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Why does a plane look and feel like it’s moving more slowly than it actually is?

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Why does a plane look and feel like it’s moving more slowly than it actually is?

Without a point of reference, it can be hard to tell just how fast an airplane is traveling.
Daniel Berehulak/Getty Images News via Getty Images

Sara Nelson, Iowa State University

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


Why does a plane look and feel like it’s moving more slowly than it actually is? – Finn F., age 8, Concord, Massachusetts


A passenger jet flies at about 575 mph once it’s at cruising altitude. That’s nearly nine times faster than a car might typically be cruising on the highway. So why does a plane in flight look like it’s just inching across the sky?

I am an aerospace educator who relies on the laws of physics when teaching about aircraft. These same principles of physics help explain why looks can be deceiving when it comes to how fast an object is moving.

Moving against a featureless background

If you watch a plane accelerating toward takeoff, it appears to be moving very quickly. It’s not until the plane is in the air and has reached cruising altitude that it appears to be moving very slowly. That’s because there is often no independent reference point when the plane is in the sky.

A reference point is a way to measure the speed of the airplane. If there are no contrails or clouds surrounding it, the plane is moving against a completely uniform blue sky. This can make it very hard to perceive just how fast a plane is moving.

And because the plane is far away, it takes longer for it to move across your field of vision compared to an object that is close to you. This further creates the illusion that it is moving more slowly than it actually is.

These factors explain why a plane looks like it’s going more slowly than it is. But why does it feel that way, too?

A passenger’s perception on the plane

A plane feels like it’s traveling more slowly than it is because, just like when you look up at a plane in the sky, as a passenger on a plane, you have no independent reference point. You and the plane are moving at the same speed, which can make it difficult to perceive your rate of motion relative to the ground beneath you. This is the same reason why it can be hard to tell that you are driving quickly on a highway that is surrounded only by empty fields with no trees.

Perspective from a plane window of the plane's shadow against a brown field with the plane's white wing visible on the left side.
Watching the speed of a plane’s shadow can help you assess how quickly a plane is moving.
Saul Loeb/AFP via GettyImages

However, there are a couple of ways you might be able to understand just how fast you are moving.

Can you see the plane’s shadow on the ground? It can give you perspective on how fast the plane is moving relative to the ground. If you are lucky enough to spot it, you will be amazed at how fast the plane’s shadow passes over buildings and roads. You can get a real sense of the 575 mph average speed of a cruising passenger plane.

Another way to understand how fast you are moving is to note how fast thin, spotty cloud cover moves over the wing. This reference point gives you another way to “see” or perceive your speed. Remember though, that clouds aren’t typically stationary; they’re just moving very slow relative to the plane.

An airplane passes over thin, spotty cloud cover.

Although it can be difficult to discern just how fast a plane is actually moving, using reference points to gain perspective can help tremendously.

Has your interest in aviation been sparked? If so, there are a lot of great career opportunities in aeronautics.


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 city where you live.

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

Sara Nelson, Director of the NASA Iowa Space Grant Consortium, Iowa State University

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

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Compassion amid chaos − how one of America’s greatest poets became a lifeline for wounded soldiers

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theconversation.com – Richard Gunderman, Chancellor’s Professor of Medicine, Liberal Arts, and Philanthropy, Indiana University – 2024-11-08 07:39:00

Richard Gunderman, Indiana University

With over 40 armed conflicts now taking place around the world, the costs of warfare are immense and continue to mount with each passing day.

Russia’s war on Ukraine is estimated to have resulted in more than 600,000 Russian casualties, with estimates of total dead and injured on both sides as high as 1 million. The war between Israel and Hamas has resulted in about 140,000 Palestinian and 10,000 Israeli casualties, and there have been at least 50,000 casualties in the ongoing Sudanese Civil War. Closer to home, the newly married son of a colleague of mine suffered grievous injuries and lost all four limbs in an explosion while serving in the Middle East.

The loss of life and limb, violations of human rights, destruction of personal property and damage to infrastructure such as power stations, hospitals and roads render such costs essentially incalculable, at least in monetary terms.

Yet war also opens up opportunities to care for the injured, displaced and forgotten. As someone who studies and writes about the intersection of medicine and the humanities, I often find myself returning to the American poet Walt Whitman.

