, along with the rest of this year’s laureates.

SEE ALSO: Three scientists who helped discover gravitational waves just won the Nobel prize in physics

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NOW WATCH: Scientists won the Nobel Prize for detecting gravitational waves — here's why that matters

• Jacques Dubochet, Joachim Frank, and Richard Henderson were awarded the 2017 Nobel prize in chemistry Wednesday for developing cryo-electron microscopy.
• The technique allows researchers to see the details of biological molecules like proteins, DNA, RNA, and viruses in ways that were impossible before.
• The new technology is revealing secrets of how biology works on molecular and microscopic levels and is essential for developing new medications.

In order to understand something — even if it's microscopic and invisible, like a protein or a virus — you need to know what it looks like.

A recently developed technique called cryo-electron microscopy creates 3D visualizations of biological molecules like proteins, DNA, and RNA, making them visible in ways previously thought impossible. Three scientists — Jacques Dubochet, Joachim Frank, and Richard Henderson — were awarded the 2017 Nobel prize in chemistry Wednesday for their work developing the method, which has given scientists an unprecedented look at what the Nobel prize committee described as "life's molecular machinery."

Being able to see the twists, turns, and shapes of molecules can reveal what types of drugs could help treat a virus or which medical molecule might fight a certain type of cancer. Just looking at these structures has filled in scientific knowledge gaps that existed for years.

Electron microscopy refers to the act of sending a beam of electrons at a small sample of a material. Unlike normal microscopes, which use light, beams of electrons can illuminate the tiniest of details in a structure, down the location of individual atoms.

The technique has existed since the 1930s, but many scientists didn't think it could be used to look at biomolecules for two main reasons. First, the force of the electron beam blasts biological material apart. Weakening the beam enough to keep molecules intact only creates a low-contrast, fuzzy image. Second, electron microscopes can't be used on anything that's in water, since the process evaporates that water. And without water (a main component of all cells), biological molecules collapse.

Advances in the field

In 1975, Richard Henderson, a molecular biologist who heads up a lab at Cambridge in the UK, used a weakened electron beam to capture a poor-contrast image of a protein. The protein was protected by a membrane, so didn't need to be kept in water.

He and colleagues gathered images from a number of angles, then used a mathematical model to create the best picture yet of a protein generated with an electron microscope. You can see it on the right. 

But the image didn't yet have the resolution Henderson wanted.

Meanwhile, Joachim Frank, a Columbia University professor originally from Germany, was working on ways to process the flat 2D images taken by electron microscopes. In the years between 1975 and 1986, he came up with a way to process a number of those fuzzy, flat images and turn them into sharper 3D models. The 3D versions could reveal the structure of a protein, advancing the technique Henderson had previously used.

In the 1980s, Swiss biophysicist Jacques Dubochet set to work solving another problem that was keeping scientists from creating images and models of biomolecules. He developed a way to "vitrify" water by cooling it so rapidly that it became a solid in its liquid form (without forming ice crystals). Essentially, he turned it into glass.

Put together, these developments set the stage for what would become known as cryo-electron microscopy, with "cryo" being the prefix for "cold."

Cryo-electron microscopy revolution

By 1990, Henderson was able to capture a far more detailed model of bacteriorhodopsin — the same protein in his original image — using cryo-electron microscopy.

The new image (right) was taken at true atomic resolution. And because of the techniques developed by Frank and Dubochet, it was possible to capture models like this of any sort of biomolecule, not only those protected by membranes.

The technique would get still more sophisticated, however.

New electron detectors and microscope technology eventually revealed far more than the uneven surface of a protein, including details of the atomic structure of the molecules. The difference is evident in the image below.

Now researchers turn to this technology immediately when they want to understand anything biological. For example, when researchers first noticed that something was causing microcephaly in newborn children, they found and imaged the Zika virus and its proteins to see if they could get a better sense of what was happening.

Creating these images helps researchers identify which components of the virus might be causing the negative effects — and that can allow them to develop ways to block those troublesome parts.

