When people use hand gestures that visually represent what they’re saying, listeners see them as more clear, competent and persuasive. That’s the key finding from my new research published in the Journal of Marketing Research, where I analyzed thousands of TED Talks and ran controlled experiments to examine how gestures shape communication.
Talking with your hands
Whether you’re giving a presentation, pitching an idea or leading a meeting, you probably spend most of your prep time thinking about what you’ll say. But what about the ways you’ll move your hands?
I grew up in Italy, where gesturing is practically a second language. Now that I live in the United States, I’ve become acutely aware of how cultures differ in how, and how much, people move their hands when they talk. Still, across contexts and cultures, one thing is constant: People do talk with their hands.
As someone who studies communication, I’d noticed how some speakers seemed instantly clearer when they gestured. This made me wonder: Do gestures actually make communicators more effective?
The short answer is yes, but only when the gestures visually represent the idea you’re talking about. Researchers call these movements “illustrators.” For example:
When talking about distance, you might spread your hands apart while saying something is “farther away.”
When explaining how two concepts relate, you might bring your hands together while saying “these ideas fit together.”
When describing how the market demand “is going up and down,” you could visually depict a wave shape with your hands.
To study gestures at scale, my team and I analyzed 200,000 video segments from more than 2,000 TED Talks using AI tools that can detect and classify hand gestures frame by frame. We paired this with controlled experiments in which our study participants evaluated entrepreneurs pitching a product.
The same pattern of results appeared in both settings. In the AI-analyzed TED Talk data, illustrative gestures predicted higher audience evaluations, reflected in more than 33 million online “likes” of the videos. And in our experiments, 1,600 participants rated speakers who used illustrative gestures as more clear, competent and persuasive.
How hands can help get your point across
What I found is that these gestures give listeners a visual shortcut to your meaning. They make abstract ideas feel more concrete, helping listeners build a mental picture of what you’re saying. This makes the message feel easier to process – a phenomenon psychologists call “processing fluency.” And we found that when ideas feel easier to grasp, people tend to see the speaker as more competent and persuasive.
But not all gestures help. Movements that don’t match the message – like random waving, fidgeting or pointing to things in the space – offer no such benefit. In some cases, they can even distract.
A practical takeaway: Focus on clarity over choreography. Think about where your hands naturally illustrate what you’re saying – emphasizing size, direction or emotion – and let them move with purpose.
What’s next
Your hands aren’t just accessories to your words. They can be a powerful tool to make your ideas resonate.
I’m now investigating whether people can learn to gesture better – almost like developing a nonverbal vocabulary. Early pilot tests are promising: Even a 5-minute training session helps people become clearer and more effective through the use of appropriate hand gestures.
While my research examined how individual gestures work together with spoken language, the next step is to understand what makes a communicator effective with their voice and, ultimately, across all the channels they use to communicate – how gestures combine with voice, facial expressions and body movement. I’m now exploring AI tools that track all these channels at once so I can identify the patterns, not just the isolated gestures, that make speakers more effective communicators.
Giovanni Luca Cascio Rizzo 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.
Mysterious blasts of radio waves from across the universe called fast radio bursts help astronomers catalog matter.ESO/M. Kornmesser, CC BY-SA
If you look across space with a telescope, you’ll see countless galaxies, most of which host large central black holes, billions of stars and their attendant planets. The universe teems with huge, spectacular objects, and it might seem like these massive objects should hold most of the universe’s matter.
But the Big Bang theory predicts that about 5% of the universe’s contents should be atoms made of protons, neutrons and electrons. Most of those atoms cannot be found in stars and galaxies – a discrepancy that has puzzled astronomers.
If not in visible stars and galaxies, the most likely hiding place for the matter is in the dark space between galaxies. While space is often referred to as a vacuum, it isn’t completely empty. Individual particles and atoms are dispersed throughout the space between stars and galaxies, forming a dark, filamentary network called the “cosmic web.”
Throughout my career as an astronomer, I’ve studied this cosmic web, and I know how difficult it is to account for the matter spread throughout space.
In a study published in June 2025, a team of scientists used a unique radio technique to complete the census of normal matter in the universe.
The census of normal matter
The most obvious place to look for normal matter is in the form of stars. Gravity gathers stars together into galaxies, and astronomers can count galaxies throughout the observable universe.
The census comes to several hundred billion galaxies, each made of several hundred billion stars. The numbers are uncertain because many stars lurk outside of galaxies. That’s an estimated 1023 stars in the universe, or hundreds of times more than the number of sand grains on all of Earth’s beaches. There are an estimated 1082 atoms in the universe.
However, this prodigious number falls far short of accounting for all the matter predicted by the Big Bang. Careful accounting indicates that stars contain only 0.5% of the matter in the universe. Ten times more atoms are presumably floating freely in space. Just 0.03% of the matter is elements other than hydrogen and helium, including carbon and all the building blocks of life.
Looking between galaxies
The intergalactic medium – the space between galaxies – is near-total vacuum, with a density of one atom per cubic meter, or one atom every 35 cubic feet. That’s less than a billionth of a billionth of the density of air on Earth. Even at this very low density, this diffuse medium adds up to a lot of matter, given the enormous, 92-billion-light-year diameter of the universe.
The intergalactic medium is very hot, with a temperature of millions of degrees. That makes it difficult to observe except with X-ray telescopes, since very hot gas radiates out through the universe at very short X-ray wavelengths. X-ray telescopes have limited sensitivity because they are smaller than most optical telescopes.
Deploying a new tool
Astronomers recently used a new tool to solve this missing matter problem. Fast radio bursts are intense blasts of radio waves that can put out as much energy in a millisecond as the Sun puts out in three days. First discovered in 2007, scientists found that the bursts are caused by compact stellar remnants in distant galaxies. Their energy peters out as the bursts travel through space, and by the time that energy reaches the Earth, it is a thousand times weaker than a mobile phone signal would be if emitted on the Moon, then detected on Earth.
