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What is an attosecond? A physical chemist explains the tiny time scale behind Nobel Prize-winning research

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What is an attosecond? A physical chemist explains the tiny time scale behind Nobel Prize-winning research

Work in attosecond physics has led to a better understanding of how electrons move around.
Oselote/iStock via Getty Images

Aaron W. Harrison, Austin College

A group of three researchers earned the 2023 Nobel Prize in physics for work that has revolutionized how scientists study the electron – by illuminating molecules with attosecond-long flashes of light. But how long is an attosecond, and what can these infinitesimally short pulses tell researchers about the nature of matter?

I first learned of this area of research as a graduate student in physical chemistry. My doctoral adviser’s group had a dedicated to studying chemical reactions with attosecond pulses. Before understanding why attosecond research resulted in the most prestigious award in the sciences, it helps to understand what an attosecond pulse of light is.

How long is an attosecond?

“Atto” is the scientific notation prefix that represents 10⁻¹⁸, which is a decimal point followed by 17 zeroes and a 1. So a flash of light lasting an attosecond, or 0.000000000000000001 of a second, is an extremely short pulse of light.

In fact, there are approximately as many attoseconds in one second as there are seconds in the age of the universe.

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A diagram showing an attosecond, depicted as an orange collection of hexagons, on the left, with the age of the universe, depicted as a dark vacuum on the right, and a heartbeat, depicted as a human heart, in the middle.
An attosecond is incredibly small when to a second.
©Johan Jarnestad/The Royal Swedish Academy of Sciences, CC BY-NC-ND

Previously, scientists could study the motion of heavier and slower-moving atomic nuclei with femtosecond (10⁻¹⁵) light pulses. One thousand attoseconds are in 1 femtosecond. But researchers couldn’t see movement on the electron scale until they could generate attosecond light pulses – electrons move too fast for scientists to parse exactly what they are up to at the femtosecond level.

Attosecond pulses

The rearrangement of electrons in atoms and molecules guides a lot of processes in physics, and it underlies practically every part of chemistry. Therefore, researchers have put a lot of effort into figuring out how electrons are moving and rearranging.

However, electrons move around very rapidly in physical and chemical processes, making them difficult to study. To investigate these processes, scientists use spectroscopy, a method of examining how matter absorbs or emits light. In order to follow the electrons in real time, researchers need a pulse of light that is shorter than the time it takes for electrons to rearrange.

Pump-probe spectroscopy is a common technique in physics and chemistry and can be performed with attosecond light pulses.

As an analogy, imagine a camera that could only take longer exposures, around 1 second long. Things in motion, like a person running toward the camera or a bird flying across the sky, would appear blurry in the photos taken, and it would be difficult to see exactly what was going on.

Then, imagine you use a camera with a 1 millisecond exposure. Now, motions that were previously smeared out would be nicely resolved into clear and precise snapshots. That’s how using the attosecond scale, rather than the femtosecond scale, can illuminate electron behavior.

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Attosecond research

So what kind of research questions can attosecond pulses answer?

For one, breaking a chemical bond is a fundamental in nature where electrons that are shared between two atoms separate out into unbound atoms. The previously shared electrons undergo ultrafast changes during this process, and attosecond pulses made it possible for researchers to follow the real-time breaking of a chemical bond.

The ability to generate attosecond pulses – the research for which three researchers earned the 2023 Nobel Prize in physics – first became possible in the early 2000s, and the field has continued to grow rapidly since. By providing shorter snapshots of atoms and molecules, attosecond spectroscopy has helped researchers understand electron behavior in single molecules, such as how electron charge migrates and how chemical bonds between atoms break.

On a larger scale, attosecond technology has also been applied to studying how electrons behave in liquid water as well as electron transfer in solid-state semiconductors. As researchers continue to improve their ability to produce attosecond light pulses, they’ll gain a deeper understanding of the basic particles that make up matter.The Conversation

Aaron W. Harrison, Assistant Professor of Chemistry, Austin College

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This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Conversation

Why can’t it always be summer? It’s all about the Earth’s tilt

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theconversation.com – Stephanie Spera, Assistant Professor of Geography and the , of Richmond – 2024-09-20 10:34:02

One hemisphere has summer, while the opposite has winter.

