We are all made of stardust

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First aired on Quirks & Quarks (22/9/12)


Each and every one of us is made of stardust. This isn't a silly romantic metaphor or childhood whimsy: it's scientifically so. Every proton and neutron, every atom and molecule in our bodies was created in the Big Bang. These molecules formed stars and these stars created more complicated molecules and, yes, even stardust. This stardust would eventually become the Earth and everything that calls the Earth home. Canadian science writer Jacob Berkowitz examines this origin story -- and the implications it has for chemistry and biology -- in his new book, The Stardust Revolution: The New Story of Our Origin in the Stars.

Scientists as far back as Isaac Newton have drawn connections between the cosmos and our planet, but it wasn't until Robert Bunsen (the developer of the Bunsen burner) and his colleague Gustav Kirchhoff that major developments took place. Bunsen, like many chemists at the time, was trying to fill in the gaps in the periodic table of elements. He tried burning substances to see what colour of flame they produced. Kirchhoff insisted that they look not at the flame's colour, but at the spectrum of the light around it. "Then there's a full rainbow of light and you're going to see variations, dark bands in the rainbow, some brighter than others," Berkowitz explained to Quirks & Quarks host Bob McDonald. This method of identifying elements was successful, and the science of spectroscopy (the study of the interaction between matter and energy) was born.


It was Kirchhoff who had the idea of applying this new science to the study of the stars -- and it worked. "This was the mind-blowing thing," Berkowitz said. "They realized by looking from Earth at the spectrum of the star, they could actually identify what the star was made of." This was an astonishing development at the time. Even just a few years previously, scientists and astronomers had considered that this would be an impossible task. Bunsen and Kirchhoff's discovery had ramifications for understanding the Earth as well. The earliest stellar spectroscopists began using this technique and came to realize that the most common elements found in stars were "hydrogen, carbon, oxygen and nitrogen" -- the very same elements that make up 96 per cent of life on Earth. "We are essentially an elemental reflection of the rest of the cosmos."

The next big development in understanding the relationship between stardust and life on Earth came from Charles Townes. A physicist, Nobel laureate and the inventor of the laser, Townes wanted to figure out what matter -- if any -- existed between stars. His colleagues believed there was nothing, that space was a vacuum and was "too harsh an environment" for molecules to survive. Townes ignored them, began conducting research and made a surprising discovery. Near the Orion nebula, Townes found water. Lots of it. "More than that would fill the Earth's oceans 50 times over a year, being produced in the same environment that stars are being produced in," Berkowitz said.

Thanks to the work of Bunsen, Kirchhoff, Townes and dozens of other scientists, we now know that more than 140 different kinds of organic molecules exist in space, and water is the "second or third most common molecule in the universe." What does this mean for modern science? According to Berkowitz, it means a lot. We need to rethink chemistry and biology and how we understand humanity's role in and relation to the universe. "We are the descendants, and we are the emergence, of a living cosmos," Berkowitz said. "When we discover other life on another living planet, we won't be discovering really alien beings. We'll be discovering distant cosmic cousins, because we are all evolved from the same cosmic processes."

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