Reconstructing the Big Bang: A 'Baby Photo' of the Universe

March 16, 2013— -- Europe's "Planck" research satellite has measured the residual radiation from the big bang with greater precision than ever before. The goal of the mission is to solve the mystery of whether the universe truly arose out of nothing.

In the beginning there was energy. When the universe was born 13.7 billion years ago, the temperature was in the quintillions of degrees. But the more space expanded, the weaker the fire of creation became.

Soon afterwards, the young, expanding universe entered a critical phase: The red-hot primeval soup had cooled sufficiently so that some of its energy was converted into matter. Over time, galaxies, suns, planets and, finally, animals and human beings emerged from these myriads of original atoms.

The rest of the original radiation no longer played a particularly important role in the development of the cosmos, and has wafted through the vast expanses of the universe ever since -- a sort of echo of the distant boom of creation as it continues to cool. To this day, every cubic meter of space contains about 400 of the original protons. Without them, it would be colder in space than it already is -- by 3 degrees Celsius, or about 5 degrees Fahrenheit.

Astrophysicists stumbled upon the light from the dawn of time in the 1960s. With the help of their radio telescopes, they discovered background radiation in the microwave range, which was being received uniformly from all directions.

Now, half a century later, astronomers have measured this residual radiation from the big bang more precisely than ever before. To do so, they used the European Space Agency's "Planck" research satellite, which was launched into outer space with an Ariane rocket in 2009. Using the data gathered by Planck, scientists have compiled a temperature map of cosmic background radiation, which resembles a colorful pattern of dots.

"It's like a baby photo of the universe," says Torsten Ensslin of the Max Planck Institute for Astrophysics in Garching, near Munich. "It's supposed to reveal to us how the big bang actually unfolded."

'Earliest Structures of the Universe'

The scientists at the institute have been performing their calculations since the space telescope completed its measurements a year ago, and cosmologists are now anxiously awaiting the analysis of the Planck satellite data. The European Space Agency (ESA) plans to unveil the results next week. But no matter what they look like, interpreting the image of the delivery room of the cosmos will probably keep astrophysicists busy for years to come.

What is so fascinating for astrophysicists seems somewhat unspectacular from a layperson's perspective. On the face of things, they are looking at almost immeasurably tiny temperature differences. That's because although background radiation comes from everywhere, it isn't always the same. In some places, the residual radiation from the big bang is a few millionths of a degree warmer, and in others a few millionths of a degree cooler.

These temperature fluctuations make up the difference between empty space and galaxies.