Category: The Conversation

Source: The Conversation – USA (3) – By Sujith Ramachandran, Associate Professor of Pharmacy Administration, University of Mississippi

Even when Americans have health insurance, they can have a hard time affording the drugs they’ve been prescribed.

About 1 in 5 U.S. adults skip filling a prescription due to its cost at least once a year, according to KFF, a health research organization. And 1 in 3 take steps to cut their prescription drug costs, such as splitting pills when it’s not medically necessary or switching to an over-the-counter drug instead of the one that their medical provider prescribed.

As pharmacy professors who research prescription drug access, we think it’s important for Americans to know that it is possible to get prescriptions filled more affordably, as long as you know how before you go to the pharmacy.

Cost of copays ranges widely

When you have health insurance and have to pay for a prescription drug at the pharmacy, you’re usually covering the cost of your copay. This is the amount patients or their caregivers are expected to pay after insurance covers the rest of the tab.

If you get your health insurance through Medicaid, the government program that covers low-income Americans and people with disabilities, you should not have to pay anything at all to obtain prescription drugs. If there is a copay, it should be low – probably less than US$5.

And if you’re insured through Medicare, the government program that mainly covers people who are 65 and older, or get your coverage through a private health insurance company, it’s important to understand what to expect when you visit a pharmacy.

Most private insurance companies charge US$5 to $50 for prescription drug copays. The copays are tiered based on what the drug costs. Brand-name and specialty medications have higher copays; older generics have lower copays.

Some generic drugs and vaccines may even require no copay at all. While a copay is a flat fee, it can change over the course of the year based on whether or not you have met your deductible. The deductible is the amount of money you have to pay out of pocket before your insurance starts covering your prescriptions. Before your deductible is fully paid, you may be responsible for the full cost of your medications. After you’ve met your deductible for the year, you will only be required to pay the copay.

As newer, more expensive drugs enter the market, cost-sharing at the pharmacy has increasingly shifted from a copay to coinsurance.

In contrast with a flat copay, coinsurance means your insurance company will cover a certain percentage of the drug’s cost, and you’ll pay the rest. Since the patient’s share is based on a percentage of the medication’s price, coinsurance often results in higher out-of-pocket costs than copays do.

New help for patients with Medicare coverage

Two new government programs could help make prescription drugs more affordable for millions of older Americans.

Starting in 2026, people who are insured through Medicare will pay no more than $2,100 out of pocket on prescription drugs over the year. That cap may be much lower than $2,100 due to a quirk in Medicare’s rules. Prescriptions filled after someone has paid the maximum allowable amount will cost them nothing at all.

In addition, the government launched the Medicare Prescription Payment Plan in 2025. This program, which is available to people over 65, helps spread what patients spend out of pocket on prescription drugs throughout the year, making that expense more predictable and easier to budget for.

Early data indicates that very few Americans are enrolled in the Medicare Prescription Payment Plan. Patients insured through private companies do not have similar opportunities.

Coupons and discount cards

What if you can’t afford a copay for your prescription drug?

Before giving up on ever getting it, ask the pharmacist about your options.

It may be worth trying to use a free online tool, such as RxAssist, sponsored by the Robert Wood Johnson Foundation, or a discount card from GoodRx, which is a publicly traded company.

GoodRx cards are free. They help people compare local pharmacy prices and to locate coupons that make prescriptions more affordable.

GoodRx works by searching for the lowest available price for the prescription at various pharmacies. Other copay coupons provided by the drug manufacturer may also work similarly by lowering the cost of the medication. On some occasions, the cash price at the pharmacy may actually be cheaper than the copay, and the pharmacist should be able to help you navigate these options.

Here’s what you should know before giving GoodRx a try:

1. GoodRx collects individual data on patients, raising significant privacy concerns.

2. Some pharmacies do not accept GoodRx. You may have to visit more than one pharmacy to be able to activate its discounts.