The ability to do all this fundamentally transforms biochemistry, medicine, and our understanding of biology.

As the Swedish Academy wrote in their announcement of the Nobel Prize winners:

"After Joachim Frank presented the strategy for his general image processing method in 1975, a researcher wrote: 'If such methods were to be perfected, then, in the words of one scientist, the sky would be the limit.'

Now we are there – the sky is the limit. Jacques Dubochet, Joachim Frank and Richard Henderson have, through their research, brought 'the greatest benefit to mankind.' Each corner of the cell can be captured in atomic detail and biochemistry is all set for an exciting future."

SEE ALSO: 3 scientists just won the Nobel Prize for discovering how body clocks are regulated — here's why that's such a big deal

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Onions are a staple of many dishes, but we use it at a cost. When chopping them up, many of us feel our eyes start to sting, then we start crying.

There are plenty of old wives' tales about how to stop the tears, from putting a piece of bread under your nose, to only using fresh onions. But what is it about onions that makes us react this way?

According to an article in The Conversation, all vegetables release chemicals called polyphenols when they are damaged and their cells are ripped open. It's a way of the plant defending itself from hungry animals and pests.

Onions have a particularly irritating chemical called propanthial s-oxide, which is very volatile. This means it quickly evaporates when it's released, and makes its way into our eyes.

In your eyes, the chemical mixes with water to create sulphenic acid, which irritates the tear glands. It's only a tiny amount of acid produced, so it's not harmful, but it's enough to make us cry.

There is some debate about why onions have this special power. It could be because there are higher levels of sulphur in the soil onions grow in.

The Conversation article says sweeter onions tend to have less of the compounds that produce the chemicals, but really there's no way to tell if an onion will make you cry until you cut into it.

If you're particularly affected by the onion's chemicals, you could try buying some goggles, boiling the onions before cutting them — although this isn't advisable — or just get someone who isn't so easily affected to cut them up for you.

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Gallium is a silvery metal and element number 31 on the Periodic Table, and it melts at 85.6 degrees Fahrenheit. That's a temperature low enough for gallium to melt in your hand — and unlike the liquid metal mercury, gallium is safe to play with, according to chemists.

SEE ALSO: This new Periodic Table shows the astounding origins of every atom in your body

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Americans take their coffee many ways: hot, poured over ice, cold-brewed overnight, and even infused with nitrogen.

Crushing an egg (shell and all), whisking it with freshly ground coffee, and boiling the mixture sounds gross. The result looks terrifying, too — like a hideous swamp creature gurgling in your pot.

However, the umber-red-colored drink that results, called "egg coffee," is almost free of bitter tannins and packs an extra-strong dose of caffeine.

I first heard about egg coffee from an article by Joy Summers at Eater, which explains how the US recipe came to Minnesota via Scandinavian immigrants. The goal? Turn weak, subpar coffee and hard water into a beverage greater than the sum of its parts.

New York City has great tap water, and you can find high-quality beans pretty much anywhere nowadays. But with the weather cooling and my curiosity piqued, I decided to try brewing my own egg coffee.

Here's how I made it and what I learned during the process.

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I don't have a stove-top coffee pot, which is ideal — though this one-quart pot did the trick. And while recipes for egg coffee vary wildly, hot water is a must. I put two cups on to boil.

Also required: coffee! Run-of-the-mill canned varieties reportedly work wonders, but I used my favorite premium whole-bean roast, since that's all I had on hand.

Source: Eater

One egg coffee recipe I saw called for 20 grams of ground beans, which is enough for two standard cups. So I measured it out...

Sources: Home Grounds, Black Bear Coffee

There's no fighting it; each of us will die at some point. What happens next is a fascinating — if frightening — natural process.

Without preservation techniques like embalming or mummification, your body slowly begins to decay the second your heart stops beating.

It starts small, down at the cellular level. Your cells die, then bacteria, animals, and even the body itself digests your organs and tissues.

