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Practical Gravity Shielding for Spacecraft?
Anonymous Coward writes, "I saw this site today:
'The Gravitational Spacecraft from Fran De Aquino
Warping to the deep space...'
A researcher in Brazil says that it can be done. What do you think? Anyone working in this area care to comment?
The site can be found
here." Slashdot has no official editorial position on the feasibility of gravitationally shielded spacecraft, but if anyone wants to send us a review unit, we'll gladly put it through its paces and do a writeup about it.
Well, ignoring the prospect of time travel (which the "scientist" in question does NOT pose as his motivation for making these calculations. I'll explain l8r), I'd still have to say that the guy is a nutter. True, it may be a THEORETICAL possiblity to negate gravity by shielding. But how will he in REALITY make a machine that not only holds ONE photon in a fixed postion relative to the machine, but an entire barrier of photons ? It's just not possible. You cannot get a photon to "stay"... These are not pets, they're not likely to do as they're told. And at any rate, if there's another physical reality INSIDE the "shield" (seeing as this would be unaffected by the forces of this universe), how would one define such basic terms as Velocity, or even distances relative to "Your" world. Nah.. This is just a load a cr*p, like the chicken and the egg, or the turtle and the rock and other such conundrums. Apply just the slightest logic to the arguments and they fall apart. As for the time travel issue: 1. I don't see the man claim to achieve such goals through the use of this technology, but on the other hand, if You create Your own little universe inside the shield, whos' to say that the laws of time would not be equally screwed up ? 2. Yes, i know that Gravity in extreme cases can attract light, thereby increasing/descreasing it's speed. But that doesn't mean that Gravity is the ONLY factor in theoretical timetravel.
IF it were 0 then it would not be effected by gravity and solar cells wouldn't work. Also gravity shielding is impossible since mass itself warps time-space and removing mass is impossible. WIth an external force you can counter-react gravity by not shield it.
Photons & mass: Ok, photons are made of energy, not matter. Classicaly speaking, they therefore can't have mass. However, in Quantum Mechanics, energy and mass are pretty much the same thing, just in different concentrations. It's been proven that photons have momentum, so they either have mass or energy. So I guess you could say that it's current mass is its momentum/c (velocity = c), and to get it's rest mass, divide that by infinity. (Or more accurately, find a number that when multiplied by infinity equals the photon's relativistic mass.) I'd like to shake the hand of the man who answers that one. Inertial frames of reference: It seems the discussion has moved away from this, but I'll mention it anyway. Einstein did say that there are no absolute inertial frames of reference. But there ARE absolute rotational frames of reference. Think of it this way: If you're in a sealed room with a pool table, can you tell by looking at the pool balls whether or not you're moving? Of course not. The cue ball will only react to an acceleration. Now, if the room is spinning, you'll see this on the pool table. Because everything other than the exact center of rotation is under constant acceleration. Issac Asimov's Psychohistory Also a forgotten item, but I like to hear myself talk. Someone here refered to it as a bunch of bullshit. Foundation was printed in the 30's. (I think) So to my knowledge, psychohistory is the first printed discussion of Chaos Theory. (Kind of a variation on thermodynamics.) Granted, the existance of individual people in positions of power proves that it can't be applied to people. But I'm still kind of impressed that he talked about a branch of science that wouldn't even have a name for several more decades. -Dave davester@provide.net
yah, april 1st isn't for another couple of days. or is this a warmup?
See, here where I am, it's 12:21am and I've been working in the studio all evening. This means that my comprehension of complex physics equation is lacking a bit (it may also have to do with the fact that he's using some funny characters).
Still, it seems completely feasible. If you can create whatever it is that makes that screensaver at the bottom, I'm sure you can push a spacecraft to superluminal velocities.
/me returns to staring at pretty swirly image.
I know of a company that are going to make an anti gravity system that can lift 160 tonnes and hold it hovering in the air indefinitely.
The system is called CargoLifter and it'll be used to transport extremely large and heavy loads thousands of miles by air rather than road.
Deleted
From the start of the website:
"As we know , the photon has null inertial
mass (mi = 0 ) and it doesn't absorbs
others photons (U = 0 ). So , if we put
mi = 0 and U = 0 in Eq.(1.04) , the result
is mg = 0 . Therefore photons have null
gravitational mass."
A little bit later, on the same website, we get this claim:
"This means that any body inside the
shield will have null gravitational mass
with relation to the Universe."
My answer: I don't think so.
Although photons may not have detectable gravitational mass, somehow, gratitational pull DOES have effects on light.
When lights from far away starts pass near huge stars and/or blackholes, the lights were bend somewhat.
That is an indication that photons _ARE_ effected by gratitational pull after all.
Muchas Gracias, Señor Edward Snowden !
How can you be the enemy of what you don't believe in? How many of you are enemies of Earth's other moon? (the delusional among you are excused from this discussion)
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Can/does a photon even exist if it isn't moving? Aren't they basically just radio waves fairly high in frequency/short in wavelength? Isn't a non-moving wave a non-event with non-properties?
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Pretty pictures, but he doesn't say, or even propose a way to build this "Gravitational Spacecraft". It works in theory, but thats like saying you could be anywhere, everywhere, anytime you want just by going as fast as the speed as light. When your able to buy a ticket, then it works.
Of course I been know to propose even more crackpot ideas then this, so who am I to criticize(sp).
Steve
Personally, I never trust these kind of articles until I've seen the application of theory in Mindstorm Legos.
Know what I like about atheists? I've yet to meet one that believes God is on their side.
I cant find a url for the program anywhere, but IIRC it wasent light per se pushing the spinining top up, but the air around the laser impact point becoming superheated.
And at the time of the news report that I saw, it wasent going up much further than 20m or so.
If the mark of a good April Fool's joke is the number of people who think it is serious, this one is a real winner.
(Posting the joke 2 days early is a little tacky, though.)
Any real scientist would rather spend time in the lab than creating pretty pictures. Just because you feel light headed doesn't mean that you've manipulated gravity.
Shielding gravitons with photons? First of all, all particles in the universe have SOME influnece of gravity and gravity can influence them in some way. Secondly gravitons have never ever ever been observed or proved with any real scrutiny, they're akin to WIMPs (weakly interacting massive particles) in that they are ideas and not much else. Tp null out gravity (in a way that has been proven) is to use two very large masses. If you're interested in the subject pick up a book on LaGrange's theorems. Maybe I should send this guy a copy...
I'm a loner Dottie, a Rebel.
hey.. personally i think the little "galaxy" java applet is cool enough it deserves to have Slashdot link to it all by itself. :)
it deserves at LEAST quickie status. At any rate it's more relevant than the page it's attatched to.
Then again, if the point of posting something on slashdot is to begin a discussion, Roblimo hit gold with this one. I've rarely seen a discussion so intelligent on slashdot. We need more theoretical physics flamewars here!
Irritable, left-wing and possibly humorous bumper stickers and t-shirts
Your argument would be true, but he measures
weight in [kg], i.e. he uses mass units.
In SI system, weight would be measured in
Newtons.
FYI, I have a Masters degree in physics and am
going for my PhD.
The rest mass of a photon is zero indeed. However, photons definitely carry energy, otherwise Sun wouldn't warm the Earth, lasers wouldn't burn and most of quantum mechanics would be impossible, because transition between different energy states would become unfavorable. Now we all know E=mc^2. Photons have E!=0, so their effective mass is non-zero. Indeed, light cannot escape black (sic!) holes because of this. In relativity, any energy clump bends time-space. Don't get hung up on the word mass (or weight, as the referred site seems to prefer the layman's language) - photons definitely bend universe, as would gravitons (if/when discovered). General relativity is highly non-linear. Live with it.
Yes, but what if it is not the light bending, it is space, and light is just following the path that space gives it. Beodd.
Well... just remember that all high-energy papers are preprints before they're published. 99% of the stuff on xxx really does get published and is meaningful science.
But as you point out, it isn't peer-reviewed, and anything that shows up there needs to be taken with a serious grain of salt until it's checked.
Saying "light bends in a gravity field" is different from saying "light has mass."
The bending effect is a distortion of space-time by the mass of whatever is causing it. For instance, our local star (yes, the bright glowing thing outside) is so massive that it actually warps the space-time surrounding it. When light passes through that altered space-time, it follows the contours of it. It's like threading a small wire through an uncooked elbow noodle - it's going to follow the curve. Whether the photons have mass or not is irrelevant to the issue; the photons will "curve" because the path they follow is curved.
Smaller objects (planets, humans, cats, the new Massachusetts quarter) also warp space-time due to their masses. However, the latter three objects provided as an example have such a small mass that the space-time warping is negligable. You'll never notice it, nor will anybody else. It's so small it is irrelevant.
As a result, the issue of whether photons having gravitational mass would now become: do photons warp space-time in their vicinity (even on infinitesimal scales)?
I, personally, would say no. Then again, I'm not a theoretical physicist, so many answer may be akin to saying, "Yes, of course the Earth is flat."
Oy vey.
Lets try this one again... correctly this time...
In water, with an index of refraction Nw (Nw=c/(velocity of light WITHIN water)), it is entirely possible that an electron exceeds the velocity of light WITHIN water (which is not c, but c/Nw). The (unhealthy) blue glow is Cerenkov radiation. The electrons do NOT go faster than c.
As for the rest of it, yes, you are wrong. Completely. Please review your copy of Sears, Zemansky, and Young, "University Physics" for more details.
It seems to me that the whole idea here is based on the assumption that gravity does not affect photons. This is an incorrect assumption. Photons ARE affected by gravity, this is theorized by General Relativity, AND it has been observed in real life. Basically GR says that as light passes near a gravity well (a planet) the light should be bent slightly. This implies that there has to be some sort of interaction between the photon and the graviton. So I don't think the gravitational sheilding would work.
Dude, pay closer attention in physics class.
...the word mass (or weight, as the referred site seems to prefer the layman's language)
He's actually using the two words correctly. Weight is the amount of force gravity exerts on an object. He is specifically trying to negate weight, not mass. The mass is still there without gravitational attraction.
Of course, he will have major problems getting the whole idea to work even if his theory is correct.
You never really know how close to the edge you can go until you fall off.
it's usually a pretty good sign that someone is saying something stupid.
In this case, it's basically someone with an AOL account who is capitalizing on the confusing things that happen to mass and energy at relativistic speeds to convince some people that he's invented an antigravity ship.
As many others have noted already, his assumptions about photons are a bit off (ie they don't have rest mass, but they do have four-momentum, which is what you really need to talk about anyway at that speed).
Also, the "superluminal" bit goes on the assumption that since his ship is "anti-gravity" it's "massless" and therefore can go as fast as it darn well pleases. This is false in enough ways that I'm sure you can all come up with your own.
Lastly, my impression of the overall idea is to use light energy to counteract gravity. Which is kind of like using rocket fuel to do the same, except it's much more efficient and we're no where near to possessing the technology to accomplish it.
Anyway, that's my 100,000DM (in less than 20 minutes, even!)
have a nice day
Actually, it *is* a particle in the sense of a proton/neutron! What exactly do you think a particle is?
:)
A particle is anything which carries energy or momentum. Period. In quantum mechanics, we can model vibrations of a lattice as collective excitations across the lattice ("normal modes").
These collective excitations are called phonons, sometimes called quasi-particles. But they are particles - they are absorbed, emitted, recoil, and diffract.
Quantum field theory (welcome to hell, boys and girls... enjoy renormalizations) is all about this - now, instead of some particles being collective excitations, *all* particles are
collective excitations.
This basically comes down to a question of exactly what is a particle, which is usually
covered in a second-semester or first-year
graduate course. Particle does have a sort
of rigid meaning, but you can't revert to
classical thinking all of the time.
Plus you just have to get rid of that wave-particle duality crap. Waves are particles.
Ever stand in an ocean? Ever get hit by a
rather strong wave? (Not a crashing one,
those are wierd... welcome to yet something
else that physics can't describe yet) You
feel it, don't you? But it's a *wave*, not
a particle.
