Slashdot Mirror
The Speed Of Gravity Revealed
redwolfoz writes "New Scientist is reporting that the speed of gravity has been measured for the first time. 'The landmark experiment shows that it travels at the speed of light, meaning that Einstein's general theory of relativity has passed another test with flying colours.' Researchers made the measurement of the fundamental physical constant with the help of the planet Jupiter. One important consequence of the result is that it will help constrain the number of possible dimensions in the Universe."
Wow, that's pretty cool. Now if we could only figure out why and how gravity works, we'd be in business.
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
is enormous!
Seriously, one of my favorite things from school used to be the concepts of gravity, and even the forces holding molecules together.
--------
Free your mind.
But of course, travelling at the speed of light, all the flying colours just appeared red due to the red-shift.
Does this make my brain look big?
Sure, this experiment will "help constrain the number of possible dimensions in the Universe" ... but will it lead to new weapons?
-kgj
I'm sorry, I don't mean to ask the stupidest question ever, but how does gravity have speed? The last I was taught on the subject (and believe me, it was a while ago) was that gravity was a force, but didn't have mass. Doesn't something need to have mass in order to have speed?
These are exciting times, we learn more and more about the fundimental nature of our universe, understanding more about our selves in the process.
Next, I propose we search for the speed of SMART, and find some way we can control it's direction.
THAT will be a great breakthrough for humanity.
Well, if gravity travels at the speed of light, wouldn't the gravitational pull of black holes be confined by the event horizon as is the case with light?
...a topic like this to be a bit more precise in the summary. There's a signifigant difference between .95 times the speed of light, and the speed of light. Not to mention the large .25 margin of error. Which theoretically shouldn't be able to get to +.25 anyhow.
Comment removed based on user account deletion
You're confusion arises because you were taught elementary Newtonian physics. In general relativity, one learns that any "information" cannot travel faster than light. Gravity is considered information because if you feel a gravitational force on you, you know that there is a body out there acting on you. That is, you have information about it (you could even estimate its mass by measuring the tug it exerts on you).
In Newtonian physics, lots of things are assumed to happen instantaneously (like gravity) so they don't have a speed per se. But in general relativity, everything has a speed -- and that speed is no greater than the speed of light.
GMD
watch this
Before the speed of light, everyone thought light was instantaneous. That is, when you turn on the lights in your room, theres actually an amount of time before the light from the light bulb reaches your eyes.
In the same way, if you suddenly created mass (ok this is impossible). It would take the same ammount of time for it to be attrached from another body... pretty zany.
"Kopeikin found another way. He reworked the equations of general relativity to express the gravitational field of a moving body in terms of its mass, velocity and the speed of gravity. If you could measure the gravitational field of Jupiter, while knowing its mass and velocity, you could work out the speed of gravity."
The theory of relativity was appearantly used to detect the speed of gravity. This would be fine if the theory of relativity didn't assume a speed of gravity. Basically, all he did was prove his given. So, if eggs are green, then eggs are green!
Karma Clown
Well, this says that Einstein's theory of relativity passed another test with flying colours.. but... According to THIS previous article on /. (and the NYT), the theory of relativity is generally flawed, so then did they really find the speed of gravity?
I'm confused...
[sig]www.masterslate.org[/sig]
light does not have mass. you may be thinking of momentum, which it does have... general relativity says that the path of light (at least as far as the light is concerned) is not really bent, but space-time is bent toward massive objects. the light just follows the straightest path it can, but in a black hole space is curled up so much that the light ends up getting trapped. to just say gravity doesnt have mass so it cant be pulled into a black hole isn't enough. because after all neither does light! you could see that since the space which gravity acts on does not appear to be bent (as far as we can see) then perhaps its path depends on another property of space-time.
The lion's share of the delay between the production of the actual photons and your perception of them is in your nervous system.
Sure, we could pull Saddam out of Iraq with a gravity generator ... pull out the Tigris and Euphrates, while we're at it -- the whole damned Cradle of Civilization.
-kgj
The article says that the discoverer used a reworking of an equation from general relativity and plugged in the mass and velocity of Jupiter to measure the speed of gravity. He ended up getting a result consistent with the predictions of general relativity. Am I missing something, or is this circular reasoning? IOW - Isn't this the same as saying: "Assuming A is true, I've proven B -- a result which lends credence to A!" There's something major I'm missing, so I apologize in advance for being an idiot and wasting our precious oxygen by sustaining myself.
