Mobile Tech & Gadgets

the minimum dose of exercise that science points to changing the health of those over 60 years of age

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In the 1980s, gerontologist Robert N. Butler launched a phrase that has become in a mantra of modern medicine: “if exercise and physical activity could be packaged as a pill it would be the most widely prescribed and beneficial medication for the population.” Forty years later, science has stopped treating that phrase as a metaphor and turned it into a mathematical calculation. The ROI of the force. Until now, we knew that sport was healthy, but data on its direct clinical profitability were lacking. The GENUD research group, led by José Antonio Casajús, published in Experimental Gerontology at the end of 2025 one of the strongest evidence to date. The essay, carried out with 123 people over 80 years oldprescribed a treatment of three weekly supervised exercise sessions for six months. The clinical results were clear: improvements in functional capacity, reduction in frailty and increase in quality of life. But the data that has aroused the interest of health managers is economic. The conclusion here was that while the cost of the intervention was only 164 euros per person, The savings to the system exceeded 1,000 euros. The clinical squat. If exercise is the ideal drug, clinical evidence points to the squat being the most important active ingredient here. Many studies have precisely validated this movement, which can mean the world to some people, not as a gym exercise but as a diagnostic and treatment tool. Biomechanics is key. Why is the squat so important to medicine? First of all because it is an exercise that demands more on the hip extensorsvital for an elderly person to be able to get up from a chair or bed without help. But in addition, it also activates the quadriceps and plantar flexors more. At the metabolic and cardiovascular level, the impact is systemic. The venous compression that occurs during the squat increases venous return and cardiac output, acting as a natural pump that combats orthostatic hypotension. Even in post-stroke patients, fast squats have been shown to activate the injured rectus femoris, correcting asymmetries and improving postural control. How long. You don’t have to work hard, since a recent study showed that a program of just one minute a day, that is, about thirty seconds of squats and thirty seconds of push-ups, is enough. This is something that was seen with prescription by primary care physicians, improving physical performance in patients over 60 years of age with excellent adherence at 24 weeks. Anti-cancer effect. Beyond the effect on adults, important implications of physical exercises in pediatric cancer have also been seen. This was evidenced by Carmen Fiuza-Luces, from the Physical Exercise and Pediatric Cancer group, who directs the “La Aceleradora” project of the Unoentrecienmil Foundation. And contrary to the belief of having “absolute rest” when you have cancer, the evidence shows that exercise during treatment of pediatric solid tumors It achieves what no drug can. For example, it reduces the side effects of chemotherapy, protects the heart from the toxicity of the treatment or prevents atrophy in sick children. The problem is not the drug. The problem with prescribing exercise in consultation is lack of knowledge about the ‘dose’ that should be given. Just as a doctor does not say ‘take an antibiotic’ without a clear duration and frequency, the same thing happens with sports. You can’t say ‘do sports’. In these cases, exercise requires a dose in the form of frequency and duration, the intensity that must be personalized to each patient and, above all, monitoring with adaptation to the patient’s pathology. Looking for the front door. The Health and Sports Working Group of the Collegiate Medical Organization, coordinated by José Ramón Pallás, is pushing for integrate exercise into the National Health System as a therapy equivalent to drugs. The goal is for the “3 sets of 10 squats” recipe to be as official and binding as any blood pressure pill. In this way, science has done the numbers and all that remains is for the administration to make a move. Images | Victor Freitas In Xataka | Neither 10,000 steps a day nor killing yourself in the gym: the “sweet spot” of exercise according to science is 30 minutes

