The footage - which appears to show an old woman talking on a mobile phone - was taken at the launch of a Charlie Chaplin film, The Circus, and features in the Extras section of a DVD release of the movie.
Since posting his narration of the footage on YouTube along with his claims that time travelling can be the only explanation, Mr Clarke's star is rising.
Hits for the YouTube video doubled overnight to more than a million, with viewer responses evenly divided between amazement and scorn.
"The biggest surprise I've gotten from the public is the fact that some forums and threads have been going strong for the whole week," Mr Clarke told NEWS.com.au.
"They are still discussing the footage, still sending me theories, and I mean thousands and thousands."
Did this woman stumble through a space-time continuum created by a Chuck Norris roundhouse kick?
Mr Clarke said he was happy to answer his critics and took some time to respond to NEWS.com.au readers' comments, which mainly fell into four variations: The "no mobile towers or satellites" comment Matt- "No cell towers means no phones....idiots!" George Clarke - "Well, the no cell towers theory lets me see how small-minded a lot of people can be in relation to the subject. The fact that the video is focusing on what could be a time traveller, should instantly point out that if that someone had the technology and ability to do so, then they would also have the technology to communicate without the needs we have today for mobile networks."
The "why release it now" comment Nick - "This guy says he had the footage a year ago...yet he's just showing it now?" George Clarke - "When I first saw the footage, I was more or less happy enough to show it to family and friends to get their views and enjoy their reactions on the piece. This went on for some time, then at my film festival in August I screened to an audience of 100 and again, got the same reactions. I'm a busy boy with my own films, festivals and such, and was always hoping to get something made for Youtube a lot sooner, but only last week - at 1:30am - was I able to do so."
The “good question” Les - "if you could time travel, why would waste your time at a Charlie Chaplin premiere?" George Clarke - "Who says the person in question went back to see the Chaplin premiere? How about, the person went back to an earlier period and got stuck there or was in town doing something else and just happened to stroll on by?"
The “CGI” comment Alf - "I own the same box set he shows in the clip. I have watched the extra's portion of The Circus and regret to advise the lady isn't there. It seems the lady was added by computer graphic imagery by someone in 2010 and agree with the comment that this was done as publicity to promote the filmmaker. Please note if you look at the supposed lady on mobile phone, you can see through her. Her image on film has a slight ghostly effect. She was added into the film."
George Clarke - "Alf obviously has a different version of the release. The extra feature in question is the 1928 Hollywood Premiere. It's on my DVD and a number of others from those who have contacted me. In fact, one of those other people put the full six-minute premiere footage on Youtube available through my account as a favourite. I can assure you that I didn't personally add anything - if I did, why would I hold up the cover, point out the DVD label and urge people to get their own? As for the guys that released the film, I honestly wouldn't think they would go to so much trouble for a two-second clip. So as for the ghostly effect - well, I can only say it strengthens the mystery of the visitor."
Mr Clarke says he hasn't had any feedback about the footage from anyone who might have been close to the original production, but with it spreading through Hollywood "like wildfire", he expected something soon.
Until then, the prize for the best theory comes from Gully Bill, who suggests that Chuck Norris "scissor kicked a hole in the space-time continuum and the old lady just walked on through on the way to the shops".
However, Mr Clarke thinks he's probably learnt enough about time travel this week to provide a plausible explanation for Norrisites.
"Why hasn't Jean Claude Van Damme went after her and 'timecopped' her ass back to where she belongs?" he said.
"It's possible Chuck messed up, and who knows, if he reads this he just might step up and admit to it."