Prasit photo/Moment via Getty Images

Stephanie Spera, University of Richmond

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Curious Kids is a for of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.


Why can’t it always be summer? – Amanda, age 5, Chile


With its long days just itching to be spent by doing nothing, summer really can be an enchanting season. As Jenny Han wrote in the young adult novel “The Summer I Turned Pretty”: “Everything good, everything magical happens between the months of June and August.”

But all good things must to an end, and summer cannot last forever. There’s both a simple reason and a more complicated one. The simple reason is that it can’t always be summer because the Earth is tilted. The more complicated answer requires some geometry.

I’m a professor of geography and the environment who has studied seasonal changes on the landscape. Here’s what seasons have to do with our planet’s position as it moves through the solar system.

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This animation shows why the Earth has seasons.

Closeness to the Sun doesn’t explain seasons

First, you need to know that the Earth is a sphere – technically, an oblate spheroid. That means Earth has a round shape a little wider than it is tall.

Every year, Earth travels in its orbit to make one revolution around the Sun. The Earth’s orbit is an ellipse, which is more like an oval than a circle. So there are times when Earth is closer to the Sun and times when it’s farther away.

A lot of people assume this distance is why we have seasons. But these people would be wrong. In the United States, the Earth is 3 million miles closer to the Sun during winter than in the summer.

An artistic diagram shows the Earth revolving around the Sun.

Our distance from the Sun is not why we have seasons.

NASA

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Spinning like a top

Now picture an imaginary line across Earth, right in the middle, at 0° latitude. This line is called the equator. If you drew it on a globe, the equator would pass through countries including Brazil, Kenya, Indonesia and Ecuador.

Everything north of the equator, including the United States, is considered the Northern Hemisphere, and everything south of the equator is the Southern Hemisphere.

Now think of the Earth’s axis as another imaginary line that runs vertically through the middle of the Earth, going from the North Pole to the South Pole.

As it orbits, or revolves, around the Sun, the Earth also rotates. That means it spins on its axis, like a top. The Earth takes one full year to revolve around the Sun and takes 24 hours, or one day, to do one full rotation on its axis.

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This axis is why we have day and night; during the day, we’re facing the Sun, and at night, we’re facing away.

But the Earth’s axis does not go directly up and down. Instead, its axis is always tilted at 23.5 degrees in the exact same direction, toward the North Star.

The Earth’s axis is tilted due to a giant object – perhaps an ancient planet – smashing into it billions of years ago. And it’s this tilt that causes seasons.

A series of diagrams showing the Earth's equator, axis and tilt.

Because of the tilt of the Earth, we are able to experience the seasons.

Stephanie Spera

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It’s all about the tilt

So that means in June, the Northern Hemisphere is tilted toward the Sun. That tilt means more sunlight, more solar energy, longer days – all the things that make summer, well, summer.

At the same time, the Southern Hemisphere is tilted away from the Sun. So countries such as Australia, Chile and Argentina are experiencing winter then.

To say it another way: As the Earth moves around the Sun throughout the year, the parts of the Earth getting the most sunlight are always changing.

Fast-forward to December, and Earth is on the exact opposite side of its orbit as where it was in June. It’s the Southern Hemisphere’s turn to be tilted toward the Sun, which means its summer happens in December, January and February.

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If Earth were not tilted at all, there would be no seasons. If it were tilted more than it is, there would be even more extreme seasons and drastic swings in temperature. Summers would be hotter and winters would be colder.

A diagram showing the Earth, its tilt and the Northern and Southern Hemispheres.

The Earth’s axis is always tilted at 23.5 degrees.