Elon Musk’s Grokipedia

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AI is drowning Wikipedia. Not only has it been trained with its content, but the AI ​​responses It’s stealing a lot of your traffic. As if that were not enough, in October of last year a competitor appeared, Grokipedia, created entirely with AI (and copied from Wikipedia itself). We now know that Elon Musk’s invention is attracting a new audience: other AIs. Source: Grokipedia. A few days ago, some tests carried out by The Guardian revealed that ChatGPT was using Grokipedia as a source in various queries and it is not the only chatbot that is citing it. According to The Vergereferences are appearing in other AI services such as those of Google, which cites it in Google Gemini, in the AI ​​summaries and the search engine’s AI mode. It has also been cited by Microsoft Copilot and, to a lesser extent, Perplexity and Claude. Volume. Speaking to The Verge, Glen Allsopp, head of SEO at Ahrefs, revealed that they did a test with more than 13 million queries and the result was that ChatGPT mentioned Grokipedia in more than 263,000 responses. Wikipedia continues to appear much more, with almost 3 million references, but taking into account that Grokipedia was born in October 2025, the volume of citations is quite large. ChatGPT’s favorite. Analysts from other SEO tools such as Semrush and Profound told The Verge that they have detected significant increases in the number of citations to Grokipedia and the majority come from ChatGPT. In the case of the rest of the chatbots, according to Ahrefs tests, Google cited Grokipedia in 6,800 Gemini responses and 567 AI summaries. Copilot named it in 7,700 responses and Perplexity only two. From the creator of MechaHitler. Wikipedia is collaboratively and transparently edited by humans, but Grokipedia is run by Grok, an AI that has had hallucinations in which I thought it was Elon Musk himselfhas published antisemitic messages, “MechaHitler” was proclaimed and recently it was in the news for help “undress” millions of women. As if that were not enough, an investigation revealed that in Grokipedia there are articles whose sources are directly neo-Nazi forums and conspiracy theory websites. The researchers warned that Grok was making his own editorial decisions, altering the focus on certain topics. That chatbots are using it as a reference is problematic, to say the least. OpenAI responds. Speaking to The Verge, an OpenAI spokesperson said that ChatGPT searches a “wide range of sources and points of view” and that users can judge their reliability for themselves. It also highlighted that they implement security filters to prevent links to potentially harmful content from appearing. In Xataka | AI is breaking one of the oldest economic paradigms in history: that cheap equals “bad” Image | Amparo Babiloni, with Wikipedia and Grokipedia logos

The ships of the oil “ghost fleet” turn off their GPS to avoid being detected. Malaysia is going to hunt them with drones

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In the crystal clear waters of Southeast Asia, where the Strait of Malacca meets the South China Sea, a war is being fought that does not appear in conventional military reports. There are no trenches, but there are rusty helmets that turn off their GPS signal to disappear from international radars. This is the kingdom of the “ghost fleet”, an ecosystem of lawless ships that, according to the latest researchhas found its safe harbor in Malaysia, doubling its activity in just twelve months. However, the time for impunity appears to be running out: from the use of artificial intelligence to the deployment of naval drones, technology is beginning to illuminate the darkest corners of the ocean. The black market boom. The situation on the east coast of Malaysia has ceased to be an open secret and has become a global security problem. According to the specialized media Seatrade Maritime“ship-to-ship” (STS) oil transfers have recently doubled, going from just seven weekly operations to peaks of fifteen in just one year. This increase responds to an infrastructure designed to circumvent the sanctions imposed on Russia, Iran and Venezuela, using Malaysian waters as a gigantic clandestine service station before the crude oil continues on its way, mainly to China. Analyst Charlie Brown, of the organization UANIhas managed to capture a disturbing reality through satellite images and direct photos. In mid-January 2026, some 60 vessels linked to Iranian oil and another 30 with Russian and Venezuelan cargoes were waiting at anchor in Malaysia’s Exclusive Economic Zone. These ships not only operate outside the law, but they do so under deplorable technical conditions. Images distributed by UANI show tankers with false names broadbrushed on their hulls and flags of convenience hidden under tarps to deceive authorities. The metamorphosis of the threat. What began as a purely economic strategy to keep Moscow’s revenue flowing has mutated into something far more dangerous for European security. As the chronicles of my colleague Miguel Jorge relate in XatakaRussia has converted part of this fleet into covert hybrid warfare platforms. It’s not just about moving barrels; Now these ships incorporate “technicians” who, under a civilian guise, are usually special forces veterans or mercenaries linked to the Wagner group. These agents wield authority that often exceeds that of the ship’s captain and have been accused of photographing military installations and monitoring underwater cables in EU and NATO waters. An example of this tension was experienced with the oil tanker Boracaywhich after embarking Russian technicians in the Baltic, was intercepted by the French navy off Brittany after suspicious drones were detected flying over critical infrastructure in Copenhagen. The ghost fleet is today, in essence, an extension of the Kremlin’s security apparatus sailing with impunity under the flags of countries like Gabon or Gambia. A new fragmented energy order. From the academic level, the Elcano Royal Institute’s analysis highlights that this phenomenon is the symptom of a “deglobalization” of the gas and oil market. In your reportresearcher Gonzalo Escribano explains that international value chains, previously based on efficiency and transparency, are being replaced by “geoeconometrically armored” circuits. Europe finds itself at a crossroads: although it seeks to disassociate itself from Russian energy, the persistence of these black markets complicates strategic autonomy. This fragmentation has even reached the LNG (Liquefied Natural Gas) market. According to Bloombergsanctioned Russian gas transfers have been documented in Malaysian waters, a technically much more complex operation than crude oil. The ship Pearlmanaged by an opaque company based in a Dubai hotel, is the face of this new network that desperately seeks buyers in Asia for the gas that Europe no longer wants. The technological response: AI and drones to the rescue. Faced with a fleet that “turns off” the real world by hacking GPS signals (spoofing) and the shutdown of transponders, the response is being purely technological. The middle CNBC highlights thatof the ships loaded with Iranian crude in 2025, 96% made dark transfers and 77% falsified their location. To combat this “blackout”, Ukraine has shown the way with an innovation that has made conventional fleets obsolete: the use of artificial intelligence in naval drones. The drones Be Baby have multiplied its capabilities thanks to AI, allowing precision attacks from thousands of kilometers away. In a recent operation near the Turkish coast, these drones hit Russian ghost fleet tankers, specifically targeting their rudders and propulsion systems. The objective is not to sink them, which would cause an ecological disaster of catastrophic dimensions, but to render them useless and turn them into an unbearable economic burden for those who operate them. This “precision offensive” is forcing insurers and shipping companies to reconsider the risk of collaborating with Moscow, raising the costs of war for the Kremlin. The dilemma of safety and the environment. The proliferation of elderly ships, without liability insurance and with dubious maintenance, is an environmental time bomb. Lars Barstad, CEO of the operator Frontline, warned in the Financial Times that organizations such as the International Maritime Organization (IMO) appear to be “sleeping at the wheel”. Barstad notes that it is only a matter of time before a major disaster occurs, as these ships operate outside of any regulatory framework. Meanwhile, diplomatic pressure increases. The US has begun a campaign of aggressive seizures, such as that of the ship Sailor (before Bella 1), which was boarded by the US Coast Guard in North Atlantic waters after a chase from the Caribbean. This “gunboat diplomacy” of the 21st century, analyzed by the Atlantic Councilposes immense legal challenges: once a steel giant full of crude oil is seized, the maintenance and storage costs are astronomical. The end of the shadow. The current geopolitical dashboard report shows that Malaysia, Spain or the waters of the Caribbean are just scenes of a larger battle for visibility. The ghost fleet survives in the shadow of legal ambiguity, but the advance of artificial intelligence and constant satellite monitoring are tightening the fence. As the analysis concludes from my partnerthis is not a frontal … Read more

Companies are replacing junior workers with AI. Now it’s time to pay the consequences