Simple answer: collective excitations of "X"
field where X is some quantum mechanical field
are particles.
Note that a graviton isn't a particle yet. We don't have a quantum mechanical gravity field yet.
Oh, I quite agree- however, if you look at these papers, they're a strong argument for some form of peer-review on preprints. :) My personal favorite is the derivation of the second law of thermodynamics... note it closely and you'll see that it didn't require anything in the article at all. (Not to mention that it's a bit strange anyway, saying "F=E" and then in the next sentence saying "F=E-TS")
Note to all Slashdotters:
:)
They are NOT papers. They are preprints. Anyone and his brother can submit a preprint. They have NOT been peer-reviewed (nor are they likely to EVER be peer-reviewed) nor have they been published at all (nor are they likely to be published at all) because they're totally bunk.
xxx.lanl.gov (arxiv.org) preprints should not be taken as being fact. Hardly! Wait till you see something actually *published* and then you can take it with some conviction that it isn't crap science.
Do not confuse a preprint with a published paper.
Summary: A photon has both energy and momentum, which are dependant on frequency. They may or may not be massless, but if they do have mass, it's less than 10e-45 kg (or somewhere in that vicinity, I don't know the exact upper limit we've calculated so far... it's small)
Question: Why did you put a Kilo (10e3) on a gram unit that is so small? Are you trying to make it look even smaller?
Quack
As far as i can tell the aol webpage is done by some antigravity fanboy, Jean Louis Naudin. The person who actually came up with all this crap is Fran De Aquino from Maranhao State University, Brazil. He has his own webpage at:_ .g_;phys-9904018
http://www.elo.com.br/~deaquino/
He apparently has presented stuff in journals, at least according to the good folks at los alamos:
http://eprints.lanl.gov/cgi-bin/w3vdkhgw?qryRDAD2
The references cite that he's been in the Electric Spacecraft Journal, i have no idea what sort of a publication this is though, it could be a trashy magazine about UFO abductions or what not parading as a journal, i'm not too sure.
Well, if a star does not generate enough photons to cancel gravity then this gadget would have to have a greater photon density than at the surface of a star. For that matter, what effects does he predict from photon-gravitron blockage; it would be nice to look for such reactions in an appropriate accelerator...but his physics isn't at that level.
Yes, but it is mentioned that the iron absorbed all of what was emitted and confirmed with an ELF meter. So he created EM pulses from the opposing antennas, with the pulses traveling in coils in opposing directions with opposing polarities, and thinks that the resulting photons cancelled the gravitational attraction to/from the iron within the iron, and he thinks there was no leakage.
Actually, Photons have a zero mass all the time. What they have is momentum... it's kind of counter-intuitive to someone used to thinking about a Newtonian universe where momentum = mass * velocity.
:)
Turns out that that's only part of the equation, you see. Bottom line, photons have no mass. They do have momentum. If you really want, I'l calculate it for you.
The Signal/Noise ratio can be improved in two ways. Remaining silent is the OTHER way.
it already is a problem: this is why one of the mars probes kept going off course (the one with the unit conversion error) It only had one array of solar panels, so the solar wind produced an asymmetrical force (moment) on the probe and the gyros had to counteract it...
I read this in the IEEE magazine a while back.
...the /. story I needed to try and read after beer.
--
+&x
Photons definitely have a nonzero stress tensor and as a result do produce gravity.
Yup, thus explaining why halogen lamps always seem to catch any airborne object.
This reminds me of the book "How to Build a Flying Saucer" by Andrew Paulicki (not completely sure on the name, were is that darn book?). The math and some of the diagrams at the web site look damn close to the book.
--Somewhere there is a village missing an idiot.
now gravitational shielding. There must be something in the water.
Well, a photon has zero inertial rest mass. Which, since as far as we know, inertial mass=gravitational mass, would mean that a photon also has zero gravitational rest mass.
The bending of light doesn't occur in Newton's world, anyway. You have to resort to general relativity, and there light does bend, even though it doesn't have mass. So this doesn't neccessarily invalidate what he's saying. Though I'm personally very skeptical.
Of course, I am not a physicist.
??? is certainly the correct choice of symbol there. Not only is there no centrifugal force, there is no centripital force.
However, there is a centripetal force, which all the posters here seem to fail to understand. When you swing a ball around your head, it maintains its circular path because _you are applying force to it_ via tension in the rope. The name for this force which you are applying is 'centripetal force' , because your hand is at the centre of the circle and that's where the force stems from.
If you stop applying this force, the ball (surprise surprise) continues to move in the direction it was moving when you stopped applying the force, and at the same velocity. Note that this corresponds to a tangent to the circular path it was moving on before.
Now, this gives me an idea. Suppose this anti-gravity research is completed, and we have a portable device which can disable gravity locally (or even better, reduce its effect by a variable amount). When you engage this device, you would start to travel upwards (like when you release the ball, _as seen from the perspective of the ball_). Once you thought you were getting too high, you could re-engage your device and drop down a bit.
Coupled with some direction-control jets, we have a portable flight device. No more paying air tickets and waiting in queues at the airport!
And, to top it all off, this flight device could run a beowulf cluster of linux machines, and you could control its flight with GIMP. And, while you were passing the time, you could watch Natalie Portman pour hot grits down her pants! Perfect.
The superb sci-fi novel "The Mote in God's Eye", by Larry Niven and Jerry Pournelle, does in fact feature this. An alien society launches a probe which has a huge light parachute , and propels it for 35 light-years using gigantic ground-based lasers. :) )
(Until humans discover it and destroy it in paranoia... but that's for you to find out
That's bugger all energy. A couple of floors of an office building probably uses that much on its lightbulbs.
wrong, i don't have a link, but sometime last year some reaserchers created a medium in which light was slowed down to like 40mph.
c is the speed of light through a vacuum.
In Capitalist America, bank robs you!
How many electrical engineers do they expect to fool with this? It's a HUGE electromagnet! I can lift _my_ sorry butt with this. I sent them this email:
Greetings,
After reading the System-G website, I began to wonder if the weight-reduction observed was simply a magnetic effect; that is, the average value of the AC magnetic field pushing against the Earth's DC magnetic field. It seems that the hysteresis induced by the iron would yield a DC component of the magnetic field, that would exist even when the AC excitation crossed zero.
I know that the field was measured with an ELF field meter, but doesn't that simply measure the electric field? Moreover, it would seem that the annealed iron core would _increase_ the external magnetic field strength, not reduce it.
To ensure that this is indeed a bonafide gravitational shielding effect, it would seem that you would need to be able to discount any magnetic effects. Walking around the device with a coil connected to an AC voltmeter would measure the external magnetic field.
I wish you the best of success in your work.
Cordially,
(QuantumHack)
www.backwoodsengineer.com
This made me wonder again ..
.. what would happen then?
.. and does gravity 'suffer' from having to use so much energy to accelerate this object? (ie the energy has to come from somewhere?) .. and what happens when the object reaches the speed of light? (and infinate mass, but does gravity care?)
:)
What if you take a planet with gravity but no atmosphere, and drop an object, it would fall down and keep accelerating. Since there is no friction to stop it it's terminal velocity is infinite? So given that the distance to the planet is long enough for an object to accelerate that far, ie towards the speed of light
It's mass increases as it approaches the speed of light, but gravity doesn't have a problem with mass
Will it stick to the speed of light? If it did, would that suggest gravity is gravitons travelling at the speed of light?
Then again, IANAP
One of the first assertions in his argument is that the gravitational mass of a proton is equal to zero. However, since light is bent by gravitational fields, this cannot be true. I haven't yet dug through his math but I'm betting basing an argument on false assertions leads to false revelations. :)- -----------------
---------------------------------------------
James C. Diggans
jdiggans@excelsior-web.com
This is, of course, totally dependant if we could direct the thing in such a way.
:-)
If it nuked out all gravity, there's still be inertia and friction (both air[fluid] or whatnot, right?
It could save on gas, at least if you were going west.
Can anyone else imagine lifting off from a pole and watching the earth rotate under you? I sometimes feels small looking at huge buildings, but the whole world. Man, what a trip it'd be. I still want to be an astronaut.
Dan
Since stores won't allow you to return buggy software, maybe you could use this to go back in time and stop yourself from buying it. :)
My QM is a bit rusty (over 12 years now since I last used it in college). But, one thing I do remember is the demonstration of how QM based equations, when taken to their limits (i.e. nullifying the minor terms), resolve to their Newtonian counterparts. It's only on the quantum level that these other term become significant.
The second thing I distinctly remember is how, when applying QM to relativity, it was shown that a moving mass has the ability to "bend/drag" space in such a manner as to exhibit a "force" equivalent to that of gravity.
This would imply that "gravitons" don't truly exist, but rather are created to explain this "gravity" effect of moving particles. And, a pointed out previously, unless you are at absolute zero, every particle has momenentum (or a non-zero velocity).
It also implies that General Relativity has not been compromised by QM. Kind of reassuring, don't you think?
Now, I don't keep up on my QM (and my knowledge is a bit dated), but I found these two lectures particularly illuminating.
RD
This technology will not be useful for Mars missions
As one approaches Mars the mass of a proton doubles
and the charge of an electron halves (this could cause a premature engine shutdown.)
Also units of measurement change within the Mars gravitational well
(This could cause navigation problems)
"Thus the body can acquire large accelerations with small forces , in accordance with Eq.(2.05)."
Wait a second, they claimed to be reducing gravitational mass, not inertial mass. That wouldn't be true. What they should be trying to claim is that the spacecraft experiences little or no acceleration in LARGE gravitational fields.
If the body indeed acquired large accelerations with small forces, it would slam into the ground faster, not fly away.
I'm really waaaaaay too tired to be posting right now, but that's the centrifugal effect, which acts counter to the centripital force.
(QUIBBLE_MODE=0)
-NOC Monkey (OOK!) Experience is what allows you to recognize a mistake the second time you make it.
If we can indeed suspend the effects of the Earth's gravity, then it follows that a larger field would allow us to escape the Sun's gravity with greater efficiency as well.
This could give satellite mission planners many more options in the way they plot their trajectories. Instead of burning fuel, generate an anti-gravity field. trajectories of satellites
Wonder if it will be cheaper than rocket fuel?
The "aircraft" you are referring to do not rely on any sort of anti-gravity device. They work quite simply: A high intensity laser beam is reflected off of the craft's more or less parabolic bottom in quick pulses. The beam focuses to a point and rapidly heats the air. The following explosion is what propels the craft.
Of course, these are really just spinning discs about the size of a frisbee. Even with a full megawatt laser, they only go a hundred feet or so into the air. Hardly practical.
--Jeff
I thought the USAF were busy back engineering this stuff out in some desert somewere. must be hard, they've been at it for 40+ years.
Cats and Buttered Bread two days in a row! Yum, yum!
C'mon guys! Let's get some _real_ news up here! Work is very boring this week and I need something to keep my mind going.
"There is no reason anyone would want a computer in their home." -- Ken Olson, 1977
Thanks for the clarification... it's been a while since I've done any physics, and I guess I'm rustier than I thought :)
a real scientist wrote a piece of fiction which (iirc) implied that if gravity could be modulated we would be able to communicate at the speed of light squared.
Yes, ch-chuck, YDRC. As any real scientist knows, the speed of light in natural units is 1. In fact, I have sitting on my desk a $14 Panasonic clock radio that takes advantage of this physics loophole to receive Rush Limbaugh at the speed of light cubed.
In all seriousness though, when you square a dimensioned quantity, like velocity, you square the dimension as well. The number you then get is not a velocity. Also, by using different units, such as megaparsecs per femtosecond, the square of the speed of light is (numerically) smaller than the unsquared speed of light.
TMTOWTDI
I'm not the real Larry Wall, but I play him on Slashdot.
Do photons ever keep still enough for this to occur? I thought they went around at about "c"...
The original Doctor Dark.