3. These cards may make the most sense for uninsured or underinsured patients, but do not always help those who have insurance because you might not get a better price. What’s more, if you use a discount card, the amount you pay may not count toward your insurance deductible for the year.

You should weigh the caveats closely depending on your circumstance.

Prescription assistance programs

Prescription assistance programs provide another cost-saving tool for Americans.

Drugmakers, nonprofits and government agencies sponsor those programs, which help patients who are uninsured or underinsured – even if they are on Medicare – fill prescriptions either at a discount or for free.

These programs include manufacturer-specific programs as well as charitable pharmacies like Dispensary of Hope, NOVA Scripts Central and the Patient Advocate Foundation. Qualifying criteria vary for these programs, but typically you must have a low income and be a citizen or a legal U.S. resident.

The Patient Access Network Foundation and RxAssist, two nonprofits that help Americans pay their medical bills, also offer helpful tools to identify programs that could work for you.

Assistance from these programs could cut your copay or even provide a prescription drug at no cost.

Separately, the Trump administration announced in November 2025 that a new White House prescription drug pricing program will soon begin to connect consumers to companies that have agreed to sell certain prescription drugs at a big discount.

Many experts don’t expect the program, known as TrumpRx, to help people who have health insurance. Instead, it could be most likely to help those with no insurance at all. The new government program is slated to begin to roll out in 2026.

Direct-to-consumer models

Beyond coupons and assistance programs, a more radical shift is in the works: direct-to-consumer platforms and cash-payment models.

In 2025, several manufacturers offered to sell medications directly to patients on websites and patient portals at cash prices. For example, the drug manufacturer Eli Lilly is offering its popular weight-loss medication, Zepbound, on its website.

These websites have out-of-pocket costs that can run upward of $300 a month, making them too high for many, if not most, Americans to afford. And insurance companies have so far refused to cover them.

To be sure, the systems underlying these programs are still being built. We believe that the Trump administration would need to make a bigger effort to make it easier for millions of Americans to be able to afford filling their prescriptions.

Sujith Ramachandran received funding from Robert Wood Johnson Foundation, and provides consulting services for the National Community Pharmacists Association for work related to this topic.

Adam Pate does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. My prescription costs what?! Pharmacists offer tips that could reduce your out-of-pocket drug costs – https://theconversation.com/my-prescription-costs-what-pharmacists-offer-tips-that-could-reduce-your-out-of-pocket-drug-costs-268067

Source: The Conversation – USA – By Bilal Haider, Associate Professor of Biomedical Engineering, Georgia Institute of Technology

Despite the nursery rhyme about three blind mice, mouse eyesight is surprisingly sensitive. Studying how mice see has helped researchers discover unprecedented details about how individual brain cells communicate and work together to create a mental picture of the visual world.

I am a neuroscientist who studies how brain cells drive visual perception and how these processes can fail in conditions such as autism. My lab “listens” to the electrical activity of neurons in the outermost part of the brain called the cerebral cortex, a large portion of which processes visual information. Injuries to the visual cortex can lead to blindness and other visual deficits, even when the eyes themselves are unhurt.

Understanding the activity of individual neurons – and how they work together while the brain is actively using and processing information – is a long-standing goal of neuroscience. Researchers have moved much closer to achieving this goal thanks to new technologies aimed at the mouse visual system. And these findings will help scientists better see how the visual systems of people work.

The mind in the blink of an eye

Researchers long thought that vision in mice appeared sluggish with low clarity. But it turns out visual cortex neurons in mice – just like those in humans, monkeys, cats and ferrets – require specific visual features to trigger activity and are particularly selective in alert and awake conditions.

My colleagues and I and others have found that mice are especially sensitive to visual stimuli directly in front of them. This is surprising, because mouse eyes face outward rather than forward. Forward-facing eyes, like those of cats and primates, naturally have a larger area of focus straight ahead compared to outward-facing eyes.

