SKY_July2014.pdf

SkyandTelescope.com July 2014 19

Inf lation

A new window has opened on what made the Big Bang.

A new branch of astronomy is beginning to peer through it.

Hold your thumb up to the blue sky of day, or to the
starry sky of night. Your thumb on the sky is about the
size and shape of the history-making polarization swirls
newly discovered in the sky’s microwave background.
Scientists with the BICEP2 project in Antarctica
announced the patterns in March, to worldwide fanfare.
The swirls were long predicted by infl ation theory, which
holds that the early universe emerged from an extraor-
dinary, exponential growth spurt. The patterns are the
greatest discovery in cosmology this century. They seem
to be the super-magnifi ed, fl ash-frozen images of micro-
scopic gravitational waves, quantum fl uctuations of space-
time itself — the long-theorized graviton particles that
convey gravity — seen before a trillionth of a trillionth of
a trillionth of second in the infl ating pre-existence that
set the Big Bang going. Marveled MIT physicist Frank
Wilczek, “We’re seeing gravitons imprinted on the sky.”
One of them is a clockwise swirl a little north of the
star Achernar in Eridanus. Another left a counterclock-
wise swirl a couple of fi nger-widths at arm’s length to
the west, in the constellation Phoenix. BICEP’s map on
the next page shows more. Their discovery appears to be
the triumphant confi rmation of the infl ationary-physics
theory of what made our universe — if the other teams
now racing to confi rm the fi nd succeed, and if theorists
have not somehow been wildly misled.
A larger issue is now in play too. The discovery drags
to the forefront of science an even more radical predic-
tion that infl ation makes: that there exists a hierarchy of
at least two kinds of infi nite multiverses, thereby posing
deep paradoxes of physical infi nities. This prediction
from infl ation will be less easy to test. But BICEP’s discov-
ery opens a new branch of observational astronomy that
will at least move in that direction.

Triumphant Announcement

Not that the discovery was easy. The 47-member team

that did it, led by John M. Kovac of the Harvard-Smith-

sonian Center for Astrophysics, has been working since

2006 to measure polarization patterns in the cosmic

microwave background using a succession of instru-

ments in the high-elevation dryness of the South Pole.

After more than a year of analysis and checking, the

team announced its fi nding on March 17th at Harvard

Observatory, a mile up the street from Sky & Telescope.

THE ANNOUNCEMENT Marc Kamionkowski (left) an d BICEP

leaders Clem Pryke, Jamie Bock, Chao-Lin Kuo, and John Kovac tell the

world about fi nding their primordial treasure. Previously, the earliest

direct observation we had of events in the Big Bang was the nucleo-

synthesis of light elements dating from the fi rst few minutes. BICEP’s

gravitational waves appear to come from the fi rst 10–38 second, argu-

ably the biggest leap of observational improvement in history.

WWhat’s Next for

RICK FRIEDMAN

Cosmo ogyl

ALAN MacROBERT