Hey, might not be too bad for just getting off the earth in the first place :). It would save quite a bit of fuel which would be more useful for navigating outside severe gravitational fields.
You're very mistaken about what would happen. First off, shielding ourselves from gravity is not like twirling a ball around your head. That ball probably makes about 1 revolution per second. The Earth on the other hand makes one revolutoin per every 24 hours. That's 86400 times slower. So you will not be flung. For a little while you would not think that you anything was happening. Then as the earth's curvature causes the planet to move away from you, you would notice that you're feet nolonger touch the ground. I could do the math and give you exact numbers, but that it would take some time for this separation to become something to worry about, so you will have time to float around. You will not find yourself suddenly flung into outer space. Since you fly off at the same tangential velocity the world is spinning at, you will remain in about the same place relative to the surface, just getting higher fairly slowly.
"To save the planet, I had to go to the worst spot on Earth, and that was Philadelphia." -- Sun Ra
I mean the page was on AOL for crying out loud! How big a clue do you guys need?
"Prejudice is wrong; you should hate everyone the same."
No, Slashdot is all about hot grits, ninjas, and petrified Natalie Portmans. Where have you been?
"Prejudice is wrong; you should hate everyone the same."
Not to mention that he'd suck away our atmosphere.
I don't follow all the math on the site, but it seems to me that all they are doing is applying another force, counter to gravity. Just basic Newtonian physics. It works great in the lab, but the ship won't go anywhere.
But on the bright side, I'm really glad there are several folks in the /. readership who know even more physics than I do. Among my friends I'm almost always called upon as the "random science answer guy". It's nice to have a place I can turn to when trivia goes too far.
Read the original report for a much better description of how this is supposed to be accomplished.
~/cybe
1- Photons DO have an inertial mass (this has been known for ~70 years)... unless they are at rest (haven't seen a photon at rest yet!)
2- Photons do have a gravitational mass is some sense (this is the base for the General Theory of Relativity). Remember stars curving light (as they curve space-time).
3- "There is a photon in opposition to each incident graviton". This either implies that photons interact with gravitons (which is not true AFAIK)... or that the forces balance, which is not correct, since the "force" (due to momentum) exerted by a photon depends on its wavelength anyway.
4- If you can have zero gravity by "opposing photons to gravitons", then you can also have negative gravity, which would violate energy conservation laws, since you could build a mass that goes up and down without energy.
5- If you consider General Relativity: "There's no such thing as the gravity force, it's just a curve in space-time", then *any* object just follow the curve. Zero-ing the gravity would mean something like "I have a device that cancels the spherical curve of the earth".
6- His "formulas" rely on special relativity, while he says it would allow him to go faster than light, which is against special (and general) relativity (if that was possible, then he can't use relativity his calculations, since relativity would be "false")
7- I don't believe a word of that.
8- Don't believe everything that's on the internet.
9- Linux rulez.
10- Hey, that's ten!
Opus: the Swiss army knife of audio codec
I'm pretty sure the thing does fly... give me 300 A and I'll make your device fly. I'm gessing that the fact that his thing flies (if it does) is a side effect of the 300 A (you know, 300 A in a coil makes an interresting magnetic field)
Opus: the Swiss army knife of audio codec
...or give me a good laser, and it'll fly too. The only thing is that it's no going to be about photons and gravitons, nor photon momentum. I'll be because the photons of the laser will create enough heat to vaporize small particles, which will produce thrust (you know ye old jet engine!)
Opus: the Swiss army knife of audio codec
--
I've got nothing to offer but confusion - throwing muses
You suck... You aren't even funny...
What a shame it must be to be you.
We have 'smart' trolls here at slashdot, we don't need the silly ignorant type that you represent.
Even the hot grits guy is funnier than you.
You are the absolute WORST troll i've ever seen...
Damn... your own mama must be ashamed of you..
Fran appears to have re-discovered maglev; they already have trains running using this principle.
"Freedom means freedom for everybody" -- Dick Cheney
Weight reduction != mass reduction.
Secondly,
2) When the power has been switched ON, and the current reachs 300 A,
this is a lot of current. You could pretty easily have magnetic fields accounting for the loss of weight here.
It says Fran De Aquino has published a paper. No info whatsoever on where it has been published. According to the date in the document it has been published on 30th Jan. Why did nobody take any notice in the preceding two months?
I haven't gone through the whole thing in detail but on the very surface at least, the guy is low on theory and very high on presentation. What is the galaxy java applet doing out there?
I wish there was a little more checking before the submission is accepted.
FarHat
***Life is a sexually transmitted disease.
At the intersection of computation and biology.
--
Mike Hoye
You know what to do with the HELLO. ...
Help create an open-source world
Did anyone else notice that this person (or these persons) put up an AOL email address for you to contact them? That should be your first clue right there.
Windows is going the way of phlogiston...
There seems to be a lot of people arguing whether or not a photon can have mass. It seems that a lot of these arguments are just differences in semantics.
Here is a good link from the Relativity FAQ which may clear up some of these issues.
I think I'll build my ship out of caverite thank you. It's as plausible and involves less math.
So far I've gotten all my Karma from telling people they are wrong... :)
Maybe a good idea would be to pull this guy's formula's through a little dimensional analysis. I mean , he gives a formula for acceleration ending up on a unit of meters per second. Maybe it's just a typo but it's my belief that acceleration is usually given in meter per second squared. The common word for meters per second is 'speed' , not acceleration. I will try to find the time to look at his other equations as well , but maybe somebody else has already done that. Apart from that , countering gravitons with photons would be neat , especially since the least that that would prove is that there IS such a thing as a graviton , which is still very much in doubt. This guy seems to be banking upon a lot of unfounded assumptions and his report would have had some comments about its brevity and lack of thoroughness from some of the professors that I studied under !
Well, he doesn't claim to make the mass zero. And as long as it's larger, it wouldn't leave earth any more than a feather or a dust particle would.
Dag Liodden dag@liodden.no
...I love the pictures. Very nice pictures. Even if you don't understand a word the guy says, just go there for the pictures!
And second, I'm not really into physics, but if my understanding of Einstein's Theory of Relativity holds true, what this guy's saying is that if one could create a way (anti-gravity generators) to cancel the gravitational affects of mass to an absolute minimum or nothing at all, the energy created when light speed is achieved would by none at all, canceling the infinite amount of energy generated at the speed of light, making light speed possible.
...at least, that's what I think he said! (Can a mathematician or physicist help me out here?)
he will tie thin fishing string to each. I noticed that the shape of the spacecraft was strangly familiar... hrrmmmm... My question is simple, does the craft have tilt steering?
A magnetic field IS made of photons. Forget photons=light: only a very narrow frequency range of varying electromagnetic fields is percieved by our eyes as light, but photons(=quanta of EM field) can be used to describe anything from a static magnetic or electric field, up to the very high energies in the particle accelerators.
So yes, the guy has photons (low energy, but also the G field is low energy), but anyway the thing is flawed for other reasons...
Well of course! How else are you going to provide the energy this thing will take?
Sleep is just a poor substitute for caffeine, anyway. -Bob Lehmann
I want a gravity sheild and a gravity sword so I can go on a graviton hunt for EXP.
...
What do you mean it's not that kind of Gravity Sheilding?
----
Don't underestimate the power of peanut brittle
ADVENTURERS! - ANTIHERO FOR HIRE - CARDMASTER CONFLICT
Someone here doesn't seem to understand the different between intinsic rest mass and effective mass. A photon has no rest mass, but it does not ever rest, so we are better off considering how its mass appears to be, based on its interactions with other matter. The momentum of a photon is the ratio of Planck's constant to its wavelength or (p = h / lambda), which can also be expressed as the Planck's constant times the frequency divided by the speed of light (p = hf/c). We also know that the momentum of an object with mass is its mass times its velocity or (p = mv). For a photon in a vacuum, v=c, so doing some simple algebra, we can solve for the inertial or gravitational mass of a photon as being the frequency times planck's constant divided by the speed of light squared (m = h * f / (c^2)). I didn't read the web site in question very carefully because its fundamental assumption that photons have no gravitational mass is completely wrong which blows the theory out of the water before it's out of the starting gate.
For further consideration, consider that an object which is moving at a constant non-zero velocity compared to you has an effective mass which is greater than its (intrinsic) rest mass. Simple Relativity.
What's with all these anti-grav news items?
From what I can tell there are two feasable theoretical forms of gravity. The first being gravitational waves that are propagated from exotic particles called 'gravitrons' - and unless someone has formed a quantum mechanical model of the gravitron, then what's all the fuss?
The one I find more feasable is the theory that any mass in some way or another curves space-time from a higher dimention. If you have a basic understanding of Lagrangian/Hamiltonial dynamics then you would know that all systems containing a potential difference will attempt to change in order to minimise this potential. So from the perspective of a higher dimention, the fold trying to unravel itself back to it's normal state is in some way inverstly proportional to the gravitational potential.
i.e: It's a property of the universes' space-time fabric and not due to exotic gravitron particles.
So has someone been able to shild the folding of space-time in a higher dimension?
hmm.. oh well back to the smurfs and munchkins in a happy magical land.
- a graviton is still a theoretical particle and hence it's properties are unknown. Some have been theorised but I'd be willing to bet there are 2 theories for every property.
- leading on from 1, this person assumes that photons will interact with gravitons. If they don't then the two sail straight through/passed one another and your ship stops.
- assuming the two do interact, it seems reasonable (from my woeful understanding of wave theory) that you would have to frequency match your photons to gravitons in some way. This means you'd need complete detailed information of the gravitational field you're travelling through.
- point sources of photons (or anything else) don't exist.
- if you don't have your 'gravity maps' (from 3) then you'd need blanket coverage. So you'd be broadcasting photons across a huge spectrum.
- stars kick out huge numbers of photons all the time, but somehow, they're not shielded from the gravational forces of their planets?
- of course, the photon density of a star may not be high enough. This doesn't bode well for your passengers who are being bombarded by photons across the spectrum (see 5), including infra-red and microwave. They'd be cooked in an instant.
- another practical problem is getting the photons out through the skin of the ship in the first place....
- and on the superluminary travel, there's one small problem there. As soon as you pass light speed, you leave your shield behind
:)
Points 3, 5 and to some extent 7 are a little iffy, but the rest are fairly conclusive. As someone once said, you can prove anything with equations...Admitedly, my understanding of physics is a little weak, but i seem to recall that mass is independent of gravity, and that in order to accelerate something you still have to condend with it's mass, regardless of any gravitational forces acting on it (or not acting on it, as the case may be).
it must be possible to build a gravitational shielding around the source, at distance rs where the radiation density is such that there is a photon in opposition to each incident graviton.
OK, lets try a little practical experiment. I'll take this 9mm pistol, and you take this shotgun loaded with buckshot. The idea here is that i shoot at you with the 9mm and you deflect my bullet with a blast from your shotgun. Ready? 1... 2...
But wait, you say. Will it work? Well sure, theoretically there should be no problem... but I wouldn't bet my life on it...
Tell you what, just to make it interesting I'll give you a whole group of guys with shotguns. Of course, your team will have to be blindfolded so you can't tell where i'm shooting from, and maybe i should have a team too, all armed with machine guns.
I think this illustrates my main problem with this theory.
But wait, you say, what if i had a whole lot of guys with a whole buttload (that's a technical term meaning "more than a lot") of buckshot? My question to you is, where do you plan on getting all that buckshot?
Then there's all the issues brought up by other posters (some really excellent info here) like different quantum states, the fact that nobody has even found a graviton, yadda, yadda, yadda...
Even though there's no way this thing could work, I think it's great that the article was posted. It made me think about stuff that i haven't thought about for a few years and I learned a lot more from posters who are more informed than I am on the relevant subjects. So all of you who are complaining about this article being posted can blow it out your apathetic arses. Oh, and I'm sorry to have used the generic male pronouns above, but i assumed that women would not be stupid enough to participate in such a pointless waste of human life.
Under capitalism man exploits man. Under communism it's the other way around.
