Empowered by artificial intelligence technologies, computers today can engage in convincing conversations with people, compose songs, paint paintings, play chess and go, and diagnose diseases, to name just a few examples of their technological prowess.
These successes could be taken to indicate that computation has no limits. To see if that’s the case, it’s important to understand what makes a computer powerful.
There are two aspects to a computer’s power: the number of operations its hardware can execute per second and the efficiency of the algorithms it runs. The hardware speed is limited by the laws of physics. Algorithms – basically sets of instructions – are written by humans and translated into a sequence of operations that computer hardware can execute. Even if a computer’s speed could reach the physical limit, computational hurdles remain due to the limits of algorithms.
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- Autor: Jie Wang
Brad Reisfeld, Colorado State University
People are exposed to numerous chemicals throughout their lifetimes. These chemicals can be from the air, foods, personal care items, household products and medications. Unfortunately, exposure to certain chemicals can cause harmful health effects, including cancer. Substances that cause cancer are called carcinogens. Familiar examples include tobacco smoke, radon, asbestos and diesel engine exhaust.
To protect the health of the public, national and international health agencies evaluate many new and existing chemicals to determine if they are likely to be carcinogens in a process called cancer hazard identification. If agencies judge the chemicals to be carcinogenic, they conduct further assessments to determine the level of risk, and legislators may put regulations in place to limit, or completely halt, the production and use of these chemicals.
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- Autor: Brad Reisfeld
Emma Beckett, University of Newcastle
Many of us want (or should I say need?) our morning coffee to give us our “get up and go”. Altogether, the people of the world drink more than two billion cups of coffee each day.
You might think coffee gives you the energy to get through the morning or the day, but coffee might not be giving you as much as you think.
The main stimulant in coffee is the caffeine. And the main way caffeine works is by changing the way the cells in our brain interact with a compound called adenosine.
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- Autor: Emma Beckett
E greu să fi ratat știrile despre progresele inteligenței artificiale din ultimele luni, în special cele din domeniul instrumentelor de IA conversaționale, precum ChatGPT. Pe de altă parte, e greu să nu fi observat lipsa de progres a motorului de căutare Google, care a modificat atât de mult algoritmii secreți, că răspunsurile pe subiecte tehnice sunt de prea multe ori de pe site-uri rusești care au motoare de traducere automată în toate limbile. Dacă ar elimina Wikipedia din rezultatele căutărilor, Google în limba română ar deveni aproape inutil.
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- Autor: Iosif A.
Hazel Flight, Edge Hill University
There’s been a lot of chat on social media over the past few months about the importance of magnesium supplements. Many suggest that symptoms such as trouble sleeping, tense muscles and low energy are all signs you’re deficient and should be taking a magnesium supplement.
As it turns out, many of us probably are somewhat deficient in magnesium. According to research, most aren’t consuming the recommended amount of magnesium to support our body’s needs. It’s also estimated that in developed countries, between 10-30% of the population has a slight magnesium deficiency.
Magnesium is one of the many micronutirents the body requires to remain healthy. It’s essential for helping more than 300 enzymes carry out numerous chemical processes in the body, including those that produce proteins, support strong bones, control blood sugar and blood pressure and maintain healthy muscles and nerves. Magnesium also acts as an electrical conductor that helps the heart beat and contracts muscles.
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- Autor: Hazel Flight
Lorcan Conlon, Australian National University and Syed Assad, Australian National University
Almost a century ago, German physicist Werner Heisenberg realised the laws of quantum mechanics placed some fundamental limits on how accurately we can measure certain properties of microscopic objects.
However, the laws of quantum mechanics can also offer ways to make measurements more accurate than would otherwise be possible.
In new research published in Nature Physics, we have outlined a way to achieve more accurate measurements of microscopic objects using quantum computers. This could prove useful in a huge range of next-generation technologies, including biomedical sensing, laser ranging and quantum communications.
We were also able to push beyond the limits of a variation of Heisenberg’s “uncertainty principle” in certain circumstances, suggesting different uncertainty principles may be necessary in different scenarios.
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- Autor: Lorcan Conlon și Syed Assad
Mandy Hagstrom, UNSW Sydney and Mitchell Gibbs, UNSW Sydney
People asking for exercise advice are usually looking for a simple answer. Do this over that. Do this many of that thing, for this long. Get these gains. In reality, things are never that simple.
That’s certainly true for the age old question of how often one should change up one’s exercise routine. Unfortunately, there’s no single, perfectly designed study that answers this question exactly; much depends on things such as how fit you already are, your goals and how you train.
But if you’re thinking about changing your routine, here are some factors to consider.
- Detalii
- Autor: Mandy Hagstrom și Mitchell Gibbs
Ian Whittaker, Nottingham Trent University
Lightning may look beautiful but every year it kills thousands of people, does huge amounts of damage to buildings and infrastructure, and causes power outages.
The only protection we have is lightning rods, which were invented 300 years ago and only protect a small area.
The cost of damage from lightning strikes to buildings is hard to determine globally, but insurance company payouts to cover repairs to homes and businesses were roughly US$2 billion (£1.6 billion) in 2020 in the US. Insurance data from the UK suggests the costs of covering lightning strikes are increasing.
