I’m An Astronomer And I Think Aliens May Be Out There – But UFO Sightings Aren’t Persuasive (Astronomy)

If intelligent aliens visit the Earth, it would be one of the most profound events in human history.

Many people who say they have seen UFOs are either dog walkers or smokers. Aaron Foster/THeImage Bank/Getty Images

Surveys show that nearly half of Americans believe that aliens have visited the Earth, either in the ancient past or recently. That percentage has been increasing. Belief in alien visitation is greater than belief that Bigfoot is a real creature, but less than belief that places can be haunted by spirits.

Scientists dismiss these beliefs as not representing real physical phenomena. They don’t deny the existence of intelligent aliens. But they set a high bar for proof that we’ve been visited by creatures from another star system. As Carl Sagan said, “Extraordinary claims require extraordinary evidence.”

I’m a professor of astronomy who has written extensively on the search for life in the universe. I also teach a free online class on astrobiology. Full disclosure: I have not personally seen a UFO.

Unidentified flying objects

UFO means unidentified flying object. Nothing more, nothing less.

There’s a long history of UFO sightings. Air Force studies of UFOs have been going on since the 1940s. In the United States, “ground zero” for UFOs occurred in 1947 in Roswell, New Mexico. The fact that the Roswell incident was soon explained as the crash landing of a military high-altitude balloon didn’t stem a tide of new sightings. The majority of UFOs appear to people in the United States. It’s curious that Asia and Africa have so few sightings despite their large populations, and even more surprising that the sightings stop at the Canadian and Mexican borders.

Most UFOs have mundane explanations. Over half can be attributed to meteors, fireballs and the planet Venus. Such bright objects are familiar to astronomers but are often not recognized by members of the public. Reports of visits from UFOs inexplicably peaked about six years ago.

Many people who say they have seen UFOs are either dog walkers or smokers. Why? Because they’re outside the most. Sightings concentrate in evening hours, particularly on Fridays, when many people are relaxing with one or more drinks.

A few people, like former NASA employee James Oberg, have the fortitude to track down and find conventional explanations for decades of UFO sightings. Most astronomers find the hypothesis of alien visits implausible, so they concentrate their energy on the exciting scientific search for life beyond the Earth.

Most UFO sightings have been in the United States.

Are we alone?

While UFOs continue to swirl in the popular culture, scientists are trying to answer the big question that is raised by UFOs: Are we alone?

Astronomers have discovered over 4,000 exoplanets, or planets orbiting other stars, a number that doubles every two years. Some of these exoplanets are considered habitable, since they are close to the Earth’s mass and at the right distance from their stars to have water on their surfaces. The nearest of these habitable planets are less than 20 light years away, in our cosmic “back yard.” Extrapolating from these results leads to a projection of 300 million habitable worlds in our galaxy. Each of these Earth-like planets is a potential biological experiment, and there have been billions of years since they formed for life to develop and for intelligence and technology to emerge.

Astronomers are very confident there is life beyond the Earth. As astronomer and ace exoplanet-hunter Geoff Marcy, puts it, “The universe is apparently bulging at the seams with the ingredients of biology.” There are many steps in the progression from Earths with suitable conditions for life to intelligent aliens hopping from star to star. Astronomers use the Drake Equation to estimate the number of technological alien civilizations in our galaxy. There are many uncertainties in the Drake Equation, but interpreting it in the light of recent exoplanet discoveries makes it very unlikely that we are the only, or the first, advanced civilization.

This confidence has fueled an active search for intelligent life, which has been unsuccessful so far. So researchers have recast the question “Are we alone?” to “Where are they?”

The absence of evidence for intelligent aliens is called the Fermi Paradox. Even if intelligent aliens do exist, there are a number of reasons why we might not have found them and they might not have found us. Scientists do not discount the idea of aliens. But they aren’t convinced by the evidence to date because it is unreliable, or because there are so many other more mundane explanations.

Modern myth and religion

UFOs are part of the landscape of conspiracy theories, including accounts of abduction by aliens and crop circles created by aliens. I remain skeptical that intelligent beings with vastly superior technology would travel trillion of miles just to press down our wheat.

It’s useful to consider UFOs as a cultural phenomenonDiana Pasulka, a professor at the University of North Carolina, notes that myths and religions are both means for dealing with unimaginable experiences. To my mind, UFOs have become a kind of new American religion

So no, I don’t think belief in UFOs is crazy, because some flying objects are unidentified, and the existence of intelligent aliens is scientifically plausible.

But a study of young adults did find that UFO belief is associated with schizotypal personality, a tendency toward social anxiety, paranoid ideas and transient psychosis. If you believe in UFOs, you might look at what other unconventional beliefs you have.

I’m not signing on to the UFO “religion,” so call me an agnostic. I recall the aphorism popularized by Carl Sagan, “It pays to keep an open mind, but not so open your brains fall out.”

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

Noise Pollution Hampers Animal Communication (Neuroscience)

Many species adjust their acoustic signals in response to human-made noise.

According to the World Health Organization, noise caused by human activities is one of the most hazardous forms of pollution. Now, a new study shows that human-made noise could hamper the communication of a variety of different animal species, from insects to frogs to birds. The meta-analysis found that animals exposed to human-made noise adjusted parameters of their acoustic signals, with potential consequences for mate attraction, territory defense, and parent-offspring communication.

Crested lark singing. Source: Artemy Voikhansky, via Wikimedia Commons. Distributed under a CC BY-SA 4.0 license.

