Final Project

Jason T.

Legislator:  Bill Ratliff, Senator

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Gravity: Pulling for Propulsion

It's been around since before man first walked across the earth. It's all around us, yet we hardly ever give a conscious thought. It plays one of the most critical roles in everything from our every day lives to holding the entire universe together. So what is it? It's gravity, of course. And ever since Newton shed the first significant amount of light on it, it has been viewed as the force that pulls us and keeps us on the surface of the planet, that keeps us spinning around the sun, and that helps to maintain the orderly movement of the cosmos. So, what's the point? The point is that this force has always been seen as hindering man's struggle to reach space, as being an obstacle that must be overcome in order to reach new boundaries. But I don't believe that it has to be this way. I believe that this force can be used to our advantage. Just as humans have discovered time and time again throughout history, we can use this obstacle to our advantage. I propose that instead of constantly trying to invent better methods of propulsion to overcome gravity's effects, instead we can use gravity as a means of propulsion in a space vehicle.

Before we can even contemplate this idea, though, we need to have a fairly firm grasp on what gravity actually is. In the shortest and simplest definition possible, gravity is the force that results from the warping of space-time. Space-time is what many scientists have deemed "the fabric of space." It is every where. If the universe were a magnificent oil painting, then space-time would be the canvas on which it was painted. But do not let this comparison throw you, because just as the spatial universe is three-dimensional, likewise, space-time, in relation, is an invisible fluid in which all matter is suspended. And just as water is displaced and pushed aside by objects submersed in it, any and all objects in space-time, which is everything, warps the space around it. This is where gravitational forces occur. The warping of space around an object creates a kind of sunken region, or a well in which other objects with less mass or density are drawn to. A way to picture this in your mind would be if you were to place a bowling ball in the center of a trampoline and several tennis balls in various locations around it. You would find that all of the tennis balls would be drawn towards the bowling ball because it is larger, denser, and therefore, creates a greater dip. Once again though, you must expand your view of this example. The dip created by the bowling ball on the trampoline only represents one horizontal plane in which space-time is warped, and space-time is all encompassing, meaning that this warping occurs at an infinite amount of planes in any relation to the object. So, in other words, the bowling ball creates a dip in a horizontal trampoline, a vertical trampoline, and an infinite number of other trampolines that all have different pitches around a spatial three-dimensional axis.

That's the basics of what gravity is. To briefly go a little bit deeper so that future explanations make sense, gravity cause different effects on objects under various conditions. Gravity holds planets and moons in orbit, while simultaneously keeping people's feet on the ground. This is because of the relationship an object has with its surroundings. For example, the moon stays in orbit rather than being pulled into the earth resulting in a relatively large problem because it is caught in a circular path around the earth at an appropriate speed. The kicker is that there is no friction to create drag and slow the moon down. Just like if you've ever seen one of those large coin funnels, where you drop your coin down a slide into the funnel and it goes around and around slowly creeping toward the hole in the center until plop, it falls to the rest of the change held within. The moon does the same thing. It travels in the earth's "funnel," but instead of finally falling into the center, it stays out there due to the lack of friction. Objects on earth, however, don't become suspended because of two reasons. One, they don't have a high enough velocity traveling around the earth, and two, the earth's atmosphere creates more than ample friction and drag to slow any object down.

Now that we have all of that behind us, we can move on to the proposition. Gravity has always been seen as increasing the difficulty of lifting an object off the ground. With the inventing of the airfoil, lift was discovered but its usage was limited to the atmosphere where there was air available to form the necessary high and low pressure regions. Even though the airfoil provided lift that overcame gravity, there still had to be propulsion to provide the thrust needed to move the air across the wing.  Thus the propeller came into usage. Then propulsion had to undergo more drastic changes from propeller to rockets with the beginning of man's voyages into space. But even in space, earth's gravity still affect's objects that are close enough to it. So methods of propulsion had to be developed for space travel. Propeller engine and jet engines wouldn't work because of a lack of air, or anything for that matter, in which to push with. But by burning solid and liquid fuels and by expelling high-pressure gases through nozzles, the propulsion methods needed were formed. But there are still some major drawbacks to all of these various forms of propulsion. They all require a propellant. Whether it is gas, solid rocket fuel, liquid hydrogen and oxygen, or compressed gases, they all require a propellant to propel them. I say kill two birds with one colossal stone. What if you could create your own gravitational field in order to pull you where you wanted to go? Not only would you have a form of propulsion that counteracts gravity because it is gravity, but it would also lack the necessity of a major exhaustible propellant.

So how exactly do we create our own gravitational field? Based on what has previously been disclosed all one would have to do would be to warp the space in the way that they would want to go, and the gravitational force of the warp would pull them in their desired direction. So here's the big question. Can one warp space without using a relatively stationary amount of matter that has both mass and density? I admit, it does get tricky from here. As it is, the majority of this topic is in the theoretical stage still. The point is that it deserves to be pursued to see if it can be made a reality.

