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  • Scientists Superheat Gold, Defying Conventional Physical Laws

    Scientists Superheat Gold, Defying Conventional Physical Laws

    In a pioneering experiment, scientists heated gold to temperatures well beyond the previously assumed thermodynamic limit for solids. They used ultrafast, intense laser pulses to heat a thin gold sheet without melting it.
    Image Credits: Metropoles

    In a pioneering experiment, scientists heated gold to temperatures well beyond the previously assumed thermodynamic limit for solids. They used ultrafast, intense laser pulses to heat a thin gold sheet without melting it.

    Discovery Challenges Long-Held Theory on Thermal Limits of Solids

    Published in Nature on July 23, the discovery challenges the “entropy catastrophe” theory, which held that solids can’t survive temperatures triple their melting point.

    Yet, the new research revealed that gold remained solid at over 14 times its melting point of 1337 Kelvin (1063°C).

    The key lies in how quickly the material was heated. Thomas White’s team at the University of Nevada used femtosecond laser pulses to heat gold rapidly without melting it.

    Ultrafast Heating Locks Atomic Structure, Preventing Melting

    The extremely fast heating stopped the gold atoms from transitioning into a liquid. The rapid energy delivery locked the atomic structure in place, leaving no time for the heat to trigger melting.

    Scientists used the Linac Coherent Light Source (LCLS) at SLAC to precisely measure the extreme temperatures. They directed ultra-bright X-rays through the superheated gold, tracking atomic vibrations to calculate the material’s internal temperature.

    Rapid Reactions Bypass Conventional Thermodynamic Limits

    Surprising as they are, the findings don’t break thermodynamic laws—they show some reactions happen too quickly for those laws to apply normally.

    According to the researchers, the study not only redefines the temperature limits at which materials can remain solid but also introduces a new approach for measuring heat in extreme conditions.

    Understanding material behavior under extreme conditions is key to advances in fusion energy, planetary modeling, and the study of hot dense matter.

    REad the original article: Metropoles

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  • A Few Minutes of Exercise Today Could Benefit Your Brain Tomorrow

    A Few Minutes of Exercise Today Could Benefit Your Brain Tomorrow

    Credit: Pixabay

    Even just a few minutes of physical activity can have a significant impact on brain function, with benefits for memory and cognitive abilities potentially lasting longer than previously believed.

    Study Shows Exercise Improves Cognitive Function Beyond the Day of Activity

    A study conducted by researchers at University College London and the University of Oxford has shown that the cognitive improvements from exercise last not just for hours, but well into the next day.

    The experiment, known as ‘micro-longitudinal,’ involved 76 cognitively healthy British adults aged 50 to 83. Over eight days, participants completed daily cognitive tests assessing attention, memory, executive function, processing speed, and psychomotor speed, which is the ability to quickly respond to environmental changes.

    Throughout the study, participants wore devices to track their physical activity and sleep patterns while going about their regular routines.

    Moderate Physical Activity Enhances Memory and Cognitive Function

    After analyzing the data, the researchers found that memory scores were highest for participants who had engaged in more moderate physical activity the previous day, such as a brisk walk or any activity that raised the heart rate. For every additional 30 minutes of moderate exercise, participants showed a notable improvement in episodic and working memory scores, with about a 0.15 standard deviation increase.

    Conversely, sedentary behavior the previous day negatively impacted working memory.

    These results remained consistent even after accounting for sleep patterns from the previous night,said Mikaela Bloomberg, the study’s lead author from University College London.

    The team also examined the impact of sleep independently of physical activity. They found that longer sleep durations linked to better episodic memory and psychomotor speed.Notably, extended periods of slow-wave sleep improved episodic memory, while more REM sleep correlated with better attention scores the following day.

    Bloomberg noted that the study was small and further research with a larger sample is needed to confirm these findings.

    Longer Lasting Cognitive Benefits of Exercise

    Although exercise is well known for providing short-term cognitive benefits, the duration and persistence of these effects remain uncertain.

    Co-author Andrew Steptoe, an epidemiologist at UCL, remarked that the study suggests that the immediate cognitive benefits of exercise may last longer than previously thought and highlights the independent role of good sleep in enhancing cognitive performance.

    Study that looked at correct matches in a game of memory among males and females immediately after just 5 minutes of exercise. (Most et al., Cognitive Research: Principles and Implications, 2017)

    Exercise improves blood flow to the brain, stimulating the release of neurotransmitters such as endorphins. One theory is that physical activity enhances the connectivity of neurons in the hippocampus, a region of the brain involved in memory and learning, which may help improve memory function.

    Exercise’s Potential to Delay Cognitive Decline

    Recent research has also shown that regular exercise can increase the size of the hippocampus, potentially delaying cognitive decline. Additionally, a study in Australia found that high-intensity interval training (HIIT) maintained for six months can help preserve cognitive function for years.

    While intense exercise may have some health risks and isn’t feasible for everyone, the fact that even moderate activity can improve brain function is encouraging.

    It’s becoming clear that sedentary lifestyles are detrimental to both physical health and cognitive function.

    Read the original article on: Science Alert

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