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When artificial intelligence appeared on the horizon, the first thing we thought was that it was going to retire us. Later, he was going to retire the most senior profiles and now we know that it is just the opposite: is stopping job access to junior profiles. In the past, companies competed fiercely to attract young talent, but now Gen Z has found its great rival in AI. Beginners? No, thanks. This Revelio Labs job report reveals that entry-level hiring has fallen by 35% in the United States since 2023. And it is one of many studies: this other of job offers estimates the drop in junior offers between 11 and 20% in the last year. The phenomenon is not exclusive to the United States: in Spain these data from El Confidencial They report that the Big Four are going to reduce the hiring of people under 30 years of age by between 10 and 20%. In the UK, more of the same. AI boosts productivity… if you’re the boss. The business premise is that artificial intelligence can carry out these tasks of those people with a junior profile such as documentation, testing or writing basic code. It is not that these tasks have disappeared within the workflow, it is that they have been absorbed by higher levels in a twist of efficiency and productivity: senior profiles supervise what the AI ​​does. And if, AI screws up. To the question of how many hours of work per week does AI save you? from the consulting company Section collection in The Wall Street Journal There is a clear divergence between managers and staff: 40% of workers think that they are not saving anything because even if there is a quick response, there are errors and hallucinations. When you take into account the time spent going through everything, checking and redoing, the beads are not so round anymore: this Asana studio shows that employees spend 4.5 hours per week correcting AI work. The boomerang effect. That youth encounter yet another obstacle to having a full adult life is a real drama in terms of unemployment, but this paradigm shift in hiring is also a total threat to the stability of the technological infrastructure as we know it: The illusion of efficiency. AI chops code faster than anyone else, but that raw data is misleading because it doesn’t consider side effects like validation. Operational risk. If the AI ​​does not have human supervision at each step, it can make critical errors, serve as an example when half the internet went down for the total automation of Amazon servers. Of costs and responsibilities. If the AI ​​makes a mistake and it reaches the final chain of the process, that is, delivery to the customer, it is paid. Let them tell Deloitte, they had to reimburse the cost of a report prepared for the Australian Department of Employment and Industrial Relations because it contained hallucinations. A demographic bomb. All of the above is a toll that many companies seem willing to pay for the sake of that efficiency, but there is a devastating effect on a large scale in the medium and long term: the knowledge gap. When these senior profiles retire, there will be no one who can replace them simply because you have eliminated the training ground that is experience. The figures have spoken: between 2024 and 2032, 18.4 million professionals in the United States will retire according to this study from Georgetown University. However, only 13.8 million new workers will gain access. About to explode. Part of the work of senior profiles includes mentoring and all its intrinsic benefits: there are studies that confirm that increases motivation, promotes psychological well-being and even reduces exhaustion. In short: saturation of tasks, inability to delegate and the loss of that added bonus of teaching: there are many ingredients for the recipe for burnout. In Xataka | If AI is going to leave us without jobs, in the United Kingdom they are already seriously discussing the solution: a universal basic income In Xataka | We believed that the AI ​​talent war is about engineers and developers. Actually, it’s about plumbers and electricians.

This website is a magnificent calculator to calculate and compare with other countries

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Talking about taxes in certain scenarios is a recipe for disaster. All the ingredients are present: ignorance about basic concepts in economics and how they work, a misunderstood selfishness and confusion between whether what we dislike is how they are managed or their mere existence. One of the most controversial is the Personal Income Tax or Income Tax. How much IPRF do we pay? Is it a lot or a little? Well it depends. In general, we don’t even like money being “taken” from us and in Spain it is quite common to hear that they “take” too much from us. Keep in mind that most states have some personal income tax similar to personal income tax (there are exceptions such as Monaco either Kuwait which they don’t have), so neighbors like Germany or France do have it and leaving the EU, in the United States they have their equivalent in the Income Tax). From here two questions arise: what part of my income goes to personal income tax and whether I would pay more or less if I lived somewhere else. Without intending to replace an economics class (or reading in depth the ministry website) and yes like brief notes on personal income taxIt is important to be clear that this tax is progressive in sections, that is, you do not pay the same percentage for all your money. This is one of the most common mistakes when we hear that someone with a high salary (for the average in Spain) pays 47%: no, the Treasury does not take almost half. That first tranche up to 12,450 euros has a withholding of 19%, from there up to 20,199 euros it is 24% and so on. On the other hand, personal income tax is also divided into sections: state and regional. Depending on which autonomous community you live in, you will pay more or less. Finally, there is a personal and family minimum for which personal income tax is not paid as it is considered to be used to cover basic needs. Defaultit is 5,550 euros per year for a single person. Personal income tax calculators There are a few on the internet and in fact, even the Treasury has its own to make sure we are with the official. Now, if we look for an intuitive alternative that allows us to compare, this website by Benjamin Akar It is an excellent option even if it is in English. An easy personal income tax calculator and comparator to estimate what you pay After choosing a country from the list and verifying that the currency is the Euro, we only have to add annual gross salary. In the advanced options you can also add other deductions such as pension plans or union dues. We see it better with an example: 25,000 euros per year in Madrid and Navarra, two very particular autonomous communities: the state capital has deflated the sections and has one of the lowest minimums in Spain. Navarra, for its part, has its own Treasury, regional regime and personal income tax law. Thus, the sections are modified and there are differences in deductions and calculations such as the structure of the savings base. For the simulation we will assume that we are single people without children. From the previous calculation it is deduced that Madrid is the best option to maximize your salary. But not everything is money in the pocket: Navarra compensates with its own management of services that sometimes entails indirect benefits in the form of personal or family deductions either more budget per inhabitant in health. Now we try changing to Germany and its capital, Berlin, to see what the personal income tax calculation looks like. Deductions from work are very low because Germany has a very high exempt minimum because you do not pay taxes, but then social contributions arrive in the form of social security, pension, unemployment taxes, among others. The EU forms a mosaic where each state has its own tax recipe, although they all share to a greater or lesser extent the objective of financing the welfare state. However, the big difference is not only how much we pay, but how it is paid. So We essentially distinguish three routes: There are states like Germany, France or Spain, with a standard progressive model where you pay based on what you earn; Others, such as Bulgaria or Romania, apply flat systems with low single rates regardless of income. Finally there is the “Nordic” model of places like Denmark or Sweden, with very high maximum rates to finance extensive public services and social benefits. He Spanish state is located in a medium-high zone of the EU. The Eurozone average in maximum rates is around 40% compared to 45% in Spain (considering the combination of state and regional average), reaching 50% or more in regions such as the Valencian Community or Cataloniawhich only affects very high incomes. In Xataka | 64% of Spaniards believe that they pay more in taxes than they receive from the State. It’s actually the other way around In Xataka | Income Tax Calendar 2025: dates and when the 2026 Income Tax return is made Cover | Jakub Zerdzicki