Noise from human activities—such as transportation, shipping, and industry—differs from the naturally occurring soundscapes within which animals have evolved.

“It is typically loud and low-frequency,” says Hansjoerg Kunc, a biologist at Queen’s University Belfast who led the new study. “Many acoustic signals are in the same frequency range as anthropogenic (human-made) noise, whereas in nature, often noise is distributed more equally across a wider range of frequencies.”

Kunc, with colleague Rouven Schmidt, conducted a meta-analysis to investigate how species differ in their sensitivities to human-made noise. The researchers analyzed data from 31 different animal species, collected from 23 experimental studies in which animals were exposed to human-made noise. They studied the effects of noise on different components of acoustic signals, including the amplitude (loudness), frequency (pitch), complexity, duration, and rate. For each of these components, the researchers quantified both the magnitude and direction of adjustments in response to human-made noise.

Calling tree frog. Source: Brian Gratwicke, via Wikimedia Commons. Distributed under a CC BY 2.0 license.

Kunc and Schmidt found that animals adjust the components of their acoustic signals when exposed to noise, but the direction of adjustments differed among species. For instance, animals changed the duration of their signals in response to noise, but some species shortened them while others increased signal duration.

Given the importance of acoustic communication to many animals, Kunc and others are concerned that these adjustments could have repercussions for individual animals and, potentially, populations and ecosystems. Females of many species decide on mates based on acoustic qualities, such as signal duration, rate, and complexity. Noise-induced adjustments to male songs could make it more difficult for females to choose the highest quality mate.

The analysis shows that noise affects acoustic signals, but whether that change is positive or negative may depend on the species or context. For instance, calling louder may make it more likely that potential mates will hear you in a noisy environment, but may also attract more predators.

Male blackbird singing. Source: Malene Thyssen, via Wikimedia Commons. Distributed under a CC BY-SA 3.0 license.

Thus far, most of the studies of the effects of noise on animals have focused on the senders of acoustic signals. To unravel the downstream ecological effects of human-made noise, more research incorporating the receivers of such signals is needed. We still have a limited understanding of the potential consequences of noise for receivers, as well as the long-term effects of noise on populations and communities.

Kunc and Schmidt argue that the difference in sensitivity among species has important conservation implications. Their analysis shows it is not enough to assess the consequences of human-made noise for only a few species. A “one size fits all” legislation cannot protect species effectively since the magnitude and direction of responses vary so much among species.

“Given what we know about the effects of noise on animals, the best conservation approach to protect different species is to preserve the natural soundscapes to which animals have adapted,” says Kunc.

“When we protect habitats, we should be including natural soundscapes, free from anthropogenic noise, as part of those habitats.”

Reference: Kunc HP, Schmidt R. Species sensitivities to a global pollutant: A meta-analysis on acoustic signals in response to anthropogenic noise. Glob Change Biol. 2020;00:1–14. Doi: 10.1111/gcb.15428.

This article is originally written by Mary Bates, who specializes in neuroscience, animal behavior, psychology, and biology. This article is republished here from psychology today under common creative licenses.

How to Heal From Painful Memories? (Psychology)

Nick Morgan offers a way to start to let go of the past in his article.

We know from a good deal of research on memory how unreliable it is, partly because retrieving a memory is an active process that changes the memory as we call it up. When accuracy is important, then, we have to be careful not to embellish or distort the memory as we recall it, talk about it, or testify about it.

The memory is going to change anyway, but let’s not make it worse.

But what about if the memory is a bad one and we want to heal? Fear, for example, is hard to forget, and dredging it up may change it in ways that make it more intense.

I had a difficult role as a young actor, singing the lead in a musical where most of the music was pitched a little too high for my voice. Every night I would work myself up into a mental cramp of terror before the curtain went up, anticipating the squeaks that were going to emanate from my mouth when I tried to launch into song. That experience led to a case of stage fright that I wrestled with for many years in a variety of settings, but especially when music was involved.

So when new research came along recently that suggested a way to lessen this fear-based memory and stage fright, I paid close attention. It turns out that if you remember your memories from a third-person perspective, as if you were narrating a story about someone else, then they get weaker, less vivid, and less emotional.

Think of it as a kind of editing of our memories. In theory, this practice should allow us to master the memories and grow beyond them.

Perhaps I could at last shed that stage fright and have a lot more fun when I’m performing in public!

More generally, we should all get to work on our memory banks enhancing the positive ones and lessening the negative ones. Put the good ones into first-person narratives and the bad ones into the third person, and you should be well on the way to having a happier brain.

Many clients I’ve worked with over the years who suffer from stage fright report an initial incident that caused the fear to crystallize or get worse. Often it’s a moment in the middle-school years where they had to give a speech to the class and something went wrong. The students laughed, or the teacher spoke harshly, and the rest is a traumatic memory. Now, perhaps, they have a way to ease that fear. Tell the story as you recall it, but in the third person, as if it happened to someone else, and watch the memories fade, the trauma heal, and the stage fright dissipate.

At least, that’s the theory. If you have a similar memory that haunts you, then please try this out and let me know what the result is. Wouldn’t it be amazing to be able to shake off those bad memories for good?

This article is originally written by Nick Morgan, who is president of Public Words Inc., a communications consulting company, and the author of books including Can You Hear Me?: How to Connect with People in a Virtual World. This article is republished here from psychology today under common creative licenses.

