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Can't comprehend the 4th dimension? Carl Sagan explains it with an apple in this classic clip.

Sagan was a master science communicator.

carl sagan, cosmos 4th dimension

via Carl Sagan Planetary Society/Wikimedia Commons and John Finkelstein/Pexels

Carl Sagan and a sliced apple

The concept of the fourth dimension seems beyond human comprehension. As three-dimensional beings, we are unable to see beyond a physical object's height, width and depth. What else could there be?

Enter Carl Sagan, revered as one of the greatest science communicators of his time. He possessed a unique gift for demystifying complex scientific concepts, making them accessible and thrilling for the general public. In 1980, on Episode 10 of the groundbreaking PBS show “Cosmos,” Sagan embarked on a mission to explain the seemingly impossible fourth dimension.

What’s excellent about Sagan’s explanation is that he uses simple and relatable objects: an apple and a Tesseract, or a hypercube.

Sagan began by discussing how a two-dimensional being living in a flat world would perceive a three-dimensional object like an apple.

“Imagine we live in this ‘flatland’/2-D plane with no concept of ‘up’ or ‘down.’ Then along comes a 3-D object like an apple. We do not even notice it until it crosses our plane of existence — and even then, we have no idea what the apple is,” Sagan explains. “We see only a fragment as it passes through our plane. There is no way we can comprehend the 3-D quality/dimension of the apple, because it is more than we can understand. We only have the evidence of what has passed through our plane.”

Sagan then related this two-dimensional experience of the third dimension to how we might try to understand the fourth. To do so, he used the Tesseract, a four-dimensional cube, to demonstrate how difficult it is for us to perceive or visualize dimensions beyond our own three. At this point, Sagan is asking the viewer to expand their minds to understand the fourth dimension metaphorically.

Sagan’s demonstration of the fourth dimension isn’t just a wonderful explanation of a scientific idea that many of us find difficult to comprehend; it’s also a great example of how to teach complex ideas by combining clear explanations with thought-provoking visuals.

This article originally appeared on 5.2.24

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Cycle for Survival

Cycle for Survival

How can riding a bike help beat cancer? Just ask Reid Moritz, 10-year-old survivor and leader of his own “wolfpack”

Every year, Reid and his pack participate in Cycle for Survival to help raise money for the rare cancer research that’s helped him and so many others. You can too.

all photos courtesy of Reid Moritz

Together, let’s help fuel the next big breakthrough in cancer research

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There are many things that ten-year-old Reid Wolf Moritz loves. His family, making watches (yes, really), basketball, cars (especially Ferraris), collecting super, ultra-rare Pokémon cards…and putting the pedal to the medal at Cycle for Survival.

Cycle for Survival is the official rare cancer fundraising program of Memorial Sloan Kettering Cancer Center (MSK). One hundred percent of every dollar raised at Cycle for Survival events supports rare cancer research and lifesaving clinical trials at MSK.

At only two years old, Reid was diagnosed with pilocytic astrocytoma, a rare type of brain tumor.

Pediatric cancer research is severely underfunded. When standard treatments don't work, families rely on breakthrough clinical trials to give their children a real shot at long-term survival.

When Reid’s chemotherapy and brain surgery didn’t work, he was able to participate in one of MSK’s clinical trials, where he’s received some incredible results. “Memorial Sloan Kettering has done so much for me. It's just so nice how they did all this for me. They're just the best hospital ever,” Reid recalls.

And that’s why every year, you’ll find Reid with his team, aptly named Reid's Wolfpack, riding at Cycle for Survival. It’s just Reid’s way of paying it forward so that even more kids can have similar opportunities.

“I love sharing my story to inspire other kids to PERSEVERE, STAY STRONG and NEVER GIVE UP while also raising money for my amazing doctors and researchers to help other kids like me.”

Reid remembers the joy felt bouncing on his father’s shoulder and hearing the crowd cheer during his first Cycle for Survival ride. As he can attest, each fundraising event feels more like a party, with plenty of dancing, singing and celebrating.

Hoping to spread more of that positivity, Reid and his family started the Cycle for Survival team, Reid’s Wolfpack, which has raised close to $750,000 over the past eight years. All that money goes directly to Reid’s Neuro-Oncology team at Memorial Sloan Kettering.

In addition to cheering on participants and raising good vibes at Cycle for Survival events, Reid even designs some pretty epic looking merch—like basketball shorts, jerseys, and hoodies—to help raise money.

