A Cosmic Sonogram
- The Big Bang began with a burst of near-exponential expansion:
cosmic inflation
- Quantum mechanical fluctuations in energy made ripples in the gas
- Fluctuations in radiation == Sound waves! Light as sound?!
- Inflation produces scale-free perturbations leading to
1/f noise.
- Cosmic redshift: Doppler shift in an expanding universe.
-
Hear how the fluctuations sounded a few seconds
after the Big Bang.
Cosmic fluctuations can be separated from emission from our galaxy by
their different spectral dependence. See the WMAP false-color maps
with the dipole due to solar system motion and
transformed to a frame where the dipole is removed. In these maps, CMB emission
is gray-scale; foreground emissions are red. The CMB emission map is a sonogram
showing the imprint of inflationary fluctuations 379,000 years after the Big Bang.