Carbon Chemist

Author: chemistadmin

  • Chemists turned plastic waste into tiny bars of soap

    Chemists turned plastic waste into tiny bars of soap

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    The time may be coming to wash our hands of plastic trash. Literally.

    About 60 percent of all plastic ever made ends up in landfills or littering the environment. Only about one-tenth of plastic waste is ever recycled, and much of that ends up being low-quality material reused in things like park benches (SN: 1/27/21). So chemists are searching for ways to “upcycle” plastic into more valuable raw materials.

    Now, there’s a way to turn old plastic into surfactants, researchers report in the Aug. 10 Science. Surfactants make up the key ingredients in dozens of products like lubricants, ski wax, detergents and soap.

    “To me, plastic waste basically [is] aboveground crude oil,” says chemist Guoliang Liu of Virginia Tech in Blacksburg. “We don’t have to go deep into the ocean or underground to mine [it] anymore” to make valuable chemicals. 

    Surfactants and the two most used kinds of plastic, polyethylene and polypropylene, are made of molecular chains of carbon atoms. But surfactants’ chains are far shorter than those of plastics and are capped with groups of water-attracting atoms.

    To turn plastic into surfactants, Liu and colleagues developed a special reactor that carefully heats and condenses plastic into a wax with short carbon chains. By capping the wax’s chains with groups of oxygen atoms and treating them with an alkaline solution, the researchers turned the wax into surfactant. Combining the surfactant with a bit of dye and fragrance produced tiny bars of soap.

    Still, upcycled plastic probably won’t be washing away messes any time soon. The researchers can make only about half a gram of surfactant at a time. If Liu and his team can figure out a way to scale up the process, they hope to partner with industry to make plastic waste a bit cleaner.

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  • Magnetic ‘rusty’ nanoparticles pull estrogen out of water

    Magnetic ‘rusty’ nanoparticles pull estrogen out of water

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    A new “smart rust” could one day help pull pollutants out of waterways, leaving cleaner water behind.

    Researchers adorned tiny particles of iron oxide, better known as rust, with “sticky” molecules that grab on to estrogen and similar hormones in water samples. A magnet can then remove both the particles and the trapped pollutants from the water, materials scientist Lukas Müller reports August 16 in San Francisco at a meeting of the American Chemical Society.

    The new technology could potentially limit excess estrogen’s harmful effects on animals, especially those that live in waterways.

    With the nanoparticles, “we are able … to clean very different kinds of environmental pollutants,” says Müller, of Friedrich-Alexander-Universität Erlangen-Nürnberg in Germany.

    Estrogen hormones typically enter waterways through humans’ and other animals’ waste (SN: 1/2/02). Even low concentrations can have harmful chronic effects on aquatic life, like higher instances of cancer or reproductive issues, says Konrad Wojnarowski, a biologist at Ludwig-Maximilians-Universität München who was not involved in the study. Wastewater treatment plants can remove some estrogen hormones, he says, but the process isn’t cheap or energy efficient.

    For now, “we still don’t have an ideal way of dealing with estrogen pollution in the environment,” but nanoparticles could help, Wojnarowski says.

    To build the estrogen-catching particles, Müller and Marcus Halik, a chemist also at Friedrich-Alexander-Universität, drew on prior experience designing iron oxide nanoparticles that can catch other kinds of pollutants like oil or herbicides (SN: 7/25/08). The tiny iron oxide cores are each about 10 nanometers in diameter. Each core is then covered in phosphonic acid molecules, which act like sticky hairs that scoop up contaminants.

    The new version of the nanoparticles specifically targets estrogen by including two types of phosphonic acid. One kind is long, repels water and attaches to the neutrally charged part of the estrogen molecule. The other is positively charged to attract parts of estrogen hormones that carry a slight negative charge.

    The smart rust removed much of the estrogen from small water samples prepared in the lab, the researchers found. Their next step is to test the nanoparticles on samples from actual waterways.

