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In a Big Year for Telescopes, Much Peering Into Wallets
"He would be knocked speechless," said Owen Gingerich, eminent astronomer and sometime historian, wandering the astronomy meeting last week with a facsimile of Galileo's first astronomical treatise.
"He would be in shock," Marvel said, "and he would want telescope time -- now."
Far From Perfect
Galileo's first instrument magnified objects about eight times their original size, Gingerich said. Galileo first looked at the moon. The ancient philosophers had seen the moon, sun, planets and stars as immaculate objects that circled the corrupt, filthy Earth, which was like the Dumpster of creation. But Galileo saw that the moon, far from being a perfect, crystalline sphere, had surface features. It had mountains and craters. It was a world.
With improved telescopes Galileo saw the phases of Venus, sunspots and then, most dramatically, four moons orbiting Jupiter. When he aimed his instrument at the Milky Way, he saw that it was full of "many, many stars" (the latest count is about 100 billion).
Galileo didn't invent the telescope -- history gives credit to the Dutchman Hans Lipperhey, among others -- and he may not even have been the first person to look at the night sky with one. An Englishman, Thomas Harriott, looked at the moon in the summer of 1609 and made some drawings of what he saw. But Galileo published his findings. Most important, he grasped the powerful philosophical implications of what he saw.
Galileo's observations validated the theory of Nicolaus Copernicus, who had died in 1543. The Copernican model featured the bewildering notion that Earth, which is seemingly stationary, is in fact spinning. And it declared that Earth isn't the center of the universe. The Vatican prohibited Galileo from teaching the Copernican model, but he hammered away, and ultimately faced charges of heresy.
Though spared a death sentence, he was forced to renounce his teachings and spent the remainder of his life under house arrest.
A Heavenly Database
Galileo had the ultimate ally in the universe itself, which revealed new wonders with each incremental improvement of the telescope.
The night sky is essentially a database, crammed with information in the form of electromagnetic radiation, known more generically as light. You can't obtain all that information with a single telescope because light exists at different wavelengths. Our eyes are of a size adapted to capturing what is, by definition, the visible part of the spectrum, but if we had giant heads with eyeballs hundreds of feet in diameter, we'd see radio waves.
Astronomers seeking to solve a cosmic mystery have to decide which kind of eyes they need. For example, to probe the mysteries of the center of the galaxy -- home to a black hole with the mass of a million suns -- they use infrared telescopes, because the infrared light can pass through the dust clouds that obscure the galactic center.
One of the big questions that the Webb telescope will address is the chicken-and-egg problem regarding black holes at the center of galaxies. It's unclear what came first. A report last week, based on observations of extremely distant galaxies formed early in the history of the universe, suggested that black holes came first, acting like galactic seeds.
An even more basic question is: How big is the universe? Theorists grapple with the possibility that the mind-boggling cosmos we see is but a tiny bubble in a much larger (beyond mind-boggling, into mind-blowing territory) multiverse.