The Curvature Blindness Illusion Strikes!

Optical illusions are puzzles for the eye. They reveal how different combinations of images — light and shadow, shape and density, foreground and background — can trick viewers into seeing something unexpected.

And we are still discovering new illusions that deceive and delight us.

In the above image, pairs of wavy lines run horizontally across the screen. In the white and black corners, they’re fine. But in the gray area, half of those wavy lines suddenly look like zigzags.

The only difference? The alternating pattern of light and dark patches on each line. In lines where the peaks of the waves are dark and the valleys are light, the wavy pattern remains.

But when the dark and light patches are the ascending and descending parts of the wave, our eyes interpret them as lines forming corners instead of wavy lines.

This is known as the curvature blindness illusion.

As with many optical illusions, this is all about contrast. The white and black backgrounds allow you to view the alternating pieces as one continuous wavy line, whereas the gray background forces you to regard those alternating pieces as individual segments.

Those individual segments are granted the illusion of three-dimensions, and our minds process the lighter ascending line and the darker descending line as “walls” forming a corner, rather than the rising and falling of a sine wave.

It’s amazing how distinctly different the pairs of lines look with just those small variations. Even knowing how I’m being manipulated, it’s still hard to convince myself that I’m not actually seeing what I’m seeing.

Very cool stuff.


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PuzzleNation Blog Looks Back on 2017!

2017 is quickly coming to a close, and as I look back on an eventful year in the world of puzzles and games, I’m incredibly proud of the contributions both PuzzleNation Blog and PuzzleNation made to the puzzle community as a whole.

Over the last year, we explored board games and card games, strategy games and trivia games, dice games and tile games, do-it-yourself puzzlers and pen-and-paper classics. We met game designers, constructors, artists, and creative types of all kinds.

We unraveled math puzzles and tackled the Crossword from Hell. We accepted the challenge of diabolical brain teasers, optical illusions, Internet memes, and more, even pondering our place in the world of puzzles as electronic solvers like Dr. Fill and AlphaGo rise in capability.

We delved into puzzle history with posts about the legacy of female codebreakers in World War II, game dice from centuries ago, theories about Shakespeare’s secret codes, and the long history of cryptography and the NSA. We brought to light valuable examples of puzzles in art, popular culture, famous quotations, and even the natural world as we pondered whether bees are verifiable problem-solvers like crows and octopuses.

We spread the word about numerous worthwhile Kickstarters and Indiegogo campaigns, watching as the puzzle/game renaissance continued to amaze and surprise us with innovative new ways to play and solve. We shared worthy causes like Puzzles for Progress, as well as amazing projects like new escape rooms, dazzling corn mazes, and the ongoing Kubrick’s Game interactive experience.

We cheered the 75th anniversary of the New York Times Crossword, and chronicled the many celebrations that marked the occasion, from guest crossword constructors like Bill Clinton and Lisa Loeb to a puzzle-centric cruise across the Atlantic!

We also mourned as friends and fellow puzzlers passed on. We said goodbye to David Lindsey and Raymond Smullyan, two underappreciated giants of the field. The pun-fueled show @midnight this year, which inspired our monthly hashtag game, also closed up shop, sadly.

We celebrated International TableTop Day, made puzzly bouquets in honor of International Puzzle Day, marveled at the records broken at the Rubik’s Cube World Championship, attended the American Crossword Puzzle Tournament and New York Toy Fair, and dove deep into an ever-expanding litany of puzzle events like the Indie 500, BosWords, Lollapuzzoola 10, and Crosswords LA.

We found puzzly ways to celebrate everything from Pi Day, the Super Bowl, and Star Wars Day to Halloween, Thanksgiving, and Christmas, and we were happy to share so many remarkable puzzly landmark moments with you. We even discovered Puzzle Mountain!

It’s been both a pleasure and a privilege to explore the world of puzzles and games with you, my fellow puzzle lovers and PuzzleNationers. We marked five years of PuzzleNation Blog this year, I recently penned my 800th blog post, and I’m more excited to write for you now than I was when I started.

And honestly, that’s just the blog. PuzzleNation’s good fortune, hard work, and accomplishments in 2017 went well beyond that.

Every month, we delivered quality content for the Penny Dell Crosswords App. From monthly deluxe sets and bonus boxes to Dell Collection sets and holiday bundles, dozens upon dozens of topnotch puzzles wended their way to our loyal and enthusiastic solvers.