To appreciate the act of offering support and comfort for the victims of war, there are few better sources of inspiration than Whitman, who spent more than three years volunteering his time and energies during the U.S. Civil War.

Compelled to help

Walt Whitman is considered one of the greatest poets in American history. Born the second of nine children in straitened circumstances in New York in 1819, he left school at age 11 to help support his family, working in a variety of jobs, including typesetting, teaching and newspaper publishing.

In 1855, he self-published his greatest work of poetry, “Leaves of Grass,” written in free verse and opening with the poem later known as “Song of Myself.” The work’s fans included Ralph Waldo Emerson, who wrote to Whitman, in a letter praising the poet, “I greet you at the beginning of a great career.”

Black-and-white portrait of bearded man seated, wearing a floppy hat, with his hands in his jacket pockets.

A portrait of Walt Whitman from 1863, when the U.S. was embroiled in civil war.

Smith Collection/Gado via Getty Images

Yet fame and fortune were slow to wend their way to Whitman, and he continued to work in the newspaper trade. With the onset of the Civil War, Whitman’s brother enlisted, and when Whitman saw his brother named among wounded soldiers, he traveled to Virginia to find him.

He eventually discovered that his brother had suffered only a minor wound. Yet during the search, Whitman encountered scores of wounded soldiers and piles of amputated limbs, which moved him to help in some way.

He secured a job in Washington, D.C., as an army paymaster’s clerk and began volunteering in the city’s military hospitals, making, by his estimate, over 600 visits, sometimes overnight, to as many as 100,000 soldiers.

Dispenser of treats, transcriber of letters

Why would perhaps America’s greatest poet voluntarily devote the better part of over three years of his life to visiting places replete with mutilation, agony and sorrow?

Lacking formal training in medicine or nursing, Whitman nonetheless felt that he had something important to offer.

“I found it was in the simple matter of personal presence, and emanating ordinary cheer and magnetism, that I succeeded and helped more than by medical nursing, or delicacies, or gifts of money, or anything else,” he wrote in “Memoranda During the War.”

Whitman managed to bring more tangible gifts as well: “Blackberries, peaches, lemons and sugar, wines, all kinds of preserves, pickles, brandy, milk, shirts and all articles of underclothing, tobacco, tea, and handkerchiefs.”

He procured these items using his own meager funds and by soliciting donations, providing others their own opportunities to give.

Consider a specific case, that of a young soldier from Massachusetts suffering from respiratory and gastrointestinal ailments.

Of him, Whitman wrote, “His heart was broken. He felt the struggle to keep up any longer to be useless. God, the world, humanity, all had abandoned him. It would feel so good to shut his eyes forever on the cruel things around him and toward him.”

Yet Whitman took his place beside him, gave him some money so that he could buy milk, and wrote a letter for him to his sister. “Trifling as it was, he was overcome and began to cry. He has told me since that this little visit, at that hour, just saved him – a day more, and it would have been perhaps too late.”

Along with all the other gifts in his haversack, Whitman “always gave paper, envelopes, and stamps” so soldiers could write to loved ones back home. Many times, he wrote their letters himself, in his own hand, often signing below their name, “Written by Walt Whitman, a friend.”

Of the letters, he noted:

“Many sick and wounded soldiers have not written home to parents, brothers, sisters, and even wives, for one reason or another, for a long time. Some are poor writers, some cannot get paper and envelopes; many have an aversion to writing because they dread to worry the folks at home – the facts about them are so sad to tell. I always encourage the men to write, and promptly write for them.”

It is remarkable to think of one of the greatest artists of the English language sitting by the bedside of so many sick and wounded soldiers, helping them compose letters to family and friends far away, sometimes simply transcribing what they said, and other times capturing what they wanted to say or what needed to be said.

He was tending not only to the soldiers before him, but also to loved ones sick with worry, hundreds of miles away.

Becoming conduits of compassion

Whitman’s dedicated service offers deep and enduring lessons for people around the world today.

A lined page featuring handwritten cursive.

The second page of a letter Walt Whitman wrote on behalf of Union soldier Robert N. Jabo, who was dying of tuberculosis. It was signed, ‘Written by Walt Whitman, a friend.’