    And the team is investigating exactly how the molecules on the nanoparticle surfaces grab and hold on to estrogen at the atomic scale. With this information, Halik says, they can improve the estrogen binding even more.


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  • Climate change: Inside the expedition to find out how humans can adapt to extreme heat

    Climate change: Inside the expedition to find out how humans can adapt to extreme heat

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    Saudi Arabian desert extreme heat experiment

    TRUDGING through hot, red sand is hard work, especially in temperatures above 40°C (104°F). After about 40 minutes, I am drenched, dehydrated and drained. I can’t imagine doing this for 40 days, dragging all my gear behind me – including 40 litres of water, enough for five days – on a two-wheeled trolley. But that is exactly what the people I am travelling with have just done.

    I am in the Nafud desert, a vast tract of sandy and rocky wilderness in northern Saudi Arabia, to experience levels of heat that I am not built to endure – and to meet 20 people participating in an expedition called Deep Climate, dedicated to understanding how humans respond to extreme conditions. “The idea is to study how human beings can adapt to a new kind of environment,” says Christian Clot, the leader of the expedition and director of the Human Adaptation Institute in France.

    As the climate warms, the issue is becoming increasingly pressing. Even under the most optimistic scenarios, the scorching heat seen in southern Europe and across the US over the past couple of months, with temperatures exceeding 40°C, will become the norm in many parts of the world.

    That means the question of what happens to our brains and bodies, and the extent to which human physiology can cope with extreme heat, matters for millions of people. “You’re going to see a great big swathe of very densely populated areas go up to unprecedented temperatures that nobody experienced in the historical climate,” says Tim Lenton at the University of Exeter, UK, who recently co-authored a research paper called “…

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  • High-tech solar ‘leaves’ create green fuels from the sun

    High-tech solar ‘leaves’ create green fuels from the sun

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    acetate: (also called acetic acid) A short-chained fatty acid that is a common byproduct of fiber fermentation in the gut. Acetate appears to play a role in preventing obesity.

    atom: The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

    bacteria: (adj: bacterial) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals). Bacteria are one of the three domains of life on Earth.

    bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.

    carbon dioxide: (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter burns (including fossil fuels like oil or gas). Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

    catalyst: (v. catalyze) A substance that helps a chemical reaction to proceed faster. Examples include enzymes and elements such as platinum and iridium.

    cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall.

    chlorophyll: Any of several green pigments found in plants that perform photosynthesis — creating sugars (foods) from carbon dioxide and water.

    climate change: Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

    electron: A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.

    engine: A machine designed to convert energy into useful mechanical motion. Sometimes an engine is called a motor. (in computer science) A computer program that performs a particular, narrow range of functions.

    ethanol: A type of alcohol, also known as ethyl alcohol, that serves as the basis of alcoholic drinks, such as beer, wine and distilled spirits. It also is used as a solvent and as a fuel (often mixed with gasoline, for instance).

    fabric: Any flexible material that is woven, knitted or can be fused into a sheet by heat.

    fatty acid: A large molecule made of up chains of carbon and hydrogen atoms linked together. Fatty acids are chemical building blocks of fats in foods and the body.

    fertilizer: Nitrogen, phosphorus and other plant nutrients added to soil, water or foliage to boost crop growth or to replenish nutrients that were lost earlier as they were used by plant roots or leaves.

    fuel: Any material that will release energy during a controlled chemical or nuclear reaction. Fossil fuels (coal, natural gas and petroleum) are a common type that liberate their energy through chemical reactions that take place when heated (usually to the point of burning).

    function: The specific role some structure or device plays.

    hydrogen: The lightest element in the universe. As a gas, it is colorless, odorless and highly flammable. It’s an integral part of many fuels, fats and chemicals that make up living tissues. It’s made of a single proton (which serves as its nucleus) orbited by a single electron.

    mineral: Crystal-forming substances that make up rock, such as quartz, apatite or various carbonates. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in regular three-dimensional patterns).

    molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

    oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).

    photosynthesis: (verb: photosynthesize) The process by which green plants and some other organisms use sunlight to produce foods from carbon dioxide and water.

