Quasars

During the 1950’s, astronomers using the first radio telescopes started discovering a mysterious class of heavenly objects.  Certain discreet points in the sky blazed brightly with low-frequency electromagnetic radiation–yet when the scientists looked at the spots through conventional optic telescopes, it was impossible to discover a source for this energy.  Some of these radio flares came from incredibly faint smudges and some issued from what seemed like empty space. Astronomers called the mystery flares “quasi-stellar radio sources” (QUASAR) because they believed such discreetly focused energy must come from stellar-like objects.  Further study revealed that the photons issuing from quasars were red-shifted, which meant that the quasars were rushing away from the solar system at high velocities.

An Artist's interpretation of a Quasar

Only in the 60’s did optical telescopes become powerful enough to associate certain quasars with the cores of extremely distant galaxies.  The reason no luminous objects were initially associated with quasars was because quasars turned out to be profoundly distant—the closest were billions of light years away.  They were visible to early radio telescopes only because of their immense energy output and their beam-like focus.

An X-ray image shows the quasar PKS 1127-145 (credit: NASA)

Scientific consensus concerning these massive energy flares did not fully coalesce until the 1980s.  Today astronomers believe that quasars are powered by accretion of material into super-massive black holes which lie at the center of dynamic young galaxies.  Such phenomena are called “active galactic nuclei” (AGN). As radio telescopes and time-space modeling grew more sophisticated it became obvious that quasars (which produce low-frequency radiation) were not the only energy flares associated with AGN.  Giant beams of different spectrums of electromagnetic radiation are possible depending on the galaxy.  Quasars and their ilk produce incomprehensible amounts of energy—the most luminous active galactic nuclei radiate exotic energy at a rate that can exceed the output of an average galaxy by a thousand times (equivalent to the energy from two trillion suns).  To produce such energy the brightest known quasars consume roughly 1000 solar masses of matter within an earth year (which is equivalent to swallowing/burning 600 Earths per minute).

Yikes

Galaxies change as they age. Today the Milky Way Galaxy is a mostly responsible middle aged galaxy (which only occasionally cuts lose with something crazy like the luminous blue hypergiant Eta Carinae) however there are reasons to think that in the past the Milky Way was a deeply troubled teen-aged galaxy ablaze with self-destructive fury just like the AGN galaxies we see at the far edges of space.  Assuming they exist, alien astronomers in galaxies billions of light years away probably see our galaxy as a blazing quasar–because they are looking at its distant violent past.

Active Galaxies Collide (painting by Don Dixon for "Scientific American")

Of course galaxies are not always quiescent.  Some astrophysicists theorize that in 3 to 5 billion years, when the Andromeda Galaxy collides with the Milky Way, the black holes in the center of one or both galaxies could begin swallowing up matter (or could merge) reigniting a super bright fountain of high energy particles again visible throughout the universe.

FAST

An artist's conception of how the under-construction Shanghai Tower will look next to the Jin Mao Tower and the Shanghai World Financial Center

I have written a post about non-human builders, unknown builders, and ambitious (but not-entirely-successful) builders.  What about the great builders of the present?  Sadly the west is moribund right now, suffering not just from the housing-bust hangover but from crooked financiers, incompetent politicians, social stalemate, and a dearth of ideas. This situation is probably not permanent but it makes me disinclined to write about the shabby projects going up right now. I suppose I could write about the monstrous white elephant skyscrapers of Dubai, that autocratic dystopia in a desert, or describe the towers of Singapore, the hard-headed, hard-hearted city state.  But not only do I not admire those societies, they are a side show on the world stage (and a tiny sideshow at that). Right now all eyes are on China.  The Middle Kingdom is sucking up the world’s energy resources and every sort of raw material at exponential rates. In return, cities are going up where no cities existed before.  China is rolling out roads, airports, and railroads at a rate never before seen.  An agricultural nation is turning into an urban one. And China’s greatest cities are becoming the great cities of earth, morphing overnight into forests of mega skyscrapers.

But that is not the subject of this post either.  The real question about China’s rise is whether the nation will be able to harness its wealth to become a titan in scientific and technological fields the same way it is dominating manufacturing. Part of the answer to that question can be found in Guizhou province in southern China where a massive bowl shape is rising from the hills. This is the initial superstructure for the five-hundred-meter (546-yard) Aperture Spherical radio Telescope (FAST) which is due to open in 2016. FAST will then supplant the Arecibo radio telescope in Puerto Rico (which was built in 1963) as the largest single-aperture telescope ever constructed. To quote ElectronicsWeekly.com:

When completed, its 500-metre diameter single dish will make it the largest and most sensitive radio telescope in the world. What’s more, although FAST’s dish will be fixed in its crater-like setting, a series of large motors will be able to change the shape of its reflective surface, allowing it to scan large swathes of the sky. FAST will be able to peer three times further into the universe than Arecibo. Astronomers expect it to uncover thousands of new galaxies and deep-sky objects up to 7 billion light years away.

FAST will be the planet’s eye into deep space (and just, in time: Arecibo’s budget is on the chopping block as congress pares away scientific funding).  The remote location is unusually free of radio interference and the natural bowl-shaped valley it is located in should help amplify its utility. According to National Astronomical Observatories at the Chinese Academy of Sciences, the telescope will be available to international astronomy researchers.

How the The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project will look when complete