The Light of a Man-Made Star
The photos, he says, are part scientific study and part propaganda, a measure of America's technological progress and the power of its arsenal. They are also, in a way the Pentagon likely never intended, a disconcerting form of art: surreal balls of fire and ash set against barren landscapes; man-made stars, as Light described them, rising over the horizon.
In 1963, President John F. Kennedy signed the Limited Test Ban Treaty, prohibiting nuclear detonations in the atmosphere, the ocean, and outer space. Bomb testing disappeared underground—but it didn't end. 'In all of these underground tests, there has been little to see and little to photograph,' Light wrote in 100 Suns. 'There is no record that helps keep an informed citizenry viscerally aware of what its government is doing.'
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
USA Today
22-07-2025
- USA Today
Lawmakers want independent re-do of Air Force missile community cancer study
The Air Force started studying cancer rates in the nuclear missile community in 2023 due to pressure from ailing missile officers. Lawmakers may soon order an independent re-do of an ongoing Air Force study on possible cancer risk in personnel manning its nuclear missiles. A provision in the House's draft defense policy bill would, if passed, require the National Academy of Sciences, Engineering, and Medicine to commission a study examining "occupational health and safety conditions" in Minuteman III intercontinental ballistic missile facilities. The sites include the underground alert facilities where Air Force missile officers spend long shifts prepared to launch in the case of nuclear war. The move comes after an independent researcher concluded there is an increase in cases of a rare cancer at an Air Force missile base in Montana, adding another wrinkle to a years-long push for answers. The new, congressionally directed research would also scrutinize the methodology and design of an ongoing Air Force study of the issue. The Air Force Medical Service and Air Force Global Strike Command, which oversees the service's nuclear-armed missile and bomber forces, began studying the missile community's cancer risks in 2023 after a Space Force officer compiled a list of cancer diagnoses at Malmstrom Air Force Base, Montana. The Air Force study's preliminary findings indicated troops in the nuclear missile community don't have higher cancer diagnosis or death rates than other active duty servicemembers or the general U.S. population. The official study's environmental surveys, however, confirmed the presence of polychorinated biphenyls − a likely cancer-causing chemical − in alert facilities at Malmstrom and at Minot Air Force Base, North Dakota. And an independent assessment of self-reported Non-Hodgkin lymphoma cases at Malmstrom released in April found an increase in diagnoses among missileers. Rep. Don Bacon, R-Nebraska, submitted the independent study amendment, which cleared a key hurdle when it passed the House Armed Services Committee on July 16. Bacon told USA TODAY that a meeting with one of his constituents − an ailing retired missile officer − moved him to author the provision. "Let's make sure that we have some outside experts working with the Air Force," said Bacon, who is a retired Air Force brigadier general. "We want to make sure there's credibility and, whatever results come out, that we've done total due diligence." The Omaha-based representative added that the Air Force needs to learn what's wrong in the aging Minuteman III launch facilities before it builds new ones for the planned Sentinel ICBM. Air Force officials defended the rigor and transparency of their ongoing study in a statement to USA TODAY. "We welcome the opportunity of scientific and medical professionals to review Air Force studies and to provide comments," said Alana Miller, a spokeswoman for the Office of the Air Force Surgeon General. Miller emphasized the internal independence of Air Force epidemiologists conducting the study and their partnerships with external researchers who review their findings. The Torchlight Initiative, an advocacy group for missile community members, praised the independent study amendment in a press release. Torchlight has documented more than 800 self-reported cases of cancer and other exposure-related diseases among ICBM airmen and veterans. "There is an urgent need for ... thorough independent research, formal acknowledgement of likely exposures, and a sustained commitment to safeguard future personnel through enhanced environmental monitoring," the group argued. For the independent study to occur, the provision must make it into the final defense policy bill later this year. The House and Senate typically pass competing versions of the legislation before negotiating a compromise bill for the president's signature. Davis Winkie's role covering nuclear threats and national security at USA TODAY is supported by a partnership with Outrider Foundation and Journalism Funding Partners. Funders do not provide editorial input.