If this theory of gravitiational propagation is true then gravity would have to exhibit doppler effects. The force of gravity would be stronger and act at a shorter distance towards the velocity vector of an object and conversely it would be weaker and act at a greater distance in the opposite direction in violation of the inverse square rule for gravitational effects. This has not been noted in any observations. All present observations of moving astronomical objects moving at anywhere near to relativistic speeds, or even those moving much slower taken as a statistical whole, show no such effect.
The observed effect is mearly an artifact of the observational process.
What next? The speed of magnetism?
I love it! Take a formula with an assumption in it, rework the formula, then get the formula to prove the assumption.
Example:
Let a = 2b + c (1)
a - 2b = c
-2b = -a + c
2b = a - c
Now substituting for 2b in (1):
a = a - c + c
a = a!! Brilliant!! Gravity travels at the speed of light!!!
So we prove relativity using relativity. Erm... what's wrong with this picture?
I am artificially intelligent.
Photons are not particles in the sense of neutrons, electrons et. al which are massy particles.
Photons are better described as 'packets of energy'. Gravity doesn't just affect mass - it affects energy as well. Light doesnt get 'pulled into' a black hole, it just gets redshifted so much (by the gravity sucking the energy out of it), that its wavelength becomes infinite, and thus immeasureable.
Photons can exert a pressure though because they have MOMENTUM. Thus they have a 'mass equivalent', but they do not have mass, and that is not why they cannot escape black holes.
-
gravity moves near the speed of light .95, but with a possible .25 margin of error, so it could be quite a bit slower too. now i think i will ask stupid question. Maybe gravity is some werid reaction, that everything reacts to, on a atomic level or something, it moves slower than light so maybe the atoms or molucles have to "see" and know theres gravity, so its a kind of information... hmmm gravity = information deliverd at lightspeed and activated (.05 the speed of light) later, fun idea.
From the article:
"We became the first two people to know the speed of gravity, one of the fundamental constants of nature," the scientists say, in an article in New Scientist print edition. One important consequence of the result is that it places constraints on theories of "brane worlds", which suggest the Universe has more spatial dimensions than the familiar three.
Three...!?
Aren't they forgetting? Professor Toichi Hikita and Dr. Emilio Lizardo already discovered the EIGHTH Dimension....in the 1930s!
"Folks just call him Buckethead." -- Les Claypool
So, Kopeikin used the equations of general relativity and found the same speed of gravity as built-in to general relativity... isn't that a bit meaningless?
Centralization breaks the internet.
Gravity distorts time. Hell, if you took gravity out of the equation instants would run together and all things which define time would go away- gravity causes time. [Okay, obvious problems with using the word "cause" here, but suffices to say that without gravity, you don't get time, got it?]
As you approach the speed of light, time is also distorted. At exactlty the speed of light, time for you is essentially brought to a halt.
What we're really looking at in these cases isnt the speed of light/gravity, because those are "instantaneous" [in quotes because of all this talk of what defines time]. What we're really looking at here is the speed of the universe- the maximum divisibility of time.
So "Gravity moves at the speed of light", no shit. Anybody coulda told you that forever ago.
I dont have a physics degree, I just say things. Unintelligent ranting follows.
-- 'The' Lord and Master Bitman On High, Master Of All
What about his Unified Field Theory? IMO that's where the meat is, e=mc^2 is just the sizzle to help explain it to the dumber scientists.
If all energy comes from a single origin, then it would make sense that they have the same speed (on or off, 1 or 0). Quite an interesting theory, i suspect that the final equation will have a third denominator though.
Hammer of Truth
and it has been /.'ed
Truth, Just Us, And Hatred For All Mankind!
'...meaning that Einstein's general theory of relativity has passed another test with flying colours.'
The above just made me remeber one of my school teachers. She used to say (translation from Russian) that "Einstein was just a pathetic jew who somehow for unknown reasons was let to do science."
Heh..
Well, now we have the speed of light AND the speed of gravity! If we can find out the Speed of Darkness, we'll be all set!
The sun couldn't suddenly disappear, although that scenario works for the purpose of explaining the speed of gravity. Consider this alternative.
Take the sun and instantly accellerate it to almost the speed of light, toward a collision course with Earth. For most of the 8 minutes between acceleration and collision, nobody would notice anything, as light, all other energy, and gravity would all present the sun as occupying its original location.