Research from early 2025 suggests the source of the bursts is the highly magnetic region around an ultra-compact neutron star. Neutron stars are incredibly dense remnants of massive stars that have collapsed under their own gravity after a supernova explosion. The particular type of neutron star that emits radio bursts is called a magnetar, with a magnetic field a thousand trillion times stronger than the Earth’s.
A magnetar is a rare type of neutron star with an extremely strong magnetic field. ESO/L. Calçada, CC BY-ND
Even though astronomers don’t fully understand fast radio bursts, they can use them to probe the spaces between galaxies. As the bursts travel through space, interactions with electrons in the hot intergalactic gas preferentially slow down longer wavelengths. The radio signal is spread out, analogous to the way a prism turns sunlight into a rainbow. Astronomers use the amount of spreading to calculate how much gas the burst has passed through on its way to Earth.
Puzzle solved
In the new study, published in June 2025, a team of astronomers from Caltech and the Harvard Center for Astrophysics studied 69 fast radio bursts using an array of 110 radio telescopes in California. The team found that 76% of the universe’s normal matter lies in the space between galaxies, with another 15% in galaxy halos – the area surrounding the visible stars in a galaxy – and the remaining 9% in stars and cold gas within galaxies.
The complete accounting of normal matter in the universe provides a strong affirmation of the Big Bang theory. The theory predicts the abundance of normal matter formed in the first few minutes of the universe, so by recovering the predicted 5%, the theory passes a critical test.
Several thousand fast radio bursts have already been observed, and an upcoming array of radio telescopes will likely increase the discovery rate to 10,000 per year. Such a large sample will let fast radio bursts become powerful tools for cosmology. Cosmology is the study of the size, shape and evolution of the universe. Radio bursts could go beyond counting atoms to mapping the three-dimensional structure of the cosmic web.
Pie chart of the universe
Scientists may now have the complete picture of where normal matter is distributed, but most of the universe is still made up of stuff they don’t fully understand.
The most abundant ingredients in the universe are dark matter and dark energy, both of which are poorly understood. Dark energy is causing the accelerating expansion of the universe, and dark matter is the invisible glue that holds galaxies and the universe together.
Dark matter is probably a previously unstudied type of fundamental particle that is not part of the standard model of particle physics. Physicists haven’t been able to detect this novel particle yet, but we know it exists because, according to general relativity, mass bends light, and far more gravitational lensing is seen than can be explained by visible matter. With gravitational lensing, a cluster of galaxies bends and magnifies light in a way that’s analogous to an optical lens. Dark matter outweighs conventional matter by more than a factor of five.
One mystery may be solved, but a larger mystery remains. While dark matter is still enigmatic, we now know a lot about the normal atoms making up us as humans, and the world around us.
Chris Impey has received funding from NASA, NSF, Howard Hughes Medical Institute, and the Templeton Foundation.
Americans tend to look to the Constitution to assess whether the nation is living up to its founding principles when navigating major social and political issues.
But it is the declaration, signed on July 4, 1776, that declares the nation’s credo, that “all men are created equal.”
Throughout history, Americans have turned to the declaration for guidance about what the nation should stand for.
As a historian of the United States and the coordinator for the University of Richmond’s Forging a New Nation initiative, which commemorates the Declaration of Independence’s 250th anniversary, I have been thinking a lot about this phenomenon.
Particularly during times of social and political upheaval, Americans have sought out the Declaration of Independence when they wanted to remedy contemporary problems and create new visions for the country’s future. Many of the nation’s greatest leaders have praised and memorialized its rhetoric and ideas in the promotion of their own.
In his 1852 speech “What to the Slave is the Fourth of July?” Frederick Douglass, the formerly enslaved abolitionist, used the declaration to set a standard for American society. As a Black American, Douglass insisted he was “not included within the pale” who enjoyed the “inalienable rights” articulated in the declaration.
Nonetheless, the “great principles of the Declaration” gave Douglass hope and cause for optimism. He predicted that the “glorious hour” would soon arrive when all Americans would be defined “by equal birth.”
Conceived in liberty
A photo by Mathew Brady of Abraham Lincoln – center, bareheaded – giving the Gettysburg Address in 1863. Bettman/Getty Images
Abraham Lincoln denounced the decision and countered by defining a more capacious view of American freedom based on the declaration.
Lincoln told one audience that Thomas Jefferson and the signers of the declaration “set up a standard maxim for free society,” which they “intended to include all men” and to be “constantly looked to, constantly labored for.”
Their goal, Lincoln said, was “augmenting the happiness and value of life to all people of all colors everywhere.”
As civil war ravaged the country and claimed thousands of American lives, Lincoln again drew on the declaration to articulate a vision for the country as president.
The nation, he said, was undergoing a “new birth of freedom” as it waged war on slavery and defended its government against domestic rebellion.
Self-evident truth
Seventy years later, the declaration provided inspiration for President Franklin D. Roosevelt as he steered the nation through a crippling economic depression and the run-up to a world war. Roosevelt advocated for building America’s first social safety net by drawing on the declaration.
Reflecting Roosevelt’s aims, the 1936 Democratic Party platform illustrated this rhetorical strategy, borrowing from the declaration at its very beginning: “We hold this truth to be self evident – that government in a modern civilization has certain inescapable obligations to its citizens.”
During his 1944 State of the Union Address, Roosevelt said the nation was built on the rights embedded in the Declaration of Independence and the Constitution. But, he argued, “true individual freedom cannot exist without economic security and independence.”
All created equal
In his 1963 “I Have a Dream” speech, Martin Luther King Jr. drew on the declaration to define America’s promises to all its citizens.
Amid the political and social upheaval of the 1960s, the Rev. Martin Luther King Jr. drew directly and self-consciously on the declaration.
In his 1963 “I Have a Dream” speech, King defined an America that “guaranteed unalienable rights of life, liberty and the pursuit of happiness” to its citizens.