This finding suggests that the specialization of the visual system to highlight the frontal visual field appears to be shared between mice and humans. For mice, a visual focus on what’s straight ahead may help them be more responsive to shadows or edges in front of them, helping them avoid looming predators or better hunt and capture insects for food.

Importantly, the center of view is most affected in aging and many visual diseases in people. Since mice also rely heavily on this part of the visual field, they may be particularly useful models to study and treat visual impairment.

A thousand voices drive complicated choices

Advances in technology have greatly accelerated scientific understanding of vision and the brain. Researchers can now routinely record the activity of thousands of neurons at the same time and pair this data with real-time video of a mouse’s face, pupil and body movements. This method can show how behavior interacts with brain activity.

It’s like spending years listening to a grainy recording of a symphony with one featured soloist, but now you have a pristine recording where you can hear every single musician with a note-by-note readout of every single finger movement.

Using these improved methods, researchers like me are studying how specific types of neurons work together during complex visual behaviors. This involves analyzing how factors such as movement, alertness and the environment influence visual activity in the brain.

For example, my lab and I found that the speed of visual signaling is highly sensitive to what actions are possible in the physical environment. If a mouse rests on a disc that permits running, visual signals travel to the cortex faster than if the mouse views the same images while resting in a stationary tube – even when the mouse is totally still in both conditions.

In order to connect electrical activity to visual perception, researchers also have to ask a mouse what it thinks it sees. How have we done this?

The last decade has seen researchers debunking long-standing myths about mouse learning and behavior. Like other rodents, mice are also surprisingly clever and can learn how to “tell” researchers about the visual events they perceive through their behavior.

For example, mice can learn to release a lever to indicate they have detected that a pattern has brightened or tilted. They can rotate a Lego wheel left or right to move a visual stimulus to the center of a screen like a video game, and they can stop running on a wheel and lick a water spout when they detect the visual scene has suddenly changed.

Mice can also use visual cues to focus their visual processing to specific parts of the visual field. As a result, they can more quickly and accurately respond to visual stimuli that appear in those regions. For example, my team and I found that a faint visual image in the peripheral visual field is difficult for mice to detect. But once they do notice it – and tell us by licking a water spout – their subsequent responses are faster and more accurate.

These improvements come at a cost: If the image unexpectedly appears in a different location, the mice are slower and less likely to respond to it. These findings resemble those found in studies on spatial attention in people.

My lab has also found that particular types of inhibitory neurons – brain cells that prevent activity from spreading – strongly control the strength of visual signals. When we activated certain inhibitory neurons in the visual cortex of mice, we could effectively “erase” their perception of an image.

These kinds of experiments are also revealing that the boundaries between perception and action in the brain are much less separate than once thought. This means that visual neurons will respond differently to the same image in ways that depend on behavioral circumstances – for example, visual responses differ if the image will be successfully detected, if it appears while the mouse is moving, or if it appears when the mouse is thirsty or hydrated.

Understanding how different factors shape how cortical neurons rapidly respond to visual images will require advances in computational tools that can separate the contribution of these behavioral signals from the visual ones. Researchers also need technologies that can isolate how specific types of brain cells carry and communicate these signals.

Data clouds encircling the globe

This surge of research on the mouse visual system has led to a significant increase in the amount of data that scientists can not only gather in a single experiment but also publicly share among each other.

Major national and international research centers focused on unraveling the circuitry of the mouse visual system have been leading the charge in ushering in new optical, electrical and biological tools to measure large numbers of visual neurons in action. Moreover, they make all the data publicly available, inspiring similar efforts around the globe. This collaboration accelerates the ability of researchers to analyze data, replicate findings and make new discoveries.

Technological advances in data collection and sharing can make the culture of scientific discovery more efficient and transparent – a major data informatics goal of neuroscience in the years ahead.

