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Why Does the Moon Sometimes Look Huge?

Have you ever seen the moon floating above the horizon of your city, and noticed that it looked oddly huge? I sure have. In fact, I've seen the effect in lots of popular media, including that one iconic shot from E.T. and other "supermoon" photos. But aside from movie magic, why does this happen in real life? If the moon gets bigger in the sky, it would have to get much closer to the Earth -- and while the moon's orbit does bring it a bit closer at times, it doesn't come close enough to account for the massively visible change in size. So how do we explain this effect?

There are several things going on here. First up, let's stipulate that our moon is really big, relative to other moons we see in our solar system -- our moon is roughly a quarter of the diameter of our planet. That's huge, and what that means from our perspective on the ground is that the moon is always quite large -- even sometimes large enough to block out the sun (in the case of solar eclipses), though the sun is of course much larger and farther away. The other major factor appears to be psychological. When the moon appears to be near other objects (as it tends to be when near the horizon), our brains register its relative hugeness and effectively inflate its size because we finally see its size relative to other objects. When the moon is all alone up in the sky, with tiny points of light around it, we have no frame of reference -- though it's still the same size it would be if by the horizon. (A related effect occurs when you can see the big ol' moon in the sky on a sunny day -- it looks weirdly big, perhaps because the sun is also up there.) Finally, there is one more odd effect relative to items approaching the horizon...but I'll leave that last one for this most excellent ASAP Science video to explain:

How you experienced the extra-huge moon? Have you tried what they suggest in this video -- looking at it upside down? I have not, though I encourage you all to try the next time the moon is near the horizon.

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iStock
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The Brain Chemistry Behind Your Caffeine Boost
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iStock

Whether it’s consumed as coffee, candy, or toothpaste, caffeine is the world’s most popular drug. If you’ve ever wondered how a shot of espresso can make your groggy head feel alert and ready for the day, TED-Ed has the answer.

Caffeine works by hijacking receptors in the brain. The stimulant is nearly the same size and shape as adenosine, an inhibitory neurotransmitter that slows down neural activity. Adenosine builds up as the day goes on, making us feel more tired as the day progresses. When caffeine enters your system, it falls into the receptors meant to catch adenosine, thus keeping you from feeling as sleepy as you would otherwise. The blocked adenosine receptors also leave room for the mood-boosting compound dopamine to settle into its receptors. Those increased dopamine levels lead to the boost in energy and mood you feel after finishing your morning coffee.

For a closer look at how this process works, check out the video below.

[h/t TED-Ed]

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Sophie Nightingale / University of Warwick
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Can You Spot Which Photo Is Fake? Most People Can’t
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Sophie Nightingale / University of Warwick

In a digital world, it’s easier than ever to fool people. Sophisticated Photoshop jobs, social media, and viral news cycles mislead readers into mistaking shots from a Lebanese music video for real scenes of destruction from Aleppo, thinking that Vladimir Putin was the center of attention at the G-20 summit, or believing that Elizabeth Taylor and Marilyn Monroe posed together for a photo shoot in the park.

While it would be nice to tell ourselves that we would never be duped by such fake images, the truth is, most people can’t distinguish between a manipulated photo and a real one. That’s the takeaway from a new study in Cognitive Research: Principle and Implications. As the team at Science reports, the participants were only able to pinpoint fake images two-thirds of the time.

First, psychologists from the University of Warwick asked more than 700 volunteers to look at real and fake images and identify the changes. The researchers used 10 color photographs sourced from Google searches, manipulating them through airbrushing, adding elements in, subtracting elements, and distorting shadows, and shearing trees. They applied each of these five manipulation techniques separately to a portion of the photos, eventually creating 30 manipulated photos and 10 real ones. All the participants saw one of each of the manipulation types in different photos.

An older man stands in the street in front of a house.
Can you spot the differences between the manipulated image at the top of the page and the original version above?
Sophie Nightingale / University of Warwick

The participants performed slightly above chance rates, identifying photos correctly as real only 58 percent of the time and spotting manipulations 66 percent of the time. Even when they did identify a manipulated photo, though, they didn’t necessarily know where it had been altered.

In a second study, the researchers did the same thing, but using photos study co-author Sophie J. Nightingale took with her Nikon camera, controlling for the fact that images found online could be manipulated before the researchers even downloaded them. They then had almost 660 people take an online survey testing their ability to spot fakes. They had to look at photos and label whether it was fake and if they could see where it was manipulated, whether it was fake but they didn’t know where it had been altered, or whether it was an original. At the end of the study, the subjects identified just 62 percent of the fake images correctly.

Woman standing outside
The first image is the original. The second was manipulated to add in a water spout, airbrush the woman's face, and make other slight changes.
Sophie Nightingale / University of Warwick

The results were the same regarding images that had been manipulated in both overtly unrealistic ways and photos that featured more plausible changes. One reason might be the way that our visual system simplifies information. As long as object geometries and shadows are roughly correct, our eyes accept them as accurate.

“It remains to be determined whether it is possible to train people to make use of physically implausible inconsistencies,” the researchers write. “Perhaps one possibility would entail ‘teaching' the visual system to make full use of physical properties of the world as opposed to automatically simplifying them.”

You can still take a 10-minute online survey for the project here and test your own manipulation awareness skills. (I had to take wild guesses on most of them.)

If this makes you weep for the future of the world, at least know that it’s a timeless problem. Manipulated, misleading images have been around since the earliest days of photography.

[h/t Science]

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