Is It Right to Love Unconditionally? (Philosophy)

Susi Ferrarello, who is a professor of philosophy at the University of California, San Francisco answered what is unconditional love? Does it make us lazy human beings? And many other questions

For those who already know

You were born and that is enough, in theory, to know what unconditional love means. When at loss for words to describe unconditional love, people often point to parental love as the easiest example to explain what unconditional love actually means.

You were born and your parents loved you despite all your flaws and strengths.

Good for you! 

What about all those who struggled with the love received from their parents? Those whose parents were emotionally immature or those who were never enough for their parents; those who grew up with aloof parents or those who felt suffocated by their parental love? The rest of my reflections are for them: 

For those who have no clue

How often have you desired to be loved for who you are? How many times have you caught yourself chasing a relationship because you just wanted to be loved? Have you ever thought that unconditional love should imply sacrifice? 

Unconditional love is often the goal of an entire life and very rarely do we stop reflecting on what it is and how it can be achieved. Our instincts might drive us to fulfill our thirst for love in a chaotic way while our mind might lead us in directions that do not necessarily make our heart happy. Where is the right balance?  How can we experience unconditional love for ourselves or others?

Christian religion, for sure, dedicated refined discussions on what agape—charitable love—is and how we can achieve it. There’s an animated debate about whether we can take agape as a synonym for unconditional love. In fact, what is called agape refers to that brotherly love that keeps the community together no matter our individual flaws. Also, unconditional seems to be the love that God holds for us regardless of what we feel for God or the damages that we might  bring to God (For, God loved all humans unconditionally by sending his beloved Son, Jesus Christ, to die on the cross for our sins—John 3:16).

Yet, again, what if we are not Christians? What if we want to understand unconditional love in less Biblical terms? How can we be capable of this form of love? More importantly, should we be striving for this form of love? Or is it somewhat unethical being so forgiving toward ourselves and others.

Love, Ethics, and Humanistic Psychology

In the mid twentieth century, a group of psychologists rose up against the limitation of Freud’s and Skinner’s interpretations of human nature in search for a more holistic approach to human beings. Their positions were strongly influenced by existential and phenomenological philosophy—which means that they were trying to make sense of human existence as it unfolds in their life-world.

It seems that it was with the psychoanalyst Erich Fromm, and then with the humanistic approach of Rogers and Myers that the term ‘unconditional love’ was first introduced under the expression of ‘unconditional positive regard’. This showed the healing power of love that developed the full potential of the human being. This term brought the sparkle of divinity to humans as it showed the importance of the unconditional acceptance of who we are in our healing.

Yet, one problem that always emerges in my practice when I talk about unconditional love has to do with the ethical boundaries. What are the ethical boundaries of unconditional love? Should we accept our children if they intentionally produce harm to ourselves and others? Should we keep loving an abusive partner?

Let’s Start with Parental Relationships

Let’s assume that parents should be an example of unconditional love for their children. Yet, how often have we encountered parents who cannot accept a son because he is gay, or a daughter because she is in love with the wrong man? In his 2012 book, Andrew Solomon reads for us a few lines from a bioethicists, Joseph Fletcher, who, in 1968, mentions a parental dilemma in relation to children with down syndrome:

“There is no reason to feel guilty about putting a Down’s syndrome baby away, whether it’s “put away” in the sense of hidden in a sanatorium or in a more responsible lethal sense. It is sad, yes. Dreadful. But it carries no guilt. True guilt arises only from an offense against a person, and a Down’s is not a person” ( Fletcher, Bard, 1968, 59-64)

This is an ethicist who clearly underestimates the power of unconditional love. In fact, now that we have higher acceptance of babies born with down syndrome, their life expectancy increased together with the quality of their life. Yet, before this, plenty of others were hidden in sanatoria or never allowed to live. 

I believe that unconditional love can be described as a force capable of bringing to existence the essence of a human being in any form it presents.

In this case, the children were the victims of blind parents. But what happens when the children are causing suffering to others? What if your children are also guilty of despicable crimes?

Let’s take Susan Klebold, mother of Dylan Klebold, the shooter at Columbine. When interviewed, she was asked what she would have said to Dylan if he were still alive. She would have asked for forgiveness—she said. She was feeling sorry for not having understood the sense of confusion that Dylan was feeling inside, for not having been able to see him.

Clearly, Dylan did something wrong and clearly those parents had to acknowledge the tragedy that this caused. Yet, in reviewing this recent tragedy, Susan realized that more than avoiding all the choices that led up to that catastrophic event—going to college, marrying her husband, having that child—what she would change is paying more attention to the human being she was raising to know who he was and accepting or at least seeing his essence.

This acceptance does not erase the ethical wrong he personally did; it just gives existential justice to his soul. This person is no longer the whole cluster of projection of his parents’ dreams and regrets but he is his own existence. 

Same problems arise in abusive relationships

Is unconditional love the ultimate goal of our lives? If we say yes, aren’t we condemned to endure abusive relationships with our romantic halves, unfair parents, or siblings? To what extent does the pursuit of unconditional love nail us to a self-sacrificing life?

I would say to no extent. Unconditional love implies the ability to see, bring to awareness the essence of the person we are living with, whether that is just ourselves or our romantic partner. 

How often do we see what we want to see in the person we have in front of us or in ourselves? In one of my previous blog posts, I was playing with the Lacan notion that “love is giving what you do not have to someone who does not want it.” I believe that there is some painful truth in this.

