upworthy

Innovation

Science

Guy uses a Ziploc bag to show why text is reversed in mirrors and people finally get it

A seemingly simple but surprisingly confusing reality.

Photo credit: Canva

Why is text reversed in mirrors?

Have you ever wondered why text shows up backwards in a mirror? It's confusing to our brains because it doesn't seem like anything else is flipped like that. If we turn our head, it doesn't move the opposite direction in a mirror. Or does it? After all, right-handed you is actually left-handed you in the mirror. Right? (Wait, is that right?)

Mirrors can be confusing, despite not being very complicated. A mirror image is simply a reflection of what's before it. But when someone else is looking at us head on, they don't see text in reverse, so why don't we see what other people see when we see ourselves in a mirror?

  Kitten Aww GIF by MOODMAN  Giphy  

(If you think this is a super stupid question with a super obvious answer, congratulations. Pat yourself on the back and scootch along so the folks who don't fully grasp the physics of mirrors can enjoy a demonstration that makes it a little easier to understand.)

"Why do mirrors reverse text?" asks the creator behind @humanteneleven on YouTube. "You might think it's just a property of mirrors—they flip things from left to right—but that's not true." He then picks up a metal arrow to show that it points the same direction in the mirror as it does in real life. So why is the text flipped when the arrow isn't?

  - YouTube  www.youtube.com  

He then holds up a book to show how the text on the book cover appears backwards, just like the shirt. But when he holds up a Ziploc bag with the word "HELLO" written on it, the word shows up properly.

That's because he had to flip the book over to see the cover text in the mirror. The baggy he could just hold up and see the letters through the transparent plastic, just as we see them in real life. If he flips the baggy over like he did the book, the text shows up backwards in the mirror, just like it does in real life.

"So it's actually not the mirror that's flipping anything from left to right," he says. "It's the human."

People appreciated the simple, straightforward explanation and demonstrations.

"One of the most insightful demonstrations I've seen. It's simple and explains the phenomenon. Well done!"

 

"While I've heard this explanation many times before, I've only recently seen it demonstrated with text-on-transparency, which is what really makes it click. Great video!"

"Love these sorts of demonstrations. It’s a bit of a complicated one, but I love seeing how different people's minds work when explaining simple things like this. My kid explains it with “left is on the left, right is on the right, things aren’t flipped, they are mirrored” but it’s true that you are the one who flips things and I’ve never thought of it that way before."

"Oh my God, I haven't understood explanations from physics videos about why mirrors flip but this, gosh this helps."

Mirrors have been hilariously befuddling people in other videos as they try to figure out how the mirror knows what's behind a barrier placed in front of objects.

@sarahcoome

this is kinda creepy 👀 #mirror #relatable #creepy

 

Is this something all of us should probably have learned in high school? Yes. Do all of us remember everything we learned in high school? No. Does the scientific explanation make perfect sense to everyone even if it's explained in detail? Um, no.

Like the reversed text question, having a simplified explanation that doesn't fully get into the nitty gritty physics and geometry of how mirrors work is helpful for some folks.

 

  - YouTube  www.youtube.com  

 

For those who do want a bit more scientific substance to their explanations, this next video does a good job of giving a bit more detail while still keeping the explanation simple. It even uses a visual diagram to explain:

  - YouTube  www.youtube.com  

 

And for those who say, "This is so basic! How do people not understand this?" here's a video that really does get into the nitty gritty physics and geometry of how mirrors work, diving into ray and wave optics, photons, wave functions, probability, and quantum mechanics. It's only 12 minutes, and it manages to entertain while explaining, but it certainly blows the notion that understanding mirrors is super simple.

  - YouTube  www.youtube.com  

 

As one commenter wrote, "I thought I understood mirrors. I understand mirrors even less now. And that's a compliment."

Isn't science fun?

This article originally appeared in May.

From Your Site Articles
science
Innovation

Welcome to the world of hyper-realistic silicone masks

The amazing disguises in "Mission Impossible" aren't as unrealistic as you think.

Canva Photos

Masks have gotten so good, 1 in 5 people can't even identify one.

In the Mission Impossible movies, you can never quite trust anything you see. That's because the films make liberal use of futuristic and wild fictional mask technology. At least, I thought it was fictional.

With a simple scan or photo of someone's face and a machine that fits in a briefcase, Ethan Hunt (Tom Cruise) and his team can 3D print a mask that's 100% indistinguishable from the real thing. Add in a little extra technology that helps the spies mimic others' voices and you've got the perfect disguise. Cruise can walk amongst the bad guys without fear, and his costars get the fun challenge of playing Tom Cruise playing themselves! It makes for incredible entertainment.

I've always loved the movies and understood that part of the viewing experience is learning to suspend my disbelief. The gadgets, stunts, and disguises are a lot of fun, but pretty out there.