If you’re looking to help kids just like Reid, and have a ton of fun doing it, you’re in luck. Cycle for Survival events are held at Equinox locations nationwide, and welcome experienced riders and complete newbies alike. You can even join Reid and his Wolfpack in select cities!

And if cycling in any form isn’t your thing, a little donation really does go a long way.

Together, let’s help fuel the next big breakthrough in cancer research. Find out more information by checking out cycleforsurvival.org or filling out this interest form.

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best of humanity

Why didn't people smile in old photographs? It wasn't just about the long exposure times.

People blame these serious expressions on how long they had to sit for a photo, but that's not the whole picture.

Public domain images

Photos from the 1800s were so serious.

If you've ever perused photographs from the 19th and early 20th century, you've likely noticed how serious everyone looked. If there's a hint of a smile at all, it's oh-so-slight, but more often than not, our ancestors looked like they were sitting for a sepia-toned mug shot or being held for ransom or something. Why didn't people smile in photographs? Was life just so hard back then that nobody smiled? Were dour, sour expressions just the norm?

Most often, people's serious faces in old photographs are blamed on the long exposure time of early cameras, and that's true. Taking a photo was not an instant event like it is now; people had to sit still for many minutes in the 1800s to have their photo taken.

Ever try holding a smile for only one full minute? It's surprisingly difficult and very quickly becomes unnatural. A smile is a quick reaction, not a constant state of expression. Even people we think of as "smiley" aren't toting around full-toothed smiles for minutes on end. When you had to be still for several minutes to get your photo taken, there was just no way you were going to hold a smile for that long.

But there are other reasons besides long exposure times that people didn't smile in early photographs.

1800s photographs Why so serious? Public domain

The non-smiling precedent had already been set by centuries of painted portraits

The long exposure times for early photos may have contributed to serious facial expressions, but so did the painted portraits that came before them. Look at all of the portraits of famous people throughout history prior to cameras. Sitting to be painted took hours, so smiling was out of the question. Other than the smallest of lip curls like the Mona Lisa, people didn't smile for painted portraits, so why would people suddenly think it normal to flash their pearly whites (which were not at all pearly white back then) for a photographed one? It simply wasn't how it was done.

A smirk? Sometimes. A full-on smile? Practically never.

"Mona Lisa" by Leonardo da Vinci, painted in 1503Public domain

Smiling usually indicated that you were a fool or a drunkard

Our perceptions of smiling have changed dramatically since the 1800s. In explaining why smiling was considered taboo in portraits and early photos, art historian Nicholas Jeeves wrote in Public Domain Review:

"Smiling also has a large number of discrete cultural and historical significances, few of them in line with our modern perceptions of it being a physical signal of warmth, enjoyment, or indeed of happiness. By the 17th century in Europe it was a well-established fact that the only people who smiled broadly, in life and in art, were the poor, the lewd, the drunk, the innocent, and the entertainment […] Showing the teeth was for the upper classes a more-or-less formal breach of etiquette."

"Malle Babbe" by Frans Hals, sometime between 1640 and 1646Public domain

In other words, to the Western sensibility, smiling was seen as undignified. If a painter did put a smile on the subject of a portrait, it was a notable departure from the norm, a deliberate stylistic choice that conveyed something about the artist or the subject.

Even the artists who attempted it had less-than-ideal results. It turns out that smiling is such a lively, fleeting expression that the artistically static nature of painted portraits didn't lend itself well to showcasing it. Paintings that did have subjects smiling made them look weird or disturbing or drunk. Simply put, painting a genuine, natural smile didn't work well in portraits of old.

As a result, the perception that smiling was an indication of lewdness or impropriety stuck for quite a while, even after Kodak created snapshot cameras that didn't have the long exposure time problem. Even happy occasions had people nary a hint of joy in the photographs that documented them.

Even wedding party photos didn't appear to be joyful occasions.Wikimedia Commons

Then along came movies, which may have changed the whole picture

So how did we end up coming around to grinning ear to ear for photos? Interestingly enough, it may have been the advent of motion pictures that pushed us towards smiling being the norm.

Photos could have captured people's natural smiles earlier—we had the technology for taking instant photos—but culturally, smiling wasn't widely favored for photos until the 1920s. One theory about that timing is that the explosion of movies enabled us to see emotions of all kinds playing out on screen, documenting the fleeting expressions that portraits had failed to capture. Culturally, it became normalized to capture, display and see all kind of emotions on people's faces. As we got more used to that, photo portraits began portraying people in a range of expression rather than trying to create a neutral image of a person's face.