And just last month, we launched our newest puzzly endeavor — Daily POP Crosswords — bringing you fresh, up-to-date cluing and relatable themes in world-class puzzles created by some of the industry’s best constructors! (Many of whom you’ve gotten to know in our recent interview series, Meet the Daily POP Crosswords Constructors!)

But whether we’re talking about the Penny Dell Crosswords App or Daily POP Crosswords, I’m proud to say that every single puzzle represents our high standards of quality puzzle content crafted for solvers and PuzzleNationers.

And your response has been fantastic! Daily POP Crosswords is thriving, the blog has over 2200 followers, and with our audience on Facebook, Twitter, Instagram, and other platforms continuing to grow, the enthusiasm of the PuzzleNation readership is both humbling and very encouraging.

2017 was our most ambitious, most exciting, and most creatively fulfilling year to date, and the coming year promises to be even brighter.

Thank you for your support, your interest, and your feedback, PuzzleNationers. The new year looms large, and we look forward to seeing you in 2018!


Thanks for visiting PuzzleNation Blog today! Be sure to sign up for our newsletter to stay up-to-date on everything PuzzleNation!

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The Floor Is Not to Be Trusted.

We love optical illusions here at PuzzleNation Blog. They’re puzzles for the eye, mind-bending ways that our senses can be tricked by clever manipulators of color, angle, and perspective.

And if you’re looking for visual trickery in flooring, look no further than the tile wizards at Casa Ceramica, a UK flooring manufacturer that decided to kill two birds with one stone. (Well, more like many tiles than one stone, but I digress.)

Supposedly, they had a problem with people running down the hallway to their store, and wanted to dissuade such shenanigans.

So they created an optical illusion to make it look like the floor was more treacherous than it really is. That way, ne’er-do-wells would be forced to slow down for their own “safety.”

And not only are they making their place safer, but they’re showing off their impressive skills while they do so! It’s a win-win.

What do you think, fellow puzzlers? Will it work? Or is it just a clever marketing scheme to draw attention to their topnotch tile skills?

Although I firmly believe it’s just an ingenious way to get the word out about their company, they’re not wrong in thinking that this sort of thing could dissuade rambunctious types. Other designers and stores have employed similar trickery in the past.

I mean, if you were trying to get across this floor, would you risk running?

I think not.


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Visual Video Trickery!

illusion1

Visual trickery plays an important role in puzzles. It can be the clever rebus that challenges you to find the words each image represents, or a visual brain teaser that forces you to think outside the box.

But nowhere in the realm of puzzles is visual trickery more obvious or more disconcerting than in optical illusions. Some are simple, like the famous old woman/young woman image above (or this hilarious video version). But others are not only more complex, they’re absolutely mind-bending.

Few optical illusions are as effective as those done on video. Drawings and photos are all well and good, but incorporating movement and performance into the illusion are something else entirely.

And stop-motion animator Kevin Parry has some doozies in his Instagram feed.

Check out this one involving a mirror and a wooded area. I’ve watched it a half-dozen times and I haven’t figured it out yet:

He’s also a dab hand at forced perspective illusions, as he shows in this video with a can of soda:

With innovators like Kevin at work, we will never run short of visual wonders, that’s for sure.


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You can also share your pictures with us on Instagram, friend us on Facebook, check us out on TwitterPinterest, and Tumblr, and explore the always-expanding library of PuzzleNation apps and games on our website!

PuzzleNation Looks Back at 2016!

The year is quickly coming to a close, and as I look back on an eventful year in the world of puzzles and games, I’m unbelievably proud of the contributions both PuzzleNation Blog and PuzzleNation made to the puzzle community as a whole.

Over the last year, we explored board games and card games, strategy games and trivia games, dice games and tile games, do-it-yourself puzzlers and pen-and-paper classics. We met designers, constructors, authors, artists who work in LEGOs and dominos, and creative types of all kinds.

We unraveled math puzzles and used statistics to play Hangman and Guess Who smarter. We accepted the challenge of diabolical puzzles, optical illusions, Internet memes, and more.