Though the nation had “defaulted on this promissory note insofar as its citizens of color are concerned,” King said, the declaration still offered him hope: “I have a dream that one day this nation will rise up and live out the true meaning of its creed: We hold these truths to be self evident, that all men are created equal.”
With the declaration’s anniversary coming up at a time when so much about contemporary society and politics are being contested, Americans may well return once again to this founding document to define themselves as a people and a nation.
Graeme Mack 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.
Source: The Conversation – USA – By Stuart Soroka, Professor, Communications and Political Science, University of California, Los Angeles
New York mayoral candidate Zohran Mamdani and U.S. Rep. Pramila Jayapal meet voters to go door-knocking in Jackson Heights on Sept. 14, 2025.Selcuk Acar/Anadolu via Getty Images
Accounts of Zohran Mamdani’s campaign for New York City mayor have highlighted both his online presence and his ground game.
Mamdani won the general election with 50.4% of the vote, a larger share than was predicted by most polls, and his get-out-the-vote campaign has received some of the credit. Mamdani claims that his campaign had over 100,000 volunteers knocking on doors across New York City.
This focus on on-the-ground mobilization stands out given the increasing attention devoted to online campaigning over the past 15 years.
Particularly during that time period, online platforms have been a major focus of political campaigns and campaign research. Targeted advertising and new media strategies are increasingly viewed as central to campaign success. So is coverage of the campaign by legacy and social media more generally.
Moreover, solid empirical evidence of the effectiveness of door-to-door canvassing is limited. Recent work finds very few effects of in-person canvassing, except in very specific circumstances. One recent paper suggests that door-to-door canvassing by the candidate can make a difference to election outcomes. But in a race in New York City, it is not likely that Mamdani himself was able to reach enough voters to make a difference.
How much did Mamdani’s ground game contribute to his victory? As a political communication scholar, I know that assessing the impact of different methods used by political campaigns is difficult – in part because political campaigns include multiple lines of communication.
‘Hybrid’ campaigns
No campaign exists in isolation — nearly every candidate’s campaign occurs alongside opposing candidates’ campaigns. The effects of one campaign are often masked by the countering effects of the other.
The size of a campaign on one platform also tends to be correlated with the size of that candidate’s campaign on other platforms. When television advertising increases alongside social media advertising and door-to-door canvassing, identifying the effects of any single platform can be difficult.
Clever research designs are in some instances able to identify effects. These generally find that the impact of not just door-knocking but also ads and online advertising can be relatively limited.
In the modern technological environment, the impact of any single aspect of a campaign may be especially difficult to assess. Campaigning increasingly occurs in what researchers have called a “hybrid media” environment. Campaigns are waged in person, on the news and across multiple social media.
Each of these platforms comes with different advantages and disadvantages. Each also prioritizes different kinds of information.
Plainly stating your policy platform may work for coverage of a campaign stop on the evening news. But if you want that policy to go viral on TikTok, then you may need to add a dance – or an influencer.
Find volunteers online, send them knocking
Candidates have increasingly recognized the need to tailor messages for different communication platforms, such as television ads, Facebook posts and TikToks, building hybrid campaigns that attempt to spread a message across multiple, different spaces.
This interactivity across platforms has been especially evident in postelection assessments of the Mamdani campaign. His social media campaign was adept at producing the kinds of content that attract attention online. That campaign also appears to have been able to convert online engagement into real-world activism, including door-to-door canvassing.
There have been growing concerns among academics and campaign organizers about “slacktivism” — activism that amounts to one or two clicks online but nothing more. One worry is that a quick online endorsement may in some instances give people a sense that they have done their share and limit more active forms of engagement. The Mamdani campaign appears to have overcome this problem, at least in part.
But 100,000 people knocking on doors probably does not happen without the success of an online campaign. Finding and mobilizing campaigners was one important focus of Mamdani’s engagement online, after all.
Do it yourself − then repeat on socials
In-person campaigning by Mamdani, on the street and in the taxi line, is almost certainly made more effective through circulation on Instagram and TikTok.
Using mass media to broadcast campaign stops is not new, of course.
The construction of campaign stops that produce good social media content is becoming more common, however. The ways in which campaigns unfold in person are increasingly intertwined with the way they unfold online.
In this way, the Mamdani campaign may have been a textbook example of a modern hybrid campaign and an illustration of the coevolution of digital and on-the-ground campaigning.
To be clear, the success of the Mamdani campaign is probably not about his online presence or his ground game, but both at the same time.
Stuart Soroka research has been funded from the National Science Foundation and the Social Sciences and Humanities Research Council of Canada.
Reducing the visibility of polarizing content in social media feeds can measurably lower partisan animosity. To come up with this finding, my colleagues and I developed a method that let us alter the ranking of people’s feeds, previously something only the social media companies could do.
Reranking social media feeds to reduce exposure to posts expressing anti-democratic attitudes and partisan animosity affected people’s emotions and their views of people with opposing political views.
I’m a computer scientist who studies social computing, artificial intelligence and the web. Because only social media platforms can modify their algorithms, we developed and released an open-source web tool that allowed us to rerank the feeds of consenting participants on X, formerly Twitter, in real time.
Drawing on social science theory, we used a large language model to identify posts likely to polarize people, such as those advocating political violence or calling for the imprisonment of members of the opposing party. These posts were not removed; they were simply ranked lower, requiring users to scroll further to see them. This reduced the number of those posts users saw.
We ran this experiment for 10 days in the weeks before the 2024 U.S. presidential election. We found that reducing exposure to polarizing content measurably improved participants’ feelings toward people from the opposing party and reduced their negative emotions while scrolling their feed. Importantly, these effects were similar across political affiliations, suggesting that the intervention benefits users regardless of their political party.
This ‘60 Minutes’ segment covers how divisive social media posts get more traction than neutral posts.
