As a fatal measles outbreak continues to spread, the United States’ leading public health official has offered some advice that’s not backed by science. Secretary of Health and Human Services Robert F. Kennedy Jr., told Fox News earlier this month that his department was delivering vitamin A to Texas, and that health officials were getting results by treating measles with cod liver oil, a substance that has high levels of vitamins A and D. 

While vitamin A is, in fact, part of the recommended treatment for measles, “It’s not good advice,” said Adam Ratner, a pediatric infectious disease expert, and member of the American Academy of Pediatrics (AAP) Committee on Infectious Diseases. “I think the problem is that he’s taken something where there’s a kernel of truth, which is that there is an interaction between vitamin A status and measles outcome, and he turned that into vitamin A and vitamin D. He’s talking about cod liver oil, which is not how you would supplement someone, in part, because there’s not a known amount of vitamin A in that.”

Kennedy’s advice couldn’t have come at a worse time. As of March 18, the Texas Department of Health and Human Services was reporting 279 cases since the end of January, with 36 patients needing hospitalization. One unvaccinated child had died in Texas, while another unvaccinated person died in New Mexico. Cases have been reported in at least seven other states. According to the World Health Organization (WHO), over 100,000 people, mostly children under the age of five, died of measles globally in 2023.

The vitamin A factor

While Kennedy may have been wrong overall, as Ratner noted, there was still a sliver of truth in his statement. Both the CDC and WHO recommend dosing children diagnosed with measles with vitamin A, which is found in foods like carrots, spinach, pumpkins, eggs, milk, sweet potatoes, and mangoes. 

Numerous studies have found vitamin A is effective in reducing the severity of measles, including lowering mortality rates. According to AAP guidelines, children who test positive for measles should be given two daily doses of vitamin A for two days, with the dosage varying by age. 

However, many of the studies that concluded vitamin A was an effective treatment were conducted on populations that tend to be malnourished in general. In more developed countries, such as the United States, vitamin A’s effectiveness is less clear. A 2021 study conducted in Italy found no significant difference between vitamin A and a placebo in treating children admitted to hospital with measles. 

Ratner noted that the Italian study suffered from a small sample size, but acknowledged that, “There’s some data on the side of saying that the impact in Italy or somewhere like the United States is likely to be less of giving vitamin A supplementation than it is somewhere with a lot of malnutrition. This goes back to observations from a long time ago that children who were malnourished had much higher rates of severe disease and death from measles than kids who were well nourished.”

[ Related: How to check your measles vaccination status amid outbreak. ]

The reasons that vitamin A is good for measles are both straightforward and complex. The vitamin “plays a vital role for immune system functioning,” said Erik Blutinger, an assistant professor of Emergency Medicine at the Icahn School of Medicine. “It helps the body produce antibodies. It helps the body mobilize T cell responses, and it prevents immunity from weakening overall.”

Vitamin A is also critical to skin health, as it helps maintain healthy cells in the epidermis, the outermost layer of skin. 

”The skin is one of our vital organs and serves as a protective barrier even for our immune system,” adds Blutinger.

Too much of a good thing

The trouble with the recent recommendation is that some parents may hear that a little vitamin A is good, so more must be better. As with most medicines, this can be dangerous thinking. In large doses, vitamin A can become toxic. Symptoms can include nausea, vomiting, headaches, and blurred vision. In extreme cases, it can even lead to permanent liver, bone, or nervous system damage.

Vitamin A is particularly dangerous “because it’s fat soluble, it gets stored in the liver,” said Ratner. “It’s very easy to give someone too much, and that can either be too much in terms of individual doses or even reasonable doses for too long a period of time. It can endanger the liver, it can endanger the bones. Vitamin A supplementation is great for people who are vitamin A deficient, and it’s a reasonable thing to do just for the two doses at the time of measles diagnosis, because we think that there’s a potential benefit just during that little window. But it’s not something that people should be doing on their own, and it’s not something that should be done long term unless there’s some very specific medical condition that someone’s treating.”

In a 2023 article published in the Journal of the American College of Emergency Physicians Open, Blutinger noted that there is no antiviral treatment for measles yet available. While two days of vitamin A doses is recommended, followed by another dose several weeks later, the study concluded that the best and surest way to combat the disease remains vaccination. 