We delved into puzzle history with posts about Bletchley Park, puzzle graffiti from ancient Greece, Viking board games, and modern mysteries like the Kryptos Sculpture and the Voynich Manuscript. We separated fact from fiction when it comes to puzzles and brain health, avoiding highfalutin promises and sticking to solid science.

We spread the word about numerous worthwhile Kickstarters and Indiegogo campaigns, watching as the puzzle/game renaissance continued to amaze and surprise us with innovative new ways to play and solve. We shared amazing projects and worthy causes like Humble Bundles and puzzle/game donation programs for schools that allowed puzzle lovers to help others.

We celebrated International TableTop Day, built a puzzle fort in honor of International Puzzle Day, attended the American Crossword Puzzle Tournament and the Connecticut Festival of Indie Games, and dove deep into puzzle events like the Indie 500, the UK Sudoku Championship, the 2016 UK Puzzle Championship, and Lollapuzzoola. We even celebrated a puzzly wedding proposal, and we were happy to share so many remarkable puzzly landmark moments with you.

It’s been both a pleasure and a privilege to explore the world of puzzles and games with you, my fellow puzzle lovers and PuzzleNationers. We marked four years of PuzzleNation Blog this year, I’m approaching my 650th blog post, and I’m more excited to write for you now than I was when I started.

And honestly, that’s just the blog. PuzzleNation’s good fortune, hard work, and accomplishments in 2016 went well beyond that.

In April, we launched Penny Dell Crosswords Jumbo 3 for iOS users, and in May, we followed that with Penny Dell Crosswords Jumbo for Android. In November, we launched our new Penny Dell Sudoku app on both Android and iOS.

But the standout showpiece of our puzzle app library remains the Penny Dell Crossword App. Every month, we release puzzle sets like our Dell Collection sets or the themed Deluxe sets for both Android and iOS users, and I’m proud to say that every single puzzle represents our high standards of quality puzzle content for solvers and PuzzleNationers.

We even revamped our ongoing Crossword Clue Challenge to feature a clue from each day’s Free Daily Puzzle in the Crossword app, all to ensure that more puzzle lovers than ever have access to the best mobile crossword app on the market today.

And your response has been fantastic! The blog is closing in on 2000 followers, and with our audience on Facebook, Twitter, Instagram, and other platforms continuing to grow, the enthusiasm of the PuzzleNation readership is both humbling and very encouraging.

2016 was our most ambitious, most exciting, and most creatively fulfilling year to date, and the coming year promises to be even brighter.

Thank you for your support, your interest, and your feedback, PuzzleNationers. Have a marvelous New Year. We’ll see you in 2017!


Thanks for visiting PuzzleNation Blog today! Be sure to sign up for our newsletter to stay up-to-date on everything PuzzleNation!

You can also share your pictures with us on Instagram, friend us on Facebook, check us out on TwitterPinterest, and Tumblr, and explore the always-expanding library of PuzzleNation apps and games on our website!

It’s Follow-Up Friday: Blind Spot edition!

[No, not THAT Blindspot. Though friend of the blog David Kwong works on that show…]

Welcome to Follow-Up Friday!

Follow-Up Friday is a chance for us to revisit the subjects of previous posts and bring the PuzzleNation audience up to speed on all things puzzly.

And today I’d like to return to the subject of optical illusions.

[Image courtesy of Geekologie.]

We’ve discussed optical illusions many times in the past, covering everything from the Necker Cube to the Dress, but today’s illusion is a little bit different.

The 12-dot optical illusion pictured above, also known as a Hermann grid, has been making the rounds lately, and although many puzzlers have accused people of using a video or an animated gif instead of a simple picture, that’s simply not true.

This is a static picture, but our eyes are not designed to capture 12 dots in view at once, so the others vanish when you focus on one dot in particular.

And the folks at ASAP Science have an explanation for this phenomenon! As it turns out, this illusion and others involve both how your brain processes visual information and how the natural structure of your eye creates a blind spot that some optical illusions exploit.

Check out the full explanation here:

So next time someone shares one of these optical illusions, you’ll be ready to explain how they work and show off your puzzly knowledge.


And thanks for visiting PuzzleNation Blog today! Be sure to sign up for our newsletter to stay up-to-date on everything PuzzleNation!

You can also share your pictures with us on Instagram, friend us on Facebook, check us out on TwitterPinterest, and Tumblr, and explore the always-expanding library of PuzzleNation apps and games on our website!