    pigment: A material, like the natural colorings in skin, that alter the light reflected off of an object or transmitted through it. The overall color of a pigment typically depends on which wavelengths of visible light it absorbs and which ones it reflects. For example, a red pigment tends to reflect red wavelengths of light very well and typically absorbs other colors. Pigment also is the term for chemicals that manufacturers use to tint paint.

    plastic: Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation. (adj.) A material that is able to adapt by changing shape or possibly even changing its function.

    protein: A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Antibodies, hemoglobin and enzymes are all examples of proteins. Medicines frequently work by latching onto proteins.

    proton: A subatomic particle that is one of the basic building blocks of the atoms that make up matter. Protons belong to the family of particles known as hadrons.

    short circuit: A low-resistance connection between two electrically conducting materials that unintentionally create a circuit. The condition causes the flow of an excessive current and may produce very high temperatures. It can potentially cause parts of the circuit to be destroyed (even explode).

    solar: Having to do with the sun or the radiation it emits. It comes from sol, Latin for sun.

    sun: The star at the center of Earth’s solar system. It is about 27,000 light-years from the center of the Milky Way galaxy. Also a term for any sunlike star.

    synthetic: An adjective that describes something that did not arise naturally, but was instead created by people. Many synthetic materials have been developed to stand in for natural materials, such as synthetic rubber, synthetic diamond or a synthetic hormone. Some may even have a chemical makeup and structure identical to the original.

    system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.

    technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

    toxic: Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.

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  • Scientists Say: Valence electrons

    Scientists Say: Valence electrons

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    atom: The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

    bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.

    chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

    chlorine: A chemical element with the scientific symbol Cl. It is sometimes used to kill germs in water. Compounds that contain chlorine are called chlorides.

    electron: A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.

    element: A building block of some larger structure. (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.

    neutron: A subatomic particle carrying no electric charge that is one of the basic pieces of matter. Neutrons belong to the family of particles known as hadrons.

    nucleus: Plural is nuclei. (in biology) A dense structure present in many cells. Typically a single rounded structure encased within a membrane, the nucleus contains the genetic information. (in astronomy) The rocky body of a comet, sometimes carrying a jacket of ice or frozen gases. (in physics) The central core of an atom, containing most of its mass.

    particle: A minute amount of something.

    proton: A subatomic particle that is one of the basic building blocks of the atoms that make up matter. Protons belong to the family of particles known as hadrons.

    salt: A compound made by combining an acid with a base (in a reaction that also creates water). The ocean contains many different salts — collectively called “sea salt.” Common table salt is a made of sodium and chlorine.

    sodium: A soft, silvery metallic element that will interact explosively when added to water. It is also a basic building block of table salt (a molecule of which consists of one atom of sodium and one atom of chlorine: NaCl). It is also found in sea salt.

    technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

    valence: (in chemistry and physics) The electrons of an atom that are involved in chemical bonding. Valence electrons usually are the outermost electrons (those orbiting farthest from the nucleus).

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  • Climate change: Something strange is happening in the Pacific and we must find out why

    Climate change: Something strange is happening in the Pacific and we must find out why

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    New Scientist Default Image

    The Pacific “cold tongue”, an area of ocean that stretches West from Ecuador is cooler than expected

    Harvepino/shutterstock

    FOR years, climate models have predicted that as greenhouse gas emissions rise, ocean waters will warm. For the most part, they have been correct. Yet in a patch of the Pacific Ocean, the opposite is happening. Stretching west from the coast of Ecuador for thousands of kilometres lies a tentacle of water that has been cooling for the past 30 years. Why is this swathe of the eastern Pacific defying our predictions? Welcome to the mystery of the cold tongue.