Spain does not know if it has too many or too few rabbits. But this town of Toledo has declared war on them at their own risk and expense.

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In Villa de Don Fadrique, province of Toledo, the town hall you have just activated an extraordinary authorization to shoot down rabbits daily. In fact, it is inviting volunteers to reduce its population to a minimum. It is a total war against these rodents that are becoming a real headache for farmers across the country. And it is curious because, if we look at the data, the truth is that the European rabbit entered the red list of threatened species from the IUCN in 2019. Can you be endangered and an indiscriminate pest at the same time? And the answer is yes, of course yes. A few days ago, it was the Union of Farmers and Ranchers of Castilla la Mancha the one that warned that “the proliferation of rabbits is a problem that has been going on for ten years, they speak of a ‘pest’ that is threatening olive groves and pistachio and almond trees, and they demand that the populations of these animals be controlled.” It is not an anecdotal impression, in a sectoral report points out that rabbits account for 64% of agricultural insurance payments for wildlife damage and averages of tens of thousands of hectares damaged per year are cited. And yet, the decline of the rabbit at a general level it’s clear. And that not only impacts the “bug” itself: whether we like it or not, there is the base of the food chain of more than 30 species (from the Iberian lynx to the imperial eagle) and its disaster alters the functioning of the Mediterranean forest. He’s been altering it for decades. Because what is clear is that this is not something recent. The decline of the European rabbit is associated with myxomatosisfirst (mid-20th century); then continue with the rabbit hemorrhagic disease in the 80s; and is complicated by the arrival in 2012 of a new variant (RHDV2) that affects populations just when they were beginning to recover. To this we must add the changes in the landscape and the disappearance of boundaries, fallow lands and traditional shelters. However, when God closes a door he opens a window. And, despite the general decline, rabbits have known how to use the gaps in human infrastructure to create authentic breeding sites. The slopes and shoulders of the roads have become tremendously favorable habitats (and even in motion vectors) and areas with constant food (irrigation/crops) are natural attractors of these reduced populations. That is to say, the explanation is simple: the populations are smaller, but they have been rearranged in areas that cause more damage to farmers. And thus, the conflict is served. While conservationists and scientists ask to recover the rabbit in the mountains, farmers ask to expel it from its areas of influence. But the curious thing is that both sides are partly right and we do not have stories that allow us to understand what is happening. Something that is also happening with all the bugs on the mountain. Image | Sönke Biehl In Xataka | In 1940 Japan removed this island from the maps to keep its activities secret. Now your creatures are dying