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- Autor: Ian Whittaker
Semaglutida, vândută sub formă de Ozempic și Wegovy, a devenit cunoscută publicului ca un medicament eficient pentru pierderea în greutate anul trecut, promovată intens pe rețelele sociale (inclusiv de celebrități precum Elon Musk).
Creșterea neașteptată a cererii pentru medicament a provocat o penurie la nivel mondial. Producerea medicamentului, livrat sub formă de injecție săptămânală autoadministrată, implică o configurație unică de producție, așa că va dura ceva timp pentru a restabili aprovizionarea globală.
Semaglutida (sub formă de Ozempic) este un medicament eficient în gestionarea diabetului de tip 2, iar deficitul le-a pus probleme unor bolnavi de diabet în ce privește găsirea în farmacii a tratamentului. Pentru multe persoane cu diabet, Ozempic asigură controlul nivelului de zahăr din sânge (și ajută la slăbit) mai eficient decât alte medicamente.
Semaglutida sub formă de Wegovy este concepută special pentru pierderea în greutate. Autoritățile de reglementare din Statele Unite și Australia au aprobat recent Wegovy în acest scop.
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- Autor: Iosif A.
Jeremy Berg, University of Pittsburgh
All life is made up of cells several magnitudes smaller than a grain of salt. Their seemingly simple-looking structures mask the intricate and complex molecular activity that enables them to carry out the functions that sustain life. Researchers are beginning to be able to visualize this activity to a level of detail they haven’t been able to before.
Biological structures can be visualized by either starting at the level of the whole organism and working down, or starting at the level of single atoms and working up. However, there has been a resolution gap between a cell’s smallest structures, such as the cytoskeleton that supports the cell’s shape, and its largest structures, such as the ribosomes that make proteins in cells.
- Detalii
- Autor: Jeremy Berg
NASA / Goddard Space Flight Center / Jeremy Schnittman
Sam Baron, Australian Catholic University
Black holes form natural time machines that allow travel to both the past and the future. But don’t expect to be heading back to visit the dinosaurs any time soon.
At present, we don’t have spacecraft that could get us anywhere near a black hole. But, even leaving that small detail aside, attempting to travel into the past using a black hole might be the last thing you ever do.
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- Autor: Sam Baron
Corey J. A. Bradshaw, Flinders University and Giovanni Strona, University of Helsinki
Climate change is one of the main drivers of species loss globally. We know more plants and animals will die as heatwaves, bushfires, droughts and other natural disasters worsen.
But to date, science has vastly underestimated the true toll climate change and habitat destruction will have on biodiversity. That’s because it has largely neglected to consider the extent of “co-extinctions”: when species go extinct because other species on which they depend die out.
Our new research shows 10% of land animals could disappear from particular geographic areas by 2050, and almost 30% by 2100. This is more than double previous predictions. It means children born today who live to their 70s will witness literally thousands of animals disappear in their lifetime, from lizards and frogs to iconic mammals such as elephants and koalas.
But if we manage to dramatically reduce carbon emissions globally, we could save thousands of species from local extinction this century alone.
- Detalii
- Autor: Iosif A.
John Pasley, University of York
Researchers in the US have finally fulfilled an objective that was set decades ago: the achievement of “ignition” – getting more energy out than you put in – using nuclear fusion.
The scientists at the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF), where the experiment took place, are no doubt both excited and relieved to finally fulfil the promise implied by the name of their facility. But how excited should the rest of us be? What does this really mean for the possibility of creating effectively unlimited amounts of clean energy, and what else needs to happen to achieve this?
While the fusion reactions released more energy that was put in to the target, this doesn’t take into account the far greater quantities of energy needed to fire the laser that was used to drive the experiment. Also the burst of energy was not in the form of electricity, but a pulse of energetic particles. Harnessing those particles to produce electricity – and keeping a fusion reactor running constantly – will entail overcoming many hurdles.
Nevertheless, ignition is a remarkable achievement, and one which promises to stimulate interest in, and possibly also leverage funds for, tackling these further challenges.
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- Autor: John Pasley
Ana Clemente, Universitat de Barcelona
We humans, like other cognitive systems, are sensitive to our environment. We use sensory information to guide our behaviour. To be in the world.
We decide how to act based on the hedonic value we assign to objects, people, situations or events. We seek out and engage in behaviours that lead to positive or rewarding outcomes and avoid those that lead to negative or punitive consequences. We construct our knowledge of the world according to how much we like elements of the environment, and we do so by learning and generating expectations about them.
Hedonic valuation is, in short, a fundamental biological mechanism. Moreover, it is crucial for survival.
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- Autor: Ana Clemente
Astăzi cercetători americani au anunțat depășirea unui prag important în efortul de generare a energiei pe baza fuziunii nucleare. Succesul a constat în obținerea eficienței în raportul energie-consumată - energie obținută, în sensul că energia utilizată de laserul folosit pentru crearea fuziunii nucleare a fost mai mică decât cea produsă în urma fuziunii. Cu toate acestea, energia utilizată pentru alimentarea laserului a fost mult mai mare decât cea produsă în cadrul experimentului de fuziune.
Deși progresul realizat este foarte important, tehnologia are nevoie de îmbunătățiri semnificative pentru a putea fi folosită pentru a produce electricitate pentru uzul consumatorilor obișnuiți (localități, fabrici etc.).
- Detalii
- Autor: Iosif A.