Why it matters
A common misconception is that people must choose between two extremes: engagement-based algorithms or purely chronological feeds. In reality, there is a wide spectrum of intermediate approaches depending on what they are optimized to do.
Feed algorithms are typically optimized to capture your attention, and as a result, they have a significant impact on your attitudes, moods and perceptions of others. For this reason, there is an urgent need for frameworks that enable independent researchers to test new approaches under realistic conditions.
Our work offers a path forward, showing how researchers can study and prototype alternative algorithms at scale, and it demonstrates that, thanks to large language models, platforms finally have the technical means to detect polarizing content that can affect their users’ democratic attitudes.
What other research is being done in this field
Testing the impact of alternative feed algorithms on live platforms is difficult, and such studies have only recently increased in number.
For instance, a recent collaboration between academics and Meta found that changing the algorithmic feed to a chronological one was not sufficient to show an impact on polarization. A related effort, the Prosocial Ranking Challenge led by researchers at the University of California, Berkeley, explores ranking alternatives across multiple platforms to promote beneficial social outcomes.
At the same time, the progress in large language model development enables richer ways to model how people think, feel and interact with others. We are seeing growing interest in giving users more control, allowing people to decide what principles should guide what they see in their feeds – for example the Alexandria library of pluralistic values and the Bonsai feed reranking system. Social media platforms, including Bluesky and X, are heading this way, as well.
What’s next
This study represents our first step toward designing algorithms that are aware of their potential social impact. Many questions remain open.
We plan to investigate the long-term effects of these interventions and test new ranking objectives to address other risks to online well-being, such as mental health and life satisfaction. Future work will explore how to balance multiple goals, such as cultural context, personal values and user control, to create online spaces that better support healthy social and civic interaction.
The Research Brief is a short take on interesting academic work.
This research was partially supported by a Hoffman-Yee grant from the Stanford Institute for Human-Centered Artificial Intelligence.
The FDA has provided no evidence that children died because of receiving a COVID-19 vaccine. Anchiy/E+ via Getty Images
The Food and Drug Administration is seeking to drastically change procedures for testing vaccine safety and approving vaccines, based on unproven claims that mRNA-based COVID-19 vaccines caused the death of at least 10 children.
The agency detailed its plans in a memo released to staff on Nov. 28, 2025, which was obtained by several news outlets and published by The Washington Post.
The death of children due to an unsafe vaccine is a serious allegation. I am a pediatric cardiologist who has studied the link between COVID-19 vaccines and heart-related side effects such as myocarditis in children. To my knowledge, studies to date have shown such side effects are rare, and severe outcomes even more so. However, I am open to new evidence that could change my mind.
But without sufficient justification and solid evidence, restricting access to an approved vaccine and changing well-established procedures for testing vaccines would carry serious consequences. These moves would limit access for patients, create roadblocks for companies and worsen distrust in vaccines and public health.
In my view, it’s important for people reading about these FDA actions to understand how the evidence on a vaccine’s safety is generally assessed.
From my perspective as a clinician, it is awful that any child should die from a routine vaccination.
However, health professionals like me owe it to the public to uphold the highest possible standards in investigating why these deaths occurred. If the FDA has evidence demonstrating something that national health agencies worldwide have missed – widespread child deaths due to myocarditis caused by the COVID-19 vaccine – I don’t doubt that even the most pro-vaccine physician will listen. So far, however, no such evidence has been presented.
While a death logged in VAERS is a starting point, on its own it is insufficient to conclude whether a vaccine caused the death or other medical causes were to blame.
In his Substack and Twitter accounts, Prasad has said that he believes the rate of severe cardiac side effects after COVID-19 vaccination is severely underestimated and that the vaccines should be restricted far more than they currently are.
In a July 2025 presentation, Prasad quoted a risk of 27 cases per million of myocarditis in young men who received the COVID-19 vaccine. A 2024 review suggested that number was a bit lower – about 20 cases out of 1 million people. But that same study found that unvaccinated people had greater risk of heart problems after a COVID-19 infection than vaccinated people. In a different study, people who got myocarditis after a COVID-19 vaccination developed fewer complications than people who got myocarditis after a COVID-19 infection.
Existing vaccine safety infrastructure in the U.S. successfully identifies dangers posed by vaccines – and did so during the COVID-19 pandemic. Today, most COVID-19 vaccines in the U.S. rely on mRNA technology. But as vaccines were first emerging during the COVID-19 pandemic, two pharmaceutical companies, Janssen and AstraZeneca, rolled out a vaccine that used a different technology, called a viral vector. This type of vaccine had a very rare but genuine safety problem that was detected.
A report in VAERS is at most a first step to determining whether a vaccine caused harm.
Death due to myocarditis from COVID-19 vaccination is exceedingly rare. Demonstrating that it occurred requires proof that the person had myocarditis, evidence that no other reasonable cause of death was present, and the absence of any additional cause of myocarditis. These factors cannot be determined from VAERS data, however – and to date, the FDA has presented no other relevant data.
A problematic vision for future vaccine approvals
Currently, vaccines are tested both by seeing how well they prevent disease and by how well they generate antibodies, which are the molecules that help your body fight viruses and bacteria.
Some vaccines, such as the COVID-19 vaccine and the influenza vaccine, need to be updated based on new strains. The FDA generally approves these updates based on how well the new versions generate antibodies. Since the previous generation of vaccines was already shown to prevent infection, if the new version can generate antibodies like the previous one, researchers assume its ability to prevent infection is comparable too. Later studies can then test how well the vaccines prevent severe disease and hospitalization.
That may seem reasonable theoretically. In practice, however, it is not realistic.
Today’s influenza vaccines must be changed every season to reflect mutations to the virus. If the FDA were to require new placebo-controlled trials every year, the vaccine being tested would become obsolete by the time it is approved. This would be a massive waste of time and resources.