I don't know that much about physics, but the very last paragraph does seem the oddest of all: the mass of the spaceship is always zero, ergo the thing can reach superluminal speeds. Oh nice, at the very beginning, he says that the mass of a photon is always zero. So photons can reach superluminal speeds also, I suppose? ... heh :-)
Also, I'd like to see how big the radius r_s of that sphere turns out to be in practice
I believe the concept you are referring to is what is utilized in the (as far as I know completely theoretical) "solar sail" system (I'm probably way off... it's beside the point, anyway). But this would work only in space. The specific example you gave, however, is not an example of that principle. I forget where I saw it, but as the other poster mentioned, it was not the mass of the photons forcing the spinning reflector up, but the air being superheated. In essence, it's across between a solar hotdog cooker and a rocket engine.
The streets shall flow with the blood of the Guberminky.
You know, it seems to me that if you can bend light with the gravity from a star or galaxy or planet or what-have-you, then you cannot say, as he does, that a photon has null gravitational mass. Sure, it might if you could get one to hold still while you weighed it. But photons move. And therefore have energy, which, as has been drilled into everyone's head, means they have what you might call an inertial mass, so he's just wrong. QED.
um, linkwise, try this site:
http://www.eetimes.com/story/OEG20000328S0061
Ma Tin-Yuan
Who can't for the life of me think of a witty thing to say rite now
Correction: photons have *momentum*, but no mass.
White Holes are called STARS.
You can't handle the truth.
OK. Here's the deal. Photons have no REST MASS, but they do have mass. As was stated above, E=mc2, so they have mass, and are affected by gravity. If they were held at rest in your frame of reference, they would have no mass. That's (in part) why lasers can work. The coherent photons have no attraction to each other, so the beam propigates in a nearly lossless manner [this is not entirely correct, but mostly right, and should cover the topic for laymen.] If I throw a baseball, the velocity that I impart to it gives it a little extra mass. This change is negligable until the velocity is a significant portion of the speed of light, but it is nonzero nonetheless. So the fact that photons have energy and are moving guarantees that they will have some mass. But they have no rest mass. Contrast with an electron, which has a mass of 511 keV (in energy units.) Accelerate an electron to 0.9 c, and it will have a total energy of 1172 keV, or 1.172 MeV. So the total mass will be 1.17 MeV, and the rest mass is .511 MeV. For a photon, the total mass is a function of frequency, just like the energy, and the rest mass is 0. Hope this helps. P.S. - I am a physicist. Regards, Aeronaut
Never generalize
For objects in motion at the speed of light, such as a photon, this equation has no meaning since v will equal c and thus the denominator becomes zero.
As a result, it doesn't matter what the mass of the photon is, zero or otherwise, since the E becomes undefined, which fits perfectly with Heizenburg's Uncertainty Principle. So all these momentum equations are meaningless.
In any case, for those of you interested in this sort of pseudo-science, here's a book for you: How to Build a Flying Saucer, and other Proposals in Speculative Engineering by T. B.Pawlioki. I don't know if it's still in print but it's a great read if you believe in this sort of thing and a huge laugh if you know science.
Chris
Back a century into the past, there was a story about a man who built a ship that was shielded from gravity. He would break down the shielding in the direction of a massive gravitational body and allow himself to be pulled towards it. I have heard that most innovation comes from ideas in the past, but this is ridiculous. Half way through reading the page, I expected him to mention lowering the shielding to travel. Thankfully he did not. This is all I can offer. Even if the school I go to taught more than classical physics and calculus AB, the math would still be beyond me. In a school of 1500 students, only 8 care about gravitational lensing, or the possibility that millions upon billions of nanoscopic black holes exist in the world around us. Non-Euclidian geometry? Too advanced for the stupid people, and too expensive for the smart people. Sorry to turn this into a rant about education, but this guy obviously went to as bad a school as I do. This isn't an idea that would work. Even if we were a type 3 society, this idea would not work.
Pax Digitalia
Jesus saves.... but Gretzky gets the rebound!
- Rei
Pinkypants -- my favorite!
As far as the topic of shielding things gravitationally: Imagine a diffraction grating. You have areas where there are bright and dark spots due to the disruption of photons. If you can figure out a way to do the same thing with gravitons, you would have roughly the desired effect. But, given that we currently can't even detect a graviton, any motivation to shield against them seems a bit silly. However, this guy does seem somewhat clever, but here's my problem with his theoretical model. The coupling of a ship to a gravitational field implies a whole lot of gravitons. The paths the gravitons take are probabilistic, and in trying to shield against them, you constrain the paths they take but cannot eliminate all paths--a graviton cannot be absorbed by a photon without being re-radiated. This is analogous to shielding against photons: if you absorb a photon, you either re-radiate it (like a mirror or an atom falling back to its ground state) or you increase your kinetic energy. The later isn't an option for a gravity shield because the increase in energy means an increase in gravity.
Disclaimer: Quantum Geo Dynamics (my favorite term for quantum gravity) is not something I understand well (no kidding). However, nobody else understands it well either. Try doing a literature search for things written by Hartle, Penrose, or Hawking. They are generally more practical (though still sound like science fiction to most), and have much more scientific merit.
Network Security: It always comes down to a big guy with a gun.
They have really cool graphics on their site, and this is all that really matters. I have also noticed that the result of experiment with EXACTLY what there formula has predicted, and you can't argue with this, dude. The formula is really cool-looking too, by the way.
Wouldn't this be better as an update to the previous article, rather than a new thread?
There is no centrifugal force. (i.e. a force away from the centre)
If you spin an object at the end of a rope, it is constantly accelerating towards the centre, and not away. This means that a constant force has to be applied by the string to the object pushing it towards the centre. Remove the centripital force, and the object will go away at a tangent, not because of centrifugal forces, (which would result in heading away at a perpendicular) but due to the disappearance of centripital force.
hey, what about all the people who laughed at einstein for saying that it was possible for man to harness the power of the atom and destroy 2 Japanese cities, and make fish with 3 eyes, and make underwear glow??!?! u guys are being mean to this person! perhaps he just needs a good pharmaceutical?- --------------------
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and the speed the milkyway is moving!
The Kruger Dunning explains most post on
1. Your ball to earth comparison isn't correct. You need to know the distance the ball is from center, calculate the diameter. now for argument sake lets say the diameter of the circle the ball makes is 1 meter. that means the ball travels at 1 meter per second. the earth is 149,600,000 km from the sun. that means the Mean orbital velocity is just over 29 km/sec.
2. If gravity had no effect on an object that means not just the earths speed comes into effect, but the suns speed as well. because that object will become an ABSOLUTE point in 'space'.Which would be cool because we could us that as a tool to learn all kinds if information.
The Kruger Dunning explains most post on
experiment. This guy is alot different from other people I've talked to in the 'wierd science' culture. Namely, he gives full directions on how to build it and the equipmant you need appears, to me anyways, to be reasonable cheap to acquire.
so anybody out there with some spare cash and time want to try and duplicate his experiment?sure it's probably a hoax but it's a win/win. if you disprove him,most likely, you get to debunc his theory, and put up a web site se we all can get a chuckle. On the other hand, who doesn't want to hack gravity?
The Kruger Dunning explains most post on
...because my ISP banned the entire AOL.com domain after the ORBS announcement.
No, seriously folks. I read it. It's utter crap. Completely, total, utter crap. This guy belongs in a graphic-design firm, not a physics lab.
Ok, here's the part I'm not sure about (if I'm wrong, correct, don't flame):
His initial conjectures appear to be quite wrong. Due to the wave-particle duality of light, light can interfere, resulting in effects that can be considered absorption. Just because it doesn't work the same way as a kitchen sponge doesn't make it not so. I remember an experiment a few years ago that got a lot of hype for "teleporting" a photon across a room. Well, that was the press going wild, but they were able to carry one light wave on another light wave by interfering the signal wave with a polarized laser, and then crossing that carrier beam with another polarized beam to undo the change. Something had to happen to those photons.
Here's the part I am sure about:
This guy assumes that you can somehow cancel out "gravitational mass" and thus eliminate the effects of relativity. Even if we assume for the moment this is true, this would NOT allow superluminal travel. It would merely cause the body in question to behave somewhat like light. If the body in question traveled at the speed of light (relative to any frame of reference, since it's always the same) nothing inside it would age. Thus, you could never stop at your destination. I remember an experiment that has either already occurred or is ongoing to determine if neutrinos have mass. The way to determine this is to see if neutrinos can change from one form to another in their travel from the sun to the earth. If they can change, they must have mass, meaning that they are subject to the progression of time. If they do not change, this allows the possibility that they do not have mass, since a massless object is not affected by time and thus cannot change internally.
In addition, recent experiments (posted on Slashdot) have shown that even photons, massless though they may be, still have momentum, allowing the possibility of laser sails.
Also, if you think about how you would block a kind of radiation (gravitons) that has not ever been detected (meaning that it could be non-existant, or as some astrophysical observations of neutron stars suggest, possibly propagate by a non-particle means), even if it is in particle form, you'd have to hit it EXACTLY on with the photon. To my knowledge, basically all particles of this nature have such non-existant or extremely small size that they are treated as non-existent. Think about neutrinos, which may have mass. (I don't know how that experiment turned out) If you shoot 3 Neutrinos at a trillion mile thick wall of lead, at least one will probably come out the other side. (I probably screwed up something in that relationship, but you get the idea.) Light waves can interfere with each other because both involved particles have magnetic fields. Unless gravitons are electromagnetic (that's quite a stretch) they would be very unlikely to collide with photons. The reactor inside that fighter jet he's got on that page would have to be more powerful than the sun (and probably the entire galaxy, if not the universe) to emit that much radiation. Sure, it might not actually take a whole load of energy to do it, as his pseudo-science suggests, but where are you going to get a 1-planck light emitter?
Assuming this technology doesn't violate the laws of physics (which I'm pretty sure it does) it would certainly be infeasible. There IS some evidence to support gravity deflection by other means (also recently on Slashdot) but this is bogus.
WARNING: there is a trojan on your
"At the end of the journey, all men think that their youth was Arcadia..." -Goethe
- Where's my karma?
- On the parking lot son!
$HOME is where the
-- silver_p
Isaac Asimov explored the idea of Gravity Powered Spacecraft in the Foundation Series of novels. It is a wonderful idea, and although I can't vouch for the validity of the math on that website it certainly remains within the realm of theoretical possibility. However, since we don't actually know WHAT gravity is or how to generate a "Gravity Shield", it becomes obvious that this website is just presenting a concept, not an actual proposal.
"Remember, no matter where you go...there you are." -buckaroo banzai
There was something about using negtive energy to build wormholes/travel superluminally in Scientific American awile back. The thing was to get most of the stuff they were talking about to work, something on the order of 10,000 times the mass of the known universe would have to be converted into negitve energy.
From what it sounds like it will not really protect the ship the way the sheilds do in Star Trek but more like the deflector sheilds. That will push space debree away as you move through space. The therory is sound but if they can really get it to work that another story.
It's got to be accurate...didn't you see all of the pretty pictures? I'm convinced....
Rob, if I put up a site telling about how I was abducted by aliens and they gave me the secret to the perpetual motion machine, the 1000 mpg fuel injector that runs on water and a bible actually autographed by God could I get a Slashdot article too?
It seems that everybody is ranting about the homepage being hosted at AOL and having just comments and almost nothing of mathematics...
o /0/1/0/all/1/1
:-)
:-)
so here we go, first a link to a page at USP (Univerty of Sao Paulo) where we have reference to his works (two):
http://xxx.if.usp.br/find/gr-qc/1/Fran+De+Aquin
then we have a link to the "Gravitation and Electromagnetism ; Correlation and Grand Unification" article:
http://xxx.if.usp.br/html/gr-qc/9910036
if there is someone who can understand all the mathematics, physics and equations and can offer comments, it would be appreciated...
the second article's title is "Gravitation, Electromagnetism and Superparticles in the Initial Universe" and the link:
http://xxx.if.usp.br/html/gr-qc/9905050
with more equations...