So, can space be significantly warped enough to create gravitational pull without using large amounts of matter? I believe so, and this is why. Lets look at a black hole for a little bit. Though black holes are still theoretical only, scientists are continuing to find more and more evidence to suggest that they might really be out there. So, if it is going to be used as an example, then what exactly is a black hole? A black hole is a star that collapsed in on itself instead of going bang. A star is really just an enormously gigantic ball of gases slowly burning away. The burning gases are what make them visible to us. And when a star nears the end of life, or the compressed hydrogen that made up its core is almost gone, it swells into a red giant. This is basically just a gigantic shell of the star, though there are still numerous layers of gases within it. The center of the star continuously gets smaller while the shell enlarges until BOOM! The star disintegrates in a violent explosion known as a supernova. After a star blows up, the remains can do several things. The debris can either disperse into space, or the large gravitational field that is left after the star explodes can draw the remnants back in. If this happens, the matter could either collect into a tiny, spinning neutron, or pulsar star. But if the gravitational field is large enough, a black hole can form. Black holes form when the gravitational pull is so strong that the debris is pulled into an infinitely dense, infinitely strong gravitational force where at its heart it is believed that the fabric of space itself is ripped. A black hole technically has no mass to it. It is void. Anything, including light, can get trapped in its pull and sucked in only to vanish completely. It has been concluded that the larger a gravitational force is, the slower the passage of time is. So at the heart of a black hole, time stops. Matter ceases to exist. The point is that a black hole is nothing tangible. It is a hole in space-time with an extremely large gravitational force. That is why I believe space can be significantly warped without using a large or dense amount of matter.

Next question. If a gravitational force can exist without matter at its core, how do we go about warping space short of creating our own black hole? To answer this question, we need to look at the force that gravity is. The force of gravity is what causes the feeling that we are being pulled down to the ground. Now, if you will, let your mind wander for a minute. Remember those thrilling tornado rides. Were you got inside of the large cylinder, and it proceeded to spin until you were being pulled against the wall. In some of these rides the bottom drops out, but the passengers defy gravity and stay pressed against the wall. The force one feels due to acceleration, as in the example given, is the same force that one would associate with gravity. In other words, they feel the same. So why do two seemingly different forces seem to have some of the same characteristics? It's because they are they same forces. Both of the forces are the result of the warping of space-time. The difference is that gravity is the warping due to a mass in space, while the effects of acceleration, which relates either to a change in speed or direction, warps space due to motion. Just as any mass warps the space around it, motion through space, in turn, creates warps whenever acceleration occurs. My theory for creating a propulsion system that warps space to create a gravitational field is possible because it uses a form of centripetal force, which now can be directly compared with the force of gravity.

To explain my idea in more detail, I'll elaborate on what my original model for such a device is. For starters, this device would use a series of spinning masses to create a centripetal force, kind of like the spinning of the tornado ride. The difference is that the masses will not spin in a complete circle. Using the tornado ride as an example again, the masses can not fully rotate because if they did there would be equal forces pulling outward from the center. Since these forces would surround the whole 360 degrees radius, they would effectively cancel each other out. So how do you overcome this? In my plan, the masses would follow a path that is only half of a circle. First, there would be stacks of these semi-circle pendulums, so to speak, on top of each other. I propose at least ten. Then by having them programmed to function in a rather fluid order, it could be made to where there would always be continuously moving masses swinging from opposite, outside edges in toward the center. These masses would cross each other precisely in the middle of the semi-circle thereby providing the maximum available force, and consequently, the greatest warp in space. Since there would always be at least two opposing masses in motion at any given time, the warp in space would stay continuous. Also, since the masses only follow a semi-circular path, there would be no resulting forces behind the device, and therefore the device and the vehicle attached to it would theoretically be pulled forward because of the warp in space-time that is created. To effectively propel these masses, I suggest they be constructed from dense, magnetic metal, and electricity used to push them Electro-magnetically, just like many new modern roller coasters are propelled. By doing it this way, the only form of propellant used is electricity, which is easily generated by any number of methods.

Well, that's really all there is to it. I've explained to the best of my abilities what gravity is, and how by warping space with the motion of an accelerated mass, that a warp in space-time could possibly be created that is strong enough to propel a vehicle through space. Unfortunately, as of the present, much of this is still in the theoretical stages only. It is my hope that through the combined efforts of many, gravity could one day become an effective form of propulsion for transportation everywhere.

Works Cited

Becklake, Sue. Space, Stars, Planets and Spacecraft. New York: Dorling Kindersley Inc., 1991.

Greene, Brian. The Elegant Universe. New York: W. W. Norton & Company, 1999.

Kaku, Michio. Hyperspace. New York: Doubleday, 1995.

Pickover, Clifford. Black Holes: A Traveler's Guide. Denver, Colorado: John Wiley & Sons, Inc., 1996.

Last Updated:  09/07/01