Earth: Our tiny enclave

Some of the most active advocates for peace have been scientists. Albert Einstein, Bertrand Russell, Linus Pauling, and Albert Schweitzer were among the scientific luminaries who worked tirelessly for global harmony.

Perhaps their understanding of Earth's preciousness as the only known planet with life helped inspire their efforts. This season, when night is longest and darkest, offers ample opportunity to reflect on our place in the universe, and to share in the sense of humility that has motivated many thinkers to contemplate ways to bring unity to Earth.

Science tells us that our planet is but a minuscule - even infinitesimal - part of the universe. In Einstein's time, humanity learned that the Milky Way is but one of many galaxies that are moving away from each other in an immense, expanding universe. Today, we know that the observable universe contains hundreds of billions of galaxies, encompassing sextillions (billions of trillions) of stars. Telescopes are exploring reaches of the universe that are more than 10 billion light-years (about 60 billion trillion miles) away.

As vast as the observable universe is, the actual universe could be much bigger - maybe even infinite.

If the universe were curved, we could imagine it being finite, like the Earth's surface: Traveling in one direction would eventually return you to your starting point, as if circumnavigating the globe. When astronomers measure the shape of the universe, however, they find it to be the three-dimensional equivalent of pancake-flat. And a prairie-flat space has no natural border: It could conceivably continue forever. That would mean Earth's size relative to the universe would effectively be zero!

Our tiny enclave seems astonishingly diverse, though, brimming with multifarious forms of life. While there could be life on other planets, we haven't found any. And while astronomers have made great advances in identifying other worlds, they haven't discovered a clone of Earth yet.

Our planet is like a garden of rare orchids that we must treasure for its delicacy and beauty. As custodians of our terrestrial garden, we need to be careful to preserve its balance. That requires unified effort.

But how can we humans get together given the differences among us? Science shows us that these differences are insignificant compared with the similarities. It is estimated that fully 99.9 percent of the human genome is shared by all of us, so our differences comprise only 0.1 percent of all our genes. Men and women; people of Asian, African, Native American, European, and other ethnic backgrounds; gay and straight people - all share genetic similarities that are more than a thousand times as important as their distinctions.

When violence strikes, we are hurting those who are almost the same as us. And we are turning our backs on our roles as preservers of our precious resources.

Fortunately, parts of the world have made tremendous strides toward cooperation. After millennia of conflict, Europe is finally at peace - an achievement applauded by last year's awarding of the Nobel Peace Prize to the European Union. Even in the midst of serious economic problems, no member of the European community is talking war or advocating dictatorship. Who would be happier about that than the prize's founder, Alfred Nobel, who wanted to be remembered for his constructive endeavors rather than his development of dynamite and other destructive technologies?

How can we ensure that the next generation inherits a more peaceful, prosperous Earth? Telescopes and science kits, rather than toy guns and violent video games, can help instill a sense of wonder about the universe. And the share of our national resources devoted to science, health, and the environment should reflect a commitment to preserving and healing our planet. In the multibillion-year timeline of the universe, we are all children, and we need to share the valuable possessions of our tiny enclave in the best spirit of cooperation.