    This isn’t just an academic puzzle. Pedro DiNezio at the University of Colorado Boulder calls it “the most important unanswered question in climate science”. The trouble is that not knowing why this cooling is happening means we also don’t know when it will stop, or whether it will suddenly flip over into warming. This has global implications. The future of the cold tongue could determine whether California is gripped by permanent drought or Australia by ever-deadlier wildfires. It influences the intensity of monsoon season in India and the chances of famine in the Horn of Africa. It could even alter the extent of climate change globally by tweaking how sensitive Earth’s atmosphere is to rising greenhouse gas emissions.

    Given all this, it isn’t surprising that climate scientists are trying to find out what is going on with increasing urgency. Like any good mystery, this is a tale of intrigue, confusion and competing theories. We haven’t quite…

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  • A single particle of light can kick off photosynthesis

    A single particle of light can kick off photosynthesis

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    algae: Single-celled organisms, once considered plants (they aren’t). As aquatic organisms, they grow in water. Like green plants, they depend on sunlight to make their food.

    bacteria: (singular: bacterium) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals). Bacteria are one of the three domains of life on Earth.

    chemical reaction: A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).

    laser: A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.

    molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

    particle: A minute amount of something.

    photon: A particle representing the smallest possible amount of light or other type of electromagnetic radiation.

    photosynthesis: (verb: photosynthesize) The process by which green plants and some other organisms use sunlight to produce foods from carbon dioxide and water.

    physicist: A scientist who studies the nature and properties of matter and energy.

    wavelength: The distance between one peak and the next in a series of waves, or the distance between one trough and the next. It’s also one of the “yardsticks” used to measure radiation. Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light. Longer-wavelength radiation includes infrared light, microwaves and radio waves.

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  • How Benjamin Franklin fought money counterfeiters

    How Benjamin Franklin fought money counterfeiters

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    Though perhaps better known for its newspapers and almanacs, Benjamin Franklin’s printing business also churned out paper money to support the colonial economy. Now, scientists are confirming some of the ways that Franklin and his associates thwarted counterfeiters to help early American paper currency succeed, including by adding a reflective mineral to bills.

    Franklin’s bills “served as an archetype for printed money” to come, says Khachatur Manukyan, a physical chemist at the University of Notre Dame in Indiana. “It was very sophisticated for that time.”

    In past studies, Manukyan and his colleagues have analyzed ancient Roman coins, medieval manuscripts and other artifacts using nuclear imaging techniques. When the researchers realized that Notre Dame housed paper money bills dating to the early colonial days of North America, the team decided to take a closer look. They examined about 600 paper notes.

    By using techniques such as infrared, electron energy loss spectroscopy, and X-ray analysis, the researchers could see features such as colored threads and muscovite — a crystalized mineral — incorporated into the paper. The blue threads are visible to the naked eye, and the muscovite produces a glimmer that reflects light — features most knock-offs wouldn’t have been able to reproduce, the team reports July 17 in the Proceedings of the National Academy of Sciences.

    The muscovite, found in about 95 percent of the analyzed Franklin bills produced after 1754, was probably sourced from the same geologic area, the team says. The mineral was also probably used to increase the durability of the notes so they could hold up better during circulation.

    It’s wonderful that scientists are using these techniques to analyze these bills, says Jessica Linker, a historian at Northeastern University in Boston who studies early moneymaking. Still, she says, historians have known for some time from historical documents that muscovite — also known as mica — and blue threads were incorporated into old paper money to fight counterfeiting.

    What’s more, while Franklin contracted with the colonial governments to print money, others were involved in the decisions about its manufacture — not just Franklin, she says.

    Two photos of Benjamin Franklin’s incorporated elements like blue thread (left) and microscopic muscovite (right) in their paper money.
    Franklin’s operations incorporated elements like blue thread (left) and muscovite (microscope image, right) in their paper money in an effort to make it difficult to counterfeit.K. Manukyan et al/PNAS 2023

    The new analyses also showed that Franklin’s operations used graphite in their black ink. Other money printers of the time, including Paul Revere, generally used a type of black ink that had a higher proportion of chemicals that came from burnt bones like phosphorus and calcium. Counterfeiters had figured out how to fake the bone black ink, and some knock-off Franklin notes are distinguishable by the fact they use this bone black rather than graphite.