[ Related: Is raw milk safe? Science has a clear answer. ]

How to stay healthy

Beyond vaccinating, the best advice Blutinger could offer parents was to “be well informed with verifiable information that comes from your primary care doctor and from the medical professionals that do not care about politics.”

“My other advice is to take measles extremely seriously and to do what you can to protect your loved ones, your children, the elderly, everyone around you, because, as we saw during COVID, pandemics are not easily tamed,” he added. “If measles continues to spread rapidly, we may be in even more serious trouble.”

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“The sun never sets on the British empire.” Variations on the phrase have been used for more than  200 years to describe the scope and power of the nation and its occupied territories. But from a logistical standpoint, Britain gave up the centuries-long imperial distinction last October, when it reached an agreement to return the Chagos Islands to Mauritius. It was a long time coming for the Chagossians, many of whom have worked for decades to regain control of the island. A joint statement issued between both countries in October vowed the deal helped to “address wrongs of the past and demonstrate the commitment of both parties to support the welfare of Chagossians.”

Technically speaking, however, sunlight continued to shine on at least one portion of British-occupied land for about another six months. The primary holdout? A section of the British Antarctic Territory, including the Pitcairn Islands that experiences perpetual sunlight six months out of the year.

But thanks to cosmic geometry, a major chapter in world history has just now come to a close. As first highlighted last year on Reddit, the spring equinox on March 20 marked the sun’s passage over the celestial equator, kicking off half a year of darkness around the South Pole. And given last year’s deal with Mauritius, this means Thursday night at 10:50 PM EST (2:50 AM on March 21 in London), the sun finally, literally set on the British empire.

It didn’t stay dark for Britain too long, however. About an hour after dusky conditions on the Pitcairn Islands, light began to peek over the horizon roughly 10,000 miles away in Akrotiri and Dhekelia, two non-contiguous British territories located on the island of Cyprus. Meanwhile, Britain is still maintaining a presence at a military base on the Chagos Archipelago’s Diego Garcia island as part of the 2024 agreement.

Britain isn’t the first or last culture with enough global territory to qualify for the “sun never sets” moniker. Similar, solar-based expansionist sentiments date as far back as the Egyptian, Mesopotamian, Persian, and Roman empires. The phrase “the empire on which the sun never sets” was first used in reference to the Spanish empire under the 16th century Hapsburg reign of King Charles I, also known as Charles V of the Holy Roman Empire. Beginning in the 20th century, similar titles were frequently used to describe the United States. If nothing else, empires may rise and fall, but the sun will outlast them all—at least for about another 5 billion years.

The post The sun has literally set on the British Empire appeared first on Popular Science.

Our bodies are always moving, even when we don’t realize it. We churn through a solar system on a wobbly planet, stand upon shifting tectonic plates, and rise and fall and toss and turn all day and night in a symphony of autonomic and somatic functions. Dizzying though this may seem, life is always in motion, right down to its fundamental building blocks — molecules.

Molecules can be thought of as atoms that share electrons. They form electronic bonds that can be visualized like springs, and they jiggle around at a rate that corresponds with the heat energy to which they’re exposed. Although molecules are neither alive nor dead, they never cease moving, even when scientists try their damndest to sap them of energy. To unpack why molecules never stop moving, and before we get lost in the fundamental weirdness of quantum mechanics, we must first clarify something a bit more straightforward: What is temperature?

In daily life, blustery weather might chill you to the bone, and a cup of tea could warm your lips. When we talk about temperature, we often do so in reference to our own comfort level, body thermoregulation, or climate change. But on a submicroscopic level, temperature measures the average kinetic energy of the molecules or particles in an object or substance. The hotter they get, the more they move; therefore, to “stop” them, we’d just need to take away all their heat energy to achieve absolute zero, or 0 Kelvin — right?

Only, “you can never really completely isolate a molecule from its environment,” said Justin Caram, an associate professor of chemistry at the University of California, Los Angeles, said in a call with Popular Science. “Whether it’s knocking into other molecules in the air — or atoms or whatever — or it’s absorbing light and reemitting light, it’s always interacting with its environment.” Caram added, “You can temporarily cool things down so that they move very, very, very little — and that’s how we define a very low temperature, right? But by the principles of quantum mechanics, you can never completely eliminate all of the motion in the system.”

But… why?