Changing our own perceptions of old photo portraits to view them as neutral rather than grumpy or serious can help us remember that people back then were not a bunch of sourpusses, but people who experienced as wide a range of emotion as we do, including joy and mirth. Unfortunately, we just rarely get to see them in that state before the 1920s.

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Brit shares the one-word 'dead giveaway' that American actors are doing an English accent

There's one word they never get right.

via Warner Bros Discovery

Peter Dinklage on "Game of Thrones?

When it comes to actors doing accents across the pond, some Americans are known for their great British accents, such as Natalie Portman ("The Other Boleyn Girl"), Robert Downey, Jr. ("Sherlock Homes"), and Meryl Streep ("The Iron Lady").

Some have taken a lot of heat for their cartoonish or just plain weird-sounding British accents, Dick Van Dyke ("Mary Poppins"), Kevin Costner ("Robin Hood: Prince of Thieves") and Keanu Reeves ("Bram Stoker's Dracula").

Some actors, such as Tom Hardy (“The Drop”) and Hugh Laurie (“House”), have American accents so good that people have no idea they are British.

Benedict Townsend, a London-based comedian and host of the “Scroll Deep” podcast, says there is one word that American actors playing characters with a British accent never get right. And no, it’s not the word “Schedule,” which British people pronounce the entire first 3 letters, and Americans boil down to 2. And it’s not “aluminum,” which British and American people seem to pronounce every stinking letter differently.

@benedicttown
The one word American actors aways get wrong when doing an English accent

What word do American actors always get wrong when they do British accents?

“There is one word that is a dead giveaway that an English character in a movie or a TV show is being played by an American. One word that always trips them up. And once you notice it, you can't stop noticing it,” Townsend says. “You would see this lot in ‘Game of Thrones’ and the word that would always trip them up was ‘daughter.’”

Townsend adds that when British people say “daughter,” they pronounce it like the word “door” or “door-tah.” Meanwhile, Americans, even when they are putting on a British accent, say it like “dah-ter.”

“So top tip if you are an actor trying to do an English accent, daughter like a door. Like you're opening a door,” Townsend says.

What word do British actors always get wrong when doing American accents?

Some American commenters returned the favor by sharing the word that British actors never get right when using American accents: “Anything.”

"I can always tell a Brit playing an American by the word anything. An American would say en-ee-thing. Brits say it ena-thing,” Dreaming_of_Gaea wrote. "The dead giveaway for English people playing Americans: ‘Anything.’ Brits always say ‘EH-nuh-thin,’” marliemagill added.

"I can always tell an actor is English playing an American when they say ‘anything.’ English people always say it like ‘enny-thin,’” mkmason wrote.

What is the cot-caught merger?

One commenter noted that the problem goes back to the cot-caught merger, when Americans in the western US and Canadians began to merge different sounds into one. People on the East Coast and in Britain pronounce them as different sounds.

“Depending on where you live, you might be thinking one of two things right now: Of course, ‘cot’ and ‘caught’ sound exactly the same! or There’s no way that ‘cot’ and ‘caught’ sound the same!” Laura McGrath writes at DoYouReadMe. “As a result, although the different spellings remain, the vowel sounds in the words cot/caught, nod/gnawed, stock/stalk are identical for some English speakers and not for others.”

American actors owe Townsend a debt of gratitude for pointing out the one thing that even the best can’t seem to get right. He should also give the commenters a tip of the cap for sharing the big word that British people have trouble with when doing an American accent. Now, if we could just get through to Ewan McGregor and tell him that even though he is fantastic in so many films, his American accent still needs a lot of work.

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Veterinarian has perfect response after being told it's 'disgusting' to let cats on furniture

It has cat people everywhere rejoicing.

@dr.mattmcglasson/Instagram

Pretty sure every cat person feel the same way.

No one would get a dog expecting it to not bark, try to eat human food or need daily walks. And yet people regularly get flummoxed when their just-as-loveable cat exhibits completely natural behaviors like climbing tabletops or scratching at furniture.

Of course, cat people, who delight in adapting their life to make it as enriching as possible for their feline fur babies, know the flaws of this logic. After all, most cats spend more time in the house than their human counterparts. So shouldn’t the house belong just as much to them?

If you answered yes—then this clapback video (from a vet, no less), should have you feeling pretty vindicated. And if you answered no—prepare to see the error of your ways.