However, brief moments before the collision, the sun's change of accelleration toward earth will be noticed. Of course, you're noticing the change that happened 93 million miles away, even though the sun is about to impact. However, one second later, the sun will appear to be almost 186000 miles closer, and it will FEEL like it's 186000 miles closer. Suddenly the gravitational accelleration has increased to reflect the new position of the sun. But within that second, you get all the accumulated influences of gravity over a much larger stretch of space than just the 186000 miles it travelled in that time. Since the sun is moving at almost the speed of light, let's say 99% of it, after 99 seconds, the influence of the sun's gravity will only be 1 second ahead of the sun. However, within that one second between the position of the sun and the gravitational influence of the sun is contained the gravitational influence of the sun over the last 99 seconds. You get the combined force in 1 second that you normally would have gotten in 99. So when the Sun's influence is finally felt by Earth, you will not get a force that implies a steady rise in gravitational force of a sun massed object until impact, you'll get a very quick rise in force of an object that is, generally, about 99 times as large as the sun.
And if you remember relativity, when an object is travelling near the speed of light, the mass increases. So the theory at least makes sense. Here's another thing to ponder. If an object the size of the sun suddenly acquired the 99x its mass, would it not either collapse upon itself, or expand rapidly, nova, and the core would collapse upon itself, causing the same result, a singularity, with a small event horizon. And it will be this singularity that will collide with Earth, ripping through it in a fraction of a second, and the sudden, combined gravitational effect on earth will cause it to very suddenly pull out of it's orbit toward the origninal center of gravity of the sun, with a nice city sized hole carved through it.
Ok, this had no purpose at all, but it was interesting to think about. Go on with your business... nothing to see here. Rant over.
-Restil
Play with my webcams and lights here
While this is very interesting, is the speed of the propogation of gravity constant or can it be affected by certain conditions? This brings to mind the experiments at slowing down light in a special supercooled gel (is this an Einstein-Bose condensate?).
I don't think I like the idea of light being the fastest anything can travel, though. Perhaps it is for many things, but what happens if some forces travel at speeds faster (or multiples), or perhaps simple fractions, and we discount those readings instead of seeing if the old model can be adapted or remade? Well, many questions, few answers from me.
Does anyone remember the 'gravity shielding' story a while back, where a spinning superconductor was supposedly responsible for changes in weight? Podkletnov comes up in a google search for 'superconductor gravity shield' but I haven't heard anything further about it.
Also, what about magnetic forces? How do those work, and at what speed do they 'travel' ?
fair.org counterpunch.com truthout.com indymedia.org salon.com
eff.org guerrilla.net debian.org gentoo.org
..a landmark conclusion!. People have been deteting the gravitational fields of planets for a long time now, but is is just a new way of looking at it. Shows the power of the Theoreticians over Experimentalists.
:)
I think the single biggest news here is that the rane world has been constrained. I wonder if this has any implications on String theory.. with a max of 26 dimensions (currently 10 I think).
I DID read somewhere that the present Standard Model assumes this... speed of gravity is c, which means funds to the LHC arent going to waste, and places this 'experiment' in importance near to the '82 Aspects experiment.
So all this means we're doing good in Physics, and possibly should expect great advances this century. Now if only someone solves the EPR paradox for good, or produce an invention that utilizes it for higher speed signalling. I can see ISP bandwidths going higher and global pings lower already
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
I prefer to think of it as having no loose ends...
___
If you think big enough, you'll never have to do it.
So how is the universe accelerating. Didn't it used to be dense, if we can see back billions of years then why is the galaxy not slowing down by a massive gravitational force.
----
Go canucks, habs, and sens!
+/- .25c Margin of error? Geez, now I know that might not seem like that much but when you talking about the speed of light .25 times is one hell of alot.
.25 of that is 74,948,115 m/s or 20,818,921 km/h
Let's take a moment to work this out.
The speed of light, C = 2.99792458 x 10^8 m/s
Thats 83,275,683 km/h.
Rounding down, these scientists could be off by 20 million kilometers per hour, thats too much for my tastes.
From that they worked out that gravity does move at the same speed as light. Their actual figure was 0.95 times light speed, but with a large error margin of plus or minus 0.25.
So, really, they're triumphantly announcing that the speed of the light is somewhere between 0.7 c and 1.2 c, and just supposing it has to be c for everything to make sense.
Physicists have been accused of being loose with rigour, but this is really stretching it.
Exactly what I was thinking!!!