By the way... the AOL page is much more beatiful than the papers
Truthfully, I have no idea if this is even feasable technology, but dem pictures sho' is purdy....
I didn't think that slashdot had an editorial position on anything!
That's right folks... It has now been scientifically demonstrated that it is possible to infer more about the world by staring at the contents of a rubbish tip, than reading slashdot. Rubbish tips contain the remains of societies most used goods, including discarded packaging indicating useful things such as food content, the largest corporates in the world (their names are printed on the side), and so on. In addition, staring at garbage can teach you a lot about the people who produced it. Staring at Slashdot teaches you that the people who run it are clueless nerds who have $old Out bigtime, and will publish anything to attract readers. $elling out is fine, but please people, stop reading Slashdot. It's now worse than garbage, and by you reading it, the crazy crew get more money from Andover (advertising).
The problem lies in the fact that inside your "gravitational sheilding", the craft will posses the same mass (inertial) that it has always had. Slap some engines on that baby and they will still have to overcome Newton's first law: an object at rest wants to stay at rest - the law of inertia.
The only way to get this thing to work is to have the propulsion module outside your gravitational sheilding. That way, the engines will be acting on a "reduced" inertial mass. So, how do you keep the propulsion module moving along with the craft but unattached to it?
Oh, and since the system described does not seem to affect an objects inertial mass, Newton's first law still holds. A mere 10N force will not give you 10^4 m/s acceleration.
The statement that photons can shield gravitation is stupid. Energy and mass are equivalent. Period. Photons are "massless" but not "energyless". Energy creates its own gravitational field regardless of mass. The most important bservation that confirmed general relativity was that light bends around massive objects, meaning light is affected by gravity. This page is drivel, my friends, pure drivel. Remember that an open mind and an empty head are completely different things.
Tony J. Fader - http://kona.superduper.net
Of course, Einstein himself demonstrated that light bends in a gravitational field...
....Paul
F U NE X N M? Son: "Dad... How do you spell 'hourly'?" Dad: "0 * * * *"
There's a patent filed in the early 1940s by Townsend Brown. Research this yourself, go to the patent office website and search on antigravity. That's what that weird dude from Area 51 saw, it's not alien. The technology has been around for a long time.
Scientists and engineers also have to take in consideration the fact that the sun makes a "pressure" on satellites that can change their trajectories.
And there is a possibility to make a solar sailboat, with a huge thin sheet of a resistant refractive material.
guillaume
give me all your garmonbozia
Fran De Aquino has published a paper ( released on January 30th, 2000 ) :" Gravitation and Electromagnetism: Correlation and Grand Unification ". This paper has demonstrated that a weight reduction of the System-G apparatus has been observed and experimentaly verified at room temperature. The experiment has also shown an important gravitational phenomenon; when System-G has been energized, it has been observed a GRAVITATIONAL SHIELDING EFFECT : the weight of everything inside of the annealed iron tube ( iron powder, ELF antenna,... ) has been nullified, the scale has just shown the weight of the steel tube with the annealed iron.
I haven't gone over the actual math, but it seems much too easy to be true. Show me the money (levitating spacecraft).
Uhh, that looks OK. We haven't seen that number yet.
photons can 'absorb' other photons: the collision of certain high-energy photons results in a matter/anti-matter pair; reversible: the collision of a matter/anti-matter pair releases energy in the form of a pair of photons.
The proof completely lacks any reference to equations which describe physical properties. That 'eq 1.04' is written by Fran, so of course it will produce the answer that a photon has null gravitational mass. Which isn't right, because photons have relativistic mass, momentum, and inertia. Thanks to the particle/wave duality of nature, though you might not be able to talk of matter when referring to a photon, but it is still affected and effects the rest of the universe.
There's talk of nullifying gravitons. Please, gravitons are theorized and still have no evidence as to their existence. Personally, I'm starting to believe that gravity along with 'dark matter' are sub-spacial effects from the extradimensional nature of the universe. Grep this /. article and its link.
By this point, I havn't even gotten past the first paragraph. And looking at the rest of the 'proof' is similarly... lacking. But seeing the really neat rendered graphics (nevermind the AOL host site), I'm tempted to say this is better off as an appendix to a web-distributed sci-fi graphic novel.
But let me give kudos to Andrea Fasce for the Galaxy Applet also running on the page. Schlick graphics.
As for the overall concept, there is some merit. There has to be some merit to wild ideas, eg Jules Verne. In this, not necessarily in reducing a spacecraft's inertial mass by shielding it from gravity, but in changing the properties of the space around it. Go pick up Six Not-So-Easy Pieces, and read Feynman's lecture on warped space-time. I don't think it'll solve the problem of making a ship go incredibly fast, but it could fix some of the problem of getting a human to travel interstellarly within their own lifetime.
But hey, I'm just another sci-fi buff with feet still on the Earth (last I checked).
Keep dreaming, keep reaching, keep working towards the unreachable goal. - me.
Yes, we understand these tags always apply: fud, dupe, typo, slashdotted, topic name
They craft consists of a reflective body which is gyroscopically-stabilized by rotation and is propelled upwards by a laser beam.
It has no other mechanism save for the groundbased laser whose light it reflects and by redirecting the photons(of finite non-zero mass) it gains momentum.
THere are some interesting articles here along a similar line at Nasa's BPP. THey are trying to develop propulsion where you don't have to throw mass out the back end of your craft (i.e. rocket fuel).
Where the hell are we going to get the dilithium crystals necessary for a warp field of this magnitude?
We don't have the goods to even produce a nanocochrane warp field, let alone a field large enough surround an entire starship.
Topher
Got Freedom?
1- Photons DO have an inertial mass (this has been known for ~70 years)... unless they are at rest (haven't seen a photon at rest yet!)
:)
If it was at rest, you wouldn't see it, silly
In post-9/11 America, the CIA interrogates YOU!
And perhaps its just me, but I have trouble believing theory posted on an AOL members website could possibly be correct.
If the human creatures will not understand Relativity, very well....Ursula K LeGuin
Hey that was sick. You're gross. You and your hairless hat should both go away..... Thanks for that....that was a totally appropriate response to a subject line that was complete BS.....does anyone actually believe what they're claiming on the website? I thought Slashdot had real geeks posting here. Were are all the physics majors to debunk this pseudo-science.
If the human creatures will not understand Relativity, very well....Ursula K LeGuin
ARRRRGH!! THE OCEAN WAVE METAPHOR!!
Is not the ocean wave composed of water and salt molecules?
STOP ASSERTING THAT WAVES ARE NOT COMPOSED OF PARTICLES - ALL REFERENCE "WAVES" -ARE- COMPOSED OF PARTICLES!!
With clear math like that, they couldn't possibly be lying. *coughs quietly* Not that I would know...
Just like room-temperature fusion.
OK, having seen this reference before, and never having seen the little note: The antigravity paint concept first appears in a turn of the century novel by H. G. Wells, which has a crew use it to take a globe to the moon, where they find gold, a breathable atmosphere, and subterranian natives. I wish I remembered the title... it was along the lines of Voyage to the Moon.
-- Still waiting for the Nike endorsement
Normally I would tend to agree with this comment as to the credibility of anyone who uses AOL. However, considering the author of the work in question is from Brazil, I find it very possible that this is a cultural difference. Perhaps in Brazil, AOL is the only ISP. Perhaps it is the only ISP that doesn't charge $50 per byte stored. Perhaps, in Brazil, AOL is actually the ISP that ALL respectable scientists use. Then again, maybe AOL is as worthless in Brazil as it is here, and this guy is a crackpot. At least it wasn't on Geocities, and I don't have 50 ad windows to close. -Ex
Then we solve it for mass:
-(SQRT((p^2 * c^2)-E^2)/c^4)=m
Shows that a highly energetic photon _can_ have some mass.
And how does it show that? (or is this just a troll day thing? I'm-a confused.)
I'm not sure where this "scientist" got the idea that a photon doesn't have inertial mass but he is wrong. This was one of the results of relativity. Photons don't have physical mass but they do have an inertial mass. Some interesting work has been done recently on light based propulsion systems in which the inertia of photons is sued to push an object through space. Since his entire argument is based on this idea, I have to reject his claims.
Photons don't have a null-mass, the formula's are incorrect because you need a relativistic approach. Furthermore, he is measuring nothing but lifting something with an induced current, so also the statement about needing less power at lower frequencies is incorrect. There is a known side effect involving gravity and supercondtors, but that's not yet explained (for as far as I know). I am interested in these things, but searching on the net only gave me long theoretically wrong and logically inconsistent stories.
Did anyone else right click on the animated graphics? Or view the source? This whole thread may be an advertisement for anfy. Or I could just be up past my bed time.
Assuming this worked what about solar wind? you still have a surface area for it to push upon. Maybe I don't understand these things as well as I should but this could really become a problem for setting a flight path.
So, photons have null gravitaional mass, and bodies with null gravitational mass aren't subject to relatavistic effects and yet, somehow, photons obey the speed of light?!?! Freaky.
Photons as well as bosons and gluons are pseudo-particles that cannot be used in such hand-waving arguments. They are concepts to deal with the quantum mechanical aspects of the fundamental forces. Nobody has ever detected a graviton although it it clear that there must be such a thing. The quantum mechanical nature of gravity is extremely unclear at the moment and is not explained at all by the standard model. In fact, this one of the central problems of physics at the moment and bright people are working on String Theory in order to get a clue. The answers to the questions about the relationship of gravity with the other forces (EM, weak and strong interactions) might be decades away. As for a serious discussion of gravity shielding, please wait for the grand unified theory that so many physicists yearn for. Anyway, talking about photons cancelling out gravitons is nonsense. This is simply not the case.
A couple non-tech quickies:
1) This would make more sense for hover-car technology, less for starship.
2) I haven't noticed bright lights interfering with my television reception, and they're both in the electro-magnetic spectrum.
I don't have my unified field theory ready yet, but it seems like gravity shielding would have to be in the same gravonic spectrum and act vector-wise out of phase.
Try shining two flashlights on the wall and get them to canel out ... this will give you an idea of how simple this process should be.
3) I hope I'm wrong, this would be so cool!
T.A.G.* You're IT
Inspired by Heinlin's 'Stanger in a Strange Land'
* - Hint: The "T.A." stands for "Thou Art"
T.A.G.* You're IT
Inspired by Heinlin's 'Stanger in a Strange Land'
* - Hint: The "T.A." stands for "Thou Art"
Before another 200 sudo scientists respond with to this posting, I suggest you check out the following site: http://www.inetarena.com/~noetic/pls/gravity.html It discusses similar gravity shielding experiments and has links to research NASA is doing in this field as well.
Fran De Aquino claims he made a gravitational shield. I can prove that he is wrong. He says that he used 220v at 52 A to subtract 23.8 Kg off the weight of the system. Well, let's say we give a 100 Kg mass enough power to subtract 100 Kg of mass. In this case, it would levitate. We would have anti-gravity. Experiment: ------------ Take this mass and place it in verticle vacuum tunnel. Nudge it a tiny bit so it creeps up very slowly to top of tunnel. (Using a minimal amount of force... This force is recoverable anyway but we just want to be conservative.) Turn off anti-gravity. (By cutting the power to the iron coils) It falls to the bottom, releasing lots of energy! Where did this energy come from??? Problem: How much energy is release when 100 Kg of matter is dropped from a height of 100 m on Earth? v = gt p = 0.5gt^2, 100 = 4.9t^2, t=sqrt(20.4) = 4.5 s v = 9.8 * 4.5 = 44.1 m/s e = mv^2 = 100 * (44.1)^2 = 194,481 joules (or 194.4 Kj) So, if you raise the mass by 100 meters while it is weightless, you are gaining 194.4 kJ of energy. If you could accomplish the 100-meter climb in a short enough time, it could possibly take less energy to raise the mass than what is consumed by the anti-gravity generators. This would violate the laws of physics!! Let's say the anti-gravity generator requires 22,000 watts to make the 100 Kg mass levitate. (I based these figures on Aquino's experiment) It would use 194.k kJ in 8.8 seconds so the acsent would have to average 11.36 m/s. If the average speed of ascent was over 11.36 m/s, you would gain more potential energy than what was consumed to levitate it. This violates the laws of physics so Fran De Aquino's claims areimplausable!
