Antonín Valda
Stories (7/0)
Why your phone battery gets worse over time
A drop of gasoline, a match, and a battery, all store energy— but, after each expends its energy, only the battery is recyclable. That's because, chemically speaking, a dead battery is actually not that different from a fresh one. Most of the batteries we use today take advantage of the fact that some metals like to release electrons and others like to accept them. For example, in a typical alkaline double-A battery, zinc metal reacts with hydroxide ions, changing into zinc oxide and releasing electrons at the negative terminal. The electrons travel through, say, a light bulb, and then return to the battery at the positive terminal, where they’re accepted by manganese dioxide. Different batteries use different combinations of metals, and sometimes non-metals like graphite, but the basic idea is to use a pair of chemical reactions to generate a stream of electrons. Almost all batteries, even single-use batteries, are theoretically rechargeable. That's because the metals and other chemicals are still right there. That’s very different than in, say, gasoline, where the liquid hydrocarbon molecules are converted to gases. You can't convert exhaust back into gasoline, but, with some work you can convert, say, zinc oxide back to zinc. So then what's the difference between these and these? The short answer is that trying to recharge a single-use battery doesn’t just force these reactions to run in reverse. It also results in a bunch of side reactions that produce useless contaminants, reducing a battery’s capacity; and it could even damage the internal structure of the battery, leading to a loss of electrical contact and failure. Rechargeable batteries are engineered to avoid these issues. Look at this lithium-ion battery. Both sides have an atomic-level structure that you can imagine as lots of docks. So when the battery is powering something, the lithium “ships” give up their electrons to power the circuit, and then sail over to the other side of the battery, dock in an orderly, organized way, and meet up with their now-lower-energy electrons. When the battery is being charged, the opposite happens. Over the course of hundreds, sometimes thousands, of charge cycles, some of the lithium ion ships sort of veer off course and engage in side reactions, producing stuff that increases the internal resistance of the battery, which in turn makes it lose efficiency and power until it inevitably dies. Even when that happens, you can bring dead batteries back to life— whether they’re rechargeable or not— by recycling them. The heart of most battery recycling is a process called smelting, which is basically just melting the metallic parts. This drives off impurities, returning metals back to their initial, orderly state. Unfortunately, in many countries you can’t just toss household batteries in with your regular recycling. You have to take them to a battery collection point or recycling center. Same goes for more complicated rechargeable batteries: you need to bring them to a collection point or send them back to the company you bought them from. It’s a pain, but absolutely worth the time and effort, because recycling batteries is critical. Not only does it prevent potentially toxic battery metals from leaking into the environment, it conserves scarce— and vital— resources. Earth has about 22 million tons of lithium— enough for about 2.5 billion EVs. That sounds like plenty, but it’s only 25% higher than the number of EVs experts believe it’ll take to reach net zero emissions by 2050, and that doesn’t even account for laptops, phones, and anything else that uses a lithium-ion battery. Currently, though, most lithium-ion batteries are not manufactured with recycling in mind. The designs are intricate and non-standard, and the components are held together by almost indestructible glues. So today, less than 5% of lithium-ion batteries are recycled. Regulations that clearly define who is responsible for a spent battery and what should happen to it can boost recycling dramatically. For example, lead-acid batteries are generally subject to stringent regulations and are recycled at much higher rates than lithium-ion batteries. Over the next century, we’ll need to recycle huge numbers of EV batteries, so scientists are working on making the battery recycling process cheaper and more environmentally friendly. Smelting uses a lot of energy and, depending on the type of battery, can release harmful by-products. In addition to regulations, industrial processes, and our own individual choices, battery tech will also continue to evolve.There are proof-of-concept batteries being developed that can convert physical force, ambient sound, and even pee into electricity. But if your top priority is to make your number one source of power, number one, sorry to say, but urine for a long wait.
By Antonín Valda7 months ago in 01
Do mosquitos actually bite some people more than others?