U.S. National Archives

For one thing, the toll of war cannot simply be counted up in numbers of lives lost or billions of dollars of damage incurred.

Behind every number is a human story. Every wounded or dead soldier is someone’s son or daughter, sister or brother, husband or wife, or mother or father. Every civilian casualty is someone’s friend, neighbor and fellow citizen.

Whitman didn’t use his poetic powers just to help share the stories of wounded soldiers with their loved ones back home. He also mined his experiences by their bedside to compose literary masterpieces such as “The Wound-Dresser” and “Come Up from the Fields Father.”

As violence permeates the globe, it’s easy to look away, or become numb to headlines and images of death and despair. But confronting this suffering head on – through an act as simple as extending a hand, a voice or an ear – is an act of courage in and of itself.

True, it may not stop or win a war. Yet this sort of attention is a form of generosity and a conduit to healing – a way, as Whitman put it in a letter to his brother, “to have our feelings so thoroughly and permanently absorbed, to the very roots, by these huge swarms of dear, wounded, sick, and dying boys.”The Conversation

Richard Gunderman, Chancellor’s Professor of Medicine, Liberal Arts, and Philanthropy, Indiana University

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

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10 states had abortion measures on the ballot – where they passed, where they failed, and what it all means

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theconversation.com – Katherine Drabiak, Professor of Health Law, Public Health Law and Medical Ethics, University of South Florida – 2024-11-08 07:39:00

When all the votes were tallied, Colorado voters approved a ballot measure establishing a right to abortion.

Chet Strange/AP Photo

Katherine Drabiak, University of South Florida

Voters in 10 states decided on measures relating to abortion on Nov. 5, 2024, many of which sought to expand access to abortion or expressly recognize a right to abortion in the state’s constitution.

Seven of the ballot measures passed, while three failed. Measures in Arizona, Colorado, New York, Maryland, Missouri, Montana and Nevada were approved by voters, while measures to expand abortion access in Florida, Nebraska and South Dakota went down.

Nebraskans voted on two competing measures. The one that passed enshrines the current law that allows elective abortions until 12 weeks into the state constitution. The measure that failed would have extended elective abortions until fetal viability, about 24 weeks.

Abortion across the US

Since the Supreme Court decided Dobbs v. Jackson in 2022, ending a federal right to abortion, states have moved in multiple directions. Abortion laws across the U.S. have changed a great deal in the past two years and vary widely.

Some states still allow abortion but only earlier in pregnancy. Nebraska, for example, allows abortions before 12 weeks.

Some states expanded or wrote into law abortion access. Colorado, eight other states and Washington, D.C., allow elective abortions until birth, without any restriction on gestational age.

Other states, like Texas, sought to restrict abortions once a heartbeat is detected at around six weeks.

All of this variation can be confusing. And, as a health law professor, I know how important it is for people to understand the law so that pregnant women, or women who have had a miscarriage, are not fearful of seeking medical care.

What abortion laws regulate

The most important thing to understand, in my view, is that laws which regulate abortion apply to actions that health care providers take to intentionally terminate a pregnancy.

Laws designed to limit abortion procedures are not meant to block access to care for women who are seeking treatment for a miscarriage or ectopic pregnancy.

Abortion laws do not penalize or criminalize women seeking an abortion; they regulate health care providers. This is true even in states with restrictive abortion laws, such as South Dakota, Indiana, Texas and Alabama.

Regulating physician conduct is not new – nor is it unique to abortion laws. Very specific laws regulate physician conduct with severe, and even criminal penalties, for possibly fraudulent billing, disregarding federal privacy rules or inappropriately prescribing medication.

Colorado enshrines a right to abortion

In Colorado, Proposed Initiative 89 passed with 62% of the vote. The initiative added language to the state constitution that expressly recognizes a “right to abortion.”

In 2022, the Colorado Legislature codified access to abortion without limits to gestational age. The initiative adds the provision to the state constitution, which makes it a permanent law, so the Legislature cannot amend or modify it.

The initiative also struck language in the Colorado Constitution that prohibited using taxpayer funds to pay for abortions for women with Medicaid or state-sponsored insurance plans. Colorado already requires private insurance to cover the total cost of abortions.

