In space, no one checks your ID (but they do on Earth)

Time warp: Stony Brook University scientists may have helped settle a great debate about the universe's actual age.
By GREGORY ZELLER //

New examinations of the universe’s “baby photos” have confirmed what some scientists suspected all along: Existence, as we know it, began 13.8 billion years ago.

That’s the word from Stony Brook University, where Associate Professor Neelima Sehgal of the Department of Physics and Astronomy has joined with a team of international researchers to shed new light on the mystery of the universe’s actual age – by studying the oldest light known to exist.

Using data from the Atacama Cosmology Telescope in Chile, researchers from 41 institutions in seven countries have essentially looked backward through time, studying images of the universe in its earliest stages – essentially, the afterglow of the Big Bang – to confirm the long-held (though recently challenged) theory that the ongoing party we commonly refer to as “existence” kicked off approximately 13.8 billion years ago.

Neelima Sehgal: Cosmic quest.

That theory stems from data collected by Planck, a space observatory operated by the European Space Agency from 2009 to 2013 that was aces at tracing cosmic microwaves and infrared frequencies back through time.

Since the ESA space probe ended its mission seven years ago, new studies have emerged suggesting Planck was wrong, and the universe is actually hundreds of millions of years younger – perhaps billions of years younger – than previously thought.

Those studies explored the movement of individual stars and whole galaxies to guesstimate the age of the universe, calculating a much quicker Hubble constant – the speed at which the universe expands from any particular point in space – to make their point.

But this newest research, funded by the National Science Foundation and published in a series of papers by several of the international astrophysicists collaborating on the Atacama effort, throws shade on that ancient-light theory – and suggests Planck was right all along.

For those keeping score: The Atacama measurements calculate a Hubble constant of 67.6 kilometers per second per megaparsec – meaning an object 1 megaparsec from Earth (about 3.26 million lightyears) is moving away from us at 67.6 kilometers per second.

The speed at which the universe expands helps scientists calculate its age; the faster the expansion, the younger the universe. The 67.6 KPS per megaparsec calculated by the Atacama teams matches, almost precisely, the 67.4 KPS per megaparsec predicted by the Planck satellite – and is far slower than the 74 KPS per megaparsec championed by those post-Planck galactic studies.

Time machine: The Atacama Cosmology Telescope in Chile, looking back through the ages.

Sehgal, who as part of the NSF-funded project led a team that analyzed radioactive echoes of the Big Bang (known as cosmic microwave background), said she and other SBU researchers are essentially “restoring the ‘baby photo’ of the universe to its original condition, eliminating the wear and tear of time and space.”

With those distortions removed, scientists can draw firmer conclusions about the earliest moments of existence. That knowledge is critical, according to Sehgal, not only for understanding the universe’s precise age, but for understanding how galaxies form, how life evolved on Earth and where it’s all headed – even offering hints as to how the universe might end, and when.

“Only by seeing this sharper ‘baby photo,’ or image of the universe, can we more fully understand how our universe was born,” the professor added.