On July 8 President Donald Trump stood in the East Room of the White House and delivered a speech celebrating his administration's environmental leadership. Flanked by his Secretary of the Interior David Bernhardt, a former oil and gas lobbyist, and EPA head Andrew Wheeler, a former coal lobbyist, Trump extolled his team's stewardship of public lands, its efforts to ensure “the cleanest air and cleanest water,” and its success in reducing carbon emissions. In reality, Trump has opened up millions of acres to drilling and mining and sought to reverse multiple air- and water-pollution regulations. As for carbon emissions, they spiked an estimated 3.4 percent last year, and this administration is withdrawing the U.S. from the Paris climate change agreement that nearly every other nation on the planet is participating in.

The speech was surreal but apparently strategic: It came on the heels of polls showing that Americans are growing increasingly worried about the environment. It remains to be seen whether Trump will sway environmentally concerned voters by using false claims, but clearly his team thinks that's a possibility. Truly we live in interesting times. How did we get here, and how do we get out?

In this special issue of Scientific American, we set out to explore how it is that we can all live in the same universe yet see reality so differently. Basic science illuminates the deep roots of this phenomenon. Even in physics and mathematics, truth is not entirely clear-cut. And mounting evidence from neuroscience indicates that our perceptions are not direct representations of the external world. Rather our brains--each one unique--make guesses about reality based on the sensory signals they receive.

Still, there can be no doubt that factors specific to our modern era are exacerbating our collective unmooring--technological developments that abet the warping of truth and the normalization of lies. Social media amplifies toxic misinformation on an unprecedented scale. Cyberattacks on election machinery and voter-registration systems threaten not only election outcomes but democracy itself.

Uncertainty in the world makes us all the more susceptible to such campaigns. But it’s not all doom and gloom. By understanding how we instinctively deal with unknowns and how bad actors exploit the information ecosystem, we can mount defenses against weaponized narratives--and build mutual understanding to solve society’s most pressing challenges.

—Seth Fletcher, Jen Schwartz and Kate Wong, Issue Editors
Video animations by Red Nose Studio