Sometime Thursday afternoon, the denizens of the Internet (that’s all of us, if you didn’t know) turned on each other like hyenas fighting over an antelope carcass. The reason can be found in one young Scottish woman’s Tumblr account.

Wednesday, Tumblr user “swiked” posted this photo with the simple question, “Guys please help me – is this dress white and gold, or blue and black?” When pressed for details, the user, who identified herself to Business Insider as 21-year-old Caitlin McNeill from the Scottish Hebredian island of Colonsay, said, “It was the mother of the brides [sic] dress at my friend’s wedding! She posted it on Facebook and everyone started freaking out.”
blue n black
blue n black1

And we shall, Mia. It turns out McNeill already gave the answer if you were diligent enough to stay with her Tumbler. Later Thursday, in response to a user who claimed the dress was gold and white, she wrote, “[I]n real life the dress was blue and black. But in that photo and that photo only … some people see white and gold.”

So there you have it. If you’re interested in a scientific explanation, here’s one from WIRED.

“Light enters the eye through the lens—different wavelengths corresponding to different colors. The light hits the retina in the back of the eye where pigments fire up neural connections to the visual cortex, the part of the brain that processes those signals into an image … Without you having to worry about it, your brain figures out what color light is bouncing off the thing your eyes are looking at … This image, though, hits some kind of perceptual boundary.”

So take a bow, black and blue people. You won this round.