Also, detecting vaccine-related myocarditis at the low rate at which it occurs would have required clinical trials many times larger than the ones that were done to approve COVID-19 mRNA vaccines. This would have cost at least millions of dollars more, and the delay in rolling out vaccines would have also cost lives.
Placebo-controlled trials would require comparing people who receive the updated vaccine with people who remain unvaccinated. When an older version of the vaccine is already available, this means purposefully asking people to forgo that vaccine and risk infection for the sake of the trial, a practice that is widely considered unethical. Current scientific practice is that only a brand-new vaccine may be compared against placebo.
While suspected vaccine deaths should absolutely be investigated, stopping a vaccine for insufficient reasons can lead to a significant drop in public confidence. That’s why it’s essential to thoroughly and transparently investigate any claims that a vaccine causes harm.
Vaccine vs illness
To accurately gauge a vaccine’s risks, it is also crucial to compare its side effects with the effects of the illness it prevents.
For COVID-19, data consistently shows that the disease is clearly more dangerous. From Aug. 1, 2021, to July 31, 2022, more than 800 children in the U.S. died due to COVID-19, but very few deaths from COVID-19 vaccines in children have been been verified worldwide. What’s more, the disease causes many more heart-related side effects than the vaccine does.
A monument to Sebastian Castellio in Geneva – using a French spelling of his name – reads, ‘Killing a man is not defending a doctrine; it is killing a man.’MHM55/Wikimedia Commons, CC BY-SA
Ideological division was tearing the country apart. Factions denounced each other as unpatriotic and evil. There were attempted kidnappings and assassinations of political figures. Public monuments and art were desecrated all over the country.
This was France in the middle of the 16th century. The divisions were rooted in religion.
The Protestant minority denounced Catholics as “superstitious idolaters,” while the Catholics condemned Protestants as “seditious heretics.” In 1560, Protestant conspirators attempted to kidnap the young King Francis II, hoping to replace his zealous Catholic regents with ones more sympathetic to the Protestant cause.
Two years later, the country collapsed into civil war. The French Wars of Religion had begun – and would convulse the country for the next 36 years.
I am a historian of the Reformation who writes about the opponents of John Calvin, a leading Protestant theologian who influenced Reformed Christians, Presbyterians, Puritans and other denominations for centuries. One of the most significant of Calvin’s rivals was the humanist Sebastian Castellio, whom he had worked with in Geneva before a bitter falling out over theology.
Soon after the first war in France broke out, Castellio penned a treatise that was far ahead of its time. Rather than join in the bitter denunciations raging between Protestants and Catholics, Castellio condemned intolerance itself.
He identified the main problem as both sides’ efforts to “force consciences” – to compel people to believe things they did not believe. In my view, that advice from nearly five centuries ago has much to say to the world today.
Foreseeing the carnage
Castellio rose to prominence in 1554 when he condemned the execution of Michael Servetus, a medical doctor and theologian convicted of heresy. Servetus had rejected the standard Christian belief in the Trinity, which holds that the Father, Son and Holy Spirit are three persons in one God.
Already condemned by the Catholic Inquisition in France, Servetus was passing through Geneva when Calvin urged his arrest and advocated for his execution. Servetus was burned alive at the stake.
Castellio condemned the execution in a remarkable book titled “Concerning Heretics: Whether They are to be Persecuted and How They are to be Treated.” In it, Castellio questioned the very notion of heresy: “After a careful investigation into the meaning of the term heretic, I can discover no more than this, that we regard those as heretics with whom we disagree.”
But it took centuries for religious toleration to take hold.
In the meantime, Europe became embroiled in a series of religious wars. Most were civil wars between Protestants and Catholics, including the French Wars of Religion, a series of conflicts from 1562 to 1598. These included one of the most horrific events of the 16th century: the St. Bartholomew’s Day Massacre of 1572, when thousands of Protestants were slain in a nationwide bloodbath.
Castellio had seen the carnage coming: “So much blood will flow,” he had warned in a treatise 10 years earlier, “that its loss will be irremediable.”
Castellio’s 1562 book, “Advice to a Desolate France,” was a rarity in the 16th century, for it sought compromise and the middle ground rather than the religious extremes.
With an extraordinarily modern sensibility, he decided to use the terms each side preferred for themselves, rather than the negative epithets used by their opponents.
“I shall call them what they call themselves,” he explained, “in order not to offend them.” Hence, he used “Catholics” rather than “Papists” and “evangelicals” rather than “Huguenots.”
Castellio pulled no punches. To the Catholics, referring to decades of Protestant persecution in France, he said: “Recall how you have treated the evangelicals. You have pursued and imprisoned them … and then you have roasted them alive at a slow fire to prolong their torture. And for what crime? Because they did not believe in the pope, the Mass, and purgatory. … Is that a good and just cause for burning men alive?”
To the Protestants, he complained, “You are forcing them against their consciences to attend your sermons, and what is worse, you are forcing some to take up arms against their own brothers.” He noted that they were using three “remedies” for healing the church, “namely bloodshed, the forcing of consciences, and the condemning and regarding as unfaithful of those who are not entirely in agreement with your doctrine.”
In short, Castellio accused both sides of ignoring the Golden Rule: “Do not do unto others what you would not want them to do unto you,” he wrote. “This is a rule so true, so just, so natural, and so written by the finger of God in the hearts of all,” he asserted, that none can deny it.
Both sides were trying to promote their vision of true religion, Castellio said, but both were going about it the wrong way. In particular, he warned against trying to justify evil behavior by appealing to its possible effects: “One should not do wrong in order that good may result from it.”
In another essay, he made the same point to argue against torture, writing that “Evil must not be done in order to pursue the good.” Castellio was the anti-Machiavelli; for him, the ends did not justify the means.
Force doesn’t work
Finally, “Advice to a Desolate France” argued that forcing people to your own way of thinking never works: “We manifestly see that those who are forced to accept the Christian religion, whether they are a people or individuals, never make good Christians.”