Here's how the complete, gruesome process plays out:

Sources: Nature, Journal of Criminal Law and Criminology, Microbiology Today, EPEC Participant’s Handbook, BMJ, Australian Museum, Decomposition of Human Remains

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Why shouldn't you eat raw eggs? The risk of salmonella infection isn't the only problem. You're also robbing yourself of protein.

One egg contains about 6 grams of protein. In their natural state, these proteins are locked into a tight ball. Our bodies have a hard time absorbing protein in this shape.

When you cook the egg, the proteins unfold and combine with one another. This process turns the transparent part of the egg white.

It also makes the proteins easier to absorb. One study found that patients who ate egg protein absorbed 50$ of the protein in its raw form and absorbed 91$ when the proteins were cooked.

Plus, eggs contain all 9 essential amino acids that keep us healthy. But those nutrients are locked in the egg's proteins. So whether you prefer fried, scrambled, or hard boiled, do your body a favor and heat that egg up.

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• Water — the biggest ingredient in coffee by weight — can make or break the flavor of a freshly brewed cup, according to a chemist-barista research team.
• Tap water brings out better flavor in coffee, though there are trade-offs between hard and soft water.
• Some beans are better suited to being brewed in hard or soft water.

Making a truly great cup of coffee requires great beans, an expert roaster, the right grind, and proper technique.

But an often-overlooked element of brewing coffee at home is what constitutes perhaps 99% of the delicious drink's weight: Water.

To craft the tastiest cup o' joe, you shouldn't buy jugs of distilled or "pure" water, or spend money on expensive water-filtration devices.

In fact, in most parts of the country, the stuff out of our taps is probably the best kind of coffee-brewing H2O you could hope for.

In search of a better brew

Christopher H. Hendon, a chemist at MIT, discovered the importance of water in coffee after overhearing a conversation between two frustrated baristas.

"They were having problems with coffee that tasted good one day and not another," Hendon previously told Business Insider. While that's a frustrating mystery for a coffee shop with exacting standards, but "from a chemistry point of view, that's an interesting problem," Hendon said.

Water can be "hard" (full of minerals like magnesium) or "soft" (most distilled water falls into this category).

Below is a map of the US that shows how water hardness varies from place to place. Dark-purple areas show where the softest water flows, red shows the hardest water, and white and blue are somewhere in between. Hardness can also vary over seasons, as the dissolved minerals can be diluted by a flood of spring rain or amplified by road salts and melting snow.

Hendon teamed up with baristas Lesley and Maxcell Colonna-Dashwood — who won the 2015 UK Barista Championship — and they found that different kinds of "hardness" in water bring out significantly different flavors in coffee. (Hendon ran the experiments using a computer, while the coffee shop owners actually brewed sample cups.)

Why water hardness matters so much for brewing coffee

Roasted coffee beans are packed with compounds that give coffee is distinct aroma, mouthfeel, and taste. Those include citric acid, lactic acid, and eugenol (a compound that adds a "woodsy" taste). The amounts vary from one roasted batch of beans to the next, giving you an enjoyably different sensory experience each time.

Water, meanwhile, has a complexity all its own — higher levels of ions like magnesium and calcium make it "harder."

Here's the key: Some of the compounds in hard water are "sticky" and preferentially grab certain compounds in coffee when they meet in your brewing device. The more eugenol the water hangs on to, for example, the woodsier the taste of your coffee will be.

Magnesium is particularly sticky, so water that's high in magnesium will make coffee with a stronger flavor (and higher levels of caffeine). Hard water can also have high levels of bicarbonate, which Hendon found could lead to more bitter flavors coming through.

But while hard water is a bit of a gamble, depending on which minerals are present in higher concentrations, soft water seems to have no benefits at all. Its chemical composition "results in very bad extraction power," Hendon explained.

Soft water often contains sodium, but that has no flavor stickiness (for good or bad flavors), Hendon found. That means that you'll get a much stronger flavor from the same beans if you use high-magnesium "hard water" in place of distilled or softened water.