Stephanie Spera

Defining summer

to a meteorologist, climate scientist or author Jenny Han, and they’ll tell you that for those of us in the Northern Hemisphere, summer is June, July and August, the warmest months of the year.

But there’s another way to define summer. Talk to astronomers, and they’ll tell you the first day of summer is the summer solstice – the day of the year with the longest amount of daylight and shortest amount of darkness.

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The summer solstice occurs every year sometime between June 20 and June 22. And every day after, until the winter solstice in December, the Northern Hemisphere receives a little less daylight.

Summer officially ends on the autumnal equinox, the fall day when everywhere on Earth has an equal amount of daylight and night. The autumnal equinox happens every year on either September 22 or 23.

But whether you view summer like Jenny Han or like an astronomer, one thing is certain: Either way, summer must come to an end. But the season and the magic it brings with it will be back before you know it.


Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the where you .

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And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.The Conversation

Stephanie Spera, Assistant Professor of Geography and the Environment, University of Richmond

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Men are carrying the brunt of the ‘loneliness epidemic’ amid potent societal pressures

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theconversation.com – Alvin Thomas, Associate Professor, Phyllis Northway Faculty Fellow, University of Wisconsin-Madison – 2024-09-20 07:27:29

Singer Justin Bieber is seen on May 16, 2024, in Los Angeles.
BG046/Bauer-Griffin/GC Images

Alvin Thomas, University of Wisconsin-Madison and Quinn Kinzer, University of Wisconsin-Madison

A few weeks before Justin Bieber and his wife, Hailey, announced in May 2024 that they were expecting, the pop icon posted a selfie where he appears tearful and distraught.

While attention quickly pivoted to the pregnancy, there was little attention paid to the significance of a male celebrity and expectant father publicly sharing his vulnerability.

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Yet Bieber’s social media post is notable for making his internal struggle visible.

Emotional pain is linked to serious health issues. But the public’s response to male expressions of emotion and vulnerability is often minimizing, if not dismissive. In response to Bieber’s tearful post, for example, Hailey described him as a “pretty crier.”

A year ago, the Canadian rapper Dax released the song “To Be a Man.” He said at the time: “This is a song I poured my heart into. I’m praying this reaches everyone who needs it.”

, the song’s message remains timely. It includes the lyrics:

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Yeah, I know this life can really beat you down, uh
You wanna scream but you won’t make a sound, uh
Got so much weight that you’ve been holdin’
But won’t show any emotion, as a man, that goes unspoken

As researchers who study fatherhood and the roles that men play in their families, we recognize the loneliness and pain in these lyrics. We have heard fathers describe the toll of attempting to keep a lid on their feelings.

In a recent study we conducted on 75 new and expectant Black fathers, they spoke of the need to address individual and collective trauma. This, they said, would ultimately help their families. But they said resources to help men with their mental health are often unavailable or very limited. They said they often feel invisible to health providers.

“Being a father and a man,” one participant said, “you have to keep the peace and be strong on the outside. But on the inside, you know, you’re falling apart.”

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Dax’s lyrics and our research reflect an enduring social health challenge – the deafening silence that typically surrounds men’s mental health.

The toll of isolation on men

In May 2023, U.S. Surgeon General Dr. Vivek Murthy released an advisory highlighting what he described as an epidemic of loneliness and isolation in the country. Our research confirms this scourge.

Since men’s social support networks – colleagues, , close childhood friends – are often less robust than women’s, the epidemic disproportionately impacts men. The resulting solitude has very real health consequences.

Man walks alone along beach.
Studies show that loneliness is associated with negative health outcomes like elevated levels of heart disease and a higher risk of dementia.
Matthias Balk/picture alliance via Getty Images

In Murthy’s , loneliness is associated with negative health outcomes, including a “29% increased risk of heart disease, a 32% increased risk of stroke, and a 50% increased risk of developing dementia for older adults. Additionally, lacking social connection increases risk of premature death by more than 60%.”

