Martin Rees, United Kingdom's Astronomer Royal, gave a gripping presentation about the possibilities of space travel, interplanetary exploration, extraterrestrial life, and humankind's troubled stewardship of the Earth at the sixth annual Foundation Forum.
"We are the stewards of a precious, pale-blue dot," Rees said during his remarks on Friday afternoon, referring to the Earth as it looks from space.
Any one of the topics mentioned in Rees's talk would be worthy of an all-semester, in-depth astronomy class at UCSC. But his presentation, "A Cosmic Perspective on the 21st Century," was meant to be taken as an overview and an appetizer for stargazers, designed to stimulate curiosity and invite deeper exploration.
Self-effacing humor decreased the intimidation factor, and so did the accessible graphics, which sometimes elicited gasps from the audience, including an extremely sped-up simulation of galaxies colliding, with pyrotechnic results.
Addressing the audience at the UCSC Music Recital Hall on Friday, Rees, the United Kingdom's Astronomer Royal, made his speech feel close, informal, and intimate, as if he was standing among friends.
Indeed, it was a kind of homecoming for Rees; along with Chancellor George Blumenthal, who is a renowned astrophysicist, and UCSC professors Sandra Faber and Joel Primack, Rees developed the "Cold dark matter" theory of galaxy formation in 1984.
That evening, during the Founders Celebration Dinner at the Cocoanut Grove in Santa Cruz, Rees was presented with UCSC's Foundation Medal, along with co-honorees Gordon and Betty Moore, founders of the philanthropic Gordon and Betty Moore Foundation.
While astronomers grapple with vast stretches of time, Rees said that they are also human, and so they fret as much as anyone about what happens next week.
Most astronomers take no stock in those who consider humans "the culmination of the evolutionary tree," he said. "This hardly seems credible … Any creatures witnessing the sun’s demise 6 billion years from now will not be human."
But humans, at least for the time being, are the apex species on this planet, at least when it comes to deciding the fate of other creatures, he said.
"This is the first century in which one species—ours—has had the Earth's future in its hands, and the stakes are getting higher."
The possibility of thermonuclear destruction is just one concern among many. He also spoke of more insidious troubles including unsustainable pressures on natural resources, and the far-ranging human footprint, which can tear out entire pages from the book of life "before anybody reads it."
By 2050, he said, the planet will have between 8.5 billion and 10 billion people, with most of the growth in the developing world. Even now, humans use up 40 percent of the Earth's biomass.
Untenable problems such as human-influenced global warming are difficult to address because of "next day" pressures on politicians who are concerned about short-term results, including the next election, and stockholders, who want their investments to pay off. "Can our sympathies become more international and more long-term?" he asked.
As an example of this possibility, he spoke of a 900-year-old cathedral he loves to visit in England. Most of its builders never traveled more than 50 miles in their lifetime, and had lives of deprivation.
The original builders did not live long enough to see the structure's completion, and yet they labored to produce something that elevated spirits nearly a millennium later, he said
Rees said that no one expects "any very exciting life" in our solar system. "The prospects are much more exciting if we broaden our gaze to the realm of the stars," he said.
Many of those stars have "retinues of planets" orbiting them, and astronomers have figured out a way to detect the presence of those planets indirectly, he said. Are any of those planets occupied? It is difficult because scientists understand evolution but don't have a firm grasp of life's origins, Rees said. Was the beginning of life "a rare fluke" or something scientists would hope to find in planets with environments similar to Earth?
While Rees said there is no way of knowing for sure, he still gets letters from people who claim they have seen UFOs. “They’ve been visited.
"I tell them, if these aliens had the high-tech expertise, would they just greet a few welcoming cranks, make a few circles in cornfields, and go away again?" he said. "The second thing I tell these people is to write to each other and not write to me.
If those E.T.s actually exist out there somewhere, it is possible that "the cultural gap" would be too broad for humans to communicate with them. “The philosopher Wittgenstein famously said, ‘if I lion could speak, we couldn’t understand it’ … There’s no chance of snappy repartee, as it were.”
However, these aliens, “ even if they come from Planet Zog, and have seven tentacles,” would have to be made from the same atoms as humans are, gaze out at the same cosmos, and trace their origins to the big bang, he said.
Rees spoke with a combination of caution and enthusiasm about manned space flight. Referring to satellite technology, high-powered telescopes, and space probes, Rees said he saw no purpose of sending people into space.
Then he added an important caveat. “But as a human, I am an enthusiast of space flight.” He said hoped the time would come when people will walk around on Mars, and praised private companies that could send paying customers into space for relatively low costs.
"But I would avoid the phrase 'space tourism' because it makes it seem everyday and understates the risk," he added. "It must be sold as a dangerous sport. Don't ever expect (space) emigration. We’re kidding ourselves if we think that going into space will solve the Earth’s problems."
He pointed out that the most hospitable alternative planet in our solar system is "far less inviting" than the most barren reaches of Antarctica.
Rees has just completed eight years as Master of Trinity College, Cambridge. He has been president of the Royal Society, a fellowship of the world's most eminent scientists, and is a member of the House of Lords. For 10 years he directed the Institute of Astronomy at Cambridge. Besides his research papers on cosmology and high-energy astrophysics, he has penned numerous articles on scientific and general subjects.
The latest of his eight books is From Here to Infinity: A Vision of 21st Century Science.
Prior to Rees's speech, UCSC Chancellor George Blumenthal introduced him as a friend and colleague, as well as "a thread running through all modern astronomy." Blumenthal referred to Rees's more than 500 research papers.
"A high percentage of them have real and lasting impact," Blumenthal said. "He makes it look so easy."