Starry Messenger summary

Cosmos is a big word. It encompasses every particle of matter in the universe – a vast number of galaxies in a system measuring ten billion light years in diameter. To look at life on Earth through that lens – call it the cosmic perspective – is a mind-boggling proposition. So let’s start a little smaller. We’ll come back to the stars. First, let’s rewind some 30,000 years.

Imagine a group of our distant, cave-dwelling ancestors huddled around a fire. Their “universe” is tiny. Their mental map encompasses no more than a dozen or so square miles around that cave. Beyond those frontiers lies the great unknown. Some may picture it as a vast nothingness; others see nothing but danger and death when they contemplate it. 

One day, a couple of intrepid cave dwellers consult their elders. They want to see what lies beyond. The elders are wise – you don’t live long enough to become an elder without accumulating a little wisdom, after all. They weigh the matter, and ponder the risks and rewards. No, they say – there are more pressing issues. Exploration can wait. And so the group remains in its cave, working out its cave problems. 

Now imagine the same scene playing out in a second cave. This time, however, the would-be pioneers win the argument. Perhaps these elders have greater foresight – or maybe they’re just less risk-averse. Either way, their go-ahead changes everything. 

Sometimes, you have to leave the cave to solve your cave problems. There’s danger and death in the great unknown. But it also holds the promise of plants that cure sickness and useful materials to fashion new tools – and of new sources of food and water and shelter. Most important of all, though, there are new ways of thinking to be discovered. That’s an idea dear to many scientists, but it’s also a deeply human idea. As the American poet T. S. Eliot put it: 

We shall not cease from exploration

And the end of all our exploring

Will be to arrive where we started

And know the place for the first time. 

In other words, exploration is as much about the journey as it is about the destination. When we strike out, we don’t just discover new worlds – we also learn to look at the world we already know in new ways. That, Neil deGrasse Tyson argues, is the cosmic perspective. To take that perspective is to widen our frames of reference. To recontextualize familiar ideas. To see the place from which we started in striking new ways. And it changes everything.