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5 Scientific Facts About Your Dreams

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Throughout human history, dreams have been the subject of science and pseudoscience alike. In today’s crazy online world where you can’t always believe your eyes, we hope you’ll sleep better knowing that the following facts are the real deal.

1. Dream logic is neurologically logical

Your brain’s activity looks very different when you’re asleep, which sheds some light on the nature of dreams. For starters, your primary visual cortex is out of commission during sleep (because your eyes are closed), but your secondary visual cortex (which normally interprets outside visual stimuli) is still going at it, trying to make sense of the images the rest of your brain is conjuring up.

Your limbic system (hippocampus and fornix––the wormy tangle all up in the middle of your brain) is the primary control center for your emotions, and it becomes especially active during your dreams. This explains why dreams are so emotionally charged, and often deal with feelings of imminent danger. Meanwhile, the dorsolateral prefrontal cortex, which controls logic and rationality, is practically dormant, which explains why you can dream yourself marrying Hugh Griffith in an cosmonaut suit and be like, “Can we have the guests throw sand instead of Cracker Jacks, Hughie? Birds tend to choke on the prizes.”

2. You also dream during “non-REM” sleep

By now everyone knows that we categorize human sleep in five stages: some deep stages with boring number-names, and REM, famously responsible for dream time. Au contraire! More recent research indicates that dreaming also occurs during non-REM sleep (slyly abbreviated as NREM). REM sleep is the stage closest to waking, though, so you’re more likely to remember REM dreams than those in NREM.

Since each sleep stage represents different brain activity, different stages will result in different types of dreams. During REM sleep, for instance, people typically report interacting with two to three characters outside of themselves––usually people they know in waking life––while NREM may host more characters, more of whom are strangers. At the same time, the dreamer more often initiates socially aggressive interactions in REM sleep, while NREM hosts friendlier social initiations. Makes it hard not to read a “don’t you dare wake me up” subtext into those REM dreams... 

3. Pain Can Show Up in Dreams

While it’s never been proven that dreams themselves can produce pain, a few studies have suggested that real-world pain can incorporate into dreams. In one study, a lab-induced “pins and needles” sensation manifested as a problematic shoe-fitting in the subject’s dream, while more intense pain (like that experienced by healing burn victims in a 2002 study) can produce nightmares wherein the dreamer tries to escape the source of their pain, literally and metaphorically. In short, pain transcends the barrier between waking and dreaming life, and shows up in our dreams relatively untransformed. 

4. Dreams Help You Learn

You’ve heard the term “Let me sleep on it,” from Meat Loaf and others, and it’s a good idea, scientifically speaking. That’s because your brain can teach itself while you sleep, thanks to a process Harvard neuroscience professor Robert Stickgold calls off-line memory reprocessing.

In his series of experiments, Stickgold had subjects perform simple tasks like recognizing words or hitting a digital target, and compared their progress with their sleep patterns. The logic is this: Any time you make a memory, that new information has to transfer between several different parts of your brain in order to stick around for awhile, and those same patterns correspond with the patterns of brain activity during sleep. Sure enough, subjects who slept on their lessons showed greater improvement. In his Tetris experiment, Stickgold’s subjects even reported dreaming about Tetris as the learning period went on, indicating a connection between the need to improve, dreams, and post-dream improvement.

5. Dreams do Affect Your Mood

You probably already knew this: The tone of a dream can set the tone of the following morning, for better or worse. But there’s more to it than that. “Daytime mood and social interactions” have been found to correlate with dream details––although universal patterns across dreams are almost impossible to quantify reliably. Details as seemingly arbitrary as the number of characters the dreamer encounters may have more to do with the person’s actual sleep patterns than actual dream content (see bullet #2). But as in Stickgold’s memory experiments, dreaming about stuff that’s bothering you can help the brain process during sleep what you might not be thrilled to process during the day (see bullet #5). In short: Dream on, little dreamer. It’s good for ya.

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The Curious Origins of 16 Common Phrases
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Our favorite basketball writer is ESPN's Zach Lowe. On his podcast, the conversation often takes detours into the origins of certain phrases. We compiled a list from Zach and added a few of our own, then sent them to language expert Arika Okrent. Where do these expressions come from anyway?

