Turtles All the Way Down

[Today is 10/28/03.]

Nobel Prize-winning physicist Stephen Hawking starts his book A Brief History Of Time with an anecdote about a scientist giving a public lecture on the nature of the earth, the solar system, and the galaxy. After his talk, an elderly woman rises from her chair and says “What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise.” “Ah. And what is the tortoise standing on?” asks the scientist. “You’re very clever, young man, very clever,” retorts the old lady. “But it’s turtles all the way down.”

“Movieing” along

“The Core,” starring Aaron Eckhart and Hilary Swank is also turtles all the way down. The film’s premise is that geophysicist Dr. Josh Keyes (Eckhart) discovers that an unknown force has caused the Earth’s inner core to stop rotating. Upon investigation, the cause is revealed to be human forces which have triggered earthquakes that stopped the rotation of the core.

That’s a Galapagos of a tortoise, right there.

With the planet’s magnetic field rapidly deteriorating, our atmosphere literally starts to come apart at the seams with catastrophic consequences.

Hold on to your terrapins, it gets thicker.

To resolve the crisis, Keyes and an A team of scientists ride a subterranean vessel into the Earth’s Core. There they will detonate a nuclear device that will reactivate the Core, set it spinning again in the right direction, thereby saving the world, and get back to the surface in time for bed.

My turtle’s about bent double in her plates by now.

Let us deconstruct and look at this story as though it were a teaching tale or folk tale.

Raven stealing fire

One of my favorite stories is the Pacific Northwest narrative of Raven stealing fire from the sun. Sun had Fire locked up in a box, and the world was dark and cold. Raven turned himself into a pine needle and floated downstream, entered the body of the sun’s daughter and made her pregnant. In time, she gave birth to a boy child who cried to be allowed to play with the bright, pretty Fire. When his wish was granted, the baby boy picked up a burning stick, instantly reverted to Raven form and flew back to the human world with Fire, which he presented as a gift to humanity.

An inference to be drawn is that a wise, powerful supernatural force saved humanity from the doom imposed by an unresponsive natural force. An appropriate response to Raven and to Fire is respect and gratitude. That’s a lesson to be learned, about how we should relate to the world. Oh, the goofy superstitions of the people of Turtle Island.

In The Core, the inference to be drawn is that wise, powerful humans saved humanity and the planet from a doom imposed by an unresponsive natural force. An appropriate response to the wise, powerful humans is awe and honor, and a reassurance that whatever we do to damage the clockwork of the world, we can fix it. The lesson to be learned is it’s okay to destroy ecosystems or cause global warming because we have scientists who can fix it.

Turtles all the way down, friends.

Dealing with “facts”

Human forces could arguably trigger earthquakes, but earthquakes can not halt the rotation of the magma in the center of the world. If anything did stop that whirling magma, no thermonuclear blast could restart it. The scales of forces involved are beyond human capacity. Not even white male humans at NASA can generate explosive or mechanical forces big enough to have any measurable impact on those forces.

But I’m a quidnunc; I like learning new things, so here are some facts to stand next to the movie’s fairytale.

Movie scenario…We’ll drill down into the core of the earth. It’ll be a do-able technical challenge. But it’ll trigger gargantuan volcanic eruptions and earthquakes. Nevertheless, we’ll get down into or near the core and set off a thermonuclear bomb that will restart the core’s spinning.

Unless one can project another reasonably scientific explanation, the earth can be divided into four layers, the crust, mantle, outer core, and inner core:

 

• The crust, where we live, is much the thinnest of the layers. Its composition has some of the least dense elements, such as calcium, and low-mass minerals such as sodium aluminum-silicate compounds. The crust is furthest from the core, is “cold” relative to the core, is brittle and rocky. Thus, it can be fractured by earthquakes and tectonic plate shifting, mountains rising, water seeping. The crust ranges from 25 miles thick beneath continents to about 6.5 miles thick underneath the oceans. 

   

• We call the next layer the mantle. It’s solid, but under great pressure, and so its temperature averages 1000 degrees Centigrade. Because of the heat and pressure, the mantle can change shape, deform and reform, slowly, like a terran amoeba. The majority of the Earth’s mass is found in the mantle, which contains iron, magnesium, aluminum, other metals, silicon, and their compounds. 

   

• The core of the world is composed of iron. We are the iron planet. Our core is so hot that there is an outer core that is molten. The inner core is under so much pressure that it remains solid. The inner core is a huge mass of nearly 100 billion tons. The solid inner core turns only once every 120 years or so, relative to the rest of the planet…see Earth’s Interior 
• When the iron in the outer core flows, it generates a magnetic field. This is the source of the Earth’s magnetic field….see The truth about Earth’s core?

So, could we drill down into the earth’s core?

The deepest drill holes on earth reach approximately 35,000 feet, or 12 kilometers, down into the crust. The depth from the crust to the outer edge of the liquid outer core is about 2900 kilometers…See Model for Structure of Earth

In drilling downward, pressure and temperature increase. Pressure increases due to the increasing weight of overlying rocks. The temperature in the core reaches around 5000 C or 9000 F. The pressure at the outer edge of the outer core is about 1 million times atmospheric pressure. The inner core pressure is at least 5 million times atmospheric pressure.

Those temperatures and pressures mean that it is not possible to drill to the mantle under the continents, let alone to the core. If you could open a hole to the core, it might trigger melting and a volcano might arise around the drill hole, and liquid magma might emerge or erupt. But it wouldn’t necessarily cause earthquakes….See Earth’s Interior

Turtle on the Sea

Up here on Turtle Island, we’re riding along on the earth’s crust, that rides on the earth’s mantle, that rides on the sea of molten iron. Turtle on the Sea is an apt metaphor for the planet’s morphology. Setting off bombs to save the world is an apt metaphor for the Bush Administration’s world view. It’s one of those fairy tales that’s turtles all the way down.