If the past 10 years are anything to go by, I believe such discoveries are just the tip of the iceberg, and the mighty and not-so-blind mouse will play a leading role in the continuing quest to understand the mysteries of the human brain.

Bilal Haider receives funding from NIH and the Simons Foundation.

– ref. Gazing into the mind’s eye with mice – how neuroscientists are seeing human vision more clearly – https://theconversation.com/gazing-into-the-minds-eye-with-mice-how-neuroscientists-are-seeing-human-vision-more-clearly-268334

Source: The Conversation – USA – By Sven Bilén, Professor of Engineering Design, Electrical Engineering and Aerospace Engineering, Penn State

There are about 15,000 satellites orbiting the Earth. Most of them, like the International Space Station and the Hubble Telescope, reside in low Earth orbit, or LEO, which tops out at about 1,200 miles (2,000 kilometers) above the Earth’s surface.

But as more and more satellites are launched into LEO – SpaceX’s Starlink internet constellation alone will eventually send many thousands more there – the region’s getting a bit crowded.

Which is why it’s fortunate there’s another orbit, even closer to Earth, that promises to help alleviate the crowding. It’s called VLEO, or very low Earth orbit, and is only 60 to 250 miles (100 to 400 kilometers) above the Earth’s surface.

As an engineer and professor who is developing technologies to extend the human presence beyond Earth, I can tell you that satellites in very low Earth orbit, or VLEO, offer advantages over higher altitude satellites. Among other benefits, VLEO satellites can provide higher-resolution images, faster communications and better atmospheric science. Full disclosure: I’m also a co-founder and co-owner of Victoria Defense, which seeks to commercialize VLEO and other space directed-energy technologies.

Advantages of VLEO

The images from very low Earth orbit satellites are sharper because they simply see Earth more clearly than satellites that are higher up, sort of like how getting closer to a painting helps you see it better. This translates to higher resolution pictures for agriculture, climate science, disaster response and military surveillance purposes.

End-to-end communication is faster, which is ideal for real-time communications, like phone and internet service. Although the signals still travel the same speed, they don’t have as far to go, so latency decreases and conversations happen more smoothly.

Much weather forecasting relies on images of clouds above the Earth, so taking those pictures closer means higher resolution and more data to forecast with.

Because of these benefits, government agencies and industry are working to develop very low Earth orbit satellites.

The holdup: Atmospheric drag

You may be wondering why this region of space, so far, has been avoided for sustained satellite operations. It’s for one major reason: atmospheric drag.

Space is often thought of as a vacuum. So where exactly does space actually start? Although about 62 miles up (100 kilometers) – known as the the von Kármán line – is widely considered the starting point, there’s no hard transition where space suddenly begins. Instead, as you move away from Earth, the atmosphere thins out.

In and below very low Earth orbit, the Earth’s atmosphere is still thick enough to slow down satellites, causing those at the lowest altitudes to deorbit in weeks or even days, essentially burning up as they fall back to Earth. To counteract this atmospheric drag and to stay in orbit, the satellite must constantly propel itself forward – like how riding a bike into the wind requires continuous pedaling.

For in-space propulsion, satellites use various types of thrusters, which provide the push needed to keep from slowing down. But in VLEO, thrusters need to be on all, or nearly all, of the time. As such, conventional thrusters would quickly run out of fuel.

Fortunately, the Earth’s atmosphere in VLEO is still thick enough that atmosphere itself can be used as a fuel.

Innovative thruster technologies

That’s where my research comes in. At Penn State, in collaboration with Georgia Tech and funded by the U.S. Department of Defense, our team is developing a new propulsion system designed to work at 43 to 55 miles up (70 to 90 kilometers). Technically, these altitudes are even below very low Earth orbit – making the challenge to overcome drag even more difficult.