    Franklin’s operations may have used graphite to one-up the counterfeiters, the researchers say. But Franklin wasn’t the first printer to use graphite in ink, Linker says. Black lead — the historical term for graphite — is listed in some 18th century ink recipes, she says.

    “Even if it was unique to the money or new in the mid-Atlantic, it’s possibly not a Franklin innovation, but something he read about, experimented with and used to improve the quality of the ink generally,” she says — not necessarily something to fight counterfeiting.

    Still, the discovery of the graphite in Franklin’s notes is intriguing, she says. “I don’t think historians of colonial American printing would expect it to be there,” mostly because graphite was relatively scarce in the colonies at the time. Linker wonders whether this ink was used more broadly in Franklin’s other imprints or used exclusively for paper money.

    Efforts to thwart counterfeiters of early American money were eventually upended by the British, who figured out some of the techniques when they flooded their upstart colony with fake bills as a destabilizing tactic during the American Revolution. The value of American money tanked, and in the years following the revolution, the United States typically favored coins, only issuing treasury notes during later wars.

    Even so, some of Franklin’s techniques would go on to form the basis of increasingly sophisticated methods used to combat savvier forgers, Manukyan says. “The techniques utilized in producing pre-federal American currency were refined and enhanced during the 19th century whenever new bills were printed,” he says. “For that time, [Franklin’s paper money] was really groundbreaking.”


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  • Test the effect of temperature on reaction time

    Test the effect of temperature on reaction time

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    amplitude: A measure of the height of a recurring wave in some signal, water or beam of radiation. In sound, wave amplitude corresponds with intensity — loudness or softness.

    angle: The space (usually measured in degrees) between two intersecting lines or surfaces at or close to the point where they meet.

    antacid: A medicine used to neutralize the acid in the stomach.

    app: Short for application, or a computer program designed for a specific task.

    aspirin: A common non-prescription drug, also known as acetylsalicylic acid. For more than a century, it has been widely used to treat headaches, joint pain, muscle pain, toothaches and more. It also reduces fevers and inflammation. Ancient papyrus texts indicate that as long as 5,000 years ago, the Sumerians and Egyptians were using willow bark (the source of aspirin’s active ingredient) to treat aches and pains.

    audio: Having to do with sound.

    average: (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.

    carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules.

    carbon dioxide: (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter burns (including fossil fuels like oil or gas). Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

    constant: Continuous or uninterrupted. 

    data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

    decibel: A measurement scale used for the intensity of sounds that can be picked up by the human ear. It starts at zero decibels (dB), a sound hardly audible to people with good hearing. A sound 10 times louder would be 10 dB. Because the scale is logarithmic, a sound 100 times louder than 0 dB would be 20 dB; one that’s 1,000 times louder than 0 dB would be described as 30 dB.

    degree: (in geometry) A unit of measurement for angles. Each degree equals one three-hundred-and-sixtieth of the circumference of a circle.

    dissolve: To turn a solid into a liquid and disperse it into that starting liquid. (For instance, sugar or salt crystals, which are solids, will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.)

    equation: In mathematics, the statement that two quantities are equal. In geometry, equations are often used to determine the shape of a curve or surface.

    error: (In statistics) The non-deterministic (random) part of the relationship between two or more variables.

    error bar: A line (it can be vertical or horizontal) drawn through a point or a bar on a graph. The distance from one end of the line to the other represents how precise a measurement is, or how far the real value of something might fall from the data point reported in the experiment.

    factor: Something that plays a role in a particular condition or event; a contributor.

    function: The specific role some structure or device plays. (in math) A relationship between two or more variables in which one variable (the dependent one) is exactly determined by the value of the other variables.

    glass: A hard, brittle substance made from silica, a mineral found in sand. Glass usually is transparent and fairly inert (chemically nonreactive). Aquatic organisms called diatoms build their shells of it.

