Posted on 02/11/2006 4:31:06 PM PST by PatrickHenry
On Tuesday, Feb. 14, noted physicist Dr. Franklin Felber will present his new exact solution of Einstein's 90-year-old gravitational field equation to the Space Technology and Applications International Forum (STAIF) in Albuquerque. The solution is the first that accounts for masses moving near the speed of light.
New antigravity solution will enable space travel near speed of light by the end of this century, he predicts.
Felber's antigravity discovery solves the two greatest engineering challenges to space travel near the speed of light: identifying an energy source capable of producing the acceleration; and limiting stresses on humans and equipment during rapid acceleration.
"Dr. Felber's research will revolutionize space flight mechanics by offering an entirely new way to send spacecraft into flight," said Dr. Eric Davis, Institute for Advanced Studies at Austin and STAIF peer reviewer of Felber's work. "His rigorously tested and truly unique thinking has taken us a huge step forward in making near-speed-of-light space travel safe, possible, and much less costly."
The field equation of Einstein's General Theory of Relativity has never before been solved to calculate the gravitational field of a mass moving close to the speed of light. Felber's research shows that any mass moving faster than 57.7 percent of the speed of light will gravitationally repel other masses lying within a narrow 'antigravity beam' in front of it. The closer a mass gets to the speed of light, the stronger its 'antigravity beam' becomes.
Felber's calculations show how to use the repulsion of a body speeding through space to provide the enormous energy needed to accelerate massive payloads quickly with negligible stress. The new solution of Einstein's field equation shows that the payload would 'fall weightlessly' in an antigravity beam even as it was accelerated close to the speed of light.
Accelerating a 1-ton payload to 90 percent of the speed of light requires an energy of at least 30 billion tons of TNT. In the 'antigravity beam' of a speeding star, a payload would draw its energy from the antigravity force of the much more massive star. In effect, the payload would be hitching a ride on a star.
"Based on this research, I expect a mission to accelerate a massive payload to a 'good fraction of light speed' will be launched before the end of this century," said Dr. Felber. "These antigravity solutions of Einstein's theory can change our view of our ability to travel to the far reaches of our universe."
More immediately, Felber's new solution can be used to test Einstein's theory of gravity at low cost in a storage-ring laboratory facility by detecting antigravity in the unexplored regime of near-speed-of-light velocities.
During his 30-year career, Dr. Felber has led physics research and development programs for the Army, Navy, Air Force, and Marine Corps, the Defense Advanced Research Projects Agency, the Defense Threat Reduction Agency, the Department of Energy and Department of Transportation, the National Institute of Justice, National Institutes of Health, and national laboratories. Dr. Felber is Vice President and Co-founder of Starmark.
Source: Starmark [Felber's own firm, apparently]
So if one of the twins accelerates away from the other, then SR doesn't formally apply?
Well, first of all, for a flat spacetime, any problem in SR involving accelerations can yield the correct GR answer with a simple integral. But we don't need to go there, as we can take all the accelerations out of the problem, and the "twins paradox" remains.
Suppose we use constant-velocity spaceships. As ship 1 passes the Earth, it claps hands with a certain satellite--a tricky operation near the speed of light--and the event starts time counters on the satellite and on the ship.
The ship continues on some distance--half a light year, say--and encounters ship 2, heading for Earth. They clap hands as they pass, at which moment a counter starts on ship 2, and the counter stops on ship 1. Ship 1 communicates its counter value at the instant of the clap to ship 2, which adds the value to the total.
Ship 2 proceeds to Earth, where it encounters the satellite, they clap hands and the counters stop. The sum of the moving counts will be less than the counts on the satellite. The "twins paradox" persists, even in the absence of accelerations.
So maybe if you bump into it enough, the photonic friction will slow you down?
I don't see how this is true. All objects that are moving differently from the objects marking expanding space, have undergone accelerations. In the Spaceship examples, the path could have been a continuous smooth curve. The acceleration is still apparent.
"Human travel near the speed of light has already been proven and demonstrated countless times already by the French when they retreat."
Now that's funny!
Not exactly the answer I had been *hoping* to see, but still completely kosher. (Without loss of generality and all that...)
Thanks for posting, Physicist. I had been going to ask you again for links, but my train of thought while deciding how to say it gave me brainstorm on a way to find decent links on my own. :-)
Full Disclosure: I had SR as an undergrad but my graduate work was in a completely different direction, so I never got around to GR.
Cheers!
I know a Ph.D. theoretical physicist at a reasonable university and I've known him for 35 years. I'd trust his judgement. Here's what he has to say when I asked him what he thought of the paper:
"Not much. We have been accelerating particles to near (0.99999+) light speed for many years and have not noticed any "anti-gravity" effects.
