We are going through interesting but uncertain times. Some call this the post-truth era, where debates are largely focused on appeals to emotions rather than factual realities. As the author Ralph Keyes has written, “At one time we had truth and lies. Now we have truth, lies, and statements that may not be true but we consider too benign to call false.”

A recent example of such statements that went viral in India was when the Science Channel, sponsored by Discovery Communications, released a two-and-a-half-minute video on December 11, 2017, on the Ram Setu, the shallow water coral formation in the Bay of Bengal, off the coast of Rameswaram. Some sections of the media circulated this as fresh evidence posited by a group of “American scientists” to support the theory that a rock formation within the Palk Bay is actually the bridge that Lord Ram and his army built to reach Sri Lanka as described in the Ramayana.

The political class lapped this up ignoring the fact that the video was only a promo for an upcoming series called ‘What on Earth’, which seeks to discuss the images of some attention-grabbing surficial structures as captured by satellites.

The video shows some unsurprising satellite images of a “chain of submerged objects running between India and Sri Lanka” about “30 miles long”. Other than the comments from a person who seems to be the anchor, the video also contains some comments from experts. Alan Lester, a lecturer in geological sciences from the University of Colorado, Boulder, talks about the story of Lord Ram placing a sea bridge to reach Sri Lanka. Then, Erin Argyilan, an associate professor in the geosciences department of Indiana University Northwest talks about the presence of a carbonate shoal – bright, light blue waters in a carbonate environment indicative of shallow waters between India and Sri Lanka.The third expert, Chelsea Rose, “an adjunct faculty member” from Southern Oregon University, is a historical archaeologist who says that the rocks have been dated to be 7,000 years old and that these are lying over a sand substratum that has been estimated to be 4,000 years old. However, it’s not clear from the commentary what the dating methods and their error margins were.

Rose also says that the question of how these loose blocks of rock reached their current resting place is a mystery. At which point Lester is shown again saying that the stones have “come from afar”. The commentator takes over and says, “What makes the image especially intriguing is that the rocks are in an area in the sea mentioned in an ancient Hindu poem that also refers to it as a magic bridge.” This wraps up the promo video.

The panel of scientists that participate in a story may be experts in their own areas but they may not be specifically conducting scientific research on the topic of discussion itself – as Erin Argyilan admitted to this author in an email. She further stated in her response that the show is not intended to reach a definitive conclusion on the science but only aims to present it in an intriguing way. None of the experts featured in the video makes any claim on the Ram Setu as a human construct nor does this video cite any published scientific results. The validity of any result can only be evaluated through rigorous peer review. However, what has been presented in the video has no scientific content and therefore no conclusion can be drawn on the origin of the Ram Setu based on the commentaries and visuals in it.

Sethusamundram, a national marine biosphere reserve that needs to be preserved, is part of an ocean that is being constantly bridged by natural sedimentation processes; nature has been at it for millions of years, developing coral platforms. During the peak glaciation interval 22,000 years ago, long stretches of the Indian coast, including parts of Sethusamundram, were exposed (above water).

Some studies have shown that a more recent episode of sea-level drop occurred between 1,200 and 700 years ago – during an interval called the ‘Little Ice Age’. As the sea level rose in pulses since, the coral polyps could once again grow higher on the newly submerged platforms. There is nothing surprising about finding coral boulders dated to be 7,000 and 4,000 years old and older rocks sitting over the younger in an environment as dynamic as the Ram Setu.

Such shallow sea platforms may have been used by different generations of human migrants to cross over the oceans in the distant past. The claim about rocks having been transported from somewhere else need not necessarily be due to human intervention. It is possible that the rocks were transported by cyclones, which are rather frequent in that area, not to speak of infrequent tsunamis as well. A severe cyclone that occurred on December 23, 1964, is a case in point. The storm surge not only washed away Dhanushkodi Island but transported material, including coral boulders, and redeposited them elsewhere.

Another violent cyclone happened in 1,480 CE, which reportedly eroded the central part of the isthmus. It may not be difficult to numerically model the transportation trajectories of coral boulders. It is also worth noting that the Ramayana, thought to have been written sometime between 200 BCE and 300 CE, is itself a mixture of reality, myth and fantasy, as commented by the historian Upinder Singh in her book Political Violence in Ancient India (2017) – “with the latter two increasingly taking over as the story’s locale moves southward”.

The public hears what it wants to hear, and people get their news mostly from sources whose bias they agree with. As Kathleen Higgins, of the University of Texas, Austin, wrote in an article in Nature, “The irony is that politicians who benefit from post-truth tendencies rely on truth, too, but not because they adhere to it. They depend on most people’s good-natured tendency to trust that others are telling the truth, at least the vast majority of the time.”

For scientists, the idea of post-truth should be abhorrent, and they should keep repeating the truth under any circumstances, never forgetting the transformative power of science. Scientists have the added responsibility to stress the role of critical thinking, sustained inquiry and the revision of beliefs on the basis of evidence – the virtues enshrined in our constitution. For a growing society, it is retrogressive to live in a state of constant denial of the real.

C.P. Rajendran is a professor of geodynamics in Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru.