The Internet is truly flummoxed by what appears to be an optical illusion recently posted on Twitter by user @franco_713. In it, somebody fills three supposedly different-sized fast food cups…with what appears to be the EXACT SAME amount of soda.
The video begins with what looks like a small cup of soda. The person filming then pours the full cup into a medium cup, filling it to the top. He then pours the full medium cup into a large cup, WHICH IS ALSO FILLED TO THE BRIM. WHAT IS HAPPENING?
According to the Jack in the Box menu, drinks come in four sizes — 16, 20, 30, and 40 ounces. Are fast food places ripping us off?
https://twitter.com/franco_713/status/932108760629334016
The video went viral, garnering over 120,000 likes and 74,000 retweets in under three days. Twitter, being Twitter, went wild.
https://twitter.com/ireenee_b/status/932340129137487872
https://twitter.com/Brandon22443231/status/932400571306446850
Lol I worked @ jack nah they finesse. Even the coffee lol
— D (@Dilly_Bob_) November 19, 2017
Give this man a raise for doing experiments at work 😂😂
— Fern (@Wsgoodfern) November 20, 2017
https://twitter.com/EllissDe/status/932392600404987904
Other Twitter users were more skeptical, listing possible tricks behind the optical illusion. One of these being the medium and large-sized cups already had liquid in them before the pouring from the small cup began. Since the cups are not shown from above, they could have already been partially full when the liquid from the small cup was poured.