Supporters of the initiative say that allowing taxpayer funding for abortions will stop the “discriminatory and harmful effects” of previous insurance restrictions.

About 38 states prohibit using taxpayer funds for abortion, while some states allow using taxpayer funds for abortions only in cases involving rape, incest or where the woman’s life is at risk.

A woman kisses the hand of another woman who looks crestfallen. Purple and orange balloons are in the foreground.

A ballot measure in Florida fell short of the 60% threshold needed to pass.

AP Photo/Rebecca Blackwell

Florida votes to maintain abortion law

In Florida, Amendment 4, which voters did not pass, proposed a state constitutional amendment to permanently expand abortion access. This measure would have allowed women to obtain an abortion until viability for any reason. It also would have permitted abortion after viability until birth “when necessary to protect the patient’s health.”

The U.S. Supreme Court ruled in 1973 that “health” not only includes a pregnant woman’s physical health, but also extends to considering her age, emotional state or psychological well-being.

Since Amendment 4 did not pass in Florida, the law remains the same.

Florida allows abortion only until six weeks gestation. However, Florida’s law has multiple exceptions, allowing abortions that result from crimes such as rape, incest, domestic violence or human trafficking for up to 15 weeks.

Florida also permits abortion in the first two trimesters in cases where the fetus has a fatal abnormality. Finally, Florida has exceptions that allow abortion for emergencies, or where continuing the pregnancy would pose a threat to the woman’s life or physical health.

Misconceptions about abortion laws

Several articles, including a series in ProPublica, have described cases where women who were pregnant and sought emergency medical treatment suffered complications or death.

The death of any young woman is tragic. However, in my opinion, these cases reflect a misunderstanding of what the law allows, which could make physicians unsure and slow to treat the patient. Some cases may also involve miscommunication, or potential medical mismanagement.

Unfortunately, incorrect or even missed diagnoses are common in emergency rooms, affecting 7.4 million people per year. One in 350 people who had a missed diagnosis suffers serious disability or death.

State laws that regulate abortion do not prevent physicians from intervening to provide necessary or life-saving medical care for women.

Florida’s law plainly says that if there is a conflict between trying to preserve the woman’s life or the fetus’s life, the physician “must consider preserving the woman’s life and health as the priority.”

Florida and Georgia have provided guidance to physicians to clarify what the law allows when treating their patients.

All states – even those with restrictive abortion laws like Texas and Indiana – have exceptions that allow abortion in cases of a medical emergency, or where continuing the pregnancy would pose a risk to the woman’s life or health. In addition, the Department of Justice has stated that people have a constitutional right to travel to seek medical care or abortions in other states from willing providers.

Physicians who feel uncertain can reach out for assistance from a lawyer or find information from their state health department for clarification.The Conversation

Katherine Drabiak, Professor of Health Law, Public Health Law and Medical Ethics, University of South Florida

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

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Strength training early in life can set up kids and adolescents for a lifetime of health and well-being

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theconversation.com – Zachary Gillen, Assistant Professor of Exercise Physiology, Mississippi State University – 2024-11-08 07:39:00

An age-appropriate strength training program can have significant benefits for children and adolescents.

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Zachary Gillen, Mississippi State University

“Aren’t they a little young for that?”

This is a question I used to hear regularly from parents when I’d recommend strength training for the kids I worked with, whose ages ranged from 6 to 18 years old, in youth sports. During my four years as a strength and conditioning coach, I often received questions from parents about the pros and cons of strength training – that is, training that involves weight-bearing exercises – for children.

Some of the most common questions: Is strength training safe for children and adolescents? At what age is it appropriate for them to begin strength training? What are the benefits of strength training for this age group? Is strength training beneficial even for kids who are not involved in organized sports?

Simply put, it is safe and appropriate for kids of all ages to perform strength training.

I am an exercise physiologist, certified strength and conditioning specialist and certified performance and sport scientist. My research focuses on how muscle develops from childhood to adolescence, with the goal of understanding how young people can get the most benefit out of exercise training programs, particularly strength training programs.

My experience and research has shown that strength training can help to improve sports performance for youth, and that there are significant health benefits for youth participating in strength training beyond sports performance.

Safety first

The question I receive most often, for good reason, is whether strength training is safe for youth. In a study examining injury rates in numerous sports, researchers found that, when done correctly, strength training had a lower risk of injury than nearly all other sports. This is not only true for adults but also for children.

That being said, it is important to consider a young person’s emotional maturity before handing them a dumbbell. During my career, I have designed and implemented strength training programs for kids of all ages, even as young as 6 years old. But not every child in that age range is ready for strength training. For their own safety, participants need to be emotionally mature enough to listen to and follow instructions so that they don’t hurt themselves. For some kids, that’s as early as age 6, while others may not be ready until they are a few years older.

Because correct technique is key to doing these exercises safely, it is important that strength training programs for children be designed and implemented under the guidance of a qualified trainer or coach. This means someone with valid credentials and who has received higher education in exercise science.

It’s also important to seek out professionals who use scientific evidence to back up their training programs and philosophies.

Group of kids performing side planks on mats in a gym.

Building strength during childhood and adolescence can reduce the risk of injury in various activities and help prevent falls and fractures later in life too.

SDI Productions/E+ via Getty Images

The benefits of strength training

Research has shown that stronger muscles in kids reduce the likelihood of injuries during various types of activities.

One study we conducted found that lower muscle strength and size could lead to lower performance during different activities kids typically engage in, such as running and jumping. Not only this, but kids with lower strength tend to have worse neuromuscular efficiency, which means that they are not as proficient at activating their muscles. This translates to using more energy and feeling more worn out when they’re physically active.

While it’s easy to see how strength training is important for youth who play sports, there are also incredible health benefits for kids who may not be into organized sports. Studies have shown the positive effect that strength training can have on healthy bone development in kids, leading to a lower likelihood of fractures. Research has also shown that strength training in kids can have a positive influence on psychological well-being and academic performance.

Strength training can also affect overall health and well-being as it relates to childhood obesity.

Obesity rates in children and adolescents have been rising for decades. Previous research has suggested that youth who are categorized as obese tend to have lower muscle strength than those considered normal weight. Not only this, but other research has found that youth who are obese may have a greater likelihood of sarcopenic obesity, defined as obesity with low muscle mass and function, which can have significant, negative health ramifications.

Resistance training interventions in youth with obesity have shown to have positive impacts on metabolic health, body composition, psychological health and overall quality of life.

Creating an age-appropriate program

An effective strength training program starts with setting age-appropriate expectations.

Children and adolescents are not miniature adults, and not all young people will adapt to a strength training program the same way. For instance, research shows that during puberty, there are unique differences in how muscle develops in boys versus girls.

Specifically, girls may have more neuroplasticity, which is defined as the brain’s ability to recognize new movements and patterns. This means that they may adapt to more complex movements faster than boys, while boys will see more significant changes when their muscle mass starts increasing with puberty. This doesn’t necessarily mean that girls and boys need vastly different strength training programs. It simply means not all kids will have the same rate of progression for certain exercises.

Taking that into consideration, an age-appropriate program should focus on technique over results. How much weight a child can lift is far less important than teaching them good movement patterns. For example, if a child is having difficulty performing normal pushups, a qualified professional could modify the exercise so they start with wall pushups or incline pushups. This will help that child build good movement patterns and be better for their strength in the long run.

Building off this focus on technique, a good strength training program for youth should progress from simple movements to more complex movements and lighter weights to heavier weights, taking into consideration that not all youth will adapt at the same rate.

Focusing on the long term

Obviously, most kids won’t grow up to be professional athletes, but every child can develop athleticism. A good strength training program for kids will set them on a trajectory to a healthy lifestyle from childhood to adolescence to adulthood.

Research shows that beginning exercise in childhood tends to lead to continued exercise habits in adulthood. For this reason, the National Strength and Conditioning Association, a leading organization in the field of strength and conditioning and exercise science, has encouraged a focus on improving training habits in childhood that can then be maintained into adulthood for overall better health and well-being.

Starting young with an age-appropriate strength training program can help kids develop good movement patterns and incorporate exercise into their routine, which can have lasting benefits for their health into adulthood.The Conversation

Zachary Gillen, Assistant Professor of Exercise Physiology, Mississippi State University

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

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