A MEETING WITH THE UNIVERSE
Chapter 4-1
New Windows in the Sky
Astronomy has undergone a
tremendous burst of discovery
thanks to our new ability to study
the universe through "windows"
available to telescopes flown above
the Earth's atmosphere. We are observing
radiation that never reaches
the ground: X-rays, gamma rays, ultra
violet, and infrared light. Each new
telescope in space brings the universe
into clearer focus and reveals objects
and phenomena not even imagined
when the telescopes were planned. We
are seeing further than before, with
greater sensitivity, and at wavelengths
of light that are utterly invisible
to observatories on the ground.
Observing this heretofore unseen
radiation, we are exploring what
amounts almost to a new universe.
X-rays and gamma rays from matter
heated to millions of degrees tell us
of violent explosions both in our own
galactic neighborhood and as far away
as the edge of the known universe.
At the other extreme, infrared telescopes
discern clouds of dust in interstellar
space whose temperatures are
scarcely 50 degrees above absolute
zero (-273° C). We have found places in
our own galaxy where enough matter
to make a planet apparently disappears
into a black hole each day, and
there are far-off galaxies where more
ravenous black holes may consume
whole suns every day. At the very edge
of the observable universe is a wall of
frozen fire, the remnant of the Big
Bang of creation, which appears to us
as a whisper of radiation just a few
degrees above absolute zero. No light
from behind that wall can ever reach
us, but the wrinkles in the wall remain
to tell us the very details of
creation itself, if we are clever enough
to understand them.