    hydrogen: The lightest element in the universe. As a gas, it is colorless, odorless and highly flammable. It’s an integral part of many fuels, fats and chemicals that make up living tissues. It’s made of a single proton (which serves as its nucleus) orbited by a single electron.

    ion: (adj. ionized) An atom or molecule with an electric charge due to the loss or gain of one or more electrons. An ionized gas, or plasma, is where all of the electrons have been separated from their parent atoms.

    kinetic energy: The energy held by an object due to its being in motion. The amount of this energy contained will depend on both the mass (usually weight) of the object and its speed.

    liquid: A material that flows freely but keeps a constant volume, like water or oil.

    molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

    particle: A minute amount of something.

    plastic: Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation. (adj.) A material that is able to adapt by changing shape or possibly even changing its function.

    point: (in mathematics) A precise point in space that is so small that it has no size. It merely has an address.

    range: The full extent or distribution of something. For instance, a plant or animal’s range is the area over which it naturally exists. (in math or for measurements) The extent to which values can vary (such as the highest to lowest temperatures). Also, the distance within which something can be reached or perceived.

    right angle: A 90-degree angle, equivalent to any inside corner on a square.

    sensor: A device that picks up information on physical or chemical conditions — such as temperature, barometric pressure, salinity, humidity, pH, light intensity or radiation — and stores or broadcasts that information. Scientists and engineers often rely on sensors to inform them of conditions that may change over time or that exist far from where a researcher can measure them directly.

    smartphone: A cell (or mobile) phone that can perform a host of functions, including search for information on the internet.

    sodium: A soft, silvery metallic element that will interact explosively when added to water. It is also a basic building block of table salt (a molecule of which consists of one atom of sodium and one atom of chlorine: NaCl). It is also found in sea salt.

    sodium bicarbonate: Also known as baking soda, this white, chemical powder occurs naturally. Its formula is NaHCO 3 . It also has been used as a natural product to extinguish small electrical and grease fires. When ingested, it can help settle acid stomachs. Indeed, it is the main ingredient of many antacids sold in grocery stores.

    solid: Firm and stable in shape; not liquid or gaseous.

    solution: A liquid in which one chemical has been dissolved into another.

    standard deviation: (in statistics) The amount that each a set of data varies from the mean.

    tool: An object that a person or other animal makes or obtains and then uses to carry out some purpose such as reaching food, defending itself or grooming.

    vertical: A term for the direction of a line or plane that runs up and down, as the vertical post for a streetlight does. It’s the opposite of horizontal, which would run parallel to the ground.

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  • Ozempic, Wegovy and beyond: Could the next wave of weight-loss drugs end obesity?

    Ozempic, Wegovy and beyond: Could the next wave of weight-loss drugs end obesity?

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    New Scientist Default Image

    There are TikTok hashtags with millions of followers, endless column inches over celebrities’ waistlines and streams of media coverage when trial results come out. It is rare that a new medicine gets so much attention. Then again, it is even rarer that a licensed drug causes safe and rapid weight loss with minimal effort.

    A year ago, most people hadn’t heard of semaglutide, a drug developed to treat type 2 diabetes around a decade ago under the brand name Ozempic. Then, in 2021, it was approved in the US as a weight-loss aid under the name Wegovy. The medicine can cause people to lose a whopping 15 per cent of their body weight.

    The impact of this new class of medicines could be unprecedented – potentially bringing to an end the world’s growing obesity epidemic. “I don’t think it’s fully sunk in yet,” says Jonathan Campbell at Duke University in North Carolina, who investigates how these drugs affect the body.

    For one thing, Wegovy was just the start. The next generation of these drugs is in development and will be cheaper, easier to use and, crucially, even more potent. What’s more, emerging evidence suggests Wegovy and its ilk work better when given at a younger age, so doctors are exploring their use in teenagers and young children. This raises the prospect of switching from obesity treatment to prevention. “We have watched the obesity landscape change dramatically over the last 40 years,” says Campbell. “Now, maybe we’re at a turning point where that goes backwards.”

    Why obesity is on the rise

    The rise in obesity has been happening since about the 1970s…

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