1. BY THE SAME TOKEN

Bus token? Game token? What kind of token is involved here? Token is a very old word, referring to something that’s a symbol or sign of something else. It could be a pat on the back as a token, or sign, of friendship, or a marked piece of lead that could be exchanged for money. It came to mean a fact or piece of evidence that could be used as proof. “By the same token” first meant, basically “those things you used to prove that can also be used to prove this.” It was later weakened into the expression that just says “these two things are somehow associated.”

2. GET ON A SOAPBOX

1944: A woman standing on a soapbox speaking into a mic
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The soapbox that people mount when they “get on a soapbox” is actually a soap box, or rather, one of the big crates that used to hold shipments of soap in the late 1800s. Would-be motivators of crowds would use them to stand on as makeshift podiums to make proclamations, speeches, or sales pitches. The soap box then became a metaphor for spontaneous speech making or getting on a roll about a favorite topic.

3. TOMFOOLERY

The notion of Tom fool goes a long way. It was the term for a foolish person as long ago as the Middle Ages (Thomas fatuus in Latin). Much in the way the names in the expression Tom, Dick, and Harry are used to mean “some generic guys,” Tom fool was the generic fool, with the added implication that he was a particularly absurd one. So the word tomfoolery suggested an incidence of foolishness that went a bit beyond mere foolery.

4. GO BANANAS

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The expression “go bananas” is slang, and the origin is a bit harder to pin down. It became popular in the 1950s, around the same time as “go ape,” so there may have been some association between apes, bananas, and crazy behavior. Also, banana is just a funny-sounding word. In the 1920s people said “banana oil!” to mean “nonsense!”

5. RUN OF THE MILL

If something is run of the mill, it’s average, ordinary, nothing special. But what does it have to do with milling? It most likely originally referred to a run from a textile mill. It’s the stuff that’s just been manufactured, before it’s been decorated or embellished. There were related phrases like “run of the mine,” for chunks of coal that hadn’t been sorted by size yet, and “run of the kiln,” for bricks as they came out without being sorted for quality yet.

6. READ THE RIOT ACT

The Law's Delay: Reading The Riot Act 1820
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When you read someone the riot act you give a stern warning, but what is it that you would you have been reading? The Riot Act was a British law passed in 1714 to prevent riots. It went into effect only when read aloud by an official. If too many people were gathering and looking ready for trouble, an officer would let them know that if they didn’t disperse, they would face punishment.

7. HANDS DOWN

Hands down comes from horse racing, where, if you’re way ahead of everyone else, you can relax your grip on the reins and let your hands down. When you win hands down, you win easily.

8. SILVER LINING

The silver lining is the optimistic part of what might otherwise be gloomy. The expression can be traced back directly to a line from Milton about a dark cloud revealing a silver lining, or halo of bright sun behind the gloom. The idea became part of literature and part of the culture, giving us the proverb “every cloud has a silver lining” in the mid-1800s.

9. HAVE YOUR WORK CUT OUT

The expression “you’ve got your work cut out for you” comes from tailoring. To do a big sewing job, all the pieces of fabric are cut out before they get sewn together. It seems like if your work has been cut for you, it should make job easier, but we don’t use the expression that way. The image is more that your task is well defined and ready to be tackled, but all the difficult parts are yours to get to. That big pile of cut-outs isn’t going to sew itself together!

10. THROUGH THE GRAPEVINE

A grapevine is a system of twisty tendrils going from cluster to cluster. The communication grapevine was first mentioned in 1850s, the telegraph era. Where the telegraph was a straight line of communication from one person to another, the “grapevine telegraph” was a message passed from person to person, with some likely twists along the way.

11. THE WHOLE SHEBANG

The earliest uses of shebang were during the Civil War era, referring to a hut, shed, or cluster of bushes where you’re staying. Some officers wrote home about “running the shebang,” meaning the encampment. The origin of the word is obscure, but because it also applied to a tavern or drinking place, it may go back to the Irish word shebeen for a ramshackle drinking establishment.

12. PUSH THE ENVELOPE

Pushing the envelope belongs to the modern era of the airplane. The “flight envelope” is a term from aeronautics meaning the boundary or limit of performance of a flight object. The envelope can be described in terms of mathematical curves based on things like speed, thrust, and atmosphere. You push it as far as you can in order to discover what the limits are. Tom Wolfe’s The Right Stuff brought the expression into wider use.

