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Does ‘night mode’ shift your brain out of sleep mode?
A new study suggests that a device's night mode may damage sleep hygiene even more.
- The social consensus claims that blue-light emitting devices interrupt sleep by curbing melatonin production.
- However, new research suggests that the ruddy hues of "night mode" may have a more detrimental effect on quality sleep.
- While causal effect remains unknown, the correlation between screen time and poor sleep habits is nonetheless strong.
If you're reading this, you're probably tired. When it comes to sleep, 40 percent of Americans get less than the recommended seven hours a night. Children and adolescents need even more, and this slumber deficit is costly.
Studies have linked sleep deprivation and deficiency with an increased risk of obesity, diabetes, stroke, heart disease, and high blood pressure. It further strains your brain, degrading your ability to solve problems, control your emotions, and seek gainful decisions over impulsive choices.
The consequences extend beyond the personal, too. Drivers who sleep fewer than seven hours are more likely to be responsible for a car collision, and bad sleep habits are estimated to cost the economy a staggering $434 billion next year.
And we all know what's to blame. Screen time.
Our bedtime story so far
The blue light emitted by laptop and smartphone screens is believed to suppress our brain's melatonin production and stave off sleepiness.
Because the human brain evolved in an environment free of lamps and light switches, it learned to recognize bedtime by the spectrum of light that filtered through the atmosphere.
Long wavelength blue light informs our brains that it's day time. We should be active and alert. The short-wavelength colors of sunset inform our brains it'll be dark soon. We should mellow out.
When those reds and yellows hit our retina, they signal to the pineal gland that it's time to produce melatonin. This hormone induces restfulness, reduces alertness, and keeps us sleeping throughout the night. In an environment of fairly consistent sunrises and sunsets, this circadian rhythm has served us well.
Then came screen time. According to the current social consensus, the blue light emitted by screens and LEDs mixes up these natural signals. Our brains register the wavelengths and surmise its still day time. The pineal gland doesn't receive the signal to produce melatonin, and we remain awake and alert well into the night.
To break this pattern and keep our attention firmly planted on their products, software developers have inundated every screen-brandishing device with a "night mode." This mode skews the light ratio away from blue and toward the ruddier hues. In theory, we can now watch our umpteenth episode of The Great British Bakeoff well into the night, so long as we don't mind a slightly off-color kransekake.
Got to get those midnight blues?
Using lights to change the color without altering the brightness, the researchers determined that blue light had a weaker effect on the mice's circadian clocks.
However, a recent study published in the journal Current Biology questions that consensus. Dim, cool light, its data suggest, help our circadian clocks register the approach of bedtime better than night mode.
The researchers carried out their experiments on mice. They used specially designed lights that allowed them to change the color without altering the brightness. The long-wavelength blues suppressed circadian light responses, having a weaker effect on the mice's circadian clocks compared to equivalent shorter-wavelength yellows.
The researchers reasoned that bluer light, like that discharging from unfiltered screens, more closely aligns with the spectral composition of twilight. Conversely, a device's "night mode" replaces these wavelengths with warmer reds and yellows, which our circadian clocks still associate with daylight.
"We show the common view that blue light has the strongest effect on the clock is misguided; in fact, the blue colors that are associated with twilight have a weaker effect than white or yellow light of equivalent brightness," Dr. Tim Brown, study author and senior lecturer at the University of Manchester, said in a release.
He points out that current approaches to lessen the screen's impact on sleep involve changing the ratio of short and long wavelength light with little difference in brightness. But the study suggests that brightness levels are more important, and we should shoot for dim, cool colors in the evening. If your phone's screen is too bright, the color-spectrum it favors won't matter.
Brown adds, "Research has already provided evidence that aligning our body clocks with our social and work schedules can be good for our health. Using color appropriately could be a way to help us better achieve that."
Science in the dark
Which findings should we believe? Do we forego night mode for a dim blue screen, or does night mode work as advertised? Unfortunately, science is in the dark.
Because the Current Biology study used mice, we can't say the same will hold for humans. Meanwhile, much of the research cited against blue light is based on observational and cross-sectional studies, making causality difficult to discern.
