  If life on Earth had to achieve n 'hard steps' to reach humanity's level,
then the chance of this event rose as time to the n-th power. Integrating this
over habitable star formation and planet lifetime distributions predicts >99%
of advanced life appears after today, unless n<3 and max planet duration
<50Gyr. That is, we seem early. We offer this explanation: a deadline is set by
'loud' aliens who are born according to a hard steps power law, expand at a
common rate, change their volumes' appearances, and prevent advanced life like
us from appearing in their volumes. 'Quiet' aliens, in contrast, are much
harder to see. We fit this three-parameter model of loud aliens to data: 1)
birth power from the number of hard steps seen in Earth history, 2) birth
constant by assuming a inform distribution over our rank among loud alien birth
dates, and 3) expansion speed from our not seeing alien volumes in our sky. We
estimate that loud alien civilizations now control 40-50% of universe volume,
each will later control ~10^5 - 3x10^7 galaxies, and we could meet them in
~200Myr - 2Gyr. If loud aliens arise from quiet ones, a depressingly low
transition chance (~10^-4) is required to expect that even one other quiet
alien civilization has ever been active in our galaxy. Which seems bad news for
SETI. But perhaps alien volume appearances are subtle, and their expansion
speed lower, in which case we predict many long circular arcs to find in our
sky.
