Time travel is a mysterious and so far unproven phenomenon in physics.
But just because time travel can only be observed in science fiction, doesn’t mean it isn’t possible: some people think that time travellers from the future could already be visiting us now.
Scientists from Michigan Technological University searched the Internet for time travellers and published their results in the physics pre-publication database arXiv on Dec. 26. They looked specifically for social media posts that seemed to predict the future — mentioning events before they happened.
While they didn’t find any, Doctor Who and Back to the Future fans need not worry: the results don’t disprove time travel.
This was not the first attempt by scientists to find time travellers. In May 2005, a grad student at MIT advertised for, and subsequently held, a convention for time travellers. Unfortunately no one from the future showed up.
The scientists who worked on this paper used a slightly more sophisticated method: they searched the Internet for content that “should not have been known at the time it was posted.”
They used this method to search twitter, search engines, and the Astronomy Picture of the Day website.
The search terms
The scientists decided what search terms to use based on a few criteria:
- They needed a search term that acquired a name between the period of January 2006 (because they were planning on using Twitter, and Twitter was established in 2006) and September 2013.
- They needed a search term with a unique label that wouldn’t turn up lots of closely related results.
- They needed a search term that would remain important in the future that time travellers would still be likely to communicate about.
Eventually they decided on “Comet ISON” and “Pope Francis.” They looked for any posts that existed about Comet ISON before it was discovered in September 2012, and any posts about Pope Francis before he was officially named the pope in March 2013.
They did not find any. The researchers then sent out a request to any existing time travellers to post something proving time travel would become possible in the future and if it would be possible for time travellers to change the past.
Specifically, “time travellers were requested to respond with a communication including either the hashtagged term “#ICanChangeThePast2” or “#ICannotChangeThePast2″ on or before 2013 August.”
The researchers used Twitter for this request because tweets cannot be backdated, so no one but a legitimate time traveller would be able to pull this off.
Time travellers could technically still be around
The experiment did not yield any time travellers, but the researchers outlined several possible reasons for this:
- It may be physically impossible for time travellers to leave any lasting remnants of their stay in the past.
- It may be physically impossible for us to find such information because it would violate some yet-unknown law of physics.
- Time travellers may simply not want to be found, and cover their tracks well.
- Time travellers might have not used those specific event tags.
- And of course, the researchers could have just missed them due to human error, non-comprehensive Internet searches, or inaccurate content time tags.
Either way, this is the most comprehensive search for time travellers ever conducted.
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