Hendon and his barista colleagues published their research in the Journal of Agricultural and Food Chemistry, and eventually wrote a book, "Water for Coffee," that explains why lovers of the drink should worry about more than just beans.

"Water can transform the character of a coffee," the team wrote. An updated second edition of the book hits shelves in early 2018, according to its website.

A chemically perfect cup

Unlike Hendon, the average coffee lover is not a chemist. You can't easily alter the composition of your water supply every time you want a delicious cup.

But you don't have to. Understanding that the kind of water you use matters will help you achieve the perfect brew — even if you're stuck with whatever comes out of your tap.

To start, you can look up the hardness of your water online (New Yorkers can call 311), and use that information to buy beans that are meant for "soft" or "hard" water. Hendon said that's the kind of thing upscale roasters will know.

Sure, you won't know the specific compounds in your water — that's the kind of rigorous coffee science Hendon and Colonna-Dashwood relied on to place fifth overall in the World Barista Championship. But you'll already be a step ahead if you buy from a local roaster.

When roasters test their beans, they do so using local water, so you can at least assume that locally-roasted coffee is optimized for the chemistry of your water. That's the opposite of a large chain like Starbucks, which, according to Hendon, uses totally pure water to ensure a completely uniform taste across the country.

"A lot of dark art has gone into coffee," Hendon said. "This is some real science."

Lauren Friedman wrote a previous version of this post.

SEE ALSO: Crushing an egg into your coffee sounds disgusting — but it makes an amazing-tasting drink

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NOW WATCH: How the winner of this year’s top barista championship used science to crush the competition

• Guinness cans and bottles fizz and bubble when you open them.
• Plastic devices called widgets blast the stout beer with nitrogen gas to give it a creamy head.
• In cans, widgets are spherical; in bottles, they're shaped like rockets.

Tomorrow is St. Patrick's Day, which means hordes of green-clad booze hounds will be flocking to neighborhood bars and house parties to pound some cold ones.

And what beer is more quintessentially "Irish" than a Guinness?

If you're celebrating with a bottle or a can of this Irish dry stout, you may notice the clink-clank of a tiny object rattling around the inside.

That little gadget is called a "widget," and you should be thankful for it. It's making your beer taste like it was just poured fresh from the tap.

Here's how.

What Guinness widgets look like, how they work

In cans of Guinness, the widget is a hollow, spherical piece of plastic with a tiny hole in it. As you can see in this photo (right), it looks like a little ping pong ball.

In bottles with widgets, the device looks more like a three-inch-long rocket (pictured below).

During the canning process, brewers add pressurized nitrogen to the brew, which trickles into the hole along with a little bit of beer. The entire can is then pressurized.

When you open the can, the pressure inside drops to equalize with the pressure in the room. But the pressure inside the widget is still much higher than the pressure in the beer around it, since the gas can escape only through a tiny hole. That makes the nitrogen inside the widget squirt into the beer like a jet. This blast creates a burst of tiny nitrogen bubbles that rise to the top of beer, giving it a thick, creamy head like the one you'd get from a tap.

Guinness brewers first patented the idea of the widget in 1969, but it wasn't until 20 years later that they released their first-generation widget, which was a flattened sphere that sat at the bottom of the can.

This little piece of plastic did its job well when serving the beer cold, but when served warm, the beer exploded everywhere after the can was cracked open.

So in 1997, Guinness released the floating, spherical widget you can see in cans today — which they call the "Smoothifier"— to fix this problem.

Why nitrogen and not carbon dioxide?

Breweries typically use carbon dioxide to give a beer its quintessential bitter fizz, but a drink like Guinness calls for a sweeter, silkier experience.

So brewmasters infuse the ale with nitrogen rather than with carbon dioxide, since nitrogen bubbles are smaller than CO₂ bubbles. The resulting head and taste is smoother and more delicate.

