TCS Daily


Extending Archimedes: Megastructures in Space

By Zoran Pazameta - January 8, 2008 12:00 AM

Having understood the principle of the lever, the great thinker Archimedes of Syracuse (c. 287 - c. 212 BCE) declared, "Give me a place to stand, and I will move the Earth." Archimedes, probably the world's first scientific engineer, appreciated that a tiny force could literally be leveraged, through knowledge of scientific principles and suitable technology, to move immense objects. His hypothetical planet-moving lever may well be the earliest megastructure—a concept that has long featured prominently in science fiction, but is being taken more and more seriously by scientists and engineers.


While there is no precise definition of a megastructure, the general idea is that it would have to measure at least 1,000 kilometers (one megameter, hence the name) in at least one dimension. It could extend out into space from the Earth (or another body) or float freely in the void, and be of one-piece construction ("monolithic") or composed of many substructures acting in unison (a "swarm").


Certainly, the challenges of megaengineering are formidable; yet, although few of the megastructures proposed to date could even be attempted with today's technology, the underlying physics is understood well enough that we can determine which concepts are not scientifically sound while being able to calculate the important parameters of those that are. As the discoverer of electromagnetic induction, Michael Faraday (1791 - 1867), observed, "Nothing is too wonderful to be true if it be consistent with the laws of nature."


Why bother with megastructures in the first place? One incentive is replacing today's chemical rockets with low-cost methods, such as the Space Elevator, for sending payloads into Earth orbit. Another is geoengineering (Pete Geddes, "Why Geoengineering's Time Is Coming," TCS Daily, 26 Nov. 2007)—for example, regulating global temperatures by deploying a swarm of Earth-orbiting reflector satellites to direct sunlight towards or away from our planet as needed.


Yet there is an even more compelling reason to take megaengineering seriously: All our current or future environmental, economic and geopolitical problems pale in comparison with the ultimate global catastrophe—the inevitable demise, some five billion years from now, of our Sun. One type of megastructure, however, offers us a prolonged stay of execution:


Our Sun, like all stars, emits light; and because it has energy, sunlight can produce thrust. The statite (stationary satellite), a concept patented by the late physicist and science fiction author Robert L. Forward in 1993, keeps itself in position indefinitely without using rocket motors to offset the gravitational pull of the body around which it orbits—the thrust from radiation pressure of sunlight on its solar sail does this. (A solar sail is actually a mirror, so that photons of sunlight reflecting off it exert a reaction force, or thrust, on it.) In 1987, Russian physicist Leonid M. Shkadov theorized about building a megastructure statite in interplanetary space. Its concave solar sail would reflect back to the Sun all light coming towards it, while sunlight would continue to escape freely from the Sun's surface diametrically opposite. This asymmetry would produce a thrust force, pushing the statite away from the Sun. But since the statite is gravitationally tied to the Sun, it would pull the Sun—and the rest of the Solar System—through space!


The thruster's pull is excruciatingly feeble (a half-century would pass before we reached the cruising speed of an average snail, one millimeter per second), but over a long enough timespan its effect would be significant. The three nearest stars to us, comprising the Alpha Centauri system, are just over four light-years away. (A light-year is the distance traveled by light in one year, almost six trillion miles.) It's estimated that in the 250 million years it takes for the Sun to make one revolution about our Galaxy's center, a Shkadov Thruster could deflect our Solar System by several dozen light-years. Even such a small course change would bring us within range of a number of nearby stars, to seek an energy source to replace our own dying Sun and even habitable planets to colonize.


Megastructures are an exciting interface between science fiction and science fact. While turning these concepts into reality seems daunting to us today, history has shown us many times the folly of trying to solve tomorrow's problems with today's technology. Most importantly, megastructures such as the Shkadov Thruster literally offer us a ray of hope to outlive our Sun and survive for as long as the Universe itself exists. American rocket pioneer Robert H. Goddard (1882 - 1945) said it best: "It is difficult to say what is impossible, for it has often proved true that the dream of yesterday is the hope of today and the reality of tomorrow." The lever of Archimedes may turn out to have a long reach indeed.