Only a few of the comments have hinted at the true nature of the device - it is a light-powered airship, essentially a floating light globe. One of the problems with this is that in generating the light there will be a fair quantity of heat also generated. This will probably cook anyone in the airship, or will it ? Traditionally we have thought that it was the buoyancy effect of heated air that caused the so-called 'hot air balloon' to rise, but now we know that it is the small luminous flame of the burner that does it ! (Coincidentally, the buoyancy effects due to things getting hot will make lab-scale testing of the anti-gravity generator very hard to validate.)
Very laughing this article. Do you think really that with a 300A current there is no magnetic field specially when the balance contains some metal pieces ? This is why, in his experiment, the wire weight from 39 kg goes to 19 kg. In addition, there are absolutely no considerations about influence of magnetic field on balance. It's only a poor experiment in edge of any scientific work with no consideration of surrounding effects. For the connection between magnetic field and gravitation, there is currently no theory which associate them (it's the futur part of grand unification theory on which thousands of physician works in the world). Thus, it's very funny that the guy, from very darkness formulae, arrives to prove existence of (anti)-gravitationnal field from existing models. In fact, I'm agree with the hope of this kind of discovery. It would be so great to travel through space (cfr. Cycle of Empire and Fondation, I. Asimov). But before, I is not with this very incredible hardware that you can fly... Wavman
He also explored the idea of "psychohistory". Whew, what a load of garbage that was. This is not as big garbage as it might look at first glance, although it was hidden into loads of mumbo-jumbo. I don't remember the name of the scientist who received a economics Nobel prize for describing economics as vectors, allowing predicting growths and recesses of economy quite accurately on big scale. He also postulated, that there are other factors, that influence his stuff, like new scientific breakthroughs, wars, etc. It is noteworthy, that current studies indicate, these factors can also vectorized and added to the formula, although slightly in different manner (like the number of you men in society are found to be asssociated how warlike the nation is and how easily it can be pylled into conflicts. BTW, the economical vectors are itself on reason for nation to be pulled into some sort of military campaign. It's also known that most of scientific breakthroughs are made, when nation is in the bring of war or already in war, because the need for new stuff is more important than ever from the surviaval point of view). So, although I don't agree the Asimovesque approach to the psychohistory, it's not completely without merit and should be studied in future.
@@ how do you know?
@@ have you seen a photon
@@ i have not
I suspect you have. I've seen billions of them.
dylan_-
--
Igor Presnyakov stole my hat
Yes in fact we do know that photon's have gravitational mass in the sense that photons generate a gravitational field just like other matter.
Yes photons have zero rest mass in the sense that a positive rest mass would result in infinite energy given that they travel at the speed of light. However photons are not in fact at rest and can never be at rest and do in fact have mass.
That photons have mass is easy to deduce from their possesion of energy and the equivalence of mass and energy. Moreover they must produce a gravitational field as they are affected by gravitational fields (gravitational lensing) and so by conservation of momentum must in turn generate a gravitational field.
Marriage is the "pseudo-ethics" that cloaks the messy truth of sexuality in the raiment of propriety -- it's "Don't Ask,
I'm hoping that someone can clarify this for me: I'm certainly not a Physics major, but if two particles come near each other and recoil from each other as a result of a graviton exchange, wouldn't that be a bit backwards from what actually happens? Namely, gravity is attractive (I think we all can agree on that!) and so it would seem that the absorption of a graviton would cause a particle to accelerate towards whence the graviton came.
Now, in my silly little physics-naive head, the only way to make this work with Conservation of Momentum would be to postulate that gravitons have negative mass. Is this so? Just curious. Last I heard the existance of the graviton proper hadn't yet been affirmed by observation and in fact this whole bit about integrating quantum mechanics and gravity was still causing some fair number of very intelligent people to bang their head against very solid objects.
I'd appreciate it if someone could screw my head on straight with regards to this: how does a graviton work? Might gravity actually not exhibit wave/particle duality? Please shake a clue stick in my direction.
David E. Weekly
David E. Weekly
Code / Think / Teach / Learn
h4x0r for
Anyone remember the old Ray Harryhausen movie where the mad scientist painted gravity-blocking paint over the space capsue? An I can't find an IMDB link or similar, so here's a private page about it.
I note from your formula that the gentleman's science reduces to BS. : )
I see even classic Slashdot is now pretty much unusable on dial up anymore.
They can't cancel each other out because the spin operators won't.
Why not do a review of something interesting?
I recommend Robert Forward's "Indistinguishable from magic" for a start. At least his devices, as impossible as they seem, are based on real science that could potentially be built with a future technology.
Regards,
Ben
My usual seat in the cluetrain is at A HREF="http://pub4.ezboard.com/biwethey.ht
Seriously - bending the topic from anti or shielded gravity to communications - a real scientist wrote a piece of fiction which (iirc) implied that if gravity could be modulated we would be able to communicate at the speed of light squared. So, if one of a pair of objects could be made to appear to change mass, how long does it take for the other one to 'feel' the change in force??
try { do() || do_not(); } catch (JediException err) { yoda(err); }
Seriously, any page that has the phrase "Free Energy" should never gain the honour of a /. story...
While slashdot can hardly be expected to be an expert in all areas of science, or to be a perfect, much less final, judge on the merits of specific scientific or pseudoscientific theories, I do think some common sense can be excersized in seperating speculative pseudo-science from hard science.
Perhaps a pseudo-science category, with an appropriate x-files or flying saucer logo, would be in order for articles such as this, which are on (or beyond) the fringe of conventional science. Save the scientific icon and category for hard, well established scientific articles.
This would IMHO boost slashdots credibility when publishing headlines for scientific articles, without censoring the more speculative (and often nonsensical) stories which, while having perhaps little scientific merit, do give some wonderful ideas for science fiction/fantasy stories...
Of course, there would be the incessant "this belonged in the other category!" arguments, but at least a nominal effort to seperate the wheat from the chaff would be a net positive, IMHO.
The Future of Human Evolution: Autonomy
May I suggest The Elegant Universe by Brian R Greene?
It offers an excellent, laypersons explaination for Special and General Relativity, Quantum Mechanics, String Theory, Superstring Theory, and M-Theory. It explains these theories and their ramifications in terms easilly understood, as well as their limitations.
You may not like Quantum Theory (Einstein didn't like it either), but it has been demonstrated to be correct, as far as it goes, as has General Relativity.
I too wish there was some way off this rock in our lifetimes, and there may well be if we get off our butts and build a space habitat or two. But, alas, unless M-Theory contains some interesting suprises for us over the next few decades (and it very well could), while we may make it into space, it is unlikely any of us will have the pleasure of walking beneath an alien sun, unless medical science delivers that immortality serum I've been asking for for years now, and we're willing to make a journey of hundreds or even thousands of years.
The Future of Human Evolution: Autonomy
- Well, they are, inasmuch as anything else is. A body in motion will tend to stay in motion. Other than that, they aren't perpetual motion machines, in the sense that you cannot get energy out of them indefinately, sooner or later they drop into their lowest energy state, and you can't get any enegy out of them (even if theydo still have a non-vanishing momentum)
- Not sure I see the diffrence. Every two particles with mass experiences an attractive force between them proportional to the product of the masses, and inversely proportional to the square of the distance between them. The force is towards the other particle, (this is easily demonstrated) so I'd guess you'd call it a "pull".
- This isn't a QM question, it's a relativity question (so is the last one, I guess), but I'll give it a shot anyway. It is the speed of light (in vaccum) that's constant. Multiple experiments have demonstrated this. A consequence of the effects that make the speed of light constant is that nothing can travel faster than light (also well demonstrated).
- This makes very little sense to me. Electrons are (mostly) conserved. (there are some processes that create/destroy electrons, but they all conserve charge, and/or other things related to charge). Why the universe has equal amounts of positive and negative charge is a somewhat open problem in science, but is a little deeper than your question goes...
heck me too, just this aint it. But the solar systems big 'nuff for my lifetimeQuantum physics and Newtonian physics. It sounds like you want the quantum world to be governed by the newtonian rules. I'm sure someone will correct me if I'm wrong, but that won't happen unless both fall under a Unified physics ruleset.
If you want a good general idea of why quantum physics is so odd, it's cause stuff always gets weird at extremes.
Bad Mojo
Bad Mojo
"If you can't win by reason, go for volume." -- Calvin
It's a bird!
:)
It's a plane!
It's, it's... Why, it's an anti-gravity donut stack delivery system. The future is looking good for law enforcement!
I like that java animation though. That's pretty cool. And probably the most technically impressive piece of the site.
-- What you do today will cost you a day of your life.
1) The website on AOL is someone paraphrasing De Aquino's work. De Aquino's own website isn't any better, but the papers in peer-review journals seem to be much better. Sometimes any of us can sound like a fool without a good editor.
2) I'm not sure you're interpreting 'gravitational mass' as Aquino intended. Specifically, De Aquino has papers addressing addressing the (non?) equivalence of gravitational and inertial mass (e.g.) as an underpinning of his (her) theories.
3) How do you reconcile the stress tensor and the type of gravitons you espouse (spin = 2, and therefore require quadrupolar transitions to be emitted) with the fact that gravitons must escape from black holes? It would seem that this type of graviton could not (as far as I can tell)? (Yes, gravitons interact with gravity. Hence the fact that gravitational fields have their own 'mass equivalence' induced gravitational fields.)
__________
If you can go to bed, knowing you did a valuable thing today, you're very lucky. If you can't... it's not bedtime
you talk about the two as if they were seperate things.. but in fact if you can control gravity you effectively have time travel cinched. If you take einstein's equations and make the variable for effective mass negative, you wind up with the time variable becoming negative as well. They said something like that in physics class. Or maybe that was when you're travelling faster than the speed of light..? Um, never mind. It isn't important. Trust me, i'm right. And if you don't believe me, i can make some pictures in KPT Bryce for you that will prove my correctness beyond a doubt.
Anyway, it is well known that there is a definate link between gravity-based travel and time distortions. The government scientists at Area 51 have been doing extensive testing and refining of aircraft with a gravity-based engine based on technology recovered from crashed alien spacecraft. It has been well documented that exposure to such technology frequently results in "lost time"-- things in the general area of the gravity engine temporarily move at a faster rate through time than the world around them, causing them to wind up having short amounts of time "disappear". We know this information, by the way, because agent Fox Mulder of the FBI was able to infiltrate Area 51 after the reality warping in the general vicinity after a gravity-based spacecraft malfunctioned overhead his car on the highway outside area 51 and crashed caused, causing Mulder and a high-ranking Area 51 official to temporarily swap minds in an episode spanning two weeks. As a result we were able to get much information about this fascinating technology that is directed gravity propulsion.
-mcc-baka
INTELLECTUAL PROPERTY IS THEFT
Irritable, left-wing and possibly humorous bumper stickers and t-shirts
(1) Very possibly. But the theory itself is still cracked.
:) Most importantly, string theory can correctly predict aspects of the low-energy behavior of black holes which show up when classical GR starts to fail. (Hawking's "information paradox" is such an issue)
(2) Nonetheless, de Aquino claims that the null mass of the photon (the vanishing of its inertial rest mass) implies that it is outside the effects of gravity. I argue that the way de Aquino referred to the mass of the photon as having to do with gravity is simply wrong.
(3) This is a good question and one that bugged me for a long time. The real answer is that the graviton picture - the approximation that the gravitational field can be decomposed into small excitations which behave more or less like free particles, with some additional interactions - is only valid in the limit of weak gravitational fields. For black holes and similar strong fields, the self-interactions of the gravitons are so strong that they can no longer even approximately be thought of as particles.
