“It’s called the TARDIS. It can travel anywhere in time and space. And it’s mine.”
“But it’s… look at it, it’s…”
“Go on, say it. Most people do.”
“It’s smaller on the outside!”
“Okay. That is a first.”
The Doctor and Clara in Doctor Who: “The Snowmen”
I recently watched the 7th season of Doctor Who. If you don’t know the series: He’s a time-traveling alien and his current companion is a human who works as a nanny. Although that’s like saying “Moby Dick is about a one-legged guy trying to catch a fish” (to quote an unrelated Jack Kirwan review).
Anyway, in one scene, the kids his companion governs discover photos from her in 1983, 1974, and 1893 (images below). Not being fooled by the assertion that this person only looks like her, it exposes her as a time traveler.
|Images from Doctor Who: “The Crimson Horror”
Personally, I found the explanation of the children how they got the photos harder to believe than the idea of time travel. One kid says:
“I found it at school.”
Really? How? Why?
I think a much more believable idea would have been if the companion left her notebook open, Facebook still open and logged in, and Facebook face recognition* suggested her on photos. You would just need someone uploading historic photos, e.g., on a history page.
After all, face recognition does not care whether the photos are from 1900 or 2000. It looks for matches no matter what.
So unless the photos contain date-time information in the EXIF and the algorithms filter out those photos where a match is impossible, it would find people currently living on historic photos when they could not have been living.
Sidenote: Actually such an algorithm to filter out impossible photos would make sense, it would cut down on the amount of photos that need scanning and it would allow for better face recognition. If the date of the photo is known, it could pick those personal photos as comparison that match the age of the person. Thinking further it could fill in the blanks by using an algorithm to age/rejuvenate the person on the photos. Not sure whether it is already possible, but there was talk about such a software to find missing children. If they haven’t been found for years, you might want to know how they would look like today. Actually, using Facebook photos would be a nice way to improve those algorithms, just think about the available data …
Anyway, so given that there are no hits of people currently living on historic photos (that cannot be explained by similar looking ancestors), it does not seem that time travel is possible (yet). Or just that time travelers are very clever.
But back to a more useful topic — I wonder what will be possible in the future when archives are digitized and face recognition works almost perfectly. Just imagine wanting to find out more about your family. It could make diving into the past almost effortless. Like a time machine on its own — finding people on photos and in newspaper reports.
With all the possible problems of digital technology — that is one of the bright sides when almost all data is digitized.
* If that is still a thing, I’m not on Facebook.