Our approach collects the atmosphere using a scoop, like opening your mouth wide as you pedal a bike, then uses high-power microwaves to heat the collected atmosphere. The heated gas is then expelled through a nozzle, which pushes the satellite forward. Our team calls this concept the air-breathing microwave plasma thruster. We’ve been able to demonstrate a prototype thruster in the lab inside a vacuum chamber that simulates the atmospheric pressure found at 50 miles (80 km) high.

This approach is relatively simple, but it holds potential, especially at lower altitudes where the atmosphere is thicker. Higher up, where the atmosphere is thinner, spacecraft could use different types of VLEO thrusters that others are developing to cover large altitude ranges.

Our team isn’t the only one working on thruster technology. Just one example: The U.S. Department of Defense has partnered with defense contractor Red Wire to develop Otter, a VLEO satellite with its version of atmosphere-breathing thruster technology.

Another option to keep a satellite in VLEO, which leverages a technology I’ve worked on throughout my career, is to tie a lower-orbiting satellite to a higher-orbiting satellite with a long tether. Although NASA has never flown such a system, the proposed follow-on mission to the tether satellite system missions flown in the 1990s was to drop a satellite into much lower orbit from the space shuttle, connected with a very long tether. We are currently revisiting that system to see whether it could work for VLEO in a modified form.

Other complications

Overcoming drag, though the most difficult, is not the only challenge. Very low Earth orbit satellites are exposed to very high levels of atomic oxygen, which is a highly reactive form of oxygen that quickly corrodes most substances, even plastics.

The satellite’s materials also must withstand extremely high temperatures, above 2,732 degrees Fahrenheit (1,500 degrees Celsius), because friction heats it up as it moves through the atmosphere, a phenomenon that occurs when all spacecraft reenter the atmosphere from orbit.

The potential of these satellites is driving research and investment, and proposed missions have become reality. Juniper research estimates that $220 billion will be invested in just the next three years. Soon, your internet, weather forecasts and security could be even better, fed by VLEO satellites.

Sven Bilén founder and co-owner of Victoria Defense, which seeks to commercialize VLEO and other space technologies. He receives funding from DARPA and NASA related to VLEO technologies.

– ref. The next frontier in space is closer than you think – welcome to the world of very low Earth orbit satellites – https://theconversation.com/the-next-frontier-in-space-is-closer-than-you-think-welcome-to-the-world-of-very-low-earth-orbit-satellites-258252

Source: The Conversation – USA – By Joshua Kastenberg, Professor of Law, University of New Mexico

The Department of Defense in late November 2025 announced that it would investigate U.S. Sen. Mark Kelly, a retired Navy captain and NASA astronaut, for what Secretary of Defense Pete Hegseth has called seditious behavior. The threat of investigation came after Kelly and five other Democrats, all with military backgrounds, released a video reminding U.S. service members they can disobey illegal orders issued by the Trump administration.

“No one has to carry out orders that violate the law, or our Constitution,” the lawmakers said, without specifying the orders the U.S. service members may have received. “Know that we have your back … don’t give up the ship.”

In response to the video, President Donald Trump accused the lawmakers of “seditious behavior” that could be “punishable by death.”

Sedition is a federal crime, but as a military law scholar who served as a judge in the U.S. Air Force, I believe the Democratic lawmakers articulated a correct view of military law. That is, service members subject to the Uniform Code of Military Justice have a duty to not obey unlawful orders.

There are several unique features to military law that have no analog to civilian criminal law, and if Kelly were court-martialed he would be deprived of several fundamental constitutional rights.

Military justice

In a civilian criminal trial the government normally has the burden of proof on all matters. But in a court-martial, a service member who argues that an order is unlawful has the burden of proving its unlawfulness. And the Supreme Court, in its 1827 opinion in Martin v. Mott, gave this view some credence, arguing that the president, as commander in chief, should not be questioned during a national emergency.

Second, ordinary citizens are protected by a constitutional requirement that the prosecution must convince all jurors of the defendant’s guilt beyond a reasonable doubt. A court-martial has only a two-thirds threshold to establish guilt. And the jurors – called members – are not the accused service member’s peers.

