Why Do We Get Red Eye in Photos?

iStock/Liia Galimzianova
iStock/Liia Galimzianova

Grab a partner and look into his or her eye "“ or stare deeply into it, if appropriate "“ in a normally lit room. The quick and dirty version of how you're able to view each other is this: Light enters the eye through the cornea, the clear outer dome, and goes through the pupil. Then it travels to the cornea, which focuses it on the lens. The lens further focuses the light and spreads it across the retina. The retina receives the light and transmits signals via the optic nerve to the brain, which interprets the image.

As light enters the eye, some of gets reflected back, but the amount of light in most situations is so small, you wouldn't even know it. Right now, your partner's pupils look black and everything's normal. Now grab a camera and take a picture of your partner with the flash on. There's that demonic red eye.

Here's what happened: When you took the picture, the camera flash sent a lot of light into the eye in a very short time, the light reflected off the back of the eye and out through the pupil and, because the camera lens is close to the flash and able to capture images very quickly, it caught the light reflecting back out.

Seeing Red
So why is that light red?

Because the fundus, the interior surface of the eye that includes the retina, is loaded with melanin, a pigment that gives it a brownish-reddish color. Was that anti-climactic? Sorry.

Red eye is fairly easy to curb by using the "red eye reduction" setting found on most digital camera flashes. This setting causes the flash to go off once before the picture is taken, which causes the subject's pupils to contract and let less light in and out, and then another time to take the picture. Cameras with a flash farther away from the lens also reduce red eye because the flash hits the subject at a different angle than lens captures it.

Of course, red eye isn't all bad. The same mechanics of light reflection that ruin photos also allow doctors a non-invasive way to see inside the eye. Hermann von Helmholtz, a German physician, discovered in the 19th century that he could examine the retina by holding a bright light near his eye and shining it into patients' pupils.

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Why Do We Eat Pumpkin Pie at Thanksgiving?

gjohnstonphoto/iStock via Getty Images
gjohnstonphoto/iStock via Getty Images

While it’s possible—even probable—that pumpkins were served at the 1621 harvest festival that’s now considered the predecessor to Thanksgiving, attendees definitely didn’t dine on pumpkin pie (there was no butter or wheat flour to make crust).

The earliest known recipes for pumpkin pie actually come from 17th-century Europe. Pumpkins, like potatoes and tomatoes, were first introduced to Europe in the Columbian Exchange, but Europeans were more comfortable cooking with pumpkins because they were similar to their native gourds.

By the 18th century, however, Europeans on the whole lost interest in pumpkin pie. According to HowStuffWorks, Europeans began to prefer apple, pear, and quince pies, which they perceived as more sophisticated. But at the same time pumpkin pie was losing favor in Europe, it was gaining true staple status in America.

In 1796, Amelia Simmons published American Cookery, the first cookbook written and published in the New World colonies. Simmons included two recipes for “pompkin pudding” cooked in pastry crust. Simmons’s recipes call for “stewed and strained” pumpkin, combined with a mixture of nutmeg, allspice, and ginger (yes, it seems our pumpkin spice obsession dates back to at least the 1500s).

But how did pumpkin pie become so irrevocably tied with the Thanksgiving holiday? That has everything to do with Sarah Josepha Hale, a New Hampshire-born writer and editor who is often called the “Godmother of Thanksgiving.” In her 1827 abolitionist novel Northwood, Hale described a Thanksgiving meal complete with “fried chicken floating in gravy,” broiled ham, wheat bread, cranberry sauce, and—of course—pumpkin pie. For more than 30 years, Hale advocated for Thanksgiving to become a national holiday, writing regular editorials and sending letters to five American presidents. Thanksgiving was a symbol for unity in an increasingly divided country, she argued [PDF].

Abraham Lincoln eventually declared Thanksgiving a national holiday in 1863 (to near-immediate outcry from Southerners, who viewed the holiday as an attempt to enforce Yankee values). Southern governors reluctantly complied with the presidential proclamation, but cooks in the South developed their own unique regional traditions. In the South, sweet potato pie quickly became more popular than New England’s pumpkin pie (mostly because sweet potatoes were easier to come by than pumpkins). Now, pumpkin pie reigns supreme as the most popular holiday pie across most of the United States, although the Northeast prefers apple and the South is split between apple and pecan, another Southern staple.

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What's the Difference Between Stuffing and Dressing?

iStock
iStock

For carbohydrate lovers, nothing completes a Thanksgiving meal quite like stuffing—shovelfuls of bread, celery, mushrooms, and other ingredients that complement all of that turkey protein.

Some people don’t say stuffing, though. They say dressing. In these calamitous times, knowing how to properly refer to the giant glob of insulin-spiking bread seems necessary. So what's the difference?

Let’s dismiss one theory off the bat: Dressing and stuffing do not correlate with how the side dish is prepared. A turkey can be stuffed with dressing, and stuffing can be served in a casserole dish. Whether it’s ever seen the inside of a bird is irrelevant, and anyone who tells you otherwise is wrong and should be met with suspicion, if not outright derision.

The terms are actually separated due to regional dialects. Dressing seems to be the favored descriptor for southern states like Mississippi, Tennessee, South Carolina, and Georgia, while stuffing is preferred by Maine, New York, and other northern areas. (Some parts of Pennsylvania call it filling, which is a bit too on the nose, but to each their own.)

If stuffing stemmed from the common practice of filling a turkey with carbs, why the division? According to HuffPost, it may have been because Southerners considered the word stuffing impolite, and therefore never embraced it.

While you should experience no material difference in asking for stuffing or dressing, when visiting relatives it might be helpful to keep to their regionally-preferred word to avoid confusion. Enjoy stuffing yourselves.

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