Dr. Matt McGlasson is a veterinarian in Kentucky, who also happens to be the proud dad of a 5-year-old special needs cat named Rupaul.

McGlasson recently was told by a viewer that it’s "disgusting" that he allows Rupaul on his furniture (as opposed to human butts only, which are okay, I guess?).

McGlasson’s response to this comment recently racked up over 11.8 million views, with good reason.

In a clip posted to his Instagram, McGlasson holds up Rupaul, who can’t use her hind legs, and shamelessly lists off all the other things he would allow for his kitty, including:

-Cosigning a loan for Rupaul

-Letting Rupaul do his taxes

-Giving Rupaul the passwords to all of his accounts.

-Capital Punishment, which he’s not normally a support of. But if someone hurts Rupaul, “that’s another story."

-Going into a business with Rupaul

-Giving Rupaul $20,000 for bringing him a dead mouse

-Making Rupaul the beneficiary on my life insurance policy.

And last, but certainly not least…letting Rupaul on the furniture.

Put simply: “My cat can do whatever she wants. It's her world. I'm just living in it.”

See on Instagram

Down in the comments, fellow cat owners couldn’t agree more with McGlasson’s sentiment.

“My husband picked his new chair based on the cat , the arm had to be wide enough for her to sit whenever she chooses to have quality time with him.”

“I would donate my kidneys to Square if she needed them. Yes… I mean both 😂”

“‘You let your cat sleep with you?’ Ma’am, I’d let him represent me in court.”

“I bought my house for my senior kitties. I wanted to get out of our apartment so they could feel grass beneath their paws again before their time was up.”

Others reiterated how it’s a gift to be able to create a healthy, happy life for a pet, and freaking out about furniture is kind of missing the joint.

“Like I don't understand ppl who r so against cats on furniture. If ur against pets on furniture probably don't have them. Treat your pets with love and respect. When you take an animal into ur home it becomes their home and safe place. All of the things in ur house become a part of their world and cats like to naturally be elevated. My cats do what they want because they aren't pets they are family. They own the place I just live here. Lol,” wrote one person.

Bottom line: climbing is part of a cat’s inherent programming. And if cat owners truly want their home to be a safe space for their kitty, then this should be taken into consideration.

The good news is, there are plenty of cat-friendly ways you can coax them off of furniture, like making sure there are plenty of dedicated cat trees to climb and scratching posts to sink their claws into, or opting for furniture with fabrics that cats don’t love as much, like microfiber.

And as a general rule, cats respond to positive reinforcement, rather than punishment. Contrary to outdated, yet still popular belief, cats don’t “know” when they're being bad. And they will learn to associate their own with negative attention. That’s not fun for anyone.

As McGlasson, or any other pet owner can attest, having their presence in our homes provides so much fulfillment and connection, that small compromises—or large bank loans—are well worth it.

By the way, McGlasson’s TikTok and Instagram are full of hilarious cat content, so be sure to give him a follow.

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Dad recorded his baby’s sounds for a year, then used them to remake AC/DC’s ‘Thunderstruck’

You've been thunderstruck.

Representative photo credit: Canva

Ever seen a baby "sing" a rock song before they can talk?

Few things bring as much joy to a parent’s heart as the adorable sounds their babies make. But when a dad with a vision, a camera and a year's worth of footage uses those sounds to recreate one of the most iconic rock songs ever…let's just say joy alone doesn't quite cover it.

In one of the most epically adorable and adorably epic song renditions ever, dad and video editor Matt MacMillan spliced together tiny snippets of his baby's sounds to make AC/DC's "Thunderstruck." And it's one of those things you just have to see to believe.

Baby Ryan singing "Thunderstruck" is jaw-droppingly awesome

Nothing but awe and respect for a guy who takes a whole year to get just the right sounds at the right pitches and figures out to put them together to create this masterpiece:

- YouTubewww.youtube.com

Making a sneeze into a cymbal? Are you kidding me?

People have been understandably impressed, with the video getting over 6 million views.

"Ryan becomes the vocalist of AB/CD."

"I need a cover in 17 years whenever he is an adult singing over the instrumentals lol"

"'I recorded my son for a full year. I edited for the next 5'"

"The fact that he genuinely found clips that fit every note he need instead of just pitch shifting like most videos like this do really makes this stand out. Good job he’s adorable."

"This dude had a kid just so he could make this song. What a Legend."

"Other parents: 'I want my child to create masterpieces.' This guy: 'my child IS the masterpiece.'"