13. CAN’T HOLD A CANDLE

We say someone can’t hold a candle to someone else when their skills don’t even come close to being as good. In other words, that person isn’t even good enough to hold up a candle so that a talented person can see what they’re doing in order to work. Holding the candle to light a workspace would have been the job of an assistant, so it’s a way of saying not even fit to be the assistant, much less the artist.

14. THE ACID TEST

Most acids dissolve other metals much more quickly than gold, so using acid on a metallic substance became a way for gold prospectors to see if it contained gold. If you pass the acid test, you didn’t dissolve—you’re the real thing.

15. GO HAYWIRE

What kind of wire is haywire? Just what it says—a wire for baling hay. In addition to tying up bundles, haywire was used to fix and hold things together in a makeshift way, so a dumpy, patched-up place came to be referred to as “a hay-wire outfit.” It then became a term for any kind of malfunctioning thing. The fact that the wire itself got easily tangled when unspooled contributed to the “messed up” sense of the word.

16. CALLED ON THE CARPET

Carpet used to mean a thick cloth that could be placed in a range of places: on the floor, on the bed, on a table. The floor carpet is the one we use most now, so the image most people associate with this phrase is one where a servant or employee is called from plainer, carpetless room to the fancier, carpeted part of the house. But it actually goes back to the tablecloth meaning. When there was an issue up for discussion by some kind of official council it was “on the carpet.”

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15 Facts About the Summer Solstice
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It's the longest day of the year in the Northern Hemisphere, so soak up some of those direct sunrays (safely, of course) and celebrate the start of summer with these solstice facts.

1. THIS YEAR IT'S JUNE 21.

June 21 date against a yellow background
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The summer solstice always occurs between June 20 and June 22, but because the calendar doesn't exactly reflect the Earth's rotation, the precise time shifts slightly each year. For 2018, the sun will reach its greatest height in the sky for the Northern Hemisphere on June 21 at 6:07 a.m. Eastern Time.

2. THE SUN WILL BE DIRECTLY OVERHEAD AT THE TROPIC OF CANCER.

A vintage mapped globe showing the Tropic of Cancer
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While the entire Northern Hemisphere will see its longest day of the year on the summer solstice, the sun is only directly overhead at the Tropic of Cancer (23 degrees 27 minutes north latitude).

3. THE NAME COMES FROM THE FACT THAT THE SUN APPEARS TO STAND STILL.

Stonehenge at sunrise.
CARL DE SOUZA, AFP/Getty Images

The term "solstice" is derived from the Latin words sol (sun) and sistere (to stand still), because the sun's relative position in the sky at noon does not appear to change much during the solstice and its surrounding days. The rest of the year, the Earth's tilt on its axis—roughly 23.5 degrees—causes the sun's path in the sky to rise and fall from one day to the next.

4. THE WORLD'S BIGGEST BONFIRE WAS PART OF A SOLSTICE CELEBRATION.

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Celebrations have been held in conjunction with the solstice in cultures around the world for hundreds of years. Among these is Sankthans, or "Midsummer," which is celebrated on June 24 in Scandinavian countries. In 2016, the people of Ålesund, Norway, set a world record for the tallest bonfire with their 155.5-foot celebratory bonfire.

5. THE HOT WEATHER FOLLOWS THE SUN BY A FEW WEEKS.

Colorful picture of the sun hitting ocean waves.
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You may wonder why, if the solstice is the longest day of the year—and thus gets the most sunlight—the temperature usually doesn't reach its annual peak until a month or two later. It's because water, which makes up most of the Earth's surface, has a high specific heat, meaning it takes a while to both heat up and cool down. Because of this, the Earth's temperature takes about six weeks to catch up to the sun.

6. THOUSANDS OF PEOPLE GATHER AT STONEHENGE TO CELEBRATE.

Rollo Maughfling, the Archdruid of Glastonbury and Stonehenge, conducts a Solstice celebration service for revelers as they wait for the midsummer sunrise at Stonehenge on June 21, 2012, near Salisbury, England.
Rollo Maughfling, the Archdruid of Glastonbury and Stonehenge, conducts a Solstice celebration service for revelers as they wait for the midsummer sunrise at Stonehenge on June 21, 2012, near Salisbury, England.
Matt Cardy, Getty Images

People have long believed that Stonehenge was the site of ancient druid solstice celebrations because of the way the sun lines up with the stones on the winter and summer solstices. While there's no proven connection between Celtic solstice celebrations and Stonehenge, these days, thousands of modern pagans gather at the landmark to watch the sunrise on the solstice.