Indeed, the court-martial members are military personnel who outrank the accused service member and are picked to serve by senior commanding officers. Military judges are also uniformed officers and, like the rest of the military, are subject to the chain of command.

At times, senior officers have inserted themselves into the military justice system and tried to direct a court-martial to convict an accused service member. This has created the problem of unlawful command influence, the improper use of superior authority to interfere with the court-martial process.

Kelly is still theoretically subject to the Uniform Code of Military Justice and could be court-martialed because he is a military retiree. This concept of a lifetime military jurisdiction did not exist when the Constitution was instituted in 1789. It came into existence during an emergency session of Congress in 1861.

The Supreme Court has never held that lifetime jurisdiction is constitutional. But in 2022 the U.S. Court of Appeals for the District of Columbia did, in a 2-1 decision.

It reasoned that if the Constitution’s creators had thought such a jurisdiction were a threat to the republic, they would have prohibited it. The dissenting judge in that case pointed out the frightening possibility of a president using the Uniform Code of Military Justice to curb free speech.

Lines of defense

Kelly is different than an ordinary retiree, and this case is bigger than a single senator. That’s because it goes to the heart of what the Constitution’s framers intended by preserving liberty through a republican form of government.

In 1648, Oliver Cromwell, who had become a military dictator over England, used the army to curb the Magna Carta – a revolutionary basic rights document dating to 1215 – and the ability of Parliament to debate matters and pass laws. The Constitution is designed to prevent anything coming close to such an occurrence.

So, what would Kelly’s defense likely be, other than that he exercised free speech and gave a correct recitation of the law?

Kelly’s first defense might be that under the Constitution, the president, as commander in chief, has no power to court-martial or otherwise administratively penalize him. Doing so would diminish Congress’ authority.

In 1974, the Supreme Court determined in Schlesinger v. Reservists Committee that although the Constitution prohibits a member of Congress from holding a position in the executive branch, citizens had no standing to sue in the federal courts to prevent this from occurring. Taken literally, the clause means that no member of Congress could hold a military commission and be beholden to the commander in chief, since this would erode Congress’ independence and authority.

Kelly’s second defense could be that after the Constitution and statutory law, the military law is governed by tradition, or the military’s own past practices, which used to be referred to as “lex non scripta.”

American history is replete with retired officers criticizing presidents or even joining in hate groups that accused a president of being beholden to subversive interests. Past presidents have ignored these men.

They include George Van Horn Moseley, who sided with pro-Nazi groups and accused President Franklin Roosevelt of being a communist. Retired generals Albert Coady Wedemeyer and Bonner Fellers formed organizations that undermined Presidents Harry Truman and Dwight Eisenhower.

None of these men were court-martialed or administratively penalized.

Finally, Kelly could argue in federal court that the military has no jurisdiction over him because of the issue of unlawful command influence. One only needs to look at Hegseth’s statements in the case to see the specter of this problem in regard to Kelly.

When Congress formulated the Uniform Code of Military Justice, it criminalized unlawful command influence. But as military law scholar Rachel VanLandingham has pointed out, no person has ever been prosecuted for violating the prohibition.

Kelly could argue that there are no safeguards in his case to ensure a fair hearing and that the case should move from military courts to federal courts. The federal judge assigned the case can then ponder whether siding with the administration’s claims is a step toward establishing a Cromwellian future and away from the Constitution’s protection of a republican form of government.

Of course, Congress could put a stop to any persecution of Kelly by informing the president that he is acting contrary to the Constitution and explaining to do so is a high crime or misdemeanor.

During the Vietnam War, scholar Robert Sherrill said that “military justice is to justice what military music is to music.” In the past, military justice has been able to accomplish fair trials of military members, but it is dangerously open to influence by military leaders, all the way up to the commander in chief.