They don’t have the AI ​​but they already have the energy

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In the AI ​​race, The United States has the chips and China has the energytwo different starting points that make them follow divergent trajectories. But both chips and energy are essential for the technology industry from a broader point of view. Guaranteeing supply is the first step to dominating emerging industries and China has taken it very seriously by stepping on the accelerator in the construction of energy infrastructure. The figures. According to data from the China National Energy Administration of which echoes BloombergIn 2025 alone, the Asian giant added 542.7 GW of capacity to what it already had to reach a total capacity of 3,890 GW. As collects China Newsthis is 16.1% more in just one year. In perspective. The cold data may not give an idea of ​​the magnitude of the Chinese attack, but those 542.7 GW added in the last year is more than the total capacity of powers such as India, Germany or Japan, according to data from the International Energy Agency. Only the United States and its 1,373 GW available on the electrical grid surpass it. However, if we extend the time frame four years ago, we find that in that period China expanded its capacity by 1,515.3 GW, more than everything the United States has today. Among China’s objectives With this ambitious commitment to energy, we are guaranteeing a stable and abundant supply, minimizing dependence on fuel imports and making it a competitive advantage in growth and intensive industries such as AI, robotics or advanced materials technology. Why is it important. From an engineering point of view, what China is doing in recent years is a feat: it has replicated the West’s largest power grid at lightning speed. What took the United States approximately a century, China has only required less than half a decade. But building electrical infrastructure (What happens with Data Centers?) is neither easy nor immediate: it requires planning, logistics and a highly qualified workforce. Not to mention permits or environmental evaluations. This level of manufacturing and installation involves overcoming a learning curve that reduces technology costs for global implementation. How has he done it. Achieving that capacity in record time is difficult, but it is not only how much but how: a good part of this growth comes from solar and wind energy. This type of energy, unlike fossil fuels, is intermittent. That is, it is not limiting itself to installing panels and wind turbines, but it is also redesigning the management of the network in the event of eventual events such as no sun or wind. However, coal and gas thermal power plants are also in record numbers. China has not forgotten nuclear and hydroelectric energy either, with more modest increases. What the graph doesn’t say. That China’s current capacity is immense does not mean that, for example, solar or wind plants are producing 24/7: their plant factor It is lower than those of gas or coal plants. Hence they need to build much more to achieve the same. And to move all that energy from one side of the country to the other, for example from the sunny Gobi Desert to industrial Shanghai, China has set up a kind of energy highway: the High Voltage Direct Current network, with the largest ultra-high voltage transformer in the world. You have another challenge ahead: where to store the excess energy. For now, is investing big time in lithium batteries and also in hydraulic pumping. In Xataka | The race for AI has placed China in an unthinkable scenario: forcing the United States to leave its comfort zone In Xataka | China needs chips and the United States needs energy: in the AI ​​race the two great powers have divergent paths Cover | Raisa Milova and Dominic Kurniawan Suryaputra