7. PAGANS CELEBRATE THE SOLSTICE WITH SYMBOLS OF FIRE AND WATER.

Arty image of fire and water colliding.
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In Paganism and Wicca, Midsummer is celebrated with a festival known as Litha. In ancient Europe, the festival involved rolling giant wheels lit on fire into bodies of water to symbolize the balance between fire and water.

8. IN ANCIENT EGYPT, THE SOLSTICE HERALDED THE NEW YEAR.

Stars in the night sky.
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In Ancient Egypt, the summer solstice preceded the appearance of the Sirius star, which the Egyptians believed was responsible for the annual flooding of the Nile that they relied upon for agriculture. Because of this, the Egyptian calendar was set so that the start of the year coincided with the appearance of Sirius, just after the solstice.

9. THE ANCIENT CHINESE HONORED THE YIN ON THE SOLSTICE.

Yin and yang symbol on textured sand.
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In ancient China, the summer solstice was the yin to the winter solstice's yang—literally. Throughout the year, the Chinese believed, the powers of yin and yang waxed and waned in reverse proportion to each other. At the summer solstice, the influence of yang was at its height, but the celebration centered on the impending switch to yin. At the winter solstice, the opposite switch was honored.

10. IN ALASKA, THE SOLSTICE IS CELEBRATED WITH A MIDNIGHT BASEBALL GAME.

Silhouette of a baseball player.
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Each year on the summer solstice, the Alaska Goldpanners of Fairbanks celebrate their status as the most northerly baseball team on the planet with a game that starts at 10:00 p.m. and stretches well into the following morning—without the need for artificial light—known as the Midnight Sun Game. The tradition originated in 1906 and was taken over by the Goldpanners in their first year of existence, 1960.

11. THE EARTH IS ACTUALLY AT ITS FARTHEST FROM THE SUN DURING THE SOLSTICE.

The Earth tilted on its axis.
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You might think that because the solstice occurs in summer that it means the Earth is closest to the sun in its elliptical revolution. However, the Earth is actually closest to the sun when the Northern Hemisphere experiences winter and is farthest away during the summer solstice. The warmth of summer comes exclusively from the tilt of the Earth's axis, and not from how close it is to the sun at any given time. 

12. IRONICALLY, THE SOLSTICE MARKS A DARK TIME IN SCIENCE HISTORY.

Galileo working on a book.
Hulton Archive, Getty Images

Legend has it that it was on the summer solstice in 1633 that Galileo was forced to recant his declaration that the Earth revolves around the Sun; even with doing so, he still spent the rest of his life under house arrest.

13. AN ALTERNATIVE CALENDAR HAD AN EXTRA MONTH NAMED AFTER THE SOLSTICE.

Pages of a calendar
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In 1902, a British railway system employee named Moses B. Cotsworth attempted to institute a new calendar system that would standardize the months into even four-week segments. To do so, he needed to add an extra month to the year. The additional month was inserted between June and July and named Sol because the summer solstice would always fall during this time. Despite Cotsworth's traveling campaign to promote his new calendar, it failed to catch on.

14. IN ANCIENT GREECE, THE SOLSTICE FESTIVAL MARKED A TIME OF SOCIAL EQUALITY.

Ancient Greek sculpture in stone.
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The Greek festival of Kronia, which honored Cronus, the god of agriculture, coincided with the solstice. The festival was distinguished from other annual feasts and celebrations in that slaves and freemen participated in the festivities as equals.

15. ANCIENT ROME HONORED THE GODDESS VESTA ON THE SOLSTICE.

Roman statue of a vestal virgin
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In Rome, midsummer coincided with the festival of Vestalia, which honored Vesta, the Roman goddess who guarded virginity and was considered the patron of the domestic sphere. On the first day of this festival, married women were allowed to enter the temple of the Vestal virgins, from which they were barred the rest of the year.

A version of this list originally ran in 2015.

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