While Murthy’s report focuses on both men and women, research shows that men are less likely than women to seek mental health services. Additionally, men hold more negative attitudes toward seeking help, and they prematurely terminate treatment more often than women.

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With these consequences in mind, a caring society may ask: Why are men carrying the brunt of this health risk, and what can be done about it?

Redefining men’s value beyond breadwinning

Many factors can contribute to feelings of isolation and disconnection among men.

In “To Be A Man,” Dax points toward one prominent factor:

As a man, we gotta pave our way
Our only function is to work and slave
There’s no respect for you if you ain’t paid
You’re disregarded as a human and you can’t complain

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Traditional definitions of masculinity emphasize the importance of men’s role as breadwinners.

An uncertain economy and increasingly expensive housing and food prices make the ability to financially for a family elusive for many men. These factors also undermine men’s sense of self and contribute to loneliness and feelings of isolation.

As partners and fathers, men are still often perceived as deficient if they can’t provide economically. And societal norms stress that they are not valued for their capacity as caregivers, even if they are more involved in raising their children than ever before.

This is out of touch with reality.

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Men play an important role as caregivers in their children’s lives, according to our research, and exert a powerful influence on children’s health and well-being. Men also find meaning in their roles as fathers.

As Dax says:

As a man, our son is our horizon

The cost of suppressed vulnerability

Beyond pressures to provide, men also have to overcome enduring stereotypes that suggest they should be stoic and keep their fears and sadness to themselves.

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Here, too, gender norms are in need of an . and men need to feel comfortable presenting their true, authentic selves to the world. When they suppress their vulnerability, it creates a barrier to seeking help. It also perpetuates stigma and the epidemic of loneliness.

Man sitting in hospital room.
Men are less likely than women to seek mental health care.
Getty Images

There is a complex interplay between society’s assumptions and beliefs about men and fatherhood.

Men, consequently, are less likely than women to seek mental health services. Health providers, as a result, are more likely to underdiagnose and misdiagnose men. Additionally, when health resources are made available, they are often not tailored to men’s needs.

Societal expectations can create unbearable pressure for men. And the most marginalized groups, like low-income Black fathers, bear a disproportionate burden, research shows. This became more evident during the COVID-19 pandemic, when Black fathers working in high-risk and essential jobs prioritized supporting their children and families over their own risk of infection and mental health.

As men continue to redefine their roles within families and communities, it’s important for society to create a space that acknowledges and embraces their vulnerabilities and full humanity in all social roles.

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Men need outlets for their pain. They would benefit from relationships – with partners, family and friends – that support and nurture them in times of joy and through the emotional challenges. Their loneliness will continue to be disproportionate without the necessary connection to services.

Men can consider engaging in low-stakes discussion groups in their communities, with online groups and in their churches. They may also seek out therapists in person or online for introductory sessions to test out the therapeutic interaction before establishing a more consistent pattern of therapy services.

In “To Be a Man,” Dax sings:

No wonder most men are so depressed
All the things that they can’t express
It’s the circle of life, as a man, you provide
They don’t know what you’re worth ‘til the day that you die

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As the Biebers adjust to life as parents, Justin may find people he can talk to about his experiences and emotions, people who see and value him fully. And we hope the same for every man and father, living their life out of the and doing the best they can for themselves and for their family.The Conversation

Alvin Thomas, Associate Professor, Phyllis Northway Faculty Fellow, University of Wisconsin-Madison and Quinn Kinzer, Graduate student and PhD Candidate, Department of Consumer Science, University of Wisconsin-Madison

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Wind phones help the bereaved deal with death, loss and grief − a clinical social worker explains the vital role of the old-fashioned rotary phone

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theconversation.com – Taryn Lindhorst, Professor of Social Work, of Washington – 2024-09-20 07:26:00

The first wind phone was built in 2010 in Otsuchi, Japan.
Matthew Komatsu/Wikimedia Commons

Taryn Lindhorst, University of Washington

My mother died in my home in hospice in 2020, on the day my of Washington went into COVID-19 lockdown. Her body was taken away, but none of the usual touchstones for grief were available to our family. There was no funeral or supportive gathering, no deliveries of food and no hugs. For months afterward, as the nationwide lockdown continued, thousands of other families like mine saw these rituals – society’s social supports for grieving – stripped away.

