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A vehicle that can "turn off" gravitational influence would be the most efficient spacecraft we could build. There would be no need for any propulsion mechanisms other than playing with the gravity settings. The size of the spacecraft would make no difference which means we could concievably build a ship to bring 1000 poeple to Mars and little extra cost compared to a small crew. The ship could travel close to the speed of light then decelerate without worrying about g-forces.
So how close are we to this? The first step would be to develop the unified field theory whihc scientists are continually working on. Gravity waves probably exist and once their existence is proven, methods could be developed to counter them. Perhaps any Mars mission money could be spent towards this goal instead. In the long run it would be much more valuable to humanity to conquer gravity (assuming it could be done).
[http://www.light-science.com/gen2.html]http://www.light-science.com/gen2.html
Danny------> MontrealRacing.com
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Methinks you are a little too optimistic about building a "gravity shield" propulsion system... One of those things that probably isn't possible, and even if it were, we certainly wouldn't see it in our lifetimes or the next.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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I have been playing around with the idea of unified field theory for 30 years. One concern I have is that the amount of energy in a gravity well is extreme; it's close to the energy you would get from the mass of the object generating the gravity (e=mc^2). However, the strength of gravity at a given point is the slope of the curve while the total energy of the gravity well is the volume under the curve, so you could reduce the energy requirement by tightening the gravity well. But how do you do that? If you move closer to the centre of gravity that will increase the slope, but it will also increase the gradient (how much different gravity is from your nose to your toes). Too strong a gradient could tear you apart.
Another concern is how far does your gravity shield apply? If it reduces gravity for everything above the shield, then you will not only be lifting the spacecraft but also a column of air up to the top of the atmosphere. That is a lot of mass to lift. How much energy will that take? Efficiency of a gravity shield may be so low you are better off with traditional rockets, or to find something higher-tech, nuclear rockets or scram jets.
One researcher did create a device that appears to reduce gravity. It uses a superconducting disk that smoothly (as far as they can manufacture) transitions from superconductor on one side to simple copper on the other. This disk is magnetically levitated and spun to 10,000 rpm. It has to be kept in a liquid nitrogen bath to keep the superconductor superconducting. Every test so far has found no explanation for why a test weight above the disk does reduce its measured weight. Magnetic fields, electrostatic fields, and air currents have been isolated from the test mass. However, the best result so far has been 2% reduction in weight, and that is with a finely tuned setup; less finely tuned experiments result in 0.2% or less reduction in weight. There are no accepted explanations for the physics. One wild speculation is that frame dragging results in levelling the gravitational gradient. Or it could be quantum entangled electron pairs in the superconducting disk transferring gravitational energy instantaneously across the diameter of the disk. Basically the gravitational gradient becomes the average of the space that the disk spins through. This starts with the assertion from General Relativity that a massive object directly causes time dilation and a distortion in space, and gravity is the effect of that, not the cause. If this is correct then the limit of gravity reduction is the average of the gradient the disk spins through; basically the disk flattens a patch of the curved gravity well, and the slope determines strength of gravity so flattening it could reduce the slope.
But experiments with this spinning superconducting disk do demonstrate reduced gravity all the way up to the ceiling so you are affecting a column of air, probably all the way up to the top of the atmosphere. The mass within that column will affect the gravity well, so that will feed back to the spinning disk. The more mass you lift, the more resistance to disk rotation, so the more energy you have to put into the system. This means the energy required will be that necessary to lift a rather massive column of air in addition to your spacecraft. Conservation of energy is preserved. This limit makes non-gravitic means of propulsion sound more practical.
One more thing: the spinning superconducting disk is spun horizontally, but the curvature of space-time is vertical, curved into the 5th dimension that is used to represent gravity. This means flattening the gravity gradient is across the depth of the disk, not its diameter. Oops. I guess the gradient between the superconducting side and normal conducting side is necessary to drag electrons down through the depth of the disk, separating quantum entangled electron pairs so they can exchange gravity energy across the depth of the disk. So a thicker disk will reduce gravity more, but it?s still limited to the average. In this case the reduction of gravity above the disk is the difference in strength of gravity at the top and bottom surfaces of the disk. If that?s the case, any physicist can calculate it for you; and it isn?t much. Additional effects would be difference in gravity between one side of the disk and the other (even less), and averaging the peak and trough of gravity waves (I think they?re so small on Earth as to be irrelevant).
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Well, until we can develop a proper unified field theory and fully understand the nature of gravity, we do not know the answer to that question. Modifying gravitational influence may be:
A) Impossible
B) Possible but impractical
C) Practical
We simply do not know yet...
