  The large-scale maximum at k~0.05 identified in the power-spectrum of galaxy
fluctuations provides a co-moving scale for measuring cosmological curvature.
In shallow 3D surveys the peak is broad, but appears to be well resolved in 1D,
at ~130 Mpc (k=0.048), comprising evenly spaced peaks and troughs. Surprisingly
similar behaviour is evident at z=3 in the distribution of Lyman-break
galaxies, for which we find a 5 sigma excess of pairs separated by Delta
z=0.22pm0.02, equivalent to 85Mpc for Omega=1, increasing to 170 Mpc for
Omega=0, with a number density contrast of 30% averaged over 5 independent
fields. The combination, 3.2\Omega_m -\Omega_{\Lambda}=0.7, matches the local
scale of 130 Mpc, i.e. Omega=0.2\pm0.1 or Omega_{m}=0.4\pm0.1 for the
matter-dominated and flat models respectively, with an uncertainty given by the
width of the excess correlation. The consistency here of the flat model with
SNIa based claims is encouraging, but overshadowed by the high degree of
coherence observed in 1D compared with conventional Gaussian models of
structure formation. The appearance of this scale at high redshift and its
local prominence in the distribution of Abell clusters lends support to claims
that the high-z `spikes' represent young clusters. Finally we show that a spike
in the primordial power spectrum of delta\rho/\rho=0.3 at k=0.05 has little
effect on the CMB, except to exaggerate the first Doppler peak in flat
matter-dominated models, consistent with recent observations. \\effect on the
CMB, except to exaggerate the first Doppler peak in flat matter-dominated
models, consistent with recent observations.
