Humanity almost seems extraneous; some special-effects planetarium shows introduce us to the most exotic aspects of matter and time, but are not very revealing about the ordinary human experience of the heavens.

Image FOOD AND FAUNA Cricket crispy treats at the Audubon Insectarium in New Orleans. Credit... Cheryl Gerber for The New York Times

Of course, the insignificance of human existence is one of the fearsome lessons of modern science. But when we are young, we learn differently. We begin by learning to value our own understanding and only gradually come to recognize its limits. We begin by making sense of the world before we see how much lies beyond sense. The process doesn’t work well in the other direction: we can be left mystified by the world and lose respect for the human.

Something like this has started to happen in some museums. This decentering of the human can become a devaluing of the human; the museum may even begin to see human frailties as a great flaw in the cosmic order that must be repaired. So this new variety of science museum must not just display or explain. It must be relevant, useful, practical, critical  something that helps with fund-raising as well.

Right now environmentalism has become the dominant theme for this kind of museum. The California Academy of Sciences, a research institution in San Francisco, conceived of its new 409,000-square-foot building, which opened in 2008 with a design by Renzo Piano, as a declaration of environmental sensitivity, making it metaphorically green in its use of resources and literally green with an undulating sod-covered rooftop. Its major rainforest exhibition emphasizes ecological frailty. Another exhibition urges visitors to change eating habits and “make a pledge” to alleviate the “climate crisis.” Little new science is learned here, but many arguments are taught. But a Foucault pendulum on display in a spare spot  once a major feature of science museums, with its demonstration of earth’s rotation  seems as irrelevant to the academy’s current purpose as its fossil collection.

Leaping into the same fray, an exhibit on climate change in 2008 at the American Museum of Natural History seemed so intent on urging consciousness change that it became uncharacteristically sloppy. Data was used selectively, and a scary model showing southern Manhattan smothered by a five-meter rise in sea level turned out to be  if you read the label  something that “experts consider unlikely anytime soon” but could take place “thousands of years in the future.” Issues about assessing probabilities or the cost of technologies were left unexplored in order to cultivate apocalyptic fears.

This model of advocacy has even become explicit at the Liberty Science Center in New Jersey, where its president, Emlyn Koster, has stressed his wish for “relevancy” and an interest in developing “social and environmental responsibility.” The flaws in the natural order remain precisely the same. Humans, we learn in various exhibitions, “pose the greatest danger” to certain creatures, “damage” the climate and are in turn threatened by disaster and pandemic. Humanity isn’t only decentered; it is decentering.