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You are referring to Podkletnov's Ring Robert? Iiii don't think that anybody has even been able to replicate the effect, and Tampere University & New Scientist have withdrawn papers concerning the work... Nasa has tried without sucess to make the thing work too, if memory serves.
Although we aren't sure, I think we can take a pretty good guess at "no," several hundred years of physics has not been vain idleness...
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Yup, I'm referring to Podkletnov's idea. It's the only progress on anti-gravity. I read something about a non-symmetrical capacitor but that works by inducing an air current. Podkletnov's work is the only thing with any promise to affect gravity in any way. There are some people who will dismiss any progress because it isn't their idea; I don't dismiss his work, but I think it has practical limits. You can't create a perpetual motion machine or violate the laws of physics. I do have a copy of his paper and that paper did report an updraft within the area above the spinning disk. That would be consistent with reducing gravity: it would reduce the weight of air pressing down so it would reduce pressure, air would rush in to the reduced pressure area, but leak out in the upper column. This strong up-draft would consume energy. That energy has to come from somewhere, so the power maintaining the gravity shield would provide it. I also read that NASA was interested and funded a project to recreate it, but the two scientists working on it got into a squabble and refused to continue to work with each other. That stopped the project. If NASA has continued the work I would like to read it.
It's an interesting project. E.E. Podkletnov was experimenting with a continuous change from superconductor to normal conductor just to see what would happen. Spinning and magnetic levitation are the traditional means to demonstrate a superconductor. He didn't expect to create a gravity shield, but a wooden weight suspended on a cotton thread in a glass tube above the disk does have reduced weight. The glass tube shielded against air flow, glass and wood are not magnetic. All very interesting. If there is something else at work, it would still be worth investigating. Remember, the "cold fusion" fiasco? That wasn't nuclear fusion but I believe it was a way to unbalance the modes of heat. If you can increase the translational mode of heat and reduce the electronic mode, then you make heat easier to transfer across a heat exchanger. That principle can make power plants more efficient, so it's still worth investigating. I'm sure I read that one scientist was able to replicate Podkletnov's work, although not to the 2% weight reduction. If it isn't a reduction of gravity it could still be a practical and valuable technique. Since it's the only lead to affecting gravity at all, I say it's worth a try. Let NASA complete at least one experiment to recreate his results. After all, what does it take? One scientist and one ceramic disk, a magnetic thing to hold it and some liquid nitrogen. That sounds like a university lab experiment.
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It is not progress until it is proven to work
Frankly, I reguard Mr. Podkletnov's device with great skeptisism and if it were so revolutionary, it would be all the buzz in physics and media... no buzz that I can see... are you really sure that you read that someone replicated his results? I have trouble believeing that the "experiment" was conducted in the first place.
And "building a disk..." that withstands the strain of spinning at 5,000rpm while several hundred degrees below zero that is made of a material (the superconductor) the consistancy of pencil lead... takes quite a bit.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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It's amazing that we can look at the physicists from a long time ago who said the Earth was flat and you'd fall off the edge if you sailed too far and laugh at them. The funny thing is that they KNEW they were right.
I would think we would be more objective today but that doesn't seem to be the case. Why are far-fetched ideas always greeted with skepticism? I could definitly see anti-gravity vehicles and spacecraft within my lifetime. Heck, in 1900 the airplane was not invented and in 1969 we walked on the moon. I frown upon any scientist who says something cannot be done no matter how far fetched. I sense that same sort of skepticism in this very thread.
The spinning disk seems interesting but I was refering to a 100% reduction in weight ? la Star Trek. I have no doubt this will be developed at some point in time.
Danny------> MontrealRacing.com
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It's amazing that we can look at the physicists from a long time ago who said the Earth was flat and you'd fall off the edge if you sailed too far and laugh at them. The funny thing is that they KNEW they were right.
I wouldn't stretch that analogy so far. Our current science is based upon hundreds of years of observations, iteratively improving our models and understand of the laws of nature. (From Newton's simple physics, to Einstein's relativity, to Quantum physics, to ... well whatever comes next) To compare that with the dogmatic beliefs in the middle ages is just absurd, IMO. They did not even wont to look into early telescopes, to get visible proof that the moon was not a perfect sphere. In addition, the flat world idea was just based upon an assumption, not actual observations.
The scientific community does have a lot of inertia and can be conservative, but don't confuse that with being dogmatic. The moment anyone can come of with a reproducable exeriment that demonstrates ability to modify the effects of gravity (or "cold fusion"), I can guarantee you that pretty much every physicist out there is going to be itching to work on it.
To know you are right is not the same position as wanting proof. Any scientist worth their salt knows that our knowledge is not complete by any means.