If there is to be an exercise in accountability for Kelly, it could more fairly be administered through a real constitutional analysis conducted by the independent federal judicial branch – or through a congressional intervention. Without either occurring, we may as a nation find ourselves a closer step toward a Cromwellian future.

Joshua Kastenberg does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. If tried by court-martial, senator accused of ‘seditious behavior’ would be deprived of several constitutional rights – https://theconversation.com/if-tried-by-court-martial-senator-accused-of-seditious-behavior-would-be-deprived-of-several-constitutional-rights-271990

Source: The Conversation – USA (2) – By Scott Brame, Research Assistant Professor of Earth Science, Clemson University

When Santa is done delivering presents on Christmas Eve, he must get back home to the North Pole, even if it’s snowing so hard that the reindeer can’t see the way.

He could use a compass, but then he has a challenge: He has to be able to find the right North Pole.

There are actually two North Poles – the geographic North Pole you see on maps and the magnetic North Pole that the compass relies on. They aren’t the same.

The two North Poles

The geographic North Pole, also called true north, is the point at one end of the Earth’s axis of rotation.

Try taking a tennis ball in your right hand, putting your thumb on the bottom and your middle finger on the top, and rotating the ball with the fingers of your left hand. The place where the thumb and middle finger of your right hand contact the tennis ball as it spins define the axis of rotation. The axis extends from the south pole to the north pole as it passes through the center of the ball.

Earth’s magnetic North Pole is different.

Over 1,000 years ago, explorers began using compasses, typically made with a floating cork or piece of wood with a magnetized needle in it, to find their way. The Earth has a magnetic field that acts like a giant magnet, and the compass needle aligns with it.

The magnetic North Pole is used by devices such as smartphones for navigation – and that pole moves around over time.

Why the magnetic north pole moves around

The movement of the magnetic North Pole is the result of the Earth having an active core. The inner core, starting about 3,200 miles below your feet, is solid and under such immense pressure that it cannot melt. But the outer core is molten, consisting of melted iron and nickel.

Heat from the inner core makes the molten iron and nickel in the outer core move around, much like soup in a pot on a hot stove. The movement of the iron-rich liquid induces a magnetic field that covers the entire Earth.

As the molten iron in the outer core moves around, the magnetic North Pole wanders.

For most of the past 600 years, the pole has been wandering around over northern Canada. It was moving relatively slowly, around 6 to 9 miles per year, until around 1990, when its speed increased dramatically, up to 34 miles per year.

It started moving in the general direction of the geographic North Pole about a century ago. Earth scientists cannot say exactly why other than that it reflects a change in flow within the outer core.

Getting Santa home

So, if Santa’s home is the geographic North Pole – which, incidentally, is in the ice-covered middle of the Arctic Ocean – how does he correct his compass bearing if the two North Poles are in different locations?

No matter what device he might be using – compass or smartphone – both rely on magnetic north as a reference to determine the direction he needs to move.

While modern GPS systems can tell you precisely where you are as you make your way to grandma’s house, they cannot accurately tell which direction to go without your device knowing the direction of magnetic north.

If Santa is using an old-fashioned compass, he’ll need to adjust it for the difference between true north and magnetic north. To do that, he needs to know the declination at his location – the angle between true north and magnetic north – and make the correction to his compass. The National Oceanic and Atmospheric Administration has an online calculator that can help.

If you are using a smartphone, your phone has a built-in magnetometer that does the work for you. It measures the Earth’s magnetic field at your location and then uses the World Magnetic Model to correct for precise navigation.

Whatever method Santa uses, he may be relying on magnetic north to find his way to your house and back home again. Or maybe the reindeer just know the way.

Scott Brame does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. The North Pole keeps moving – here’s how that affects Santa’s holiday travel and yours – https://theconversation.com/the-north-pole-keeps-moving-heres-how-that-affects-santas-holiday-travel-and-yours-271488