A literature review on the research lists several potential mechanisms that may cause screen devices to damage sleep and deter healthy habits. All are backed by research.
One is psychological stimulation. Players of exciting video games show increased heart rates, slightly delayed sleep-onset, and decreased REM. (Apparently, it's difficult to wind down after shot-gunning your way through the deepest pits of hell.) But even non-violent media have been shown to induce states of arousal that disrupt sleep patterns—such as the emotional devastation of a stodgy stollen.
Another potential sleep-thieving culprit is time displacement. Poor self-control and unstructured screen habits lead us to replace the time we would otherwise spend sleeping with multimedia.
The review also surveyed the research regarding screen light and sleep patterns. Its authors note that some studies support the view that light-emitting screens suppress melatonin levels and delay sleep, but others have found no changes with evening exposure to light-emitting devices, even in adolescences.
They conclude that it is "impossible to determine whether longer sleep latency or reduced REM sleep duration was due to decreased sleepiness before bedtime, suppression of melatonin, a phase delay of the circadian clock, or a combination of these factors." Further research on the effects of screen time and sleep, especially on youth, is needed.
But while causality cannot yet be determined, there is an unequivocal and strong correlation between screen time and poor sleep. The review's authors cite one meta-analysis that merged 20 studies and over 125,000 young participants. It found a consistent pattern that bedtime media usage links with insufficient sleep, poor sleep quality, and daytime sleepiness.
Even as we wait for the science to build its casual case, the path forward is evident. Put down the devices an hour or two before bed, and perform some relaxation techniques or read a good book. Not an ebook.
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What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
With just a few strategical tweaks, the Nazis could have won one of World War II's most decisive battles.
- The Battle of Britain is widely recognized as one of the most significant battles that occurred during World War II. It marked the first major victory of the Allied forces and shifted the tide of the war.
- Historians, however, have long debated the deciding factor in the British victory and German defeat.
- A new mathematical model took into account numerous alternative tactics that the German's could have made and found that just two tweaks stood between them and victory over Britain.
Two strategic blunders<p>Now, historians and mathematicians from York St. John University have collaborated to produce <a href="http://www-users.york.ac.uk/~nm15/bootstrapBoB%20AAMS.docx" target="_blank">a statistical model (docx download)</a> capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different. </p><p>Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.</p><p>"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a <a href="https://www.york.ac.uk/news-and-events/news/2020/research/mathematicians-battle-britain-what-if-scenarios/" target="_blank">statement</a>. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.</p><p>"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."</p><p>Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.</p><p>Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.</p>
A tool for understanding history<p>This technique, said co-author Niall Mackay, "demonstrates just how finely-balanced the outcomes of some of the biggest moments of history were. Even when we use the actual days' events of the battle, make a small change of timing or emphasis to the arrangement of those days and things might have turned out very differently."</p><p>The researchers also claimed that their technique could be applied to other uncertain historical events. "Weighted bootstrapping can provide a natural and intuitive tool for historians to investigate unrealized possibilities, informing historical controversies and debates," said Mackay.</p><p>Using this technique, researchers can evaluate other what-ifs and gain insight into how differently influential events could have turned out if only the slightest things had changed. For now, at least, we can all be thankful that Hitler underestimated Britain's grit.</p>
We’ve mapped a million previously undiscovered galaxies beyond the Milky Way. Take the virtual tour here.
See the most detailed survey of the southern sky ever carried out using radio waves.
Astronomers have mapped about a million previously undiscovered galaxies beyond the Milky Way, in the most detailed survey of the southern sky ever carried out using radio waves.
A new study shows our planet is much closer to the supermassive black hole at the galaxy's center than previously estimated.
Arrows on this map show position and velocity data for the 224 objects utilized to model the Milky Way Galaxy. The solid black lines point to the positions of the spiral arms of the Galaxy. Colors reflect groups of objects that are part of the same arm, while the background is a simulation image.
Apple sold its first iPod in 2001, and six years later it introduced the iPhone, which ushered in a new era of personal technology.