Americans, I believe, would do well to bear Castellio’s words in mind today. The country’s two dominant political parties have become increasingly polarized. Students are reluctant to speak out on controversial topics for fear of “saying the wrong thing.” Americans increasingly think in binary terms of good and evil, friends and enemies.
In the 16th century, Christians failed to heed Castellio’s advice and continued to kill each other over differences of belief for another hundred years. It would be wise to apply his ideas to today’s bitter divisions.
Michael Bruening 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.
The rapid expansion of artificial intelligence and cloud services has led to a massive demand for computing power. The surge has strained data infrastructure, which requires lots of electricity to operate. A single, medium-sized data center here on Earth can consume enough electricity to power about 16,500 homes, with even larger facilities using as much as a small city.
Over the past few years, tech leaders have increasingly advocated for space-based AI infrastructure as a way to address the power requirements of data centers.
In space, sunshine – which solar panels can convert into electricity – is abundant and reliable. On Nov. 4, 2025, Google unveiled Project Suncatcher, a bold proposal to launch an 81-satellite constellation into low Earth orbit. It plans to use the constellation to harvest sunlight to power the next generation of AI data centers in space. So, instead of beaming power back to Earth, the constellation would beam data back to Earth.
For example, if you asked a chatbot how to bake sourdough bread, instead of firing up a data center in Virginia to craft a response, your query would be beamed up to the constellation in space, processed by chips running purely on solar energy, and the recipe sent back down to your device. Doing so would mean leaving the substantial heat generated behind in the cold vacuum of space.
As a technology entrepreneur, I applaud Google’s ambitious plan. But as a space scientist, I predict that the company will soon have to reckon with a growing problem: space debris.
The mathematics of disaster
Space debris – the collection of defunct human-made objects in Earth’s orbit – is already affecting space agencies, companies and astronauts. This debris includes large pieces, such as spent rocket stages and dead satellites, as well as tiny flecks of paint and other fragments from discontinued satellites.
Space debris travels at hypersonic speeds of approximately 17,500 miles per hour (28,000 km/h) in low Earth orbit. At this speed, colliding with a piece of debris the size of a blueberry would feel like being hit by a falling anvil.
Satellite breakups and anti-satellite tests have created an alarming amount of debris, a crisis now exacerbated by the rapid expansion of commercial constellations such as SpaceX’s Starlink. The Starlink network has more than 7,500 satellites, which provide global high-speed internet.
The U.S. Space Force actively tracks over 40,000 objects larger than a softball using ground-based radar and optical telescopes. However, this number represents less than 1% of the lethal objects in orbit. The majority are too small for these telescopes to reliably identify and track.
In November 2025, three Chinese astronauts aboard the Tiangong space station were forced to delay their return to Earth because their capsule had been struck by a piece of space debris. Back in 2018, a similar incident on the International Space Station challenged relations between the United States and Russia, as Russian media speculated that a NASA astronaut may have deliberately sabotaged the station.
The orbital shell Google’s project targets – a Sun-synchronous orbit approximately 400 miles (650 kilometers) above Earth – is a prime location for uninterrupted solar energy. At this orbit, the spacecraft’s solar arrays will always be in direct sunshine, where they can generate electricity to power the onboard AI payload. But for this reason, Sun-synchronous orbit is also the single most congested highway in low Earth orbit, and objects in this orbit are the most likely to collide with other satellites or debris.
As new objects arrive and existing objects break apart, low Earth orbit could approach Kessler syndrome. In this theory, once the number of objects in low Earth orbit exceeds a critical threshold, collisions between objects generate a cascade of new debris. Eventually, this cascade of collisions could render certain orbits entirely unusable.
Implications for Project Suncatcher
Project Suncatcher proposes a cluster of satellites carrying large solar panels. They would fly with a radius of just one kilometer, each node spaced less than 200 meters apart. To put that in perspective, imagine a racetrack roughly the size of the Daytona International Speedway, where 81 cars race at 17,500 miles per hour – while separated by gaps about the distance you need to safely brake on the highway.
This ultradense formation is necessary for the satellites to transmit data to each other. The constellation splits complex AI workloads across all its 81 units, enabling them to “think” and process data simultaneously as a single, massive, distributed brain. Google is partnering with a space company to launch two prototype satellites by early 2027 to validate the hardware.
But in the vacuum of space, flying in formation is a constant battle against physics. While the atmosphere in low Earth orbit is incredibly thin, it is not empty. Sparse air particles create orbital drag on satellites – this force pushes against the spacecraft, slowing it down and forcing it to drop in altitude. Satellites with large surface areas have more issues with drag, as they can act like a sail catching the wind.
To add to this complexity, streams of particles and magnetic fields from the Sun – known as space weather – can cause the density of air particles in low Earth orbit to fluctuate in unpredictable ways. These fluctuations directly affect orbital drag.
When satellites are spaced less than 200 meters apart, the margin for error evaporates. A single impact could not only destroy one satellite but send it blasting into its neighbors, triggering a cascade that could wipe out the entire cluster and randomly scatter millions of new pieces of debris into an orbit that is already a minefield.
The importance of active avoidance
To prevent crashes and cascades, satellite companies could adopt a leave no trace standard, which means designing satellites that do not fragment, release debris or endanger their neighbors, and that can be safely removed from orbit. For a constellation as dense and intricate as Suncatcher, meeting this standard might require equipping the satellites with “reflexes” that autonomously detect and dance through a debris field. Suncatcher’s current design doesn’t include these active avoidance capabilities.
In the first six months of 2025 alone, SpaceX’s Starlink constellation performed a staggering 144,404 collision-avoidance maneuvers to dodge debris and other spacecraft. Similarly, Suncatcher would likely encounter debris larger than a grain of sand every five seconds.
Today’s object-tracking infrastructure is generally limited to debris larger than a softball, leaving millions of smaller debris pieces effectively invisible to satellite operators. Future constellations will need an onboard detection system that can actively spot these smaller threats and maneuver the satellite autonomously in real time.
