While on vacation in the Canadian wilderness a few months ago, I got to thinking. Now, although I’m a physics professor and thus get paid for thinking throughout most of the year, I have to admit that little good has ever come from my vacation musings. But this time I came up with a use for the moon.
Before you can properly appreciate the great worth of my idea, you’ve got to have a bit of background. Chances are, if you were brought up on Earth, at some time a science teacher told you that one day the sun is going to blow up and destroy our planet. But do you remember where you were when you heard this news? Probably not, right? Because unlike, for instance, the breakup of the Beatles or the day you passed your driver’s test, it didn’t really matter to you. I have, of course, gathered some data to support this assumption: in a poll of seven parents watching our kids’ Little League game, I learned that 1) most didn’t quite remember for sure that Earth is doomed but didn’t doubt they had been taught it at some point, and 2) they certainly could not recall where they were when first exposed to this truth. They did point out that the key factor leading to their indifference to the toasted Earth problem was that it lies millions, possibly gazillions, of years in the future and by that time maybe there won’t be people, or they’ll be off in spaceships, or whatever. . . .
Well, that’s just not okay with me. I mean, come on. We’re talking about Earth, our ancestral home, with billions of years of history etched into its surface and probably some of the finest beaches in the cosmos. Just because by the time it’s toast we’ll all be flitting about the universe, we’re supposed to believe that we’ll have no interest in this old fleabag of a planet?
And another thing--let’s put gazillions of years in perspective. To make a long story short, stars have a definite life span, and our sun is no exception. A star of our sun’s size emits a surprisingly constant, cozy glow for about 9 billion years and then sort of falls apart. When its hydrogen fuel is used up, the sun will expand dramatically in a dying gasp and torch Earth and anything else nearby. Now, experts figure life on Earth got going soon after the sun was born 4.5 billion years ago, so we’ve already used up 50 percent of life’s lifetime. In the cosmic view of things, life on Earth has just turned 40, an age at which it is not unusual to ponder the alleged finiteness of our individual durations.
By the way, I just turned 40--but I digress. Let me return to Earth’s prospective doom and my long-range plan. I believe that people will eventually learn to live in harmony with Earth’s other life-forms and that we will choose to continue evolving mentally while preserving and cherishing our natural ecosystem and our relationship to it. That is, we will still wear cotton and go camping. I predict that even if a giant spaceship-exodus plan becomes possible, our descendants will not like it. My guess is that they would be no more interested in living the rest of their lives in a spaceship, however big and fancy, than most of us would be in spending the rest of our lives in, say, a big and fancy car wash. From this perspective, the scheduled destruction of our planet could be viewed as something of a problem.
This is where the moon fits in. To appreciate the connection, you have to understand that our moon is really special. First of all, the diameter of the moon is 27 percent that of Earth. For a moon, this is huge. By this criterion, our moon ranks first in the solar system, followed distantly by Ganymede, which is a measly 4 percent of the diameter of Jupiter. Second, the moon, in a stunning cosmic coincidence, is exactly the right size, relative to its distance from Earth, to appear to us to be the same size as the sun. Anybody who has seen a total eclipse is familiar with this.
Nobody can explain these two facts as anything other than highly unlikely accidents, but in my unguarded moment of vacation musing, I couldn’t help wondering if there could be some useful role for our moon that would take advantage of its fortuitous properties. Certainly the answer would appear to be no. If this wasn’t already obvious, it was confirmed by the fact that although the brave souls of the Apollo program went there for some picnics, a few joyrides, and a game of golf, there has been very little subsequent interest in setting up a vacation resort on that parched orb.
And it’s not as if the moon needs to have a purpose. The moon is just the moon, after all, and it already serves us very well by inspiring poetry and making tides. But still, I wondered, couldn’t the moon be used in a way that would take advantage of its unique features--possibly, for example, to save the Earth from incineration?
You have to understand how big a problem this sun-blowing-up business is likely to be. Some might suggest that a solution could involve simply moving our planet farther away from the problematic sun. This would involve the application of a new force capable of doing so, along with some artificial means of heating our home after the move. But it isn’t fair to assume that some new laws of physics will be discovered just because they’re necessary to solve this problem--it’s quite likely that won’t happen. I further maintain that this is too important a predicament to count on a magic solution turning up in the nick of time. That would be like allowing the national debt to grow indefinitely in the hope that some surprise new law of economics might be found that would make the problem go away. Therefore I contend that our solution should be based on the laws of physics as we know them today. The one minor detail I am willing to allow is that people will eventually be able to convert matter almost entirely into energy.
Perhaps you recall that in one of the Back to the Future movies the mad scientist, needing fuel for his futuristic sports car, chooses some nearby garbage, which he throws into a thing under the hood labeled Mr. Fusion. The idea is that this unit could take any old matter and convert it into energy. (We know that matter can be changed into energy; for example, an electron and its antimatter cousin, the positron, can meet and transform completely into energy in a process appropriately called annihilation. The great thing about this is Einstein’s E = mc2, which says that a pound of matter is the energy equivalent of 300 million gallons of gasoline. But we don’t know how to convert regular matter completely into energy--even atomic bombs convert just a tiny fraction of their mass. I am hopeful, however, that over the next 4 billion years we can figure this out.)