And then I saw this video, and it opened the door to the new, and more than a little frightening, world of hyper-realistic silicone masks.

In the clip shared by Science Girl on X, a man tries on a lifelike mask in real time, sliding it over his head, and in just a moment and with one small wiggle of the nose, he's completely transformed. I thought for sure the whole thing had to be AI-assisted, but no. The clip originated from a mask manufacturer called FL Silicone Mask. They've got tons of demonstrations all over their Instagram page.

The final result of this mask in particular is a little unnerving, a little uncanny valley. There's something off with the way it looks but it's really hard to say what. The details are incredible, the eye-sockets seamless. The mouth can even move open and closed.

In passing, without looking for it, you'd probably never have any idea that this person was wearing a mask. Just see for yourself. It's no wonder the post clocked over 27 million views on social media.

Realistic masks like this one have actually been researched. Studies have shown that about one in five people can be fooled by someone in a realistic silicone mask.

A research study out of the Universities of York and Kyoto asked volunteers to look at photographs of people wearing a realistic mask, and photos of people not wearing a mask. They had to guess which was which, and an astonishing 20% of the selections turned out to be wrong. Considering this was a controlled environment where participants were actively looking to see if someone was wearing a disguise, it's even scarier to Imagine how easy it would be to get fooled in real life when you aren't on your guard.

- YouTubewww.youtube.com

The technology for hyper-realistic masks has grown by leaps in bounds in recent years. The fit and detail work on them is astonishing, so much so that it's becoming cause for concern.

While Tom Cruise uses his disguises to save the world, not everyone is so altruistic. Police forces all over the world are facing more and more challenges with criminals using creative camouflage.

The "Geezer Bandit" once terrorized San Diego banks for years, robbing them while disguised as an old man. He or she was never caught.

Realistic silicone masks are expensive, usually costing several thousand dollars, and good ones are hard to find. Mesh masks that can be worn under a hoodie are a lot more cost-effective and incredible at fooling security cameras from a distance. Worse yet, masks can be made in the likeness of almost any person, making identity theft a serious concern.

There might be a bright side to this bizarre technological advancement, though.

For years now, wigs have been helping people with various forms and causes of hair loss find their confidence again. It's a chance to blend in with the public and not feel othered by stares or field any questions. It allows people to just exist the same way anyone else does.

Masks haven't been able to do the same thing because, well, they've always looked like masks. But you have to wonder if the technology has finally reached a tipping point where they too could become a source of confidence and normalcy for people with facial deformities or disfigurations.

When mangled soldiers were returning from WWI by the hundreds, a British sculptor named Francis Derwent Wood opened up a shop that specialized in creating masks that would hide their scars. According to Forces News, "Wood's painted metal mask work was an attempt to give back to veterans the sense of self-worth and pride they once had in their appearance and help them 'fit in' back on civvy street."

Maybe these stunningly-accurate silicone creations could do that for a new generation of people who could use a little help feeling like themselves again. No one should ever feel like they have to wear a mask or hide their face. But if you're going to wear one, it might as well be the best quality you can find!

From Your Site Articles
camouflage
Badge
Pura
Pura Fragrances
Justice

Walking Alongside Martu: A journey with one of the world’s oldest living cultures

Pura’s inaugural impact collection honors both sacred traditions and sustainable futures.

James Roh
True

In a world driven by speed, efficiency, and immediate results, it’s easy to forget that lasting change is built on trust. Real impact doesn’t come from rushing toward an end goal or measuring success through lofty metrics. It comes from falling in love with the problem, building a community around it, and sharing a vision for lasting transformation.

Pura, the smart home fragrance company that marries premium fragrance with innovative technology, recently launched its inaugural impact collection with K Farmer Dutjahn Foundation (KFDF) and Dutjahn Sandalwood Oils (DSO). The Pura x Dutjahn partnership began with a clear purpose: to source a sacred ingredient directly from its origin while honoring the land and the people who’ve cared for it. Our goal wasn’t simply to find sandalwood — it was to find a community and an ingredient that embody exceptional land stewardship, ethical harvesting, and transformative, community-led impact. After careful research and over three years of development, we saw an opportunity to secure a premium, luxurious ingredient while supporting a regenerative supply chain that invests in Indigenous-led education, economic opportunity, and land stewardship.

James Roh

Over the past several years, we’ve walked alongside Martu, an Indigenous tribe from the vast Western Australian desert. Martu are one of the oldest living cultures in the world, with a history spanning 60,000 years. As nomadic hunter-gatherers, they have unparalleled ecological knowledge, passed down through generations, making them the traditional custodians of the land. Their approach to sandalwood harvesting isn’t driven by market demand but by a deep respect for seasonal rhythms, land health, and cultural law. Their work adapts to the environment—whether it’s “sorry time,” when mourning pauses activities, or the harsh desert conditions that make travel and communication difficult. Martu operate on Martu time, a deliberate rhythm shaped by millennia of experience, far removed from the rapid-swipe, hyper-productive pace of Western systems.