Unconditional love does not mean that we are condemned to accept the rightness of an abusive partner, it means that we can see his unfair violence, but we stop making excuses for them in the pointless effort to justify our life in relation to them. 

Unconditional love means to be compassionate toward our child, partner, or ourself especially after the realization that not all the expectations are met; it means to have eyes to see what kind of life is unfolding in front of (and within) us and to have a heart big enough to accept the social implications of that life—whether that involves having a son who is a mass murderer or a daughter who wants to devote her life to justice. Human capacity to love unconditionally is a means to living a meaningful life. 

To conclude with a quote from Frankl’s Man’s Search For Meaning: “Love is the only way to grasp another human being in the innermost core of his personality. No one can become fully aware of the essence of another human being unless he loves him”.

References: (1) Frankl, V. (1946). Man’s Search For Meaning, Beacon Press. (2) Fletcher, J. & Bard, B. (1968). “The Right to Die”, Atlantic Monthly, 221, 59-64. (3) Solomon, A. (2012). Far from the Tree, Simon & Shuster.

This article is originally written by Susi Ferrarello, who is a professor of philosophy at the University of California, San Francisco, and a philosophical counselor and is republished here from psychology today under common creative licenses.

A Memory Exercise to Rekindle Your Relationship’s Romance (Psychology)

New research on couple memories shows the value of mutual reminiscing.

During times of high stress, you may feel that taking time for your relationship is the last thing on your to-do list. As a result, that relationship can become less and less of a resource to bolster your emotional well-being. Perhaps you’re engulfed right now with the demands of your job, your children, other relatives, and the strains of trying to survive economically. As much as you’d like to rebuild old bonds with your partner, you just don’t know when you’ll be able to make the time.


Stress can be particularly detrimental when one or both partners in a couple are what relationship scientists call “insecurely attached.” As the term implies, people who fit this definition feel anxious about the future of their relationship, believing that their partner cannot be completely trusted to care for them. The insecurely attached may also try to fight off feelings of intimacy due to fear of being abandoned. In either case, as much as you try to balance your life’s many demands, that fear of something going wrong in your relationship can only compound your overall sense of worry and anxiety.

According to University of Quebec at Montreal’s Alexandre Lejeune and colleagues (2020), “beneficial romantic relational outcomes” come from “the sense of felt security derived from the support of an attachment figure” (p. 2). Securely attached individuals can comfort themselves during times of stress with mental representations of those comforting figures. When things aren’t going well, they can time travel back to situations in which they felt that everything would be okay. It’s these memories that can bolster their confidence that they’ll make it through whatever tough times they’re experiencing now.

Think now for a few moments about a time when you did feel comforted by a romantic figure, whether your current partner or a relationship partner from the past. Do you find yourself reflecting back on those times in your daydreams, allowing you to push out of consciousness your own current troubles? For people who are insecurely attached, drawing on these comforting memories could be particularly important in helping them achieve greater satisfaction in their current relationships, as the Canadian authors propose.

In addition to whatever effects simple recall of a comforting memory could have, Lejeune et al. predicted that people could gain even more emotional sustenance if that memory invoked a time in which one of their significant needs became met. For example, you might remember the first time you met your significant other and how attracted the two of you felt. In the process, though, can you also recall how your partner made you feel about yourself? As your relationship developed beyond that initial attraction, were there times you felt particularly connected?

To test the role of attachment security and need satisfaction in couple-enhancing memory recollections, Lejeune and his fellow researchers developed a theoretical model in which the association between attachment security and need satisfaction was evaluated in contributing to couple adjustment. Their samples were drawn from young adult, primarily female, samples associated with a university. This is important to keep in mind, as the participants were not, by definition, involved in longstanding relationships.

The memory task itself consisted of two parts, in the first, participants were asked to describe in detail their recall of an event in their current romantic relationship, an event that revealed “how they perceive themselves” in this relationship and that often comes to mind. In the case of one participant described in the Lejeune et al. paper, this memory was of a first kiss. The participant went on to recall that “It was the first time I had the impression to be that important for someone.”

For the second component of the task, participants were asked to describe other memories related to this event that came to mind spontaneously. In the case of this particular participant, one of these memories involved a situation in which she was at her boyfriend’s place and became ill while in the bathroom. She recalled that “I was very ashamed of myself, but at the same time I was very touched that he was taking care of me like that.” The authors interpreted this memory as suggesting the extent to which the participant felt her boyfriend could be caring and non-judgmental.

The needs evaluated by the Canadian research team fell in the categories of those suggested by a well-known theory of motivation, self-determination theory, which proposes that the ideal state of need satisfaction occurs when you feel that you control your own actions, are competent, and have the opportunity to be close to other people.

As predicted, the authors reported that insecurely-attached individuals were less well-adjusted in their current relationship. However, the ability to retrieve those need-satisfying “networked” or associated memories mitigated against this otherwise detrimental impact on their ability to feel satisfied with their partner. In the words of Lejeune et al. “Instead of exclusively relying on insecure relational schemas in their interactions with their partner, they might also recruit a sense of security from their memories in which they felt high satisfaction for their basic psychological needs” (p. 17).

Returning now to the question of how you can overcome your own daily stresses to improve your relationship, the findings seem to have clear practical applications. Indeed, although the study was conducted on individual participants and not couples, the potential to bring this method “home” to your relationship with your partner now seems even clearer.