you will never see a green star

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There will be those who are too lazy to walk the dog at night (especially in winter) or at 6:30 in the morning, but I love finding it all asleep and being able to calmly raise my head so that, while I walk around the outskirts of my city so that my dogs can do their things, look at the sky to see what I find. One of my hobbies is, like when I was little, trying to distinguish what I find: The Polar Star, at this time of year also El Carro, the very bright Sirius with a bluish white or orange tone Aldebaranthe red Betelgeuse or the blue supergiant Rigel. Although there is light pollutionFortunately, I live near several municipalities starlight and it doesn’t take much to find authentic shows. I have seen stars of a few colors, but never green. The reality is that I look at the stars with no other instrument than my eyes and that implies only see those bright enough to emit enough light to activate the conesthe color-sensitive cells that are in the retina. But still, the stars I encounter seem white, blue, red, orange or yellow. Viewing the sky with a telescope things change and there you can see fainter stars or even go up a level and take a look (and try to interpret what space telescopes see). What is hard to see are green stars. Spoiler: it is as much a matter of the stars as it is of our eyes and their way of perceiving color. The Sun’s peak emission is green. There are several reasons why we never see it that color. A star behaves like a black bodythat is, it emits light depending on its temperature. Simply put: they emit light because they are hot. In fact, their color depends on their temperature: the coldest ones emit red light and those that are very hot glow blue. Different Planck curves for stars of classic colors: blue, yellow, red. POT However, this is a simplification: they actually emit in a wide range of colors but in different proportions in an asymmetrical bell shape (the Planck curve that you see above these lines) and it is the mixture that gives that final color. The relationship between the temperature of a star and the color where it emits the greatest amount of energy (the tip of the curve) is obtained from the Wien Displacement Law. If a star has a temperature of about 5,500K (very similar to that of the Sun), its peak emission would be precisely in that green zone. But we have never seen the sun be green. Here our eyes come into play: the color of a star is not an intrinsic property of light, but rather an interpretation of our eyes against that jumble of photons. The eyes have three types of coneseach of them sensitive to red, green or blue light respectively. That is, if an object emits or reflects red light, only the red cones would send a signal to the brain to perceive it that way. Obviously the brain can interpret more colors: the key is that these three types of cones can send the signal in different proportions and then they are mixed in the brain. Precisely what happens with the Sun, which although it emits the greatest amount of light in blue and green, simultaneously emits so much red and blue light that the combination ends up averaging in the brain as white (another thing is that is classified like a yellow dwarf star. Due to the physics of black bodies, there is no stellar temperature that excites only the green cones of the eye without also activating the red and blue cones. And since cameras imitate the vision of the eyes, the stars do not appear green in the photos either. Yes, but. After all this explanation it turns out that there are a couple of stars that some people claim to see green, but no: in reality They are brain tricks. It is the case of Almacha star system formed by a giant, bright orange star and a triple system of three blue stars so close that from our perspective they cannot be distinguished separately, but rather blend into a point of light. Our brain tries to balance orange with its complementary color, green. The result: we can perceive it as orange. Of course, the cameras do not take issue with this biological processing error. The other is Zubeneschamalia solitary star whose color we confuse either by subjective perception or by effects of the atmosphere. That doesn’t mean there aren’t green celestial objects in the sky. There are a few nebulae with a very striking green tone thanks to the intense emission of oxygen atoms, we have also seen emerald green comets (the blame lies with diatomic carbon) or planets like Earth for obvious reasons and even Uranus because of the methane in its atmosphere and how it absorbs light. In Xataka | We thought that the red color in a galaxy told us that it was dead. There are those who believe that we are wrong In Xataka | We have been deceived by the distances of the Solar System: the closest neighbor to Neptune is Mercury Cover | Parastoo Maleki

In their obsession with overprotecting them, parents are depriving their children of something very important: frustration.