Dr. Zoran Pazameta is Associate professor Physical Sciences Department
Eastern Connecticut State University.

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3 Comments

All due respect to Archimedes, but now we do not need a place to stand...
Greetings Professor Zoran Pazamzto, January 11 2008

All due respect to Archimedes, but now we do not need a place to stand in order to move the Earth.   

I have discovered a process by which we can have action with reduced reaction. The net result is Action Without Reaction. Mankind can now build a device that will create a force that will move a vehicle without the need to push on anything in return. The main value of this device will be up in space because there is nothing in the space between planets to push against.

But large installations on Earth could push the Earth itself. We could increase or decrease the length of the day by increasing or decreasing the speed of rotation. We could also push on the Earth in some other controlled direction, which inturn would pull on the our entire solar system - the same as your Sail.

Below is part of my text explaining my process and invention.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -
Space travel needs advanced propulsion systems in order to get humans from Earth to other places in this and other solar systems in an acceptable timeframe.  It is correct to call this lacking a major problem. In the past, suggested propulsion systems have ranged from
collecting space dust via a frontal funnel and then shooting it out the rear at high speeds, to passing atomic bombs out the rear and exploding them for the push of the blast wave - ouch. Currently, NASA is working on an ION generator of high cost and low propulsion.  If we are ever going to visit extraterrestrials we will need a better
solution - I have that better solution because I am willing to bypass a law of physics.

There is a well known law of physics that states: For every action there is an equal and opposite reaction.  The absolute obedience to this law has prevented mankind from developing a mechanical means of space propulsion, that is, until now.  I have discovered a new and useful process by which an electrically powered mechanical machine can deliver a force with a reduced counter force. The net result is action without reaction.  In other words mankind can now bypass this law of physics when it is useful to do so.  Mankind will find it useful to do so in order to gain the ability to push space vehicles long distances.

The process is simple, maybe that is why it took all this time to be discovered.  First step in the process is to make a device that will cause reaction to lag behind action, then after each action pulse of force, the energy is taken out of whatever part that is making the action so that there will be reduced reaction.  This can cause the
power of the reaction to be reduced down to less than ten percent of the power of the action. The net result is action without reaction, or in other words, motion without the need to push on anything in return.

I have an invention (patent pending) of a machine based on this process and it works, surprise surprise - it moves without the need to push against anything - no pushing against my driveway nor pushing against the air, like I said, no pushing against anything.  Exactly what is needed up in space because there is nothing to push against
in the space between planets.

A well engineered and stronger version of my invention would be the ideal propulsion system for any vehicle traveling through space.  Think of an atomic powered submarine type vehicle up in space, it could travel for years.

Long space travel is only one use, there are more uses for my invention:

One: A manual powered device could be used as a backup way of bringing the shuttle out of orbit in case of a loss of power.

Two: A small handpowered unit could be used during spacewalks. If one spacewalker passed out drunk and started to drift away, another spacewalker could give chase and bring him/her back to the shuttle and save a life.

Three: Levitation may be in the works, if not on the Earth, maybe on Mars, or at least on the Moon.  On a Wired Science program, Peter Diamandis of X-Prizes spoke of the small amount of energy needed to get a person into orbit - $100 worth of electricity.  Machines that give us levitation will be needed in order to approach that low amount of energy. While my invention is good enough to push a space vehicle to Mars and maybe give us levitation on the Moon, it is not strong enough to give us levitation here on Earth, but my invention is only the first invention in this new field of science, there will be more
inventions, if not by me, then by others, we will get levitation here on Earth. The first step has been taken and there will be more steps to come - this is a whole new branch of science and engineering.

When I discovered this process, I also discovered a new branch of science and the door to a new and unknown room in which scientist and engineers can now work.  It will be interesting to see what they will do with Action Without Reaction.- are you ready for the Brave New World?


For more details:  http://www.dialup4less.com/~donald/index.html


Thank you for looking,
Donald Eric Davison
donald@dialup4less.com



Solar Sail will merely go into a higher stable orbit.

Greetings again Professor Zoran Pazameta,         January 15 2008

Since I wrote you my Archimedes comments, I have been thinking about the Solar Sail pulling our solar system to a new location. I now take the position that it will not work, that is, the Sail will not move our Solar System at all.