Begin by recreating the exact situation posed to the university students in Lejeune et al.’s study. Sit down for a few minutes with your partner while each of you conjures up a “defining” moment in your relationship. Was it the first time you met, or was it some other experience later down the road, such as the time your first child was born? Perhaps it wasn’t even as significant as these life-changing experiences but instead involved more of your day-to-day events, such as lighting the candles before a particularly enjoyable dinner at home.

Now move on to the associations that this memory stimulates. Do you recall any of those three basic needs that you felt were met? How do these link back to the original couple-defining moment?

What the Canadian researchers could not do, but you can, is to compare notes with your partner. If you’ve written down those memories it’s even easier, but just by the retelling, you can still gain access to the key themes in your partner’s feelings about your relationship. You’ve probably already decided some time ago whether your partner is securely or insecurely attached, but perhaps you weren’t aware of just how much you have contributed to helping your partner gain a greater sense of comfort.

To sum up, fulfillment in long-term close relationships can come from many sources. The everyday stresses can sometimes make that fulfillment difficult to experience. However, a brief glimpse into the memories you and your partner have of yourselves and your times together can help you regain your faith in your relationship and your partner.

References: Lejeune, A., Bouizegarene, N., & Philippe, F. L. (2020). Association between attachment insecurity and couple adjustment: Moderation by couple memory networks. Personal Relationships. doi: 10.1111/pere.12360

This article is originally written by Susan Krauss Whitbourne, who is a Professor Emerita of Psychological and Brain Sciences at the University of Massachusetts Amherst and republished here from psychology today under common creative licenses.

Kids These Day: How Youth Behavior Really Stacks Up (Psychology)

Research shows how adults form their beliefs about youth.

If you haven’t said it yourself, you’ve certainly heard others utter the statement that typically begins with “Kids these days…” and describes some deficiency of modern youth. Usually, it’s said with a lofty tone that suggests today’s young people are less responsible and well-behaved compared to previous generations.

Source: JackF/Adobe Stock

Researchers from the University of California, Santa Barbara set out to better understand this phenomenon. They conducted a series of studies to determine what makes adults believe that today’s kids are deficient when compared to previous generations, and whether that belief is true.

In three of the studies, researchers aimed to characterize the traits of adults who believe there is something wrong with “kids these days.” In the first study, they asked participants to complete a questionnaire that measures authoritarianism; then they asked participants whether they thought today’s youth are less respectful of their elders compared to past generations. Overall, the researchers found that adults thought that contemporary young people were less respectful. Interestingly, respondents who were more authoritarian were more likely to believe youth do not respect their elders.

In the second study, researchers measured adults’ authoritarianism and intelligence, then asked if today’s youth are more or less intelligent than previous generations. This time, the measure of authoritarianism didn’t have an effect; instead, adults who scored higher on the intelligence test believed that “kids these days” were becoming less intelligent. (By the way, this statement is categorically false according to systematic reviews on patterns of intelligence over decades.)

In the third study, researchers gave participants an author recognition test designed to measure how much they read. Then they asked to what extent they believed “kids these days” enjoy reading. On the whole, participants believed today’s youth enjoy reading less; adults who read more were more likely to believe that children today no longer like to read.

The fourth and fifth studies took deeper dives with adults who like to read. The researchers found that prolific readers were more likely to say that today’s adults don’t like reading as much as adults from previous generations. Their views were also affected by inaccurate memories and their own perceptions of their reading skills.

“It is important to remember that the results of this study reveal more about the beliefs of adults than the realities of youth,” said Anthony Burrow, director of the Bronfenbrenner Center for Translational Research and PRYDE, the Program for Research on Youth Development and Engagement. “In this light, it may be worth considering what it feels like to be a young person navigating a society comprised of adults who harbor pessimistic impressions of youth.”

The bottom line: Our talents and perceptions influence how we view others, especially young people. But how are young people actually doing these days?

What We Know About Youth and Risky Behaviors

It turns out we have 28 years’ worth of data on the decision-making behaviors of U.S. teens. Each year since 1991, the U.S. Centers for Disease Control and Prevention has conducted a nationally representative survey of teens in grades 9 through 12 to ask about risky sexual behavior, alcohol and drug use, tobacco use, and safety precautions. The study also monitors the prevalence of obesity, asthma, and unintentional injuries. Here’s a run-down of the study findings:

  • Fewer kids are smoking. In 2019, only 24 percent of kids had tried smoking (even one puff)—down from 70 percent in 1991. And 6 percent considered themselves smokers, down from 28 percent in 1991.
  • Fewer kids are drinking. In 2019, 29 percent of kids said they had an alcoholic drink within 30 days of taking the survey—down from 51 percent in 1991.
  • Kids take more safety precautions than they used to. In 2019, kids were significantly more likely to wear a seatbelt and avoid driving with someone who has been drinking alcohol compared to 1991.
  • Violent behavior has decreased. In 2019, 13 percent of kids report carrying a weapon—down from 26 percent in 1991. And 22 percent report being in a physical fight in the last year—down from 43 percent in 1991.
  • More kids are smoking marijuanaThirty-seven percent report trying it and 22 percent report using it regularly—both increases since 1991. Cocaine use among teens peaked in 1999 but is now down to its lowest level since 1991—about 4 percent.
  • Obesity rates have steadily risen since the survey began, and are at their highest levels now. More than 15 percent of U.S. teens were considered obese in 2019.
  • A lower percentage of kids are having sexJust 38 percent in 2019 reported having sex, compared to 54 percent in 1991. Kids were significantly less likely to have sex before the age of 13 and more likely to use a condom or another form of birth control.
  • Nearly 19 percent of teens have seriously considered suicide. This is up from a low of 14 percent in 2009, but significantly lower than the 29 percent who reported considering suicide in 1991.