Nitrogen gas also doesn't easily dissolve in water, so when you crack open a beer, most of the gas is released into the air, but the foamy bubbles in the head still remain. This — along with the smaller bubbles — gives the brew a thicker, more velvety "mouthfeel" without the acidic bite of carbonation with CO₂.

Because of the fleeting nature of nitrogen gas in liquid, it's hard to maintain tasty levels of the gas in packaged beers once you open them.

"With nitrogen, you would require way higher (and dangerous) levels of pressure, and still loose plenty of nitrogen (and beer due to foaming) during packaging," Xavier Jirau, scientific advisor of the homebrew club The Brewminaries, previously told Tech Insider via email. "In order to deal with this issue, brewers got little creative, and there is where Guinness plastic widgets come into play."

The popularity of widgets have caught on since Guinness introduced them in the late 80s. Other beers such as Old Speckled Hen, Young's Double Chocolate Stout, Murphy's Stout, and Boddingtons Pub Ale all have widgets in their cans.

So go crack a cold one on this glorious day, and thank that little plastic sphere for delivering your delicious, velvety brew.

This story was updated with new information. It was originally published on March 17, 2018, at 10:58 a.m. ET.

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NOW WATCH: Is draft beer better than bottled beer?

People often have strong opinions about how they drink their soda. Some people prefer it in a can, others prefer a glass or plastic bottle. While soda companies claim that the recipe doesn't change, there are a few factors that might affect the way you taste a soda depending on the container. Following is a transcript of the video.

Narrator: People have strong opinions about soda containers.

Cans are significantly better than bottles.

I think bottled probably tastes the best to me.

A can keeps it colder.

I prefer a glass bottled soda.

Narrator: But does the container really affect the flavor? Soda companies claim to use the same proportion of ingredients. A company spokesperson for Coca-Cola told us that Coca-Cola uses the same recipe regardless of the package type, and that it's best enjoyed ice cold. But there are a few factors that could still affect the way you taste it.

First, let's take a look at the ingredients in the containers. Glass bottles are pretty basic and contain no other chemical ingredients besides the glass, so there's nothing in it that could really change the taste.

Cans are typically aluminum, lined on the inside with a polymer that can contain BPA or Bishphenol A.

Rick Sachleben, a retired chemist with the American Chemical Society, says this has little effect on the taste. -

Rick Sachleben: The amount of that material that would get into the contents of a container are so low I don't think it would have any effect on the flavor.

Narrator: This lining protects the taste of the soda and keeps it from being contaminated by the metal.

Sachleben: The likelihood of having a break in that lacquer coating, that plastic coating, and exposing the contents to the metal are pretty, pretty low. 

Narrator: Despite protective lining, some people still think there's a metal taste. 

I actually think it tastes like can.

Sometimes cans can taste a little bit metallic.

Narrator: So where is this sensation coming from?

Sachleben: Your tongue is very sensitive to metal. The one time when the product is exposed to the metal itself is when the can's opened. You put your tongue on a metal can it's entirely possible, especially people who are sensitive to it, there would be just enough to come off to change the way things tasted on their tongue.

Narrator: Plastic bottles are typically made with PET, or Polyethylene terephthalate. While both cans and plastic bottles contain chemicals you probably wouldn't want to consume in large quantities, they are perfectly safe to drink out of.

Sachleben: All containers that they use, glass, plastic, metal, have been extensively tested for what will leech into the liquid that's put in them. 

Narrator: The FDA also regulates the amount of contaminants allowed in drinks to make sure they're safe. But humans have been known to detect even minute amounts of contaminants according to Christy Spackman, a researcher at Harvey Mudd College, who studies taste.

Christy Spackman: Here too to remember that zero is not always zero. People can detect certain things at levels well below instrumental detection; it depends on the molecule and it depends on the human. -

Narrator: So while unlikely, it's possible that even the slightest bit of contamination might affect the taste for some. Now let's take a look at carbonation. Humans taste carbonation using the same taste receptors that recognize sour foods according to a 2009 study by Science Magazine, and we can also detect carbonation from soda in another way.

