Can we find time travellers using science?

Time travel is a popular theme in the science fiction and fantasy genre. But did you know that real scientist are trying to find traces of time travel with serious scientific methods?

When we hear about time travel we think of stories from books and movies. Like “Terminator”, where the evil Cyborgs travel back in time to change the course of history.  If this would happen in our world, it is reasonable to assume that such an event would leave a trace in historical records.

Two physicists from the Michigan Technology University, Robert Nemiroff and Teresa Wilson, have come up with a method, with which we might be able to find traces of time travellers in our time.

But let us first start by defining the terms they are using in their article and research.

They distinguish between different types of time travel:

Time travel to the future

Going into the future is the only form of time that is concordant with the laws of physics as we know them today. The theory of special relativity does explain travel to the future like this: Non scientificly speaking, the faster an object moves, the less time passes for it. You may have heard about the twin paradox. One sibling stays put on earth, while the other one  is sent out on a spaceship with near light speed. After his or her return to earth, years will have passed for the stay-at-home twin, while it will have been only weeks or month for the traveling one. This “time travel” phenomenon has been experimentally verified using synchronized clocks. One clock was sent on an airplane and one stayed on earth. Afterwards a delay could be detected in the moving clock in comparison to the earthbound  one.

Despite this physical support for time travel into the future,  the authors of the article dismiss a search for such time travellers in today’s world. They, quite convincingly, argue, that there is no record of time traveling devices in our past. So when looking for time travellers, they will most likely come from our future, where such devices might be developed some day.

Time travel to the past

No physical basis exists for time travel into the past. The same theory that explains moving to the future, only allows travel to the past for objects that move faster than light speed. Nemiroff and Wilson quote some scientific works that may provide loopholes for traveling to the past in very special circumstances. But these theories are highly debated in the physical world.

An important distinction between travellers to the past is also made of whether these travellers would be able to interact with the past, and therefore change it, or if they would be only passive observers. Only in the former case traces could be left of their presence.

The place to look for time travellers – the internet

Given the omnipresence of the internet today, it appears to be logical, that travellers from the future, that visit our times, could leave traces there.

One traceable clue would be, if we could find prescient content about an important event. That means the mentioning of something that only happened weeks, month or years after the entry.

It has to be an event or name that could not have been typed on the internet by chance or because something similar has already happened in the past. It also would have to be an event, that would still be known in the distant future of the time travellers origin.

The authors came up with two events that match these criteria. The first one is the discovery of the Comet ISON in September 2012. The second one is the election of Pope Francis in March 2013. Both events are likely to be remembered in the future. And for both terms “Comet ISON” and “Pope Francis” there is little reason to appear on the internet before their detection/election – unless mentioned by someone with prescient knowledge.

Looking for prescient content on Twitter

Equipped with these two terms the Nemiroff and Wilson went to look for prescient knowledge on various internet platforms. Unfortunately, they discovered that nether search engines nor social networks gave scientifically found answers to that question. Mostly due to technical imprecision or because the original date of content could not be traced. Only Twitter offered precise enough recording to allow a scientific sound experiment. So Nemiroff and Wilson searched for prescient knowledge of “Comet ISON” and the election of “Pope Francis” on Twitter.

Sadly – but not unexpected – the scientist did not detect any prescient content with their search and thus could not detect any signs of time travellers.

But as every scientist knows:

The absence of evidence is not the evidence of absence.

So time traveller could be among us, but might just not be detectable with the methods used.

Why did I write about this?

As a fan of science fiction, I find this paper highly interesting. Someone actually went through the trouble of conducting a scientific experiment to answer a question I have often been asking myself: Do time travellers exist?

From a scientists standpoint I find this paper to be a really good example of how (good) science is done. I admire the thought and methodology that was put into this research, even though many “serious” scientist might find it an unworthy topic to pursue.

You can find the original publication with a lot of additional information here: http://arxiv.org/abs/1312.7128 

What do you think about time travel?