The bottom line: Today’s teens are doing pretty well in contrast to 28 years ago. Although they are more likely to be obese, use marijuana, and consider suicide, they are less likely to abuse alcohol, engage in violent behavior, and smoke. They’re also more likely to take safety precautions, including practicing safe sex. 

These decades of surveys confirm that our beliefs about “kids these days” have more to do with our own perceptions rather than actual irresponsible youth behavior.

As Burrow said, it’s important to realize that those perceptions are worth changing.

“Part of that change may come from sharing more positive and uplifting narratives of youth, and recognizing the generative contributions young people make to society as well,” he said. “Such sharing is as important in personal anecdotes and media coverage of youth, as it is in the scientific findings showcasing widespread interest in positive youth development. There, we might find reasons to celebrate the ways young people today may be even more impressive than in generations past.”

Visit Cornell University’s Bronfenbrenner Center for Translational Research’s website for more information on their work.

Study of Heat Diffusion Suggests Neutron Star Outer Crust Has Specific Heat-accumulating Properties (Astronomy)

In the recent paper, Yokolev and colleagues studied heat diffusion after an energy release in a deep spherical layer of the outer neutron star crust (10^7 ≤ ρ ≤ 4 × 10¹¹ g cm-³). They demonstrate that this layer possesses specific heat-accumulating properties, absorbing heat and directing it mostly inside the star. Their study published in journal ArXiv.

Outermost layer of neutron star © C. O. Dorso et al.

Many neutron stars demonstrate bursting activity. For instance, accreting neutron stars in low-mass X-ray binaries show X-ray bursts and superbursts powered by explosive burning of accreted hydrogen and helium in surface layers and subsequent more powerful burning of carbon in deeper layers. These processes involve complicated physics of thermal evolution of accreting neutron stars, steady-state and explosive nuclear burning with extended reaction networks, various mass and heat transport mechanisms (hydrodynamical motions, convection, thermal diffusion) and so on.

Yokolev and colleagues mainly focus on heat diffusion after energy generation in deep layers of the outer crust of neutron stars. In order to study heat diffusion after a burst in deep layers of the outer neutron star crust, at sufficiently high densities and temperatures, they have developed a simplified analytic model (‘toy model’). The applicability of their model is quite restricted. It cannot follow nuclear reaction networks and associated evolution of microphysical properties of the matter. Also, it does not allow one to study the stages of accretion, accumulation and procession of Nuclear fuel, the appearance of shocks and precursors before a burst, dynamics of nuclear burning and nucleosynthesis, heat outflow due to neutrino emission. However, the toy model is simple and requires no special computer resources. It can simulate important fragments of real events and predicts generic features of real bursts.

“The outer crust is a relatively thin layer which extends from the stellar surface to the neutron drip density (ρdrip ≈ 4.3 × 10¹¹ g cm-³). Its width is only some hundred meters, and its mass is ∼ 10^-5 M. It consists of electrons & ions (atomic nuclei). We call it crust for simplicity; actually, the atomic nuclei can constitute either Coulomb solid, or Coulomb liquid or gas, depending on density ρ, temperature T and nuclear composition (our ‘crust’ includes thus the liquid ‘ocean’).”, write authors of the study.

They demonstrated that this layer possesses specific heat-accumulating properties, absorbing heat and directing it mostly inside the star. It can absorb up to ∼ 10⁴³–10⁴⁴ erg due to its high heat capacity, until its temperature exceeds T ∼ 3 × 10^9 K and triggers a rapid neutrino cooling.

They also note that a warm outer crust of a neutron star has large heat capacity and operates as a huge heat reservoir. It can easily keep the heat generated in a burst for a few months. Generic features include the appearance of a quasi-isothermal zone above the layer, where the main burst energy is released and a very slow heat diffusion to the inner crust. This leaves the bottom of the outer crust sufficiently cold and thermally decoupled from the heated zone in the upper layers. The burst energy is mainly transported inside the star although some fraction can be carried away by neutrinos from the bursting layer while another fraction diffuses to the surface and can be observable. Typically, the burst that is seen from the surface fades before the heat wave reaches the inner crust. Researchers have shown that the toy model can be useful to describe the late stage of the afterburst relaxation.

They also found that their method can be inaccurate at lower temperatures, T ≤ 10^8 K. In that case, the heat capacity is strongly reduced by quantum effects in the motion of ions. Also, the thermal conductivity of degenerate electrons becomes essentially dependent on temperature and on the presence of impurities. Moreover, the toy model cannot be directly applied to the inner crust of the neutron star, where free neutrons appear in the matter, in addition to atomic nuclei and strongly degenerate electrons. These free neutrons are numerous there. If they were normal, they would be the source of large heat capacity, but they most likely are superfluid. Their superfluidity greatly reduces the heat capacity of the inner crust. Generally, the inner crust seems to be a poorer heat reservoir than the outer crust.

“The toy model can be generalized to include the effects of neutrino cooling. Such models can be used to guide more elaborated numerical simulations of bursting neutron stars.”, Concluded researchers of the study.

