Let us speculate that humanity survives its intellectual infancy. Let’s imagine that it’s now 10,000 A.D. (that’s right, the Year of the Lord) and our smartest Earth scientists have calculated that by 100,000 A.D. the Earth’s magnetic field is going to shut down for good. I have no reason to believe this is an accurate number. By all accounts we should have many millions of years on the warranty for the magnetic field but just let’s say for the sake of discussion it will.
Well, there we are ultra-modern humans with a world government, a genetically engineered genome that includes a third set of teeth and a three-hundred-year lifespan. We hear that our distant descendants are going to lose their atmosphere, oceans and have to wear SPF 50,000 rated sunscreen for days at the {dry) beach. So, what will they do? Well, with a ninety-thousand-year window of opportunity, if they’re my descendants they’ll probably waste the first twenty thousand years dithering. After that they’ll start engineering the crap out of their options. But what will that be? Let me try to guess.
So, the Earth’s liquid iron core produces a magnetic field because it is a moving electric field. So, all we have to do is produce a moving electric field between Earth’s atmosphere and the sun (and to a lesser extent all of the universe around us. Well then shouldn’t we install solar panels in orbit around the Earth and run a current through a really long piece of copper wire that is moving and thereby set up an electromagnet? Now someone with any kind of electrical engineering knowledge or a physicist who specializes in E-M would slap me across the face and say, “What the hell are you rambling about?” And he would be right. But just for the sake of getting through this exercise let’s say that it is theoretically possible to have a framework around the Earth that converts solar energy into enough of a moving electric field to induce a magnetic field as strong as the current field we enjoy today.
Postulating that, is it technically feasible? Or would the amount of mass needed to create this device be completely ridiculous from the point of view of the energy needed to boost it into space ? Would the weight of the conductive material and the photoelectric cells be just so enormous that it would be beyond all of the resources of even a distant future civilization to put in orbit from Earth?
Now this is a cheat. I don’t know the answer. I haven’t tried to estimate the amount of material needed to produce such an enormous electrical field. Something with a diameter of more than 24,000 miles and with the structural integrity that that requires seems absurd. I, of course am aware of the science fiction convention of a ring or (Dyson) sphere around a star used to harness some significant portion of the energy output of the fusion reaction going on inside every star but I don’t know that anyone with enough of a technical background has tried to do a back of the envelope calculation to see if the numbers are just too scary to make any sense.
So, I’ll throw this one out to the readership. What have you heard?
Let us assume that in 10,000 years human physical science has achieved at least a limited degree of chemical element transmutation, and resolved the Unified Field Theory. This would put them at least at the intellectual level of Latty Niven’s Protectors, who built the Ringworld. According to the books, the Protectors used the mass of a Jupiter-sized planet to build a 295-million mile-long ring, a million miles wide, with 1000-mile-high walls to hold in the atmosphere. The structural material, Scrith, must possess sophisticated electro-magnetic properties, since it also would have to shield the surface from solar and cosmic radiation. I… Read more »
What I think about is whether instead of trying to preserve the magnetic field would it be better to shield some fraction of the atmosphere and oceans at the surface of the Earth. I don’t think it could be a large proportion but maybe that would be the direction that is taken. Save a part.
I see three basic kinds of solutions CYA (cover Your A**) – Make smallish(smaller than continent size) domes. If you have room temp superconductors you coat the dome and that excludes magnetic and/or electric fields. You do need some serious heavy duty construction materials (and transparent to boot, oh Scotty have that formula for transparent Aluminum?). Of course the domes have to be like Biosphere 2 (except actually work 🙂 ). This leaves most of the planet (And the Oceans) screwed we get an extinction event that make the Devonian one look mild.Then A Miracle Occurs – It seems to… Read more »
It is a lot of fun to think about what we might know in eight thousand years more of science than we do now. After all, less than a hundred and fifty years ago the ideas of nuclear fission and fusion were null concepts. Who knows what will turn up in eight thousand years? Maybe we really will figure out a way to reach the stars.
We could always return to the caves, or live in domed cities underwater and/or bioengineer ourselves to the environment so we wouldn’t need the domes. I don’t know what depth would be required. Maybe find some substance or field that would reflect electromagnetic radiation in that frequency range.
By the way, Ed, it is so rare that I come into contact in any context with anyone who has ever even heard of Larry Niven or Jerry Pournelle. Considering the number of books sold, it has to be a bunch of people but as a percentage of the population—-
Tom, as far as Niven and Pournelle, we have to face the fact that the people who know the names of our generation’s stars are disappearing at a pretty steady rate.