Strictly speaking, the garbage converter should be called Mr. Annihilator. This would be a good name for another reason--an inevitable by-product of such annihilation would be lots of deadly radiation. So though I have faith that our descendants will develop such a limitless energy source, I have to assume that it will not be clean and safe. This and other problems rule out any solution involving a giant rocket on Earth powered by Mr. Annihilator, flinging mass off into outer space in an effort to push Earth away from the terminally ballooning sun. This might move Earth, but the cure would be as bad as the disease. Massive earthquakes and tidal waves would be one result, as well as atmospheric destruction. The radioactivity problem would make Chernobyl look like a minor inconvenience. No, it just won’t work. Whatever method we employ to save Earth must treat our fragile ecosystem with the utmost care.
So here is my proposed solution:
1) Put a really big Mr. Annihilator on the farside of the moon and use it to transform moon rock into the enormous amount of energy needed for (2) and (3). The moon will thus act as a shield to protect Earth from the annihilator’s deadly radiation.
2) Set up some large, efficient rockets on the moon to create a big force--but not big enough to disturb the moon’s orbit around Earth. The rockets would be carefully controlled to maintain a stable orbit while producing an effective net force of a few percent of Earth’s gravity on the moon, in the direction of Earth’s orbital path around the sun. Even though the force of the rockets would be applied only to the moon, it would affect Earth because the two bodies are connected by their gravitational attraction. Imagine the way a propeller pushing a tugboat connected to a freighter by a long line would slowly move the tugboat and the freighter; it’s a bit more complicated for orbiting bodies, of course, but the net effect would be that Earth’s orbit around the sun would become a gradual outward spiral. After about a thousand years of this, Earth would be free of the sun’s gravity. We would be riding Interstellar Spaceship Earth.
3) As the sun recedes into the distance, replace its energy with light from a great many electric lamps placed on the nearside of the moon, beaming their light at Earth and keeping us from freezing once we’re gone.
In a nutshell, the moon becomes the sun. It would have the same brightness, color, and apparent size. Everything would look the same on good old Earth--golden sunshine, blue sky, fleecy clouds, rainbows, and sunsets. Trust me. I have seriously investigated and confirmed this idea’s technical feasibility. I even checked the physics calculations with some of my colleagues who are, perhaps, more middle of the road in their pursuits than I am, and they could find no fundamental flaws in the argument.
I’ll admit there is one catch--we would lose the nighttime moon. The moon would now be the sun, so when it is on the other side of Earth (that is, at night), there would be no visible moon. We would be in a perpetual state of new moon. Could that do any damage? Well, if so, it would be pretty minor. We would still have tides, but they would happen at the same time each day. Also, each day would be a bit longer--about one extra hour--but I think most of us would actually be happy with that. And we would have no seasons, so there would be a constant state of fall- spring, but I think most of us would prefer that to the end of the world. Yes, it is possible that some nonhuman life on Earth would be, shall we say, perturbed, just as it’s possible that my proposed changes might ameliorate our current vampire and lunatic situations, but I’d rather not speculate too far outside my field of expertise.
As far as feasibility goes, though, take my word for it that the orbital dynamics work and that there is enough energy available from Mr. Annihilator’s eating up a reasonably small chunk of the moon. But what about this business of the lights? Surely to produce the glow of the sun artificially would require some unrealistic feat of science fiction? Well, surprisingly, no.
You can find this out for yourself. Where would you look for a really big light--say, the world’s biggest? Right. The Guinness Book of World Records lists the brightest lamp as a high-pressure argon arc lamp, made by Vortek Industries in Vancouver. It turns out that Vortek is in the business of solar simulation (a few billion years ahead of time). Vortek makes a lamp that has the same surface brightness as the sun’s, and each of its lamps would be able to simulate the sun over an area of 100 square feet of moon. This means it would take about a trillion Vortek lamps to do the job. A trillion is a lot, but you can look at this as about 200 lamps per person (calculating from today’s population), which I don’t think is an impossibly large number if your life depends on it.
By now I’m sure you’ve begun to realize the dilemma this vacation thinking has put me in. Basically, the world is doomed, and I’ve got this moon-as-cosmic-tugboat/lighthouse solution. What should I do with it? Well, first of all, the University of British Columbia--where I trust I am still employed--has rules about this sort of thing. If I have a practical idea (which actually has happened before), the university will sometimes help out by patenting and licensing it. Generally we start with a patent search. So the other day, while working on something more routine, I searched our computer database for patents containing the words moon, artificial sun, tugboat--that sort of thing--and found none! I could patent this invention! But patents expire in about 20 years, while I won’t see the real payoff from my invention for 4.5 billion.
An alternative is trademark protection, which can last forever. For example, I could try to develop brand recognition for Whitehead Earth Tugs and Artificial Suns. But this could be tough during the course of a 4.5-billion-year sales drought.
Another small problem is that I may be dead 4.5 billion years from now. After all, I’m already 40. Of course, I could leave the proceeds to my descendants, but statistics suggest many, many human beings by that time will probably be descendants of mine. So the simplest thing all around is just to present the idea to mankind, which is what I’ve just done by telling you about it. You are hereby free to save Earth by this method, if you are inclined.
I hope that knowing this will help you sleep better tonight. I know I will.