Reference: D. G. Yakovlev, A. D. Kaminker, A. Y. Potekhin, P. Haensel, “Model of heat diffusion in the outer crust of bursting neutron stars”, ArXiv, pp. 1-17, 2020. https://arxiv.org/abs/2011.06826v1

– written by S. Aman

Electrons Falling Flat: Germanium Falls Into a 2D Arrangement on Zirconium Diboride (Physics)

Scientists reveal ‘flat band’ behavior in 2D ‘bitriangular’ lattice of germanium, confirming earlier theoretical prediction.

Scientists have recently revealed, both theoretically and experimentally, that germanium atoms can arrange themselves into a 2D “bitriangular” lattice on zirconium diboride thin films grown on germanium single crystals to form a “flat band material” with an embedded “kagome” lattice. The result provides experimental support to a theoretical prediction of flat bands emerging from trivial atomic geometry and indicates the possibility of their existence in many more materials.

Germanium atoms (light and dark blue) spontaneously crystallize into a two-dimensional (2D) “bitriangular” lattice on zirconium diboride thin films grown on germanium single crystals (green: Zr atoms, orange: B atoms). © JAIST

The human mind is naturally drawn to objects that possess symmetry; in fact, the notion of beauty is often conflated with symmetry. In nature, nothing epitomizes symmetry more than crystals. Since their discovery, crystals have attracted a great deal of attention not only by their unique “symmetrical” aesthetic appeal but also by their unique properties. One of these properties is the behavior of electrons inside a crystal. From a physical point of view, an electron within a crystal can be fully characterized by its energy and a quantity called “crystal momentum,” which relates to how fast the electron moves in a crystal. The relationship between the energy and crystal momentum of electrons is what scientists refer to as “band structure,” which, put simply, is the allowed energy levels for the electrons within the crystal.

Recently, materials scientists have turned their attention towards what are called “flat band materials”–a class of materials possessing a band structure in which the energy does not vary with the crystal momentum and hence resembles a flat line when plotted as a function of crystal momentum–owing to their ability to give rise to exotic states of matter, such as ferromagnetism (iron-like spontaneous magnetism) and superconductivity (zero resistance to electricity flow). Generally, these “flat bands” are observed in special 2D structures that go by names like “checkerboard lattice,” “dice lattice,” “kagome lattice,” etc. and are typically observed either within the crystal or at the surface of layered materials. A pertinent question thus presents itself–is it possible to embed such lattices into completely new 2D structures? Efforts to design 2D materials have focused on answering this question, and a recent finding suggests that the answer is a “yes.”

Now, in a study published in Physical Review B as a Rapid Communication, an international team of scientists from the Japan Advanced Institute of Science and Technology (JAIST), the University of Tokyo, the Japan Atomic Energy Agency, and Institute for Molecular Science in Japan and Tamkang University in Taiwan, led by Dr. Antoine Fleurence and Prof. Yukiko Yamada-Takamura, has reported a possible new flat band material obtained from germanium (Ge) atoms arranging themselves into a 2D “bitriangular” lattice on zirconium diboride thin films grown on germanium single crystals. The published study is also trending as a #PRBTopDownload on the official Physical Review B handle on Twitter: https://twitter.com/PhysRevB/status/1327606715630620674. While the team had already grown this 2D material years ago, they were only recently able to unveil its structure.

Last year, a part of the team published a theoretical paper in the same journal underlining the conditions under which a 2D “bitriangular” lattice can form a flat band. They found that this is related to a “kagome” (meaning weaved basket pattern in Japanese) lattice–a term originally coined by Japanese physicists in the ’50s to study magnetism. “I was really excited when I found out that the electronic structure of kagome lattice can be embedded into a very different-looking 2D structure”, recalls Prof. Chi-Cheng Lee, a physicist at Tamkang University, Taiwan, involved in the study, who predicted the presence of flat bands in the “bitriangular” lattice.

The prediction was finally confirmed after the team, in their current study, characterized the prepared 2D material using various techniques such as scanning tunneling microscopy, positron diffraction, and core-level and angle-resolved photoelectron emission; and backed up the experimental data with theoretical calculations to reveal the underlying “bitriangular” lattice.

“The result is really exciting as it shows that flat bands can emerge even from trivial structures and can possibly be realized in many more materials. Our next step is to see what happens at low temperature, and how it is related to the flat bands of the Ge bitriangular lattice,” says Dr. Fleurence, who is also the first author of this paper.

Indeed, who would’ve thought that a typical, run-of-the-mill semiconductor like germanium could offer such exotic and unprecedented possibilities? The 2D world might have more surprises up its sleeve than we imagine.

Reference: A. Fleurence, C.-C. Lee, R. Friedlein, Y. Fukaya, S. Yoshimoto, K. Mukai, H. Yamane, N. Kosugi, J. Yoshinobu, T. Ozaki, and Y. Yamada-Takamura, “Emergence of nearly flat bands through a kagome lattice embedded in an epitaxial two-dimensional Ge layer with a bitriangular structure”, Phys. Rev. B 102, 201102(R) – Published 4 November 2020. https://journals.aps.org/prb/abstract/10.1103/PhysRevB.102.201102

Provided by Japan Advanced Institute of Science and Technology

About Japan Advanced Institute of Science and Technology, Japan

Founded in 1990 in Ishikawa prefecture, the Japan Advanced Institute of Science and Technology (JAIST) was the first independent national graduate school in Japan. Now, after 30 years of steady progress, JAIST has become one of Japan’s top-ranking universities. JAIST counts with multiple satellite campuses and strives to foster capable leaders with a state-of-the-art education system where diversity is key; about 40% of its alumni are international students. The university has a unique style of graduate education based on a carefully designed coursework-oriented curriculum to ensure that its students have a solid foundation on which to carry out cutting-edge research. JAIST also works closely both with local and overseas communities by promoting industry-academia collaborative research.

