Here’s the Science Behind How the Sharpie Shock Challenge Works

Here's the Science Behind How the Sharpie Shock Challenge Works

Earlier this week, we published an article on the most recent in a long line of viral internet “challenges” – the Sharpie Shock Challenge. The Sharpie Shock Challenge, which involves drawing a dark square or other shape on your skin with a black permanent marker, and proceeding to “shock” yourself on the darkened shape with the flash of your smartphone, has thousands of children and teens around the world posting images and videos on Instagram, Youtube, Twitter, and pretty much any other form of social media you can think of.

If you read the last article, you probably came to the same conclusions that we did: that the sensation produced by the “challenge” is really more of a burn than a shock, and that the Sharpie Shock Challenge is relatively safe – at least when compared to similar “challenges” and other stupid and potentially dangerous acts many teenagers carry out. That said, although many of the videos depicting people performing the challenge are grossly exaggerated, it does produce a slight pinching, shocking, or burning sensation on the skin. So let’s take a look at why the Sharpie Shock Challenge actually works.

The Sharpie Shock Challenge, as was mentioned earlier, involves darkening a patch of skin (usually on the inside of the wrist or back of the hand) with a black permanent marker. From there, the person performing the challenge must place the flash of their smartphone camera directly on the darkened spot, and snap a photo, activating the flash, which will produce a slight “shocking” sensation on the hand.

As was also discussed previously, the actions don’t produce a “shock” per se, but actually a very slight burn. Really, it boils down to simple physics – most people realize that lighter-colored objects tend to reflect light, while darker-colored objects tend to absorb light. That’s why it’s not a great idea to wear black clothes on a hot summer day, or why black cars tend to heat up in the sun much faster than white ones do. HowStuffWorks offers a simple and concise explanation of the effect – “what does the absorption of light have to do with heat? When an object absorbs light, it converts that light to thermal energy, and emits it back out as heat. So, because black objects absorb more light, they also emit more heat.”

As you can probably figure, the spot on your skin that has been darkened with the Sharpie will absorb more light, and thus emit more heat than other, lighter spots on your skin. As you can also probably figure, the flash on your smartphone emits a short, but pretty intense, burst of light. The darkened spot of your skin will absorb all of the light, and thus thermal energy (heat) from the flash, resulting in a slight burning sensation on your skin. In fact, there are several videos on YouTube in which the person performing the challenge uses a more intense flash from a higher quality camera, and you can actually see a bit of smoke emit from where hair is burned on the back of their hands – a burn, not a shock.

As we discussed in our past article, the Sharpie Shock Challenge isn’t necessarily dangerous. If someone repeatedly performed the challenge on the same spot of skin, there is probably risk of a slight burn, but nothing serious. If you feel the need to test the challenge on yourself, you know, in the name of science, you’ll probably leave yourself a bit underwhelmed. Now that you understand the science behind the challenge, there’s really no need to perform it anyway – feel free to move on to the next questionable viral challenge that the internet is sure to come up with soon.

Sharpie Shock Challenge Update

[Update: 5/18/2017] It’s been a year since the “Sharpie Shock Challenge” began circulating across the internet, but the fad is still going strong — if the plethora of YouTube “challenge” videos still being uploaded is any indication.

Of course, despite its popularity, there’s still a relative lack of actual science that can explain what’s actually at play during the challenge. The best physical explanation is this: there’s no actual “shock” going on, but rather just a transfer of heat energy from a camera or phone’s flash. A camera’s flash mechanism is designed to produce a lot of energy in a very short amount of time — so it makes sense that placing the source of that energy directly on your skin is going to result in a transfer of said energy. That’s where the Sharpie comes in: the “color” black absorbs more light, so it absorbs more of that energy as heat.

But that bring us to the question of whether people with darker skin tones actually need the sharpie to feel a “shock.” If you search through Reddit and various internet comment sections, you’ll find plenty of anecdotes trying to argue for or against that point, but it gets a bit confused from here. Human skin color is largely determined by melanin, but even the darkest possible skin tones don’t have as much concentrated pigment as black sharpie ink. While it stands to reason that darker hues will absorb more energy than lighter hues, barring an actual scientific study, all we have is anecdotal evidence when it comes to the context of the challenge. Take note, also, of those who report that the challenge even works with lighter-colored ink.

Does the Sharpie Shock Challenge Actually Work?

But beyond all that, the explanation that seems to fit best (especially considering the young age of Sharpie Shock Challenge participants) is that people are just exaggerating. Take a look at some the challenge videos, and you’ll see exactly that. Also, factor in the “nocebo effect” — a lesser-known phenomenon similar to but opposite that of the placebo effect. In this context, having the anticipation or expectation of a certain outcome could actually cause you to feel said result, or possibly intensify it. In any case, we still can’t recommend that you try this at home.

How do you feel about the Sharpie Shock Challenge? Let us know in the comments below. 


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