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We live in the era of hyperparentingsince never before had there been so much information about parenting, and paradoxically, never had so much guilt been felt. The fact that some parents are terrified of giving a bad answer, a separation or too much screen time will irreversibly ruin their children. But the truth is that we are overprotecting children. An expert. Faced with this anxiety, child psychologist Ana Aznarauthor of ‘Educating also means saying no’proposes a paradigm shift: realistic parenting. His thesis is that overprotection is creating a generation with low tolerance for frustration and that parents need to regain authority (not authoritarianism). And given this, science has a lot to say about the true weight that parental decisions have in children’s adult lives. The myth of determinism. One of the greatest sources of anxiety in these cases may be the idea that what happens in childhood is an immutable destiny. But this is not entirely the case. A classic study that followed thousands of people born in 1958 and 1970 pointed out that all childhood variables together, such as economic status, family traits or health, only explain between 2.8% and 6.8% of the variability in life satisfaction at age 30. This does not mean that childhood does not matter, of course it does. The evidence indicates that human development is cumulative and plastic, causing subsequent factors to take a greater step in the adult phase. With this we we refer to adolescencethe first social relationships or the work environment that have great weight. Paradox of overprotection. Although the pretext, which is basically to avoid the child’s suffering, the truth is that this style of education has important side effects. This is something that has been validated by sciencewhich found that parental overprotection is positively associated with internalizing problems such as anxiety and depression. The mechanism is perverse in this case, because by “clearing the path” of obstacles, we prevent the child from Build your frustration tolerance. Recent studies link intrusive parental overinvolvement with less autonomy and poorer emotional adjustment in adulthood. This means that making a child never get frustrated by being in a constant cloud makes the adult break down at the first “no” in real life like at work. The problem of screens. Currently one of the big questions is when to give the mobile phone to children for the first time. Science suggests that the important thing is to offer it but educate about its use from the first moment. A study on the Canadian population showed a clear relationship here: exceeding 2 hours a day of recreational time in front of screens is associated with a greater probability of anxiety and psychosocial difficulties. The real thing. However, the key nuance provided by organizations such as the American Pediatric Association is displacement. The problem is not always the pixels themselves, but what the child stop doing by looking at the screen: sleeping less, moving less and socializing less face to face. The strategy backed by science is not just to “remove your cell phone”, but to “fill your life” with alternatives such as sports, sleep or free play and monitor the quality of the content, rather than obsessing only with the stopwatch. The conflict. Something that can be deeply internalized in families is that witnessing a divorce within the family destroys a child. But the reality is that the most important thing is the climate of coexistence as a study that analyzed hundreds of families points out. This clearly showed that the quality of the relationship between parents, such as support or the absence of hostile conflict, is a much more reliable predictor of child well-being than whether or not they live with both biological parents. In this way, a home with two parents in constant war is, according to PMC data, a more toxic environment for the development of children than having a single-parent family where there is calm. Images | Christian Mai In Xataka | Those born between 1950 and 1970 have a psychological advantage over other generations: they are entering their “peak”

online sale on the day

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Costco, the American chain that has been operating in Spain for more than ten years, has recently launched your online sales service with delivery on the same day. It does so together with Instacart, a delivery platform with which it already collaborates in North America. It’s not that the chain is having great results in our country, but she is convinced that her large-scale American business model can end up being profitable in Spain. What’s up with Costco?. The chain really represents in Spain the opposite of the model that predominates in the country: it charges for membership (about 36 euros per year), operates with giant warehouses of more than 15,000 square meters and sells products in a wholesale format. Now it goes one step further and enters a field that Mercadona, which we could consider its rival (although with different concepts), has already dominated for a long time: home delivery. How it works. Costco members in Spain can place orders through your website and receive them on the same day in Madrid, Bilbao, Seville and Zaragoza, the four cities where the chain has a physical presence. Prices are the same as in store, but there is a fixed service fee of 15 euros per order and a minimum purchase of 35 euros. The logistics model. Instacart, which manages the operation through Storefront Pro, says it will work with “European partner companies” for the selection, packaging and delivery of orders. According to its official statement, the logistics models “align with local laws, regulations and market conditions.” Just like account CincoDías media, in the United States, Instacart operates with a ‘gig economy’ model in which delivery people only charge for deliveries made, choose the orders they prefer and are rated by customers. This system, precisely, is what motivated the Government in Spain to approve Rider Law in 2021, which forces delivery workers to be hired. Between the lines. Costco maintains its loss-controlled strategy while building market share. Just like we explained In October, at that time the Spanish subsidiary had accumulated 150 million euros in the red since 2014, although in 2024 its sales shot up to 607 million and added 15% more partners. Now it is betting on a channel that can accelerate its growth without having to open more physical centers, something expensive and slow. The clash of models. Mercadona dominates Spain with a 28% market share, having achieved this through stores close to its customers and optimized margins. Costco, for its part, pursues volume, loyalty and gradual expansion. It remains to be seen whether or not the arrival of the online service can attract more customers and whether the American hypermarket model also has a place in Spain. Expansion in Europe. Along with Spain, Costco has launched the same service in France, where it operates in the metropolitan area of ​​Paris and Mulhouse. “This step enables a new level of accessibility and ease for its members,” said Chris Rogers, CEO of Instacart. For his part, Pierre Riel, executive vice president of Costco’s International Division, stressed that the service “complements the services we already offer” and represents “another step to make Costco more accessible.” Cover image | Marcus Reubenstein In Xataka | The white label has been conquering supermarkets for years. It has done so well that it is now the pillar of the Spanish diet

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