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Hello, World.

A viral video of mathematics professor Dr. Khristo Boyadzhiev’s 12 identical classroom greetings captivates the Internet

Internet celebrity tends to come in two flavors: good and bad. But for Ohio Northern University professor of mathematics Dr. Khristo Boyadzhiev, the experience has been nothing short of great.

“I was very amused by the video. I think it is fun!” he says. “I am happy I’ve been able to connect with so many young people around the world with my ‘hello.’”

I recorded my professor every day.

— Brock Hersch (@bhersch04) September 3, 2015

His “hello,” or more accurately, 12 identical “hellos” and classroom entrances captured on video last spring by former student Brock Hersch and published to Twitter as a looping 17-second video, has been viewed by millions of people and become a bit of a sensation due to Boyadzhiev’s impeccable consistency.

The exact numbers are impossible to know with any certainty based on the number of different social media platforms the video appears on and the number of times it has been reposted by others, but it has definitely gone viral. The seven-second Vine version of the video has nearly 18 million loops, and Hersch’s original tweet has 125,000 retweets and 170,000 favorites.

Also on Twitter, Hersch’s video was pinned to the top of the timeline at @FillWerrell, a Will Ferrell parody account that has 2.5 million followers. On Facebook, a post by the account BestofVines featuring the video had 3.2 million views before it was taken down. On YouTube, the most popular version of the video (there are several) has more than 1.1 million views.

Hersch posted the video at 6:13 p.m. on Wednesday, Sept. 2. By the next morning, Boyadzhiev’s 18-year-old daughter informed her father that he was all over the Internet. The video made the front page of the pop culture nerve center and had mentions on the websites for GQ magazine and the English newspapers The Daily Mirror and The Daily Telegraph.

As a member of the American Mathematical Society and an author of 70 papers published in professional journals, Boyadzhiev is used to seeing his name appear online, but never his likeness and certainly never quite like this.

While many of these mentions incorrectly cite the video as taking place at Ohio State University, this week's most famous doorway on the Internet is actually the entrance to ONU’s Mathile 210, where Boyadzhiev teaches MATH 2651 Differential Equations 4. As strange as it sounds, there is a chance that had it been any other room, the video may not have gone viral at all. You see, of the hundreds of comments people left on Hersch’s original Tweet, the one aspect of Boyadzhiev’s repeated entrances that everyone seemed to notice was that while his shirt changes with each entrance, his pants do not.

“Same pants everyday?” asked @StinkyTTR, just one of the many who raised the issue.

As you might expect from a mathematics professor, Boyadzhiev has a perfectly logical explanation.

“When I teach, I tend to move around a lot in front of the chalkboard, and sometimes I have problems with chalk dust. Some years ago, I decided to wear white trousers to make this dust invisible,” he says. “I have several pairs of white khakis. They’re like a work uniform for me.”


— andy (@ABoyadzhiev) September 4, 2015

Boyadzhiev’s daughter even took to Twitter herself to prove to the world that, yes, her father owns more than one pair of pants.

While most ONU classrooms have whiteboards, Mathile 210 has chalkboards. And the presence of those chalkboards is ultimately the impetus for many of the conversations that viewers have had around the video. Assistant professor of public relations Alisa Agozzino teaches courses that comprise ONU’s social media minor, and she explains how engagement is key to a post’s popularity.

“The more followers that comment or otherwise engage with a post, the more that post rises to the top of everyone’s newsfeed. Why is this important? If it’s at the top of the newsfeed, it has a better chance of being seen by even more followers who may also engage. It becomes a cycle that can help the post go viral,” she says.

And in case you have Dr. Boyadzhiev for class and are perplexed why he never greets you with “hello,” here’s why. As a rule, Boyadzhiev greets his morning classes with “good morning” and his afternoon classes with “good afternoon.” But this class met at noon, so there was only one logical greeting. But before anyone gets the idea for a sequel or two, know that he doesn’t approve of cell phones in his classroom.

“Using phones in class is generally not allowed, as they can be very distracting,” he says.

For the millions around the world who can’t stop watching a professor greet his class over and over and over, he’s absolutely correct.