Sachleben: When you drink it you get two things going on: one is you get that tingly thing from the bubbles, but you also get that carbon dioxide going up in your nose; it carries the other flavors into your nose as well.

Narrator: So carbonation levels can affect the taste, but how can the CO2 levels change based on the packaging?

Spackman: So carbonation can slowly, potentially, leak out of a plastic bottle in a way it can't leak out of a glass bottle. That's assuming they've both been appropriately filled.

Sachleben: The structure of the glass is pretty tight, okay? It's like a really tight mesh rather than a loose mesh. The diffusion rates through glass are really, really slow. And in metal it's the same thing. 

Narrator: But most bottles are typically designed to prevent CO2 from escaping quickly.

Sachleben: A plastic bottle is a multilayered thing: Some of them provide rigidity, some of them provide a barrier to the oxygen going in and the CO2 coming out, and then there's a final barrier that just protects the contents.

Narrator: And if the container is warm more CO2 will be released when you open it making the soda taste flat.

Spackman: Light can also affect flavor, assuming the bottle does not contain any light protective layers. -

Narrator: Light can cause chemical reactions to occur, and some of the substances in there may change some of the flavor compounds.

Sachleben: A lot of the flavor compounds are really subtle molecules; they're the sort of things that can really a little change can change their flavor a lot.

Narrator: So how a soda is stored can prevent any rapid alteration in taste.

Spackman: So something that's bottled in glass and stored away from light is going to have a flavor profile that can last much longer, and also carbonation levels that will stay consistent much longer, than something in plastic.

Narrator: But there's also more to taste than what happens on a molecular level. Spackman says experience can also affect the way we taste. People who drink Diet Coke a lot, every day for example, might be able to tell a difference more than someone else.

Spackman: So they have a sensory awareness just because their memory is so constantly being refreshed about what sensory experience is like.

Sachleben: It's really hard to separate the objective and subjective sides to taste. What we can taste sometimes is as much affected by what we expect as what's actually there. 

Narrator: So soda drinkers aren't likely to change their habits any time soon.

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• Enceladus, an ice-encrusted moon of Saturn, hides an ocean of saltwater that blasts ice into space.
• NASA flew its Cassini spacecraft through the ice geysers in 2015.
• Scientists continue to analyze the data, and on Wednesday a group announced that it had detected complex organic molecules.
• Though not definitive proof of alien life, the molecules are a good sign for the habitability of Enceladus. 

Two years before NASA destroyed its Cassini spacecraft in the clouds of Saturn, the space agency flew the robot through geysers of ice blasting out of the planet's moon Enceladus.

The plumes come from a giant saltwater ocean hidden beneath the moon's icy crust. The water seeps through cracks at Enceladus' south pole, where it boils into the vacuum of space and forms 300-mile-tall curtains of ice particles.

Ever since Cassini's nuclear-powered geyser-dive in October 2015, scientists have pored over the probe's trove of data. They've found all sorts of eyebrow-raising chemicals, including small organic (carbon-containing) molecules such as acetylene, formaldehyde, methane, and propane.

But this week, researchers announced the detection of long, messy strings of organic molecules that could be indicative of water that's habitable to life — or perhaps something even more exciting.

"We cannot decide whether the origin of this complex material is biotic or not, but there is astrobiological potential," Nozair Khawaja, a researcher at Heidelberg University, told Gizmodo.

Translation: The chemicals might be signs of microbial aliens, though it's too soon to say.

Khawaja and 20 other space scientists published a study in the journal Nature on Wednesday about their discovery of the organic molecules, which they call macromolecular compounds.

"The discovery of macromolecular compounds originating from a moderately warm water environment will fuel interest worldwide in such icy moons as possible habitats for extraterrestrial life," Mario Trieloff, another author of the study, said in a press release.

How Enceladus might brew complex organic muck

Life as we know it is carbon-based. The element makes it possible to store and copy genetic information, is essential to building proteins, and helps store and shuttle energy. Liquid water is an essential ingredient too — so when scientists find the two together in space, the stakes become interesting.