Some swear they’re cursed to be hunted by mosquitoes while their close-by companions are regularly left unscathed. But is this an illusion? If it's not, what's going on? And what can we do about it? It all comes down to how— and why— mosquitoes find us. While male mosquitoes stick to nectar for sustenance, females also seek out blood to provide the nutrients they need for their eggs. Different mosquito species evolved to feed on different animals. And, probably within the last 10,000 years, multiple mosquito lineages independently evolved a predilection for people. As human settlements became more permanent, they provided plenty of standing water, even through intense dry seasons, which supported mosquito reproduction year-round. Female mosquitoes are equipped with antennae covered in hair-like appendages that contain odor-sensing receptors and neurons. These pick up on the signals of their preferred hosts, And over thousands of years, the mosquitoes that target humans have gotten extremely good at tracking us down. They also target parts of our bodies where we’re less likely to notice them. And they’re sensitive to visual cues and changes in airflow, so when we try to defend ourselves, they can make swift escapes. They even learn to avoid particularly defensive people altogether. But before these close encounters happen, several factors alert mosquitoes to people's presence. Female mosquitoes can pick up on the carbon dioxide humans constantly exhale from about 10 meters away. Once they’ve gotten the CO2 cue, they become especially interested in dark, high-contrast objects and the hues found in human skin. As they follow the carbon dioxide plume to its source, they eventually sense body heat and odors. These smells are generated by the many microorganisms that live on our skin. They break down the secretions our bodies produce, like sweat and sebum. In doing so, our skin microbes create smaller organic compounds that can vaporize and get picked up as smells— smells that human-homing mosquitoes are especially attuned to. Getting extra sweaty can temporarily make people more attractive to mosquitoes— as can ingesting alcohol or being pregnant. And the Plasmodium parasite that causes malaria makes the people it infects more appealing to mosquitoes by increasing the amounts of certain fruit-smelling aldehyde compounds on their skin. This is extremely helpful to the parasite because it depends on both humans and mosquitoes to reproduce. But in addition to these temporary factors, about 20% of people are thought to be naturally high attractors, or mosquito magnets, who are disproportionately targeted year after year. If you’re one of them, you’re probably well aware. Sorry about that. Why this is seems to come down to some skin-specific characteristics. While carbon dioxide exhalations and body heat consistently signal the presence of warm-blooded animals, human body odor is more distinctive. And everyone hosts different microbial communities on their skin, which contribute to unique body odors that likewise vary from person to person. Researchers reveal that the receptors mosquitoes use to detect acidic compounds are especially important in helping them navigate towards humans. And, indeed, humans with more abundant skin acids prove to be consistently more attractive to mosquitoes. Because it’s such a persistent trait, certain genes may play a role, perhaps by helping determine the skin’s microbial composition. Scientists have observed that mosquitoes demonstrate similar levels of attraction among identical twins while responding more variably to fraternal twins, which supports that there may be some genetic basis at play. But beyond confirming that mosquitoes are, in fact, conspiring against some of us specifically, understanding what makes people mosquito-magnets has serious, large-scale implications. Every year, hundreds of thousands of people die from mosquito-borne diseases. And resources aren’t reaching those who need them most. This knowledge can help inspire solutions, like more effective insect repellents that manipulate the skin's microbiome and odors. And knowing that some people are especially strong mosquito attractors could also help efforts to get them resources like repellents, bed nets, vaccines, tests, and treatments. The results could not only be less itchy, they could break transmission cycles and save countless lives.
By Antonín Valda7 months ago in Earth
Why don’t we cover the desert with solar panels?
