The Bright Universe Below

IMG_1898Astronomers bemoan the amount of light produced by cities and suburbs at night. The bright glow from below interferes with their ability to see the stars above.

I saw a good example of the “light pollution” as I flew into Newark on a clear night earlier this week. Ironically, the light from the houses, parking lots, and shopping centers on the ground reminded me of the stars and constellations of the evening sky.

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Unimaginably Distant, Unimaginably Old

The space-based telescopes keep making amazing discoveries.  The latest is the Hubble space telescope’s identification of the most distant galaxy ever detected — a galaxy that is more than 13 billion light years distant from Earth.  That means that the light we are seeing now has traveled for 13 billion years to reach our space.  In fact, the light we are seeing from that galaxy emanates from stars that blazed only 600 million years after the Big Bang.  Those stars almost certainly exist no longer, having long ago gone supernova or turned into one of the other stellar objects that are created when stars die.  In that sense, the Hubble telescope is a real-life time machine that allows us to peer into the distant past.

The Hubble space telescope

Astronomers will study the new discovery with great interest, because it may help to provide answers to some very provocative questions.  What was the life cycle of early stars, whose intense heat produced the heavy element “star stuff” (to use Carl Sagan’s phrase) of which our universe is made?  How did the earliest galaxies form?  Why is light from such galaxies visible through the “fog” of hydrogen that should have resulted from the Big Bang?

We can expect more amazing discoveries along these lines as new ground-based and space-based telescopes using new technology come on line and begin to probe the heavens.