A warm, salty ocean with organic molecules is no guarantee of alien life, of course. Some oceans, such as the one under Pluto's icy crust, are most likely deadly to us. But researchers keep finding more evidence that Enceladus' environment is conducive to life, rather than dangerous.

Recent studies using Cassini's water-spray data suggest hydrogen is bubbling up from the moon's ocean bottom, possibly from structures called hydrothermal vents. Khawaja said in the press release that gas bubbles that most likely hail from Enceladus' seafloor "probably transport the molecules to the surface, where they form an organic film."

He added that the bubbles are hydrophobic, or water-repelling, which is why they form a film on top of the water as opposed to dissolving.

"From there," he said, the film "is launched into space together with ocean water droplets."

Hydrothermal vents can generate hydrogen gas. They litter Earth's seafloor near volcanically active regions, spewing nutrient-rich hot water that may make them bastions of life. In fact, scientists last year announced the discovery of what may be 3.77- to 4.28-billion-year-old fossils that originated at hydrothermal vents on Earth.

But the new study in Nature is far from definitive proof of organic alien goop.

Water is being pulled toward Enceladus' core and heated up under pressure, so it's possible that carbon that's been present in Enceladus since its formation (every world contains a little) is reacting with minerals to form more complex molecules. Ancient asteroids that drift through space also harbor complex organic molecules but are almost certainly devoid of life.

Cassini's instruments weren't designed to analyze organic molecules for alien or non-alien origins, and the spacecraft is now gone.

It may be decades before we find out for sure. There's no funded mission to return to Enceladus, and Saturn's increasingly famous moon is roughly 890 million miles away, so it can take nearly seven years to get a probe there.

Seeking signs of life at Europa

Those hoping to find signs of alien life shouldn't despair, though.

Both NASA and the European Space Agency are planning to send spacecraft to Jupiter's moon Europa. That ice-covered world has an even larger subsurface ocean, is spraying water, and might also be rich with a soup of organic molecules that alien microbes could feed on or generate.

The ESA's probe, called the Jupiter Icy Moons Explorer, is scheduled to launch in 2022 and reach Jupiter in 2030. The mission calls for two flybys of Europa from about 200 miles away.

The other mission is NASA's roughly $2 billion Europa Clipper probe, which may launch sometime between 2022 and 2025 and arrive about five years later.

The Europa Clipper is expected to make 47 flybys and come within 20 miles of Europa's surface. That would give the probe unprecedented access to water plumes and the ability to sample the water for salts, organic compounds, and other chemicals.

"The instruments are designed with Europa's plumes in mind, allowing us to infer the ocean's composition and thus its suitability for life, and even to look for direct chemical signs of extant life," Steve Vance, a planetary scientist at NASA's Jet Propulsion Laboratory, previously told Business Insider.

Bob Pappalardo, another JPL scientist, also previously told Business Insider that oceans on moons like Europa may be the most common habitats for life that exist in the universe.

"If there's life at Europa, it'd almost certainly be an independently evolved form of life," Pappalardo said. "Would it use DNA or RNA? Would it use the same chemistry to store and use energy? Discovering extraterrestrial life would revolutionize our understanding of biology."

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NOW WATCH: NASA just discovered the first food source for potential aliens

• The fireworks you enjoy every 4th of July are the result of a chain of chemical reactions.
• When a firework container is lit, its contents of colored explosives called "stars" light up the sky.
• The colors that sparkle in the sky are chemical reactions happening right before your eyes.

The spectacle of a fireworks display may leave you wondering what it took to get that color-changing, dazzling sequence into the sky.

We're here to help.

Fireworks are the result of a whole bunch of chemical reactions. And it all leads to an explosion. 

Simply, a firework is a container — typically a tube or ball shape — that holds explosives hitched up to a time-delay fuse.