As a clinical social worker and health scholar with 40 years of experience in end-of- care and bereavement, I knew that I needed some way to tend to my grief for my mother. While in lockdown, I began looking for resources to help me. Then I heard about the wind phone.

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One of the wind phones is in Olympia, Washington.

What is a wind phone?

At its simplest, a wind phone is a rotary or push-button phone located in a secluded spot in nature, usually within a booth-type structure and often next to a chair or bench. The phone line is disconnected.

People use the wind phone to “call” and have a one-way conversation with deceased loved ones. Here they can say the things left unsaid. Wind phones offer a setting for the person to tell the story of their grief, to reminiscence and to continue to connect to the person who is gone. For many, it is a deeply moving, life-affirming experience.

About 200 wind phones are scattered throughout the United States. Wind phones are open to the public, of charge and usually found in parks, along walking trails and on church grounds. Typically, they are built by those who want to honor a lost loved one.

The wind phone began in Japan in 2010, when Itaru Sasaki, a garden designer, built a phone booth in his yard so he could “” with a deceased relative. Months later, the Fukushima earthquake and tsunami hit; in a matter of minutes, more than 20,000 people died.

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Sasaki opened the phone booth to his neighbors, who urgently needed a place to express their grief. Word spread, and soon people came on pilgrimage from around Japan to speak through the “phone of the wind” to those they loved.

Since then, wind phones have spread throughout the world.

The story of the first wind phone.

Do wind phones work?

Grief is a universal human experience; it affects us psychologically, socially, spiritually and even biologically. Some of our first rituals as humans are those surrounding death, with some practices more than 10,000 years old, such as using flowers in burial ceremonies and positioning the deceased as if asleep, with a pillow under their head.

Yet there is still no clear guidance on how people should deal with grief. But the power of speaking to rather than about the deceased has long been at the root of many grief interventions worldwide, including Gestalt therapy, which encourages to role play or reenact life experiences. A common approach taken by a Gestalt therapist is letting the client speak directly to an empty chair while imagining the person they’ve lost is sitting there. A similar approach is to write a letter to the deceased and then read it out loud.

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What these techniques and the wind phone have in common is the use of a conversational approach that allows connection, reflection and the safe release of strong emotions. By their very nature, both speaking and writing encourage direct emotional expression; this helps release physical and psychological tension in the body.

What’s more, the spontaneity of saying it out loud can reveal subconscious insights. That’s because talking can outpace internal censorship of painful .

Using a wind phone can elicit strong feelings, and not all are positive ones. They may elicit tears, anger, guilt and shame. Some conversations become confessional. The wind phone setting provides a way to contain feelings that the bereaved worry might overwhelm them.

Research is needed

In American culture, it’s common to talk about obtaining closure for the loss of a loved one – to get over it and move on. It is true that the initial period of deep sadness and trauma typically fades over time, but some grief can persist across a lifetime. In the weeks, months and years after the death, feelings can erupt unexpectedly in “grief attacks,” or as sudden waves of emotion, triggered by a memory, a smell, an event or a thought.

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To my knowledge, no research has been conducted on wind phones, so it’s not yet possible to say from a scientific perspective whether they definitively help a person cope with their grief. This is not surprising; studies on grief have not received as much research attention as mental disorders, such as depression or anxiety, although grief can lead to either of these disorders.

Yet the rapid spread of wind phones over the past decade suggests, if nothing else, that there is an almost universal need for those in mourning to engage with grief. And for the thousands who have tried it, there is comfort to be found through a one-way call.The Conversation

Taryn Lindhorst, Professor of Social Work, University of Washington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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