Let’s start with a classically familiar factor in play here: the observer effect. In this case, simply attempting to measure the temperature of something can affect its temperature, because “the molecule can interact with other things, including the measurement apparatus,” explained A. F. J. Levi, an engineering, physics, and astronomy professor at the University of Southern California, in an email to Popular Science. But things get a lot weirder in quantum mechanics, where the uncertainty principle enters the picture, per Levi — who, by the way, called our broader question about molecular movement “deceptively simple.” 

When we talk about how molecules move, this motion “can be separated into the center of mass and relative motion between atoms,” Levi explained. “Because the molecule consists of atoms bound together, at least one lowest-energy bound state is assumed to exist (the idea that a lowest energy ‘ground state’ exists is a very important assumption justified by experiment).” 

Levi went on: “The mathematics of quantum mechanics can be thought of as the linear algebra of non-commuting operators, and this leads directly to the uncertainty principle, which does not allow the lowest-energy bound state of a molecule to simultaneously have zero momentum and a definite, precisely measured position. Physically, it is impossible to precisely measure a molecule’s position without giving it momentum.” 

Levi’s response initially made my brain fuzzy, so I got Caram on the phone a second time to discuss the matter some more. That’s when he offered a Chemistry 101-level explanation of Heisenberg’s uncertainty principle.

“The uncertainty principle just says that position and momentum don’t — okay, there’s a mathematical term. They say they don’t commute. But what that really means is that you can’t measure them simultaneously.” A more accurate way to put that, per Caram, has less to do with measurement. Fundamentally, he explained, “an object cannot possess both properties at the same time.”

This is because quantum theory tells us everything is a wave, including particles, when you look closely enough.

As I start to go existential about wave–particle duality on the phone, Caram offers some words of comfort: “This is just one of those fundamental, really upsetting weirdnesses about quantum mechanics,” Caram said. “[We] have to describe matter as waves. Like, that’s a weird thing; it doesn’t have much meaning to you or me just thinking about it, but the mathematics and the observations work out.”

I ask Caram if he ever thinks about the constant motion going on within our bodies, at molecular and macro levels, and he tells me he tries not to think about it. “It’s a little unsettling to think of all the things that our bodies are doing. Yeah, I don’t know. I don’t know how to answer that, other than to say: I like to not think about it that much, because sometimes I do worry, ‘What if it’ll just stop?’”

Okay! Enough! Beyond the philosophical, molecular motion also connects to the sometimes-buzzy realm of quantum computing.

At UCLA, Caram said that “one of the research areas we work in is related to developing molecules that move as little as possible.” He went on: “Obviously, like I said, there are limits to that — fundamental limits — but the more you’ve slowed down those molecules and controlled their states, the more you can sort of do quantum algorithms and make the quantum computers work better.” 

While humans can’t stop molecules from moving altogether, we’re getting good at slowing them down a whole lot. In fact, “we have achieved colder places on Earth than we have than anywhere in deep space,” according to Caram, “because deep space is always permeated with something called microwave background radiation, and so it has a temperature.” (That temperature is about 2.7 Kelvin.) 

Compare that to the coldest temperature recorded in a lab to date, which is 38 trillionths of a Kelvin — or around -273.15 degrees Celsius. German scientists achieved this feat in 2021 for only a couple of seconds, when they trapped rubidium atoms in a vacuum and mimicked zero gravity at a drop tower at the University of Bremen.

As humans go to great lengths to push the limits of cold, the universe itself is cooling. It was “born with a given amount of energy” in all sorts of forms, “kinetic, chemical, nuclear, whatever,” said Caram, citing the Big Bang theory and the process by which things exchange heat with their environment, known as thermalization. Indulging me, Caram said his “very philosophical” view is that “in the endless, infinite timescale, you know, as the universe expands — we’ll just all sort of slowly move towards some time where things move less and less. That’s the heat death of the universe,” explained Caram, who cautioned me not to worry about it because there really are more pressing things to ponder today. Still, the concept that everything has been spreading out since the “initial kick” of the Big Bang suggests that our lives on Earth are profoundly and uniquely active. (Unless the universe, uh… starts contracting somehow.)

“What we’re really doing is a sort of an extreme fluctuation, where things happen to be moving a little bit more to give rise to complexity” before everything just falls apart, said Caram. “But it will never stop moving entirely, because, like I said, you can never really stop moving.”

This story is part of Popular Science’s Ask Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something you’ve always wanted to know? Ask us.

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