Equipping Suncatcher with active collision avoidance capabilities would be an engineering feat. Because of the tight spacing, the constellation would need to respond as a single entity. Satellites would need to reposition in concert, similar to a synchronized flock of birds. Each satellite would need to react to the slightest shift of its neighbor.
Detecting space debris in orbit can help prevent collisions.
Paying rent for the orbit
Technological solutions, however, can go only so far. In September 2022, the Federal Communications Commission created a rule requiring satellite operators to remove their spacecraft from orbit within five years of the mission’s completion. This typically involves a controlled de-orbit maneuver. Operators must now reserve enough fuel to fire the thrusters at the end of the mission to lower the satellite’s altitude, until atmospheric drag takes over and the spacecraft burns up in the atmosphere.
However, the rule does not address the debris already in space, nor any future debris, from accidents or mishaps. To tackle these issues, some policymakers have proposed a use-tax for space debris removal.
A use-tax or orbital-use fee would charge satellite operators a levy based on the orbital stress their constellation imposes, much like larger or heavier vehicles paying greater fees to use public roads. These funds would finance active debris removal missions, which capture and remove the most dangerous pieces of junk.
Avoiding collisions is a temporary technical fix, not a long-term solution to the space debris problem. As some companies look to space as a new home for data centers, and others continue to send satellite constellations into orbit, new policies and active debris removal programs can help keep low Earth orbit open for business.
Mojtaba Akhavan-Tafti receives funding from NASA and Intelligence Advanced Research Projects Activity (IARPA). He teaches space systems engineering and mission design and management at the University of Michigan’s College of Engineering.
Source: The Conversation – USA – By Melinda Haas, Assistant Professor of International Affairs, University of Pittsburgh
A new Trump administration policy threatens to undermine foundational American commitments to free speech and association.D-Keine, Getty Images
A largely overlooked directive issued by the Trump administration marks a major shift in U.S. counterterrorism policy, one that threatens bedrock free speech rights enshrined in the Bill of Rights.
National Security Presidential Memorandum/NSPM-7, issued on Sept. 25, 2025, is a presidential directive that for the first time appears to authorize preemptive law enforcement measures against Americans based not on whether they are planning to commit violence but for their political or ideological beliefs.
This structure allows the president to direct law enforcement and national security agencies, with little opportunity for congressional oversight.
This seventh national security memorandum from the Trump White House pushes the limits of presidential authority by targeting individuals and groups as potential domestic terrorists based on their beliefs rather than their actions.
The memorandum represents a profound shift in U.S. counterterrorism policy, one that risks undermining foundational American commitments to free speech and association.
The presidential memorandum signed by Donald Trump identifies ‘anti-Christian,’ ‘anti-capitalism’ or ‘anti-American’ views as potential indicators that a group or person will commit domestic terrorism. Andrew Harnik/Getty Images
Presidential national security powers
Executive memoranda instruct government officials and agencies by delegating tasks and directing agency actions.
They can, for example, order a department to prepare reports, implement new policies, coordinate interagency efforts or review existing programs to align with the administration’s priorities.
Unlike executive orders, they are not required to be published. When these memoranda, like NSPM-7, relate to national security and military and foreign policy, they are called national security directives, although the specific name of these directives changes with each administration.
Many of these directives are classified. They may not be declassified, if at all, until years or decades after the end of the administration that issued them.
The stated purpose of NSPM-7 is to counter domestic terrorism and organized political violence, focusing mainly on perceived threats from the political left. The memorandum identifies “anti-Christian,” “anti-capitalism” or “anti-American” views as potential indicators that a group or person will commit domestic terrorism.
The memorandum claims that political violence originates with “anti-fascist” groups that hold the following views: “support for the overthrow of the United States Government; extremism on migration, race, and gender; and hostility towards those who hold traditional American views on family, religion, and morality.”
The strategy laid out in NSPM-7 includes preemptive measures to disrupt groups before they engage in violent political acts. For example, multiagency task forces are empowered to investigate potential federal crimes related to radicalization, as well as the funders of those potential crimes.
‘Domestic terrorist organizations’
The memorandum directs the Department of Justice to focus the resources of the FBI’s approximately 200 Joint Terrorism Task Forces on investigating “acts of recruiting or radicalizing persons” for the purpose of “political violence, terrorism, or conspiracy against rights; and the violent deprivation of any citizen’s rights.”
NSPM-7 also allows the attorney general to propose groups for designation as “domestic terrorist organizations.” That includes groups that engage in the following behaviors: “organized doxing campaigns, swatting, rioting, looting, trespass, assault, destruction of property, threats of violence, and civil disorder.”
Existing laws allow the secretary of state to designate groups as “foreign terrorist organizations” that are then subject to financial sanctions.
Would protesters like these at a Washington, D.C., ‘No Kings’ demonstration be seen as potential domestic terrorists by the Trump administration? Jose Luis Magana/AP
Defining terrorism
NSPM-7 marks a major conceptual shift in U.S. counterterrorism policy. Its focus on domestic terrorism significantly departs from historical approaches that primarily targeted foreign threats.
Since Ronald Reagan’s presidency, the U.S. government had treated terrorism as a global menace to democratic institutions, emphasizing protection of citizens and allies abroad. By moving away from a traditional law enforcement framework and recasting terrorism as an act of war, the Reagan administration situated the issue within the broader realm of Cold War geopolitics and military advantage.
After the 9/11 attacks, the Bush administration fused counterterrorism with national defense. The Bush-initiated global war on terrorism expanded the concept of who constituted a threat to include countries that harbored or aided terrorist organizations.
This standard was not focused on ideology but rather on tactical considerations, such as the feasibility of capture and continued threat to U.S. interests.
For example, the lethal drone strike on al-Qaida propagandist Anwar al-Awlaki in 2011 was justified on the basis that he was actively involved in plotting attacks and remained unreachable for capture.
