Years ago, when the Hubble and Chandra beamed back life-altering photographs of the universe, I watched an astrophysicist cry on the PBS Newshour and say, "We really are made of stardust." Of course, I wept, too. And I wrote a long poem, one part of which read,
II.
1999
On the television
a Harvard astrophysicist
points to an image of Cas A.
In the Milky Way plain
the soupy sea of red star shreds,
remnants of an explosion
more than 380 years old,
moves out at more than
10 million miles per hour.
He says, “I find myself
grinning all the time. This
nourishes our humanity.
That stuff is made up
of oxygen and silicon,
sulfur and calcium,
all the way up to iron.
The calcium in your bones,
the oxygen you’re breathing,
the iron in your blood —
all of it came from stars
that went off
before the Sun and the Earth
formed. We really are
made of stardust.”
Second
Three days ago, another scientist/journalist moved me to tears with an essay I wish I had written. He captured my own impressions of two recent science stories and did so beautifully.
New York TimesAugust 5, 2013
Who was it that first said that people are stardust?
Some people, of a certain age, might say Joni Mitchell,
who sang, “We are stardust, we are golden, and we’ve got to get ourselves back
to the gar-ar-den,” in her paean to the Woodstock festival. Others will say
Carl Sagan, the author and host of “Cosmos.”
In fact, the answer goes back before those acolytes of
beauty and consciousness were born. In 1929, the Harvard astronomer Harlow
Shapley declared, “We organic beings who call ourselves humans are made of the
same stuff as the stars” — a remarkable observation, considering that at the
time nobody even knew what made the stars shine.
It would be 30 years before Geoffrey and Margaret
Burbidge, William Fowler and Fred Hoyle showed in a classic paper that
the atoms that compose us are not only the same as the ones in stars — most of
them were actually manufactured in stars. Starting from primordial hydrogen and
helium, denser elements like iron, oxygen, carbon and nitrogen were built up in
a series of thermonuclear reactions and then spewed into space when these stars
died and exploded as supernovas in a final thermonuclear frenzy.
Any gardener knows that ashes make good fertilizer. Our
atoms were once in stars.
I was reminded of all this by a pair of recent news
items. One involved dung beetles, among the least lordly occupants of this
cosmic garden, which apparently navigate by orienting themselves to the light
of the Milky Way.
The other was the announcement last month that astronomers had
tentatively traced the existence of gold in the universe to a cataclysm known
as a gamma-ray burst, which can light up a galaxy. As Joel Achenbach wrote in The
Washington Post, “The bling apparently begins with a blam.”
The blam in question happened — or rather was noticed
here on Earth — on June 3. It was then that astronomers, alerted by a brief
flash of high-energy gamma rays in the sky, think a pair of dead, ultradense
neutron stars collided, leaving behind only a distant radioactive glow. Edo
Berger of the Harvard-Smithsonian Center for Astrophysics said the explosion
could have created an amount of gold equivalent to the mass of 20 Earth Moons.
Neutron stars are themselves a result of cataclysms,
those supernova explosions that can squeeze the space out of atoms and compress
a mass more than the Sun into a ball 10 miles across — essentially a great ball
of neutrons, hence the name. On Earth, a teaspoon of the stuff would weigh
about five billion tons.
Astronomers have always wondered whether ordinary
supernova explosions could produce very heavy elements like gold, whose nucleus
has 79 protons and 118 neutrons — a far cry from the single proton that is a
hydrogen nucleus. If a pair of neutron stars are in orbit around each other,
they can collide — a second cosmic act that will add to the universe’s
repertory of elements, the bling from blam.
Indeed, Dr. Berger and his colleagues suggested that all
the gold in the universe might have been produced by neutron star collisions,
which have been termed “kilonova” explosions.
Of course we aspiring gardeners have other names for what
is left behind after an object’s energy has been metabolized into light and
heat to nurture the cosmos.
Which brings us back to the lowly dung beetle, the
scarab.
These creatures,
which live on the feces of larger animals, have a problem. Once a beetle has
found some dung and rolled part of it into a ball, he’s got to get it out of
there, rolling it in a straight line away from the dung pile, or the other
beetles will come and poach it.
How they manage this, even on moonless nights when
obvious cues and landmarks are absent or invisible, has been a mystery.
Last January a team of Swedish and South African
researchers reported that African dung beetles, Scarabaeus satyrus, can use the
Milky Way as their guide.
In a series of experiments in a game preserve and a
planetarium, a team led by Marie Dacke of Lund University in Sweden found that
when the beetles were fitted with little caps that prevented them from seeing
the sky or the stars were clouded out, the beetles wandered aimlessly, putting
their little dung treasures at risk.
But a starlit sky, or just a dim band representing the
disk of our humble home galaxy, is a enough to keep them on track.
“Although this is the first description of an insect
using the Milky Way for their orientation, this ability might turn out to be
widespread in the animal kingdom,” the scientists wrote in
Current Biology.
It’s hard to imagine a more beautiful or humbling
connection between the sacred and the profane, the microscopic and the large,
inner space and outer space.
The Milky Way is one of nature’s grandest creations:
hundreds of billions of glittering stars, wreathed in ribbons of gas and dust,
a cloudy, starry pinwheel so vast that a light beam would take 100,000 years to
cross it and the Sun with its planetary entourage takes a quarter of a billion
years to circle it once.
And it is only one of countless galaxies, scattered like
sand from here to eternity, rushing outward in the great expansion, whose
meaning, if we are honest, is as fathomless to us as it is to a scarab pushing
its carefully wrought investment portfolio through this garden of Earthy
delights.
Scarabs were sacred to the ancient Egyptians for their
ability to create life from waste. They were a symbol of the eternal renewal of
life from death, not unlike the waxing and the waning of the stars themselves.
Egyptians wore representations of them as amulets. And
wouldn’t you know, in one of the ultimate symbols of recycling, some of them
were even gold.
This article has been revised to reflect the following
correction:
Correction: August 8, 2013
An
article on Tuesday about the connections between stars, gold, dung beetles and
people misspelled the term for explosions resulting from collisions of neutron
stars. They are known as kilonova explosions, not kilanova.
Third
This I believe: I am, and nature is, and we are of the same good stuff, now and forever.
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