The funny thing is that they KNEW they were right. ... I have no doubt this will be developed at some point in time.
I hope you see the irony of these two statements of yours...
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I don't see any irony. They are meant to complement each other. The first one shows the ignorance of the middle ages and the second was a response to the same ignorance I percieve today.
Danny------> MontrealRacing.com
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Hydrogen and Helium defy gravity. Both elements make it through our atmosphere every day to space.
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Hydrogen and Helium defy gravity. Both elements make it through our atmosphere every day to space.
They are still normally bound to the planet by gravity, or there would be none at all. It is only when they are acted upon by some external force giving them enough energy to reach an escape velocity which if the motion of the molecules/atoms is in the correct direction means they exit the atmosphere into space.
There was a young lady named Bright.
Whose speed was far faster than light;
She set out one day
in a relative way
And returned on the previous night.
--Arthur Buller--
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What is that external force?
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Either solar, or collision with other molecules.
There was a young lady named Bright.
Whose speed was far faster than light;
She set out one day
in a relative way
And returned on the previous night.
--Arthur Buller--
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Can we replicate that force to send objects to space? Also,It will take millions of years to exhaust all the Earths H2 to space or even longer if comets add water to the Earth at the same time.
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Almost exclusively collision with other molecules; if a molecule is hit by a another one, momentum will be transferred. Now, if a slow molecule is hit repeatedly in the same general direction by many molecules, then it can take on a very high velocity, high enough to leave the Earth's pull. However, this is governed by temperature and statistics, it is possible but unlikly for a molecule to be hit like that and reach high enough speed, hence why it is very slow. The temperature governs how much momentum each molecule has, so if you raise the temperature you need fewer collisions to reach such speeds. The Earth, upper atmosphere imparticularly, is pretty cold though.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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[http://scitation.aip.org/vsearch/servle … &chapter=0]American Institute of Physics 2003 Conference Proceedings Vol. 654
I thought this was interesting. Download or view the pdf and take a look at page 1200.
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C'mon! Doesn't anyone like to read anymore?
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I'd read it if the PDF weren't password protected...
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Crap! I got it off of OhioLink. It is a college service.
Wow! It must be really important to keep out the hands of the general public. The pdf won't allow me to copy the relevant text. Just as well, I suppose, someone in the AIP may decide that the info is enough to sue over. It simply discussed research that scientists have done in gravity research. Some of it seems impossible, like reducing mass with electromagnetism. The paper is called "Implications of Outside-the-Box Technologies on Future Space Exploration and Colonization" by Theodore C. Loder III. He is at: The Institute for the Study of Earth, Oceans and Space; University of New Hampshire, Durham, NH 03824. 603-862-3151.
If you know a student in college, you may ask them if they have a resource like OhioLink. It allows one to read just about any scientific journal or paper published. If you have something like that in your state, it may be worth it just to take a class to get access. There is more info there than anyone could read. I just happened across the paper I cited. I suppose you could also join the AIP to see the paper. I wouldn't suggest doing that for that reason only. The paper does not go into great detail.
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some older stories on "anti-gravity"
http://www.janes.com/aerospace/civil/ne … _1_n.shtml
some discussion of podkletnov's concept
http://www.americanantigravity.com/podk … etnov.html
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More to figure out:
http://www.mail-archive.com/vortex-l@es … 4.html]The Problem of finding slight excess mass
http://tachyonics.com/]Dipole Antigravity
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Rather than an anti-gravity machine it would be better to have a gravity machine. Like Bob Lazar's crazy ufo propulsion system. Some metal called element 115 has a gravity field that extends out from the surface and somehow an anti-matter machine applies energy to it and the gravity field extends. The metal is ice cream cone shaped so the field generated surrounds the ship and extends very far. Supposedly this compresses all the gravity/space in that direction and the ship simply moves across this small area, then the machine is turned off and the ship appears in the other place.
The thing I found neat about it is it doesn't violate the speed of light but is capable of traveling much quicker than light.
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No gas "defies gravity" anymore then anything else does. All gas molecules are in continuous, random motion at various direction and speed. Sometimes, just sometimes, a small number of particles are accelerated by repeated collision until they reach escape velocity and traveling away from Earth. Only then do those particles escape. No magic. No trickery. No exceptions to the rules.
The energy that causes this random motion is thermal, or rather, this random motion causes thermal... If you add heat, then the molecules move faster. The trouble is, even at moderatly elevated temperature, the percentage of molecules that reach escape velocity is essentially zero.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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....actually, hydrogen and helium are preferentially lost because they're light. It's the same reason hydrogen is a preferred rocket fuel: its light weight means that it gains more velocity from any given amount of energy than a heavier molecule such as oxygen.
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