What are we? Human? Well, in the cosmic sense, we are all stardust!

By stardust, it literally means, we are made of the dust particles of stars that used to exist billion years ago.

Let me share from the very start of our root story.

Billions of years ago, when the universe was just born after the Big Bang, there existed only one element from our periodic table and that is Hydrogen. However, the stars of that time were like big furnaces that took Hydrogen as fuel and converted it into something else. For instance, those stars from billions of years ago worked as nuclear reactors and converted one-atom hydrogen into two-atom Helium, then into four-atom Carbon and later on, Nitrogen, Oxygen, and other elements were come into being, throughout millions of years. Thus, after the nuclear reactions happening one after another, stars would get heavy enough to explode in a supernova. However, the death of those stars in explosions were not their end, but the very beginning of something even more beautiful!

It is believed by a lot of astrophysicists that those heavy explosions occurred billion years ago emitted millions of sparks or residues in our galaxy and those residues or specks of dust eventually created a beautiful life form on a beautiful planet we know as Earth. Anyway, the process was not that simple.

The solar system was kind of preparing the perfect environment since the big bang for life forms to evolve. For instance, other than hydrogen and helium, many more natural elements from our current periodic table were created through a passage of millions of years of reactions. Earth pulled the space clouds in the atmosphere with its gravity and the earth’s surroundings were getting more and more convenient for the accommodation of life forms. And the space dust from the star explosions of billion years ago, combined with the recent particles flowing in the galaxy and voila! Life was created for the first time on earth. The later story is known to all about how we evolved from the first generation of life forms.

Maybe now, after this explanation, these lyrics from Joni Mitchell might make more sense!

“We are stardust, billion-year-old carbon. We are golden!”

Now, at this point, some of us might wonder how, on earth, scientists came to such an interesting conclusion that we are stardust. Actually, it is not just a groundless belief or hypothesis anymore. There have been a lot of observations based on it.

“It’s a great human-interest story that we are now able to map the abundance of all of the major elements found in the human body across hundreds of thousands of stars in our Milky Way,” Jennifer Johnson, the science team chair of the SDSS-III APOGEE survey and a professor at The Ohio State University, said in the statement. “This allows us to place constraints on when and where in our galaxy life had the required elements to evolve, a sort of ‘temporal galactic habitable zone.'”

To put into simpler words, as we know, there are thousands and millions of stars in our current galaxy and for years, scientists have been observing how those stars form, evolve, die and eventually give birth to newer elements again. Just like the current stars, our ancestral stars, the cosmic cauldrons, created two atoms of oxygen that now give us breath, twelve atoms of calcium that bind our bones, atoms of phosphorus that light up our neurons, and similarly of silicon that give form and solidity to the very earth beneath our feet.

So, in the cosmic sense, it can definitely be said that we, humans, are almost as old as the universe itself! Anyway, we are not only old but also new. Sounds confusing? Well, while most of our raw elements like Carbon, Nitrogen, Hydrogen, Oxygen, Sulphur, Phosphorus, etc. come from the ancient stardust, our human body is always evolving by accepting the newer particles of our very current universe.

For instance, our bodies are made of not only the burned-out embers of ancient stars, but also the atoms that formed only recently as ultrafast rays slammed into Earth’s atmosphere.

So, it will not be irrational to say that we have inherited billions of years of history in literally our bodies and we are also connected with the most recent cosmic events.

All of that history is not remote at all but part of us now: our human body is inseparable from nature all around us and intertwined with the history of the universe.