Martu’s ecological knowledge isn’t documented in baseline reports. It’s lived, carried in stories, and practiced with rigor and respect for the changing needs of the ecosystems. True partnership means unlearning the typical approach. It means standing beside—not in front—and recognizing that the wisdom and leadership we need already exist within these communities. Our role isn’t to define the work, but to support it, protect it, and learn from it.

James Roh

Tonight, as I spoke with Chairman Clinton Farmer and the KFDF team about our focus for this piece, I learned that Clinton’s truck had broken down (again), leaving him to “limp” back to town from the desert at low speeds for hours and hours. He had been awake since 3:00 a.m. This is a common and costly setback, one that disrupts the harvest, demands days of driving, and brings real financial and emotional strain. These barriers are relentless and persistent, part of the harsh reality Clinton and his community face daily. It's easy for outsiders, detached from the reality on the ground, to impose rules, regulations, and demands from afar. Rather than continuing to impose, we need to truly partner with communities — equipping them with the resources to operate sustainably, avoid burnout, and protect the very land they love and care for. All while they endeavor to share these incredible, sacred ingredients with the world and build an economic engine for their people.

There is much to learn, but we are here to listen, adapt, and stay the course. The future we need will not be built in quarterly cycles. It will be built in trust, over time, together.

To learn more about the partnership and fragrances, visit Pura x Dutjahn.

Related Articles Around the Web
indigenous people
Science

Researchers hacked 5 people's brains so they could see a new and impossible color

The new color 'olo' is neat, but the technique behind it could be groundbreaking.

Canva Photos

Only five people in the world have seen the mysterious color "Olo"

Color is one of the great joys of being alive. The brilliant blue sky, the green grass, the exotic pinks and purples and teals in coral or tropical fish. Soaking it all in is truly a feast for the eyes, and some studies even show that certain colors can trigger specific emotions in people. Orange may evoke feelings of joy, and red may conjure feelings of love, while blue may have a calming effect.

One of the most interesting things about colors, though, is that they are finite. Though the world is full of undiscovered plants, creatures, and even elements, the entire color spectrum is known and documented. Due to the nature of light in our universe and how it reflects off of physical objects, all perceived color must be created by some combination of the primary colors (blue, green, and red — yes, green, not yellow!). There are essentially unlimited combinations, but they all exist on a known spectrum — different hues and shades of pink or emerald or orange.

However, a team of researchers recently decided to push the limits of human perception. They "hacked" participants' retinas to allow them to see an impossible color.


color, green, blue, color wheel, physics, light, wavelengths, scienceThe paint companies are dying to know the secret formula for the new color.Giphy

Scientists from the University of California, Berkeley, developed a new technique called "Oz," which would allow them to activate specific cones in the retina. Cones are light-sensitive cells that respond to different wavelengths of light. When the three types of cones are activated in different ways, our brains perceive colors.

One fascinating bit of background is that the "M" cone, which typically responds strongest to green (Medium wavelength), can not naturally be activated without also activating the Long and Short cones. So even the purest green on the planet would also, to a smaller degree, stimulate the parts of our eyes that are mostly correlated with red and blue.

retinas, eyes, oz, retina scan, retina cones, vision, colorsA close-up of the human eye. Swapnil Potdar/Unsplash

The team wanted to find out what would happen if they could isolate and activate only the M, or green, cone using the new technique.

The result? The five participants reported seeing an absolutely unreal, brilliant shade of green like nothing they had ever experienced. Imagine a bright green laser cranked up to the highest saturation and brilliance possible, the purest and brightest green your brain could possibly comprehend. Participants noted that a bright green laser pointed looked "pale" in comparison to the new color.

The name of the new, impossible color? Olo, or 010 (indicated zero stimulation of the L and S cones and full stimulation of the M cones).

- YouTubewww.youtube.com

It's fair to wonder, if olo is impossible and can never naturally exist without manual stimulation of the retinal cones, what's the point of the experiment?

The introduction of a "new color" is certainly interesting and makes for a good headline, but the real value of this study lies in the future applications of the Oz technique.

The research team hopes that the detailed retinal maps they have developed, along with their ability to stimulate specific rods and cones in the eye in any combination, will enable major breakthroughs in the study and treatment of various visual impairments.

For example, Oz could one day cure color blindness or unlock new treatments for cataracts or glaucoma. It could even play a role down the line in curing certain types of blindness. Isn't it wild how our understanding of how our eyes perceive color tells us so much?

But those days are a long way off, for now. In the meantime, only five people in the world have experienced the brilliance of olo, and the rest of us will just have to imagine it.

From Your Site Articles
science
Trending Stories