the size of the universe -- 4/18/18
Today's selection -- from The Accidental Universe by Alan Lightman. The universe is almost inestimably large:
"[With every increase in our ability to understand and measure it], the cosmos has gotten larger and larger. At each new level of distance and scale, we have had to contend with a different conception of the world that we live in.
"The prize for exploring the greatest distance in space goes to a man named Garth Illingworth, who works in a ten-by-fifteen-foot office at the University of California at Santa Cruz. Professor Illingworth studies galaxies so distant that their light has traveled though space for more than thirteen billion years to get from there to here. You can hardly turn around in his office. It is cramped with several tables and chairs, bookshelves, computers, scattered papers, copies of Nature magazine, and a small refrigerator and microwave to fortify himself for research that can extend into the wee hours of the morning.
"Like most professional astronomers these days, Illingworth does not look directly through a telescope. He gets his images by remote control -- in his case, quite remote. The telescope he uses is the Hubble Space Telescope, which orbits the Earth once every ninety-seven minutes, high above the distorting effects of the Earth's atmosphere. Hubble takes digital photographs of galaxies and radios these images to other orbiting satellites, which relay them to a network of earthbound antennae; these, in turn, send their signals to the Goddard Space Flight Center in Greenbelt, Maryland. From there the data are uploaded to a special website that Illingworth can access from a computer in his office.
|UDFj-39546284 appears as a faint red blob|
"The most distant galaxy Illingworth has seen so far goes by the name of UDFj-39546284, documented in early 2011. This galaxy is about 100,000,000,000,000,000,000,000 miles away from Earth, give or take. It
appears as a faint red blob against the speckled night of the distant universe -- red because the light has been stretched to longer and longer wavelengths as it makes its lonely journey through space for billions of years. The actual color of the galaxy is blue, the color of young, hot stars, and it is twenty times smaller than our galaxy, the Milky Way. UDFj-39546284 was one of the first galaxies to form in the universe.
" 'That little red dot is hellishly far away,' Professor Illingworth told me recently. At the age of sixty-five, Illingworth is a friendly bear of a man, with a ruddy complexion, a thick mane of strawberry-blond hair, wire-rimmed glasses, and a broad smile. 'I sometimes think to myself: What would it be like to be out there, looking around?' "