Yahoo
20-07-2025
- Yahoo
Don't panic if you get a lot of light sleep — expert explains why it's just as important as deep sleep
When you buy through links on our articles, Future and its syndication partners may earn a commission. Light sleep makes up a significant portion of our rest but the term might cause alarm in some if they think they're getting too much 'light sleep' and not enough 'deep sleep.' Sleep trackers label it vaguely, but what does light sleep actually do for the body and mind? Spencer Dawson, PhD, Assistant Clinical Professor and Associate Director of Clinical Training at Indiana University's Department of Psychological and Brain Sciences describes the stages of 'light sleep' as well as what happens during them. Remember, if you're monitoring sleep using wearables, try not to put too much weight into their sleep tracking and scores. They aren't looking at brain activity—which is how sleep professionals know what's truly happening and when you're in specific sleep stages and those who love to know their sleep score, here's a trick that can get it to the 90s. What is light sleep? "When I see the term 'light sleep,' it's usually in association with someone using wearables,' says Dr. Dawson. This includes non-REM (rapid-eye movement) 1 and non-REM 2 sleep, he says. "Previously, these were called stages one and two, but now they're more specifically categorized as NREM1 and NREM2." NREM3 is considered deep sleep, and all three stages stand for Non-REM, with REM sleep meaning 'rapid eye movement'. NREM1 is the lightest stage of sleep. You might not even think you've dozed off. It can last only a few minutes. Dr. Dawson says he's heard it described as if someone dozing off in a recliner in front of the TV wakes up when the TV is shut off, saying, 'I was watching that.' In NREM2, the heart rate and breathing slow. The body can move a bit but the brain appears to have less activity happening. Why is light sleep important? REM sleep gets a lot of attention for its contributions to health, but you still need light sleep as part of a healthy sleep cycle. Sleep researchers find specific neural activity patterns occur during the NREM2 sleep stage. The ones referred to as 'sleep spindles' and 'K-complexes' indicate patterns involved with brain processes, including learning, memory, and stimulus processing, according to research. When does light sleep occur? The NREM1 stage of sleep is transitional from wake to sleep. 'It's fairly junky,' says Dr. Dawson. 'If you had a lot of that, you wouldn't feel good.' It usually makes up about five percent of a night's sleep. That's followed by NREM2 sleep which makes up about 50% of one's sleep. It's estimated that someone goes through four or five sleep cycles each night of about 90 minutes each. Those include REM and NREM sleep and bouts of waking up—even if you don't recall those wakeups. Sticking to a regular sleep schedule can help you get the light sleep and deep sleep you need. What happens during light sleep Light sleep or (Non-REM sleep) plays a role in the sleep cycle helping the body move into deep sleep modes. You usually spend more time in 'light sleep' in the early part of the night. 1. Heart rate slows The heart rate decreases during N1 and N2 sleep. This is likely how wearables make predictions that you're in those 'light stages' of sleep since they're usually monitoring your heart rate. Heart rate variability tends to be greater during REM sleep. 2. Brain waves slow During light sleep, your body can move but the brain looks like it's at rest, says Dr. Dawson. Sleep researchers look at brain activity in 30-second chunks of time, he says. During light sleep, we see these large, high amplitude, slow oscillations of brain activity. In REM sleep, the brain looks 'awake' and active while the body is immobile. 3. Body temperature drops The body temperature decreases as you move into 'light sleep' but recent research says the brain temperature also falls during this time. It's suspected that this temperature drop helps the body save energy where it can before the brain temperature increases during REM sleep. 4. Eye movement stops Since REM sleep involves 'rapid eye movement' — often side to side behind the eyelids — it's worth noting that during NREM2 sleep, eye movement stops. REM is the stage of sleep in which we dream, but you're unlikely to dream during light sleep. How much light sleep should we get? In general, about 50% of one's overall sleep should be 'light' sleep, which we're calling NREM1 and NREM2 sleep stages. That being said, everyone's needs differ and vary according to their ages. 'The amount of deep sleep your body goes into tends to reflect your sleep need,' says Dr. Dawson. 'It's a homeostatic process. So basically, your brain knows how much it needs, and if it needs more, it will do more [deep sleep]. And if it needs less, it'll do less.' Simply put, you can't do much to control which stages of sleep your body goes between each night. What happens if you spend too much time in light sleep? If you spend too much time in light sleep—instead of deep sleep—you're not going to feel good. You might never feel 'rested' even if you're in bed for the recommended seven to nine hours of sleep a night. You cycle through all of these sleep stages throughout the night, including briefly waking up between them, which is perfectly normal. 'While transitioning between REM and NonREM sleep and back, you might see some of the NREM1 sleep in there as well,' says Dr. Dawson. However, an indication that you're not cycling through the stages properly and spending too much time in light sleep is daytime irritability, fatigue, mood swings and sleep deprivation. Improving your sleep hygiene and maintaining a consistent sleep schedule, as well as aiming for seven to nine hours of sleep a night, will help you experience full and healthy sleep cycles
WIRED
18-07-2025
- WIRED
Einstein Showed That Time Is Relative. But … Why Is It?
