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closer to home. The distances to the nearby stars were known, and their brightness varies only with their distance. By applying the inverse-square law for the brightness of starlight, Hubble derived a distance to the star in Andromeda, placing the nebula far beyond any known star within our own stellar system. Andromeda was actually an entire galaxy, whose fuzz could be resolved into billions of stars, all situated more than 2 million light-years away. Not only were we not in the center of things, but overnight our entire Milky Way galaxy, the last measure of our self-worth, shrank to an insignificant smudge in a multibillion-smudge universe that was vastly larger than anyone had previously imagined.
     
     
    ALTHOUGH THE MILKY WAY turned out to be only one of countless galaxies, couldn’t we still be at the center of the universe? Just six years after Hubble demoted us, he pooled all the available data on the motions of galaxies. Turns out that nearly all of them recede from the Milky Way, at velocities directly proportional to their distances from us.
    Finally we were in the middle of something big: the universe was expanding, and we were its center.
    No, we weren’t going to be fooled again. Just because it looks as if we’re in the center of the cosmos doesn’t mean we are. As a matter of fact, a theory of the universe had been waiting in the wings since 1916, when Albert Einstein published his paper on general relativity—the modern theory of gravity. In Einstein’s universe, the fabric of space and time warps in the presence of mass. This warping, and the movement of objects in response to it, is what we interpret as the force of gravity. When applied to the cosmos, general relativity allows the space of the universe to expand, carrying its constituent galaxies along for the ride.
    A remarkable consequence of this new reality is that the universe looks to all observers in every galaxy as though it expands around them. It’s the ultimate illusion of self-importance, where nature fools not only sentient human beings on Earth, but all life-forms that have ever lived in all of space and time.
    But surely there is only one cosmos—the one where we live in happy delusion. At the moment, cosmologists have no evidence for more than one universe. But if you extend several well-tested laws of physics to their extremes (or beyond), you can describe the small, dense, hot birth of the universe as a seething foam of tangled space-time that is prone to quantum fluctuations, any one of which could spawn an entire universe of its own. In this gnarly cosmos we might occupy just one universe in a “multiverse” that encompasses countless other universes popping in and out of existence. The idea relegates us to an embarrassingly smaller part of the whole than we ever imagined. What would Pope Paul III think?
     
     
    OUR PLIGHT PERSISTS , but on ever larger scales. Hubble summarized the issues in his 1936 work Realm of the Nebulae , but these words could apply at all stages of our endarkenment:
Thus the explorations of space end on a note of uncertainty…. We know our immediate neighborhood rather intimately. With increasing distance our knowledge fades, and fades rapidly. Eventually, we reach the dim boundary—the utmost limits of our telescopes. There, we measure shadows, and we search among ghostly errors of measurement for landmarks that are scarcely more substantial. (p. 201)
     
    What are the lessons to be learned from this journey of the mind? That humans are emotionally fragile, perennially gullible, hopelessly ignorant masters of an insignificantly small speck in the cosmos.
    Have a nice day.

FOUR
     

THE INFORMATION TRAP
     
    M ost people assume that the more information you have about something, the better you understand it.
    Up to a point, that’s usually true. When you look at this page from across the room, you can see it’s in a book, but you probably can’t make out the words. Get close enough, and you’ll