"I'm a residential plumber and I've had an absolutely horrible day on a work shift that's lasted 13 hours and even after crawling through human poop all day this made me smile laugh and giggle like a small baby."

Believe it or not, it's not autotuned or pitch-shifted. Those notes are all baby.

The question is: How did he do it? This isn't just some autotune trick. MacMillan really did it all manually, going through each video clip of Baby Ryan, organizing them by pitch and figuring out what notes they were.

Perhaps most impressively, he didn't even know the notes of "Thunderstruck" to begin with and doesn't really read music. He had to pluck the song out on the piano and then match those notes with his baby's sounds.

As he wrote, "It took forever." But he shared an inside look at how he did it here:

- YouTubewww.youtube.com

Seriously, doesn't seeing how he did it make it even more impressive? Pure human creativity and perseverance on display. What a delightful gift Ryan will have for the rest of his life. Much better than a standard baby book.

Baby Ryan's "Thunderstruck" was not MacMillan's first foray into baby covers, either. He previously created a rendition of "Carol of the Bells" using Baby Ella's sounds, and it is just as impressive (and adorable) as Baby Ryan's. Here's one to add to your holiday playlist:

- YouTubewww.youtube.com

Here's to the humans who wow us with their ambitious, innovative projects that exist purely to bring a smile to people's faces.

You can follow Matt MacMillan on YouTube.

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Watch this mom accurately predict every adorable thing her toddlers say

My favorite is "Oh, yeah, pancake time!"

haileyosbrne/TikTok

Funny things start to happen when you live with people. You notice their patterns, words and phrases they use over and over, their behaviors. Sometimes those things rub off on you and affect your personality. Other times, you just start to know them so well you could almost literally finish their sentences.

Nowhere is this more true than for people with young kids. Children have no filter, very little inhibition, and terrible self-awareness — so they tend to do and say a lot of the same things repeatedly.

One mom on TikTok capitalizes on her intimate knowledge of the inner working of her kid's brain in a series of hilarious TikToks.

Hailey Osborne's videos, aptly named "Predicting everything my toddler says!" border on demonstrations of paranormal psychic powers.

They're also absolutely hilarious.

When she tells her daughter "It's snack time, sis," Hailey immediately mouths along with perfect synchronization as her toddler responds, "What kind of snack?"

At the zoo, she points out a snake, then accurately predicts — "It's kinda spooky!"

For breakfast, "I'm gonna make some pancakes." The response? "Oh yeah, pancake time!"

You've got to watch the whole series. Hailey's prediction skills are pretty amazing (though she also posts plenty of hysterical fails), but the joy and love you see on her face throughout the entire series will make it the best thing you watch all day.

@haileyosbrne
Last one is still my favroite👶🏻😭 haha here are this weeks predictions! I added a few from the last video that got taken down😒 #momlife #sahm #momsoftiktok #toddlermom #momtok #mom #funnytoddler #toddlermom #toddlers

Hailey's viewers are obsessed with the series.

Every time Hailey posts a video, the comments pour in:

"You're so attuned to your children! Love it!"

"In case no one has told you today... You are a great mom."

"I love this. You know your babies so well!"

"That's the sweetest thing I ever saw."

One thing almost everyone seems to admire is how Hailey gets amazing content out of her kids without hardly ever showing their faces. It's awesome to see a parenting influencer crushing it without completely sacrificing the family's privacy!

@haileyosbrne
The last one is my favorite hehe love my girl! #momlife #mom #sahm #momsoftiktok #toddlermom #toddlers #funnytoddler

As much as I love watching the videos, personally, what I really want to do is try this at home.

The "psychic connection" demonstrated in Hailey's videos is actually a documented scientific fact — and it's something you can work on.

A fascinating recent study out of the University of Washington took incredibly detailed brain scans of mothers and their 5-year-old children. It showed that during some interactions, the neurons in both mother and child's brain appeared to behave in the exact same way "doing a dance together at the same rhythm at the same time in the same places in these two brains.”

When babies sync their brainwaves to their parents (mostly mom), it helps them learn to interpret social cues and develop crucial socio-emotional skills.

For example, the stronger the link between brains, the more likely a baby or young child is to take social and emotional cues from mom. In one study, researchers had moms react positively or negatively to toys. Kids with strong synchrony with mom were more likely to react the same way.

And if you're looking to strengthen your neural synchrony with your own baby? Try making lots of eye contact.

Sharing lots of eye contact from a young age means that you, too, one day may be able to predict every word out of their mouths!

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