Jul 18, 2025 7:00 AM The mind-bending concept of time dilation results from a seemingly harmless assumption—that the speed of light is the same for all observers. Video:So, you're driving a car at half the speed of light. (Both hands on the wheel, please.) You turn on the headlights. How fast would you see this light traveling? What about a person standing by the road? Would they see the light beam moving at 1.5 times the speed of light? But that's impossible, right? Nothing is faster than light. Yes, it seems tricky. The problem is, our ideas about the world are based on our experiences, and we don't have much experience going that fast. I mean, the speed of light is 3 x 108 meters per second, a number we represent with the letter c. That's 670 million miles per hour, friend, and things start to get weird at extreme speeds. Illustration: Rhett Allain It turns out that both the driver and the person on the road would measure the light as traveling at the same speed, c. The motion of the light source (the car) and the relative motion of the observers make no difference. Albert Einstein predicted this in 1905, and it's one of the two main postulates behind his theory of special relativity. Oh, it doesn't sound so 'special' to you? Well, what he then showed is that if the speed of light is a universal constant, then time is relative . The faster you move through space, the slower you move through time. The clock on a hyper-speed spaceship would literally tick slower, and if you were in that ship, you would age more slowly than your friends back home. That's called time dilation. A Commonsense Example The idea that everyone sees light traveling at the same speed seems like common sense. But let's look at a more familiar situation, and you'll see that it's not how things usually work. Say you're driving at 10 meters per second, and someone in the car takes a tennis ball and throws it forward with a speed of 20 m/s. A bystander who happens to have a radar gun measures the speed of the ball. What reading do they get ? Illustration: Rhett Allain Nope, NOT 20 m/s. To them the ball is moving at 30 m/s (i.e., 10 + 20). So much for common sense. The difference arises from the fact that they are measuring from different 'reference frames,' one moving, the other stationary. It's all good, though; everyone agrees on the outcome. If the ball hits the person, the miscreants and the bystander would calculate the same time of impact. Yes, the people in the car see the ball moving at a slower speed, but they also see the bystander moving toward them (from their perspective), so it works out the same in the end. This is the other main postulate of special relativity: The physics are the same for all reference frames—or to be specific, for all 'inertial,' or non-accelerating, frames. Observers can be moving at different velocities, but those velocities have to be constant. Anyway, now maybe you can see why it's actually quite bizarre that the speed of light is the same for all observers, regardless of their motion. Waves in an Empty Sea How did Einstein get this crazy idea ? I'm going to show you two reasons. The first is that light is an electromagnetic wave. Physicists had long known that light behaved like a wave. But waves need a medium to 'wave' in. Ocean waves require water; sound waves require air. Remove the medium and there is no wave. But then, what medium was sunlight passing through as it traveled through space? In the 1800s, many physicists believed there must be a medium in space, and they called it the luminiferous aether because that's fun to say. In 1887, Albert Michelson and Edward Morley devised a clever experiment to detect this aether. They built a device called an interferometer, which split a beam of light in half and sent the halves along two paths of equal length, bouncing off mirrors, and merging again at a detector, like this: Illustration: Rhett Allain Obviously they didn't have a laser, but they had a similar light source. Now, if the Earth was moving through an aether as it circled the sun, that aether would change the speed of light, depending on whether the light was moving in the direction of Earth's motion or at a right angle to that motion. And here's the genius part: They didn't have to actually measure the speed of light, they only