The Sail is in orbit around the Sun.  Anything that is in orbit is both falling towards and going away the same distance in the same time.  Let us assume that we start with the sunlight off and then turn it on. Also let us assume that the sunlight will cause a force on the Sail in the direction away from the Sun.  When the Sun is turned on, this force will merely offset part of the force of gravity towards the Sun.  The reduced gravity will cause the Sail to fall less towards the Sun, but the Sail will still go away from the Sun the same amount that it had been going away without the sunlight.  This will result in the Sail going up until the going away will be reduced to match the reduced falling towards the sun. Once again the Sail will be both falling towards and going away the same distance in the same time - a new stable higher orbit.

The Sail is merely in orbit and bodies in orbit do not move the Sun to a new location.

If the sunlight happens to get blocked, the Sail will come down to the original orbit.

The Solar Sail will not pull our Solar System anywhere.

Thank you for looking.
Donald Eric Davison
donald@dialup4less.com


http:www.dialup4less.com/~donald/index.html



Ice Ages are a more pressing problem than the demise of the Sun:
Greetings again Professor Zoran Pazameta,
January 17, 2008

You wrote in your TCS article titled: Extending Archimedes: Megastructures in Space.

"...there is an even more compelling reason to take megaengineering seriously: All our current or future environmental, economic and geopolitical problems pale in comparison with the ultimate global catastrophe - the inevitable demise, some five billion years from now, of our Sun."

While the demise of the Sun will be of great concern four billion years from now, Ice Ages are a more pressing problem now because the next regular one comes in far less than five billion years - in only about forty thousand years, and they will keep coming one after the other 80 to 120 thousand years apart - and they will be getting colder and colder and move deeper and deeper into the South with their glaciers.

There are three sizes of ice ages, Little Ice Ages, Regular Ice Ages, and Major Ice Ages. Little Ice Ages are merely the lower fluctuations of temperature that take place during an Interglacial Warm Period. Regular Ice Ages are sections of a Major Ice Age that have been divided by Interglacial Warm Periods. We are two million years into a Major Ice Age. It is not known how long this Major Ice Age will last, but the average is sixty million years if we toss out the longest (700M) and shortest (2M) - we are allowed to do this in statistics. It should be clear that we are no where near the bottom of our current Major Ice Age. Therefore we can expect that the glaciers that cover the land will go deeper and deeper into the South with each Regular Ice Age.  The glacier of the last Regular Ice Age came to what is now known as the Ohio River - the river was made by the glacier melt.  We should expect the next glacier to  go well south of the Ohio River.

Anyway, what can be done?  We can move our Earth into a lower orbit closer to the Sun.  This can be done using my invention the Davison Drive. The difference in temperature from the bottom of the last Regular Ice Age and our current Interglacial Warm Period is about 20 F degrees. If we move the Earth enough to gain that twenty degrees we should be able to avoid glaciers covering the land. Someone will need to do the math first. As the Ice Age ends, we can move the Earth back up for the next Interglacial Warm Period.

Trial Runs: In the next ten to twenty thousand years there will be many windows in which trial runs can be made to fine tune our ability to control the temperature of the Earth by moving its orbit up and down. I am thinking of the many Little Ice Ages that are coming in the future of our current Interglacial Warm Period. The next Little Ice Age will be here inside one to three hundred years.

Another solution: If the world does not want to mess with the orbit of the Earth, I can see the possibility of some countries getting together and considering placing a large mirror in orbit to reflect extra sunlight onto their countries, Canada and Russia together might consider this for their northern areas, but it would have to be a very large mirror in order to reflect sunlight most of the day. Eight hours per day would require a mirror eight time zones wide. To be effective it should be able to shine sunlight on at least one thousand miles of land north to south. All this material would have to be put up into orbit using expensive rocket power - which raises the question: What is this Space Elevator you speak of?  I hope it is not some more science fiction like the Solar Sail.


Anyway, thank you for looking
Donald Eric Davison
donald@dialup4less.com


http://www.dialup4less.com/~donald/index.html


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