  The CMB has distinct peaks in both its temperature angular power spectrum
(TT) and temperature-polarization cross-power spectrum (TE). From the WMAP data
we find the first peak in the temperature spectrum at l = 220.1 +- 0.8 with an
amplitude of 74.7 +- 0.5 microK; the first trough at l = 411.7 +- 3.5 with an
amplitude of 41.0 +- 0.5 microK; and the second peak at l = 546 +- 10 with an
amplitude of 48.8 +- 0.9 microK. The TE spectrum has an antipeak at l = 137 +-
9 with a cross-power of -35 +- 9 microK^2, and a peak at l = 329 +- 19 with
cross-power 105 +- 18 microK^2. All uncertainties are 1 sigma and include
calibration and beam errors. An intuition for how the data determine the
cosmological parameters may be gained by limiting one's attention to a subset
of parameters and their effects on the peak characteristics. We interpret the
peaks in the context of a flat adiabatic LambdaCDM model with the goal of
showing how the cosmic baryon density, Omega_b h^2, matter density, Omega_m
h^2, scalar index, n_s, and age of the universe are encoded in their positions
and amplitudes. To this end, we introduce a new scaling relation for the TE
antipeak-to-peak amplitude ratio and recompute known related scaling relations
for the TT spectrum in light of the WMAP data. From the scaling relations, we
show that WMAP's tight bound on Omega_b h^2 is intimately linked to its robust
detection of the first and second peaks of the TT spectrum.