had to see if the two beams arrived at the detector at the same time. If there was any change in speed, the beams would be out of sync and would cancel each other when recombined. That interference would show up as a dark spot on the detector. If they moved at exactly the same speed, the sinusoidal waves would align and you'd see a bright spot. They ran this experiment at all different times of year to get different angles with respect to the sun, but the result was always the same. There was no change in speed—which meant, sadly, that people had to stop saying 'luminiferous aether.' Evidently, light waves could travel through a vacuum! Maxwell's Equations and Reference Frames The reason for this, as proven by Heinrich Hertz, is that light is an electromagnetic wave—an oscillation of electric and magnetic fields perpendicular to each other. The changing electric field creates a magnetic field, and the changing magnetic field creates an electric field, and this endless cycle makes light self-propagating. It can travel through empty space because it's two waves in one. Now for the rough part (mathematically). We know the relationship between the electric and magnetic fields—it's described in Maxwell's famous four equations. If you use some math stuff (full details here), it's possible to write the following equations for the electric field (E) and the magnetic field (B). (If all these Greek symbols are Greek to you, just skip over this.) All you need to know is that, together, these equations describe an electromagnetic wave. But wait! That's not all. If we plug in the values of μ 0 and ε 0 —the fundamental magnetic and electric constants, respectively—you get a wave speed (v for velocity) that is exactly the speed of light: Einstein used this to postulate that the speed of light was the same for all observers. How? Well, since we accepted that any one inertial reference frame is as valid as another, Maxwell's equations must work in both. That means the speed of light is the same in both reference frames—even if they're in motion relative to one another. UNLIKE the tennis ball scenario above! Time Dilation Finally, imagine we build a clock to measure time. Not one of your grandfather's clocks with a swinging pendulum, which would be a problem in zero gravity. Our clock is cooler than that. Basically we get two parallel mirrors and bounce a pulse of light back and forth between them. Illustration: Rhett Allain If we know the distance between the mirrors (s) and the speed of the light (we do, it's c), then we can calculate the time for one tick. Now assume our clock is in a spaceship with a big window, like in the movies. This spaceship is moving with a constant velocity that is half the speed of light (c/2) with respect to some nearby planet. Someone on that planet uses a telescope to look through the spaceship window and peek at the light clock. Here's what that planet person would see: Illustration: Rhett Allain Notice that since the spaceship is moving, the light has to travel at an angle in order to hit the other spot on the opposite mirror. If we continued this, it would be a series of zigzags. Take a minute to think about that. It's like if you were riding in a bus and tossed a ball straight up and then caught it without moving your hand. In your reference frame, the ball just moves straight up and down. But to that guy on the street, the ball would trace out an arc, moving up and down but also forward. In our light clock, since the light has to travel at an angle to hit the correct spot, it travels a farther distance . Oh, but that light still travels at the speed of light, so it takes more time to reach the other mirror. And if the spaceship is moving at a speed of c/2, that would be a lot more time. Result? As seen from the person on the planet, the spaceship clock ticks slower. There you have it: time dilation. Does this mean that time goes slower for the people on the spaceship? Nope. In their reference frame the light just bounces up and down and time is normal. Yes, it seems very weird, but it's not. It only seems weird because we never travel anywhere near the speed of light. In fact, time slows down in any moving vehicle—even when you get in your car and drive to work—but at normal speeds the effect is so tiny that it's imperceptible.