A quick ArXiv search for any papers by Dr. Franklin Felber reveals ...
none. But he does have a Ph.D."
Looks like a publicity hound.
First, there's no preferred reference frame. There's no frame you can point to as having been "always at rest". The very word relativity means that all frames are equally valid. If you accelerate from one frame into another, you can't say that the new frame is "tainted" or less valid somehow. If your physics doesn't work equally well in all frames, it's wrong.
Second, you don't always know whether it's true that any given object has undergone accelerations, or what those accelerations might have been. I said "spaceship", but it could just as well have been an asteroid or subatomic thingumbob that has been at a constant velocity since the moment of creation. It wouldn't change the problem.
Third, it doesn't matter if the ships "have undergone" accelerations. The spaceships aren't accelerating in the problem that I posed. Everybody maintains constant velocity throughout the entire problem, from before the beginning until after the end, and still the counters don't agree, and that disagreement is quantitatively calculable based only on the velocities and distances.
In practice, spacetime is extremely flat, and the real twins paradoxes we employ as tools in the laboratory--using time dilation to prolong the lifetimes of B mesons or pions, for example--don't typically involve accelerations.
The reason I simplified the problem is because people were distracting themselves with details that were irrelevant to the fundamental issue, which is that two observers at the same place, but in different frames, view different sets of events as being simultaneous. The differences are physically real, and can be huge.
I was referring to the actual, literal twins of the paradox.
In practice, spacetime is extremely flat, and the real twins paradoxes we employ as tools in the laboratory--using time dilation to prolong the lifetimes of B mesons or pions, for example--don't typically involve accelerations.
I pinged you because I knew you'd used relativity it in your work, and that therefore you could explain the differences...
Thanks again for doing so.
Cheers!
Ah, my intuition (which is rarely reliable in such matters) has turned out to be correct. (Like a broken clock, I suppose.)
My problem was that I was conflating these two events into simultaneity -- "The pilot waits until a month elapses, and calculates what the time is on Earth. Only five days have passed; it's January 6th. Then he slams on the brakes, turns it around, and heads for home ..."
Quite obviously, a lot happens between the point at which he satisfies himself that he has gone far enough, and the point at which he actually turns around. A lot of "events" get telescoped into that interval.
Most of the infinite solutions would not produce our universe as it appears, but would produce other universes where the laws are different, and most of those universes would be very dull.
Or, if you just made a left turn, that would solve the problem.
To be fair, if you search Franklin Felber vs Felber, you could get different things.
In addition, it looks like 1-3 on your list are other topics.
4 and 5 appear on topic but I see no Journal reference. I admit I don't understand the ArXiv hieroglyphics, though.
Since I'm lazy I have not read the articles in detail, but I guess that those active in his field will do that at least on Tuesday. My 2 cents is that his conclusions are wrong.
I think I've introduced some confusion here. If the problem is looked at as assuming the frames of the spaceship and the Earth are symmetric, each inertial observer concludes the other has aged less. The only way to identify the correct frame for time dilation is to note which one has accelerated, or is moving with respect to the turnaround point.
The Earth observer sees the distant turnaround point as fixed and at a greater distance than the observer on the spaceship, after the spaceship hits cruising velocity. In your examples, the spaceship was always the one moving and frame symmetry was not mentioned.
That's not an assumption. That's a requirement of the principle of relativity. If it's not symmetric, it's not relative. You seem to want to believe that there is a "slow frame" and a "fast frame". That can't be right, unless one frame is preferred.
The only way to identify the correct frame for time dilation is to note which one has accelerated, or is moving with respect to the turnaround point.
Stop right there. Each observer notes correctly that time is slower in the other frame. All frames are equally "correct for time dilation". The final difference in the counters is caused by the fact that the traveller is not in a frame, but changes frames in transit. The difference between the frames, leveraged over the distance, causes the difference.
In your examples, the spaceship was always the one moving and frame symmetry was not mentioned.
Oh, no problem. Just turn the problem around: after one month, the Earth sends out a significantly faster ship to overtake the traveller, along with the homebound twin's time counter. From the traveller's POV, the Earth counter went outwards at some velocity from his (stationary) ship, and then came back to the same spot via another ship. When the ships meet, the counters are compared. Now it's the traveller's counter that has more counts, and by the same amount as in the first problem. The people back on Earth aren't surprised by the result, as the time dilation on the faster ship would be greater, of course.
Precisely. The solution to the twins problem is sometimes referred to as the "simultaneity gap", but I consider that a misnomer, because there isn't an actual gap, unless you contrive something like my acceleration-free example. But during the turn-around, there's a hell of a "fast-forward" that takes place back on Earth, from the traveller's point of view.
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