Every day, the sands of the Sahara Desert reach temperatures up to 80° Celsius. Stretching over roughly nine million square kilometers, this massive desert receives about 22 million terawatt hours of energy from the Sun every year. That’s well over 100 times more energy than humanity consumes annually. So, could covering the desert with solar panels solve our energy problems for good? Solar panels work when light particles hit their surface with enough energy to knock electrons out of their stable bonds. On their journey back to stability, these electrons produce electricity. However, there’s a limit to how much power panels can generate. Solar panels can only interact with certain wavelengths of light, making it impossible to convert over half the sunlight they receive. And even light particles they can convert often bounce off them without ever hitting an electron. But thanks to clever scientists and engineers and substantial government investment, solar panels are generating more electricity than ever. Anti-reflective coatings and patterns on the panels’ surface create more opportunities for incoming light particles to hit electrons. These techniques have increased commercial solar panel efficiency from the low-teens to 25%, with experimental models reaching up to 47%. What’s more, solar has gotten 89% cheaper over the last decade, thanks in part to global supply chains for other technologies that use the same materials. Together, these factors have made solar power the cheapest source of electricity on Earth. Countries including India, China, Egypt, and the US, have already taken these new panels into the desert. Their massive solar farms range from 15 to 56 square kilometers, and when the sun is high in the sky, these plants can provide energy for hundreds of thousands of local residents.But these farms also get extremely hot. Light that solar cells don’t convert or reflect is absorbed as heat, which reduces a panel’s efficiency. And the cooling systems employed by many farms can use huge amounts of energy powering fans or moving water to maintain optimal temperatures. Even with these systems, solar panels in the desert absorb far more heat than the natural sandy environment. This hasn’t been a problem on the scale of existing solar farms. But if we tried to cover the Sahara,this effect could create massive changes in the region's climate. Constructing solar farms already disrupts local ecosystems, but a plant of this scale could dramatically transform the desert landscape. Thankfully, solar panels aren’t our only option. And some of the largest solar plants in the world are trying a new approach: giant mirrors. Morocco’s Noor Power Plant, which will eventually cover roughly 30 square kilometers of the Sahara, is a concentrated solar power plant. This design reflects light onto a receiver, which converts that energy to heat, and then electricity. These mirrors still create a dangerous temperature shift for local wildlife, but they have less potential to transform the landscape. And since it takes time for the materials being heated to cool off, these plants often continue producing electricity past sunset. Whether they use panels or mirrors, industrial solar farms are often easy to fit into existing energy infrastructure. However, getting their electricity beyond local power grids is much more difficult. Some countries are working on ways to connect electric grids across the globe. And many farm store energy in massive batteries, or convert their electricity into clean gas that can be used later. But right now, these techniques are still too expensive and inefficient to rely on. Worse still, industrial renewables can share some of the same problems as fossil fuels,relying on destructive mining operations and carbon-emitting global supply chains. Fortunately, solar can exist on many scales, from industrial solar farms to smaller installations that power individual buildings and rural communities. These projects can supplement energy use or provide a passive source of energy for regions off the grid. And since solar panels rely on a few simple components, they’re quick to install and relatively easy to update. In fact, it’s this flexibility that enabled solar to become so cheap and ubiquitous over the last decade. So if we want to keep up with humanity's rising energy use, we'll need answers both big and small.
By Antonín Valda7 months ago in Earth
Mr Swirl: The Internet's Most Disturbed User
In Pattaya, Thailand, two young brothers entered a local internet cafe, took their seats, and started playing their favorite games. One boy was 13 years old, and the other was just 8. Together, they lost themselves in their screens, spending the day gaming. However, their day took an unexpected turn when one of the boys felt a tap on his shoulder.
By Antonín Valda7 months ago in Criminal
On Of TikTok's Most Disturbing Mystery
In February 2022, an urban explorer embarked on a journey down a forgotten dirt road in rural China. His ultimate destination was a mysterious, dilapidated structure, often referred to as "the laboratory." While its purpose remained shrouded in mystery, this only fueled the explorer's curiosity. The allure of this place was irresistible, as he hoped it would be the perfect backdrop for his TikTok video, potentially propelling him to fame.
By Antonín Valda7 months ago in Criminal