This actually is fairly closely associated with why quantum theories of gravity are hard. Basically one can show that a quantum field theory of spin-2 particles is inconsistent. It reduces to something consistent in the low-energy approximation, where gravity can be thought of as the exchange of individual gravitons. But as soon as the self-interactions of gravitons becomes significant, this picture of gravitons as particles stops producing meaningful predictions.
And this is exactly the point where we have to turn to our one well-defined and reasonably well-understood theory of quantum gravity: superstring theory. While this theory is not experimentally verified, there is substantial reason to believe it will be. (Which I won't go into now
So it's possible to calculate the gravitational properties of black holes using string theory and then back away and say: If I'm far away from the black hole, it just looks like an ordinary gravitating object, gravity is weak, and the graviton approximation should apply. Indeed it does; it turns out that, from far away, the black hole looks like a uniform sphere of radius equal to its event horizon, and as far as a distant observer is concerned, it does indeed emit gravitons from this distance. But all information about the internal structure of the black hole is kept within its event horizon; we can't see inside the horizon using these gravitons.
Yonatan
You are describing a radiometer, and the reason a radiometer spins is due to the black/white surfaces. Light hitting the black surface is absorbed, heating the air next to it, and causing an imbalance. It is not due to any kind of 'photonic pressure'.
Recall that his intent is not that radiated photons act as a propellant, but that they negate graivty, acting as a shield, to block gravitons.
http://linquirer.tesla.cx
So what exactly is the speed of gravity? I've always wondered about that one?
For some reason he's not using photons, he's using electrons in a 60HZ dual coil (two ELF antennas in a coil -- look at the diagrams and the coils are only connected at one end).
He doesn't describe the kind of table, room construction, or anything else which eliminates magnetic effects. Nor whether the materials might bend or expand when heated, causing the coil to lift itself by bending the input leads (and hundreds of amps should cause some heating...).
You are smarter than that.
;)
And there's another for the "Crackpot Theories" department.
Seriously, he's probably just bored and wanted to watch all the knees jerking.
The Signal/Noise ratio can be improved in two ways. Remaining silent is the OTHER way.
As might be evidenced by one or two "black holes" out there...
--The basis of all love is respect
So what exactly is the speed of gravity? I've always wondered about that one?
The speed of light, or slightly slower; gravitational waves are governed by similar constraints to the permittivity/permissivity constraints that govern light in normal space (ie. same medium, different units).
Simon
Coming soon - pyrogyra
I find this kind of story entertaining in a sick sort of way but my take on all these crackpots is that someday one of them will be right and they will get ignored. We've seen it before and well see it again.
I've read about quantum physics since I was about 10. I still don't buy it. I love Dr Feynman's books on sub particle physics made easy. One part I like the best is he makes a statement that any physical law that is complicated in the past has been untrue (early chemistry, astronomy, etc) but then goes straight into some of the most bizarre stuff in modern science. I think he was one of the few scientist that would have gladly thrown away all they knew about a subject if it was replaced by something simple and correct.
My basic problems with modern quantum physics include:
1) Electrons seem to be perpetual motion machines.
2) Does gravity push or pull and how would one prove it? If it pushes that would sure explain why all the Zero G crystal can be duplicated on earth.
3) Speed of light seems to lock down lots of physics. Is it the speed of light or the speed of gravity that is the limiting factor?
4) There always seems to be enough electrons.
I guess I'll be like the rest of the geeks and keep wishing that some one will find some way to get off this rock we call home before I die of old age.
Momentum, energy, mass and so on get a bit mixed up once you start dealing with special relativity.
In short, photons have no rest mass. However, they do have both momentum and energy, as those two are very much related in special relativity. Anything with mass or kinetic energy has momentum.
Therefore, being hit by a photon does give you a push, and shooting a photon off does make you recoil. Though not much. This is the principle behind light sails.
Here's a quick calculation of the power needed to run a 100% efficient spacecraft near the Earth (warning: very rough. =)
E=.5mv^2=.5m(10t)^2=50mt^2. (rounding, etc).
So in one second, E=50m=500,000J for a 10,000kg spacecraft... Thus, at LEAST 500,000J/s=500,000W must be used to counter the falling spacecraft, by basic conservation of energy.... That's 5,000 100W lightbulbs... This is going to be a BRIGHT spacecraft.
Where is he going to get all this energy?
PLEASE correct any wrong assumptions/simplifications... Just throwing this out there....
Move along, citizens. Nothing to see here. Just another inventor of perpetuum mobile.
--
Industrial space for lease in Flatlandia.
I think I caught the first booboo he made. Photons *do* have a rest mass of zero. But uh, they tend to travel at the speed of light relative to all frames of reference (or so I hear :). Because of some relativistic quirks, this gives them a slight mass.
Consider the speed at which the earth is spinning AND the speed at which the earth is revolving around the sun (about 18000miles/second).
Yes I realize how a TV works. How it works
makes perfect sense. A big coil that influences
the path of a stream of electrons.
I never said coild don't have uses. I just have
doubts about their ability to "nullify gravity".
Seriously...he is talking about photons...nearest
I can figure he plans to just shove so much
current through the wires that they glow like a
light bulb....then why use insulated wire? Where
will the light go?
Certainly that much heat (if thats what he
is doing) would burn righ tthough any
insulation I know of...furthermore the high
temperature would cause the metal to oxidise
very readily in normal atmosphere.
Yes it "seems bogus". No thats not a logical
statment. Its a gut feeling based on presentation,
and the fact that AFAIK the basic premise is
flawed. (not to mention that people have been
playing with putting huge currents into coils
of wire for a long time and mysteriosluy noone
has noticed this ability of theirs to
"nullify gravity".
"I opened my eyes, and everything went dark again"
I understand that those posting these news stories can't have full background knowledge on every bit of science involved, and that some things will sound good until the message board quickly fills up with what turn out to be really obvious flaws in the 'article'. Even so, shouldn't this have been taken with a grain of salt? An AC submits the story ($10 says it was the authors of the website), it's nothing more than a concept writeup on a user homepage, it has not even a GLIMMER of scientific scrutiny (doesn't come through scientific-news channels, no sign of it being submitted to any journals or universities or the like) ... the obvious prejudice of the AOL account isn't even NEEDED here.
Sure, it's possible that someone will come up witha revolutionary scientific breakthrough independantly, and publish it on their web site before the scientific community can applaud it. But what are the odds? If you really want to put up stories like this, go ahead, but don't pretend this is real science. Entertaining sci-fi, sure ... but c'mon, light being affected by gravity is knowledge just BARELY above high school physics.
You know what to do with the HELLO. ...
Help create an open-source world
Gravity Shielding, Anti-Gravity a while Back. Am I the only one to see the conspiracy going on here? Its an attempt to draw all the LINUX geeks into space on 'ISS Linux' and have the 'ISS Enterprise' shot it down?
-- Note: These Comments are Generated by ME! Not You! ME!
It looks like he is manipulating formulae in an odd manner...
And it looks like he is glossing over most, if not all, of General Relativity when it comes to spacetime, tensors, etc.
Even so, where do these photons come from? At what frequency do they have to be? At what power? Probably be so intense they'd ionize, if not completely shred, every atom nearby, including you and your spaceship. And he talks about cross-sections between the photon and graviton... Talk about mixing relativity and quantum mechanics! Not good...
At some level, this is all trickery, like Cold Fusion. Most physicists knew immediately that Pons and Fleishmann did not produce the level of neutrons they claimed, because if they had they would have been dead.
Now, I have heard a talk about negative matter (and negative anti-matter) which react like (-m) instead of (+m) in F=ma and F=GMm/r^2. But when a (-m) piece of matter runs into (+m) matter, they anihilate leaving E=0 ! Maybe the guy needs some of this stuff to build his shield. Dunno how tho... Even odder negative matter generates negative photons ...
Eric Aitala
www.f1m.com
hehe
Eric
Eric Aitala
www.f1m.com
Unfortunately for the poor crackpot - there are quite a few problems with his physics.
;-). (Light sails accelerate extremely slowly - and this guy wants to make something accelerate at 9.8m/s^2) Oops.
1) Photons _do_ interact. (Maxwells equations are linear - but theses are only an approximation of reality.) If you use relativistic quantum mechanics - you will find that there is a fourth order diagram where two photons can interact via the exchange of electron / positron pairs. This means that his parameter U is not zero as he claims.
2) Photons do have zero rest mass - however photons contain energy (E=hf) This means that they contribute to the Stress-Energy Tensor T_ab
Now G_ab = 8Pi T_ab Where G_ab describes the curvature of space-time. This means that if you have alot of photons - you can curve space. This means that his approximation of zero graviational mass for photons is also wrong.
3) For his machine to work - it needs to radiate photons. Now this costs energy. I don't think he has calculated the amount required
There is one final hint that something is wrong. At the bottom of the page are the plans for a perpetual motion machine - always a tip off....
"Would you like a cold drink with that Sir? Yes, yes, for the sake, of the future, of all mankind, I will have, a sm
The momentum formula p=mv and many other classic formulas only apply to non-relativisic velocities, generally meaning they'll give acceptable answers when v ~0,1c (10% of light speed).
//ASCII algebra suck, I know
The relativisic expression for momentum (p) is mv * gamma, where gamma is something called the Lorentz factor, (1-(v/c)^2)^(-1/2)
If you insert the values for a photon, m=0 and v=c, you get p=0/0.
As all who have studied higher math whould know, the answer 0/0 doesn't really say us much, it could be virtually anything. 0/0 usually means we have to use other methods to find our answer.
To make a long (algebraic) story short, the formula for a photon's momentum is p=E/c, where E is the photon's energy. E is expressed by hf (h=Planck's constant, f=the lights frequency), thus giving us p=hf/c or p=h/lambda(=wavelength)
Dixi
---
It seems slashdot.org is slashdotted all the time
A poster in a previous article was right. Slashdot has achieved the quality of weekly world news. The submissions often have spelling and grammatical errors, and I think pretty much everyone, however idle they may be, has something better to do than look at this tosh. Maybe if I write up a dodgy page about free energy machines using some error ridden maths (remember folks, often mathematical errors are difficult to find), and explain how men in black helicopters are stopping me from saving the world with it, I'll get slashdotted. Of course, these men in black helicopters are hired by the EVIL M$, who the Slashdot crowd ridiculously seem to believe to be worse than mining companies, agri-business, banks, and military-industrial complex corporations.
IANAPP (I Am Not A Professional Physicist), but I believe I can answer some of your questions.
:)
> 1) Electrons seem to be perpetual motion machines.
Not really, it only seems that way. Entropy (slow loss of energy due to friction, gravity, magnetic fields and other elements opposing the current state) does happen, but is not observable in any way that a human would be able to notice, except for mathematically. The electromagnetic interaction between a proton and an electron provides the centripetal force necessary to maintain the electron in a stable orbit. The amount of gravitational attraction generated by an electron is so small that the orbit will not decay naturally for billions of years. Note that in this case, when the orbit decays, instead of falling inward toward the proton, like a spaceship around a planet, the electron will actually fly away from the proton.
2) Does gravity push or pull and how would one prove it? If it pushes that would sure explain why all the Zero G crystal can be duplicated on earth.
All particles push on objects they collide with, however in the case of gravitons, my understanding is that they push on the fabric of space-time rather than the physical objects. This could be seen as a mathematical hack, though, since in effect this is the same as the object itself warping space-time, as per Einstein.
3) Speed of light seems to lock down lots of physics. Is it the speed of light or the speed of gravity that is the limiting factor?
It seems to be the speed of light. And it's not really a lock-down, just a natural limiting factor in many equations. In a hyperbolic formula, one could say the asymtopes of the equation are limiting factors in much the same way.
4) There always seems to be enough electrons.