During the first Trump presidency, executive orders were used to change counterterrorism policy, most notably through several iterations of a “travel ban” that attempted to restrict immigration from terror-prone countries such as Iraq, Iran, Somalia, Syria and Yemen.
The Biden administration redirected attention toward preventing catastrophic threats, especially from weapons of mass destruction in the hands of groups or individuals outside of governments, such as terrorist organizations.
First Amendment rights at risk
There is no single official definition of terrorism in U.S. law.
Instead, laws use different definitions based on their purpose, whether criminal law or laws relating to intelligence collection or civil liability.
Definitions in all those areas typically focus on identifying violent or dangerous acts done with the intent to intimidate or coerce civilians or influence government policy.
But more than redefining terrorism, NSPM-7 reorients the machinery of national security toward the policing of belief.
The First Amendment generally prevents the government from punishing people for unpopular opinions. It also protects the ability for people to associate to advance public and private ideas in pursuit of political, economic, religious or cultural goals.
The directive’s emphasis on ideological orientations – “anti-Christianity,” “anti-capitalism” and “anti-American” views – as indicators of domestic terrorism potentially jeopardizes First Amendment rights.
Thirty-one members of Congress sent a letter to Trump expressing “serious concerns” about NSPM-7, warning that it poses “serious constitutional, statutory and civil liberties risks, especially if used to target political dissent, protest or ideological speech.”
As the ACLU warns, any definition of terrorism that includes ideological components risks criminalizing people or groups based on belief rather than based on violence or other criminal conduct.
Congress has declined to create a domestic complement to the foreign terrorist designation in large part because of the potential for impinging on First Amendment–protected association and speech.
But I fear that chilling speech may be the point.
Silencing dissent
NSPM-7 does not authorize new actions in the legal and institutional framework for counterterrorism. It does not criminalize previously legal conduct.
Law professor Steve Vladeck frames this chill as “obeying in advance,” in which organizations self-censor rather than risk investigation, prosecution or defending against the “domestic terrorist” label.
Although left-wing violence has risen in the past decade, empirical evidence proves that this violence remains at very low absolute levels, well below historical levels of right-wing or jihadist violence.
In fact, most domestic terrorists in the U.S. are politically on the right, and right-wing attacks account for the vast majority of fatalities from domestic terrorism.
Yet NSPM-7 focuses disproportionately on left-wing ideologies. NSPM-7 departs from prior U.S. counterterrorism frameworks by prioritizing the suppression of ideologically motivated dissent, even in the absence of concrete evidence of violent intent.
Melinda Haas 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.
If you use a mobile phone with location services turned on, it is likely that data about where you live and work, where you shop for groceries, where you go to church and see your doctor, and where you traveled to over the holidays is up for sale. And U.S. Immigration and Customs Enforcement is one of the customers.
The U.S. government doesn’t need to collect data about people’s locations itself, because your mobile phone is already doing it. While location data is sometimes collected as part of a mobile phone app’s intended use, like for navigation or to get a weather forecast, more often locations are collected invisibly in the background.
I am a privacy researcher who studies how people understand and make decisions about data that is collected about them, and I research new ways to help consumers get back some control over their privacy. Unfortunately, once you give an app or webpage permission to collect location data, you no longer have control over how the data is used and shared, including who the data is shared with or sold to.
Why mobile phones collect location data
Mobile phones collect location data for two reasons: as a by-product of their normal operation, and because they are required to by law.
Mobile phones are constantly scanning for nearby cell towers so that when someone wants to place a call or send a text, their phone is already connected to the closest tower. This makes it faster to place a call or send a text.
To maintain quality of service, mobile phones often connect with multiple cell towers at the same time. The range of the radio signal from a cell tower can be thought of as a big bubble with the cell tower in the center. The location of a mobile phone can be calculated via triangulation based on the intersection of the bubbles surrounding each of the cell towers the phone is connected to.
In addition to cell tower triangulation, since 2001 mobile phone carriers have been required by law to provide latitude and longitude information for phones that have been used to call 911. This supports faster response times from emergency responders.
The ‘Today’ show gives an overview of how your phone reveals where you go and what you do.
How location data ends up being shared
When people allow webpages and apps to access location data generated by their mobile phones, the software maker can share that data widely without asking for further permission. Sometimes the apps themselves do this directly through partnerships between the maker and data brokers.
More often, apps and webpages that contain advertisements share location data via a process called “real-time bidding,” which determines which ads are shown. This process involves third parties hired by advertisers, which place automated bids on the ad space to ensure that ads are shown to people who match the profile of interests the advertisers are looking for.
To identify the target audience for the ads, software embedded in the app or webpage shares information collected about the user, including their location, with the third parties placing the bids. These third parties are middlemen that can keep the data and do whatever they want with it, including selling the data to location data brokers, whether or not their bid wins the auction for the ad space.
The invisible collection, sale and repackaging of location data is a problem because location data is extremely sensitive and cannot be made anonymous. The two most common locations a person visits are their home and where they work. From this information alone, it is trivially easy to determine a person’s identity and match it with the other location data about them that these companies have acquired.
Also, most people don’t realize that the location data they allowed apps and services to collect for one purpose, like navigation or weather, can reveal sensitive personal information about them that they may not want to be sold to a location data broker. For example, a research study I published about fitness tracker data found that even though people use location data to track their route while exercising, they didn’t think about how that data could be used to infer their home address.
This lack of awareness means that people can’t be expected to anticipate that data collected through the normal use of their mobile phones might be available to, for example, U.S. Immigration and Customs Enforcement.
More restrictions on how mobile phone carriers and apps are allowed to collect and share location data – and on how the government is allowed to obtain and use location information about people – could help protect your privacy. To date, Federal Trade Commission efforts to curb carriers’ data sales have had mixed results in federal court, and only a few states are attempting to pass legislation to tackle the problem.
Emilee Rader receives funding from the National Science Foundation.