About Dr. Antoine Fleurence from Japan Advanced Institute of Science and Technology, Japan

Dr. Antoine Fleurence is a Senior Lecturer in the School of Materials Science at Japan Advanced Institute of Science and Technology (JAIST), Japan, since 2018. He received his M.S. and PhD from the University of Paris-Sud in 2004 and 2007, respectively. He was a postdoctoral fellow at JAIST from 2009 to 2012 and served there as Assistant Professor from 2012 to 2018. He specializes in thin-film surfaces and interfaces. His research interests include 2D materials, surface science, and growth of inorganic thin films.

About Professor Yukiko Yamada-Takamura from Japan Advanced Institute of Science and Technology, Japan

Dr. Yukiko Yamada-Takamura is a Professor in the School of Materials Science at the Japan Advanced Institute of Science and Technology (JAIST), Japan, since 2020. She received her PhD from the University of Tokyo in 1998. She was a research associate at Tohoku University from 2002-2006. She joined JAIST as a lecturer in 2006. She specializes in material fabrication and microstructure control, nanostructure physics,, and nanomaterials. Her research interest lies in thin films, 2D materials, and cutting-edge microscopies.

RUDN University Chemists Synthesized New Fluorescent Substances For Medical Applications (Chemistry)

Indolizines are a group of substances with biological and optical properties. A team of chemists from RUDN University developed a new approach to the synthesis of indolizines using pyridinium salts and enamiones. The new substances turned out to be able to emit light in the green range which can be useful for medical applications. The results of the study were published in the Molecules journal.

Indolizines are a group of substances with biological and optical properties. A team of chemists from RUDN University developed a new approach to the synthesis of indolizines using pyridinium salts and enamiones. The new substances turned out to be able to emit light in the green range which can be useful for medical applications. ©RUDN University

Indolizines are organic substances that contain two carbon cycles and one atom of nitrogen. They are used to produce dyes and solar panels, as well as anti-tumor and anti-diabetes drugs. Indolizines do not occur naturally but are constructed in labs, usually using the reactions of cycloaddition. These reactions involve pyridinium salts–electrically neutral molecules with positively and negatively charged ‘poles’ that balance each other. A team of chemists from RUDN University discovered an unexpected reaction in which, instead of cycloaddition, a pyridinium salt undergoes two other consecutive processes. The end products of this reaction are indolizines with fluorescent properties.

“We found out that pyridinium salts that contain a methyl group bound with ?(2) tend to enter into an unexpected domino reaction with enaminones, and consecutive cycloisomerization and cyclocondensation take place, while the reactions of cycloaddition that are typical for pyridinium salts are not observed,” said Alexey Festa, PhD, a Senior Lecturer at the Department of Organic Chemistry, RUDN University.

A team of chemists from RUDN University, MSU, and KU Leuven (Belgium) suggested an approach based on their earlier studies of reactivity of pyridinium salts. The team studied 1-(cyanomethyl)-2-alkylpyridinium salts in reactions with enaminones and chose optimal conditions for the production of indolizines. By changing the ratio of the initial components, the team managed to gain only a 50% reaction yield. However, after other pyridinium salts were used, the yield increased to 82%. The two-stage reaction turned out to be of the domino type, i.e. the first stage initiated the second one in the same flask without any additions of new reagents or changes in reaction conditions. The team used X-ray structural analysis to study the new indolizines and also paid attention to their optical properties.

© Sokolova et al.

Eight of the new indolizines were capable of intensive fluorescence (i.e. of absorbing light with a certain wavelength and emitting light with a longer one). This mechanism is based on the excitement of electrons, that is, their movement to a higher energy level under the influence of photons. This process is accompanied by energy release, and a part of it is emitted in the form of photons with reduced energy and therefore increased wavelength. The indolizines synthesized by the team were particularly effective in absorbing emissions with the wavelength of 403-420 nm that belong to the blue-violet range bordering on the UV light. The wavelength of the light emitted by the indolizines amounted to 505-528 nm which corresponds to the green range of the spectrum. These properties make indolizines a promising material for the manufacture of fluorescent tags that are used to study biological objects.

“Pyrido[2,3-b]indolizines obtained in the course of our reaction showed certain fluorescent properties. Namely, they emitted green light with a high quantum yield (a parameter that characterizes the efficiency of this process). The lowest yield values amounted to 55-63% and in the case of one new indolizine the yield reached 82%,” added Alexey Festa from RUDN University.

Reference: Sokolova, E.A.; Festa, A.A.; Subramani, K.; Rybakov, V.B.; Varlamov, A.V.; Voskressensky, L.G.; Van der Eycken, E.V. Microwave-Assisted Synthesis of Fluorescent Pyrido[2,3-b]indolizines from Alkylpyridinium Salts and Enaminones. Molecules 2020, 25(18), 4059. https://www.mdpi.com/1420-3049/25/18/4059/htm https://doi.org/10.3390/molecules25184059

Provided by RUDN University