I don't think I understand the question here
Enough electrons for what? There are atoms with fewer electrons than protons - they're called ions. You could just as well say there always seem to be enough protons, or gluons, or quarks, or photons, etc., etc. It doesn't mean anything.
In post-9/11 America, the CIA interrogates YOU!
In the future, it would be nice if Slashdot authors quietly discarded any "revolutionary physics" that have been posted up on web pages for some 2 years yet never mentioned in any scientific journals.
Think about it. Do you really think Slashdot is going to be the place where the Real anti-gravity breakthrough is going to hit first (esp. since this "research" is claimed to have taken place YEARS ago)? How many of these crappy web pages do we have to see posted on Slashdot before we figure out the pattern?
If nothing else, search for the phrase "free energy". That should be an immediate and conclusive clue that this article might not be all it's cracked up to be.
Not quite. A photon's momentum is related to its wavelength by the following relation:
p = h / lambda
so (p^2 * c^2) - E^2 = -m^2 * c^4 =>
((h^2 * c^2 ) / lambda^2) - E^2 = -m^2 * c^4
c / lambda = frequency, so:
h^2 * frequency ^2 = -m^2 * c^4
and h * frequency = energy (for photon)
so E^2 - E^2 = -m^2 * c^4, and c != 0,
so m must equal 0.
Unless you can demonstrate that either
h*frequency != Energy for photon
or h / lambda != momentum, both of which
have been established experimentally, you
cannot say a photon has mass (also see the logic in my previous reply to another poster).
Doug
Venn ist das nurnstuck git und Slotermeyer? Ya! Beigerhund das oder die Flipperwaldt gersput!
At first, this looks like a silly idea, using directed photons to counteract gravity. But, as shown by Einstein's mass-energy equivalence equation (E=mc^2), but expanded to include an object's momentum (p):
(p^2 * c^2)-E^2=-m^2 * c^4
Then we solve it for mass:
-(SQRT((p^2 * c^2)-E^2)/c^4)=m
Shows that a highly energetic photon _can_ have some mass. The problem is that the energy need is so high that any really significant change in the local measure of (g) would take enormous amounts of energy, most likely needing a direct-conversion reactor to genereate any usable mass. To give some scale to this, the fission of a single U-235 nucleus gives off enough energy to set off a mousetrap. And remember, a fissioned nucleus is not completely consumed. Only a small fraction of the mass is converted into energy. For a device like this to work, we would need to generate more energy than has been produced throughout all of human civilisation.
Nice use of Bryce, tho...
-NOC Monkey (OOK!) Experience is what allows you to recognize a mistake the second time you make it.
BS (Fig.1)
where B is a gravitating body and S is a grav-shielded spacecraft.
As the spacecraft has zero mass, it has zero potential energy with respect to the body. Now let's switch our shields off.
What happens? The spacecraft starts falling.
B<---S (Fig. 2)
This is because the spacecraft instantly acquires potential energy. This energy can be utilized when the spacecraft falls onto the body and emits lots of heat upon impact.
B*S (Fig.3)
(* signifies the great thermal explosion.) Let's switch our shields on again (presuming we've survived the impact). The craft starts to float away from the body.
Switch them off, we fall and generate more heat. On again, float away. Off again, falling, generating heat. Cycle through Fig. 1--3 ad libitum.
What we have is a perpetuum mobile of the first kind. Unless the energy required to switch the shields on and off is more than the energy we can generate. In this latter case, the shield is useless (what potential energy do you have with respect to the Andromeda galaxy?)
Note how we don't care about the exact means of establishing the gravitational shield. Use any method. Energy conservation means you cannot win.
Of course there's a smallish possibility that energy conservation does not hold. In which case we're better off fitting our cars and homes with perpetuum mobile. This has much more sense than exploring distant worlds.
--
Industrial space for lease in Flatlandia.
Ok...basically he has 2 coils next to eachother.
Look at the diagrams...thats all it is. A big
metal tube with a couple of wire loops inside...
looks like 2 or 3 turns each.
Now....he claims to be throwing 300 A into
this sucker...depending on voltage...thats a
shitload of juice. Perhaps he is producing a
magnetic feild strong enough, and properly
oriented so that the coil is actually being
suspended above the electronics in the scale
below it?
I dunno...it all seems really bogus. AFAIK the
generally accepted theories of Gravity state that
Mass warps space in 3 dimensions. So light is
effected by gravity only because the space it
is taveling thorough is bent (ie it follows
a straight line in a curved space).
Personally...I am very quick to call this pure
bunk. Its just too pretty. I notice he claims it
has been tested...yet there are no pictures of
the actual device...just diagrams.
It should also be mentioned that just because the
math works, doesn't mean it physically works.
You can play with math and make a good case for
"white holes" (ie the opposite of a black hole..
it spews out matter and never takes any in)
however...its just because the math works both
ways...there is no evidence that a white hole
would actually exist.
Perhaps this guy is just a crackpot...I would be
interested to see more evidence myself. Another
criticizm is...where are the photons comming
from? He is talking about radiation etc...yet
all he is really doing is dumping ALOT of current
through a couple of coils that are near eachother.
I am definitly skeptical.
"I opened my eyes, and everything went dark again"
Is it me or is it rather courious that these so called scientists have an AOL web page? I mean if they are reputible at all, won't they have a web page URL that either:
1] belongs to a commerical company
2] a university
but AOL? camon, no smart people comes out of AOL. no self respecting scientist would publish stuff on AOL.
Any crack pot [with some physics courses] can generate some mumble jumble drawing and formula and stuff. I won't belive it till its published in any reputible Science/Physics Journal [no, not the Playboy Science Section. The reputible journals have people that will analysis it and only publish the ones that are acutally true or promising, not any mumbe jumble. With the web, you can publish anything.
BOTTOM LINE: wait till its published in a scientific journal, that way its gone through some peer review and we can be sure its not all crap!
-- Note: These Comments are Generated by ME! Not You! ME!
OK, some physics perspective on this...
One-line summary: These guys are better at graphics than they are at physics. No, it doesn't work.
Since the discussion below is a bit more technical than I usually send to Slashdot, here's a brief summary:
* No, it doesn't work. There are in fact some very fundamental reasons why it can't be made to work, either.
* It can be shown (through some fairly messy math) that it is not possible to cancel gravity by introducing other particles, unless you somehow had negative-mass particles to strap to your spaceship.
* Even if you could do all of this, how would you hold a sphere of photons in place?!
The rest of this is a bit heavy, so you may just want to skim. If you want to get a fairly easy-to-manage and good intro to this topic, you may want to check out Rindler's _Introduction to Relativity_.
Okay, on with the show. There are three basic problems with this suggestion.
Problem 1: "Photons have a null gravitational mass." It is true that the rest mass of a photon is zero. (The rest mass of a particle is the mass of that particle as measured by an observer at rest with respect to it. Special relativity tells us that objects with nonzero rest mass must travel slower than light, and objects with zero rest mass travel exactly at the speed of light.) However, the "effective mass" of an object for gravity purposes is <i>not</i> its rest mass. The quantity which generates gravitational fields is a more complicated quantity called the stress tensor, which is nonzero any time there is energy or momentum in a system. Photons definitely have a nonzero stress tensor and as a result do produce gravity.
In fact, because of the way the stress tensor is defined, it is impossible to entirely cancel it with <i>any</i> configuration of masses, unless you somehow had something with a negative mass. If you find something like this please let the rest of us know; there are several well-known, mathematically valid, ways to design superluminal drives based on them. However there are also several results that quantum mechanics prevents the formation of more than infinitesimal quantities of such matter.
So that's problem one; photons don't have "null mass" (whatever that means) and so don't automatically cancel gravity. On to
Problem 2: If we had a shell of photons around our ship, they could exactly cancel the gravitons. Not quite. First of all, I should say that gravitons are the smallest quanta of gravity and are in many ways analogous to photons. (In the language of general relativity, where gravity is a stretching of spacetime, a graviton represents a localized deformation of spacetime. Similarly, a photon represents a local deformation of the electromagnetic field, which is the particle physics way of stating the fact that light is an electromagnetic wave.)
Now, the way gravity works (in graviton language) is that gravitons can be emitted or absorbed by anything with a nonvanishing stress tensor. (The bigger the stress tensor, the more easily this happens) So say two massive objects are moving along; Alice (having a nonzero stress) emits a graviton, and recoils by conservation of momentum. Bob (also having a nonzero stress) absorbs this graviton, and also recoils. So effectively both Alice and Bob have changed their momentum, i.e. exerted a force on one another.
Now, say I wanted to cancel this out with some shell of Mystery Particles which would give the exactly opposite forces. These particles would have to do a couple of things:
* First of all, they had better travel at the speed of light so that they arrive at the same time as the gravitons in order to cancel them out. So these had better be massless. (See note above)
* Second, they should be able to interact with any particle that has mass, and they should interact equally strongly with any two particles of the same mass. (e.g., if our mystery particle hit electrons twice as hard per unit mass as they did protons, they wouldn't just cancel the gravity, they would also knock about everybody's particles quite a bit.)
Now it turns out (and this would require some lengthy tangents to explain in detail) that these two conditions are enough to <i>uniquely</i> specify the properties of this particle! In particular, the particle must have zero mass, and (for those of you with some physics background) have spin 2 and be symmetric tensor fields. These are exactly the same as the properties of the graviton, which isn't surprising since these things have to cancel them. But...
* It's fairly straightforward to show (using a bit of field theory) that forces mediated by spin-2 symmetric particles are always attractive. (Like gravity, and as opposed to electromagnetism. EM is mediated by photons, which have spin 1 and can be either attractive [opposite charges] or repulsive. [like charges]) So unfortunately, no Mystery Particles can cancel out gravity.
OK, and just in case this isn't enough, one other point:
Problem 3: Even if you had some magic way of getting around this, e.g. introducing multiple species of graviton and giving them some extra interactions which let them exactly cancel gravity while somehow not affecting the ordinary operation of gravity in <i>any way</i>, (Which, incidentally, doesn't work; if these particles are just like gravitons, they should be produced in nature just like gravitons and so would be everywhere) How the hell are you going to keep a bunch of massless particles sitting in a perfect shell? They're <i>massless</i>. They tend to fly away.
(OK, and now a more technical note for those of you who bothered to read this far: There is actually one other possible way to satisfy the constraints for a mystery particle, allowing it to couple to matter identically to gravitons without also being a graviton. Namely, the particles can be part of a multiplet of particles which are related to gravitons by some continuous symmetry [discrete symmetries would just give multiple graviton species] and so all matter would have to couple universally to them as well. This could be done even for particles that did not have spin 2.
But some math prevents this from working. If we want our mystery particle not to have spin 2, the symmetry must relate particles of different spin. By a key result known as the Coleman-Mandula Theorem, the only way to achieve this is with a type of symmetry known as supersymmetry. If you do this, you find that it is possible to construct a complete suite of particles called a "gravity multiplet," consisting of the graviton and several particles with spins ranging from zero to 3/2, all of which couple universally to matter and do everything we wanted.
So does this solve it? Well, not quite. The condition for these supermultiplets to cancel gravity is very well-known; it's called the BPS condition, and it says that the objects exerting the forces on one another have to obey very specific relationships between their charges (electric and other) and their masses, as well as some requirements about their relative shapes and orientations. When you work it all out, there are a few very specific configurations where this happens, but (1) It doesn't happen for arbitrarily shaped objects like spacecraft, and (2) All of this would require that supersymmetry be present and unbroken in nature. This would have some <i>really</i> visible experimental consequences, e.g. atoms looking pretty much nothing like they actually do. Such a symmetry is quite definitely ruled out.
So I'm afraid that there's nothing of this sort that can cancel out gravity. Sorry...
Yonatan
You guys have lots of money now. Hire a freaking science consultant already. A responsible site that claims to be "News" does not put this story under the category of "Space" (thankfully it was not posted under "Science"). Put it under "Humor" or "Crackpot Theories".
It's time to realize that there is a lot of bogus stuff out there. Please don't be fooled. You are smarter than that.