There are two explosive parts in a firework — the one that shoots it into the sky, and a set of little balls of explosives called "stars." These stars are filled with colors that blaze brightly in the sky, but after only a certain amount of time has passed. This is why fireworks can get up high in the sky before exploding into brilliance.

When the fuse gets low enough in the firework, it reacts with a bursting charge, which in turn lights the explosive that will disperse the stars. The ignited explosive creates a high-pressure gas that blows the colorful stars outward. Afterward, the cardboard that enclosed the explosives rains to the ground as charred remains. 

Here's what that looks like:

Chemical reactions create the colors

The colors that sparkle in the sky are chemical reactions happening right before your eyes.

Inside every star is an oxidizing agent, fuel, a metal that acts as the color, and a binder that holds it all together. The fuel and oxidizing agent are the parts responsible for the intense heat and gas of the explosion, according to the American Chemical Society.

But the coolest part is the metals that act as the colors. The heat makes the atoms inside the wire move faster and faster, causing the atoms to bump into each other more, which gives off light. If you can control the temperature of the firework, then you can pick the exact time you want that firework to be a certain color.

Some fireworks heat up and cycle through red, orange, yellow, and white, depending on how hot the explosion is. But more commonly, fireworks create light by letting off specific colors that depend on which metals are in the mix.

For a complete display, fireworks often mix different metals and metal salts for vibrant, multicolored effects. Calcium salts will burn orange, while sodium salts will burn yellow. If you burn copper, it'll give off light that's blue-green.

The science behind fireworks' shapes and sounds

Fascinated by that smiley face or oddly lopsided heart in a firework display? It's nothing more than some careful organization of the stars. If they're just spread randomly, they'll expand out evenly through the sky once they explode.

But, because the explosion will push the stars out in a predictable trajectory, it is possible to organize the stars in a pattern on the cardboard cylinder on the outside of the firework. This will create specific shapes.

And of course, no fireworks display would be complete without the ear-shattering booms that freak out dogs and resonate in our chests. Those noises are caused by a sonic boom that happens as the gases inside the firework expand faster than the speed of sound.

In the end you get one bright, loud, beautiful way to celebrate the Fourth of July. 

Jennifer Welsh and Mike Nudelman contributed to earlier versions of this article.

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NOW WATCH: This artist makes paintings with firecracker explosions

It may be Independence Day, but there's nothing revolutionary about the way your 4th of July fireworks are made.

Fireworks have been built from a mix of explosive powder, chemicals, and glue for ages. The earliest fireworks shows date back more than a thousand years. 

But not all fireworks are built the same. You can't get a bright red firework to light up with the same elements inside as a blue or white one. That's because the color of a firework explosion depends on what kinds of elements are inside, from common metals to rarer minerals and even some salts.

Pyrotechnicians call these bursts of colored light "stars," and they're made of a mixture of fuel, oxidizer (to help fuel burn), color-producing elements (like aluminum or copper), and a binder (glue) packed inside a shell. That all gets fired high into the air before a time-delayed fuse spits fire onto the stars and they take off. 

California-based pyrotechnician and electrical engineer Mike Tockstein, who's prepping the Los Angeles Coliseum for a 4th of July show, told Business Insider that it takes days of pounding, digging, wiring, and "well over 10,000 pounds of equipment" to set up.

Before you peer up into the sky this Independence Day, take a look at some of the common elements that are making your celebration possible. 

SEE ALSO: A big solar storm could wreak havoc on GPS and everything else on your phone

Yellow fireworks are made from an element you might associate with the color white: Sodium.

You may think sodium belongs in your salt shaker. But burning-hot sodium produces a bright yellow explosion that's perfect for lighting up the sky.

Red fireworks come from a common element called strontium.

Strontium was used in the glass screens of a lot of old color TV sets, because it helped block x-rays from hitting us. The element has a yellowish color, but it burns red hot.

Green fireworks are a result of barium salts exploding in the sky.

Most green fireworks are made from barium nitrate, which is toxic to inhale, so it's not used for much else, though it can be an ingredient in grenades.