I found the results of this experiment particularly reassuring, in an era when all sorts of scientific and technical myths seem to crumble. I admit, after just reading the title, I thought to myself "well, it _ought_ to be the speed of light, but wtf, it's on Slashdot, it could be _anything_!!" but I calmed down quite soon after I read the rest.
:o)
Call me conservative, but I like it if at least some of the laws of physics I learned at school, still apply
Sigged!
+18 Charisma, that's how.
Imagine that the sun exploded, and formed two equally large fragments each traveling perpendicular to the plane of the solar system. (Similar to what Bruce Willis did to a Texas-sized asteroid in Armageddon.) The earth's orbit would not be affected for another 8 minutes. We would see the explosion at the same time that the gravitational perturbation arrived.
This is also why our perceived direction of the pull of the sun lines up with where it is now instead of where it was 8 minutes ago.
"mass equivalence" hmm that means photons are almost the same as that stuff that was laying on the plate on thursdays back at my old junior high. It was a meat-like equivalent.
So... if the Sun's gravity is pulling on Earth from where the Sun was (i.e. where we see it in the sky, not its actual position, which is about 8 minutes behind where the Sun actually is...), doesn't that kinda mess up the elliptical orbit somewhat? Shouldn't the Earth spiral into the Sun if gravity is pulling on the Earth at some eight minutes behind where the Sun really is?
Here's how we can do space travel.
There are a few laws of physics which are very fundamental and reliable. One of those is the law of conservation of momentum. The classical formula for momentum is as follows:
P = v * m (velocity times momentum)
The relativistic version is:
P = gamma * m * v, where gamma is the Lorentz transform. (gamma = sqrt of 1/(1-v2/c2)), and c is the speed of light.
OK, so the idea is this. As objects approach the speed of light relativity says that they become more massive. Therefore it takes asymptotically more energy to approach c. *But* if there were a way to reduce the mass of that object(by some magical means) then it wouldn't require nearly as much energy to accelerate.
Said another way, this magical technology could reduce an object's mass at the same rate it increased from relativistic effects. Thus allowing the object to approach the speed of light in a way that's energetically economical. An even better option would be to take a spacecraft wieghing say...100tons and accelerate it until it reached a speed of maybe 1000km/s. (This is possible with existing technologies, by averaging a constact acceration over 6 months or so). Then in the 2nd stage of space travel, you would invoke the *magic* technology to dramtically reduce the wieght of the spacecraft.
Since the law of conservation of momentum is true at relativistic speeds, the more the mass of the ship is reduced, the faster it would go! Said simply, if this new technology could somehow reduce the mass of the craft by 1000 times, it would then be traveling at 99% the speed of light.
Traveling at these speeds the people inside of the space craft would effectively "stop aging" with respect to thier destination. Here on earth thousands of years may pass in a single one of thier lifetimes. So we would never hear about thier journey. But the people in that craft would be able to travel all over the galaxy within thier lifetimes.
Basically it's just like star-trek, except more like voyager because there's noone to call home to anymore.
Everything here is completely feasible, and not wacko crack-pot physics stuff.
All someone has to do is invent a single technology that can reduce mass. Or if you prefer, a technology that converts mass to energy, and then converts that energy back to mass again at the flip of a switch. It needs to be 100% efficiect of course.
Any ideas on how?
*sheepish grin*
The government has a defect: it's potentially democratic. Corporations have no defect: they're pure tyrannies. -Chomsky
Sergei Kopeikin was my undergraduate physics prof.
He's one of the handful of professors I've had that really grok their discipline.
-- I'd say your post was about 3 monkeys, 18 minutes.
It's been awhile since I took any physics classes, but I do remember that the speed of light is 3.0 x 10^8 metres per second...that was the fastest anything could go, according to Einstein's theory of relativity. Now, I know that this speed is only when in a vacuum. Light moves slower in water (2.184 x 10^8 metres per second, if I recall correctly...it's supposed to be approximately 3/4 the speed of light in air). So does gravity move slower in water, and if so, by how much? Is it slower than light?
Defender of Microsoft and Communism!!!
YOU travel at the speed of gravity.
"In general relativity, one learns that any "information" cannot travel faster than light"
What about quantum pairs? Move them apart, and a change in one is reflected intantly in the other.
That's why I specifically said "In general relativity...". Quantum pairs are from the theory of quantum mechanics, not general relativity. Physicists have been working hard to try to combine relativity and quantum into a single unified theory. However, problems arise when the two theories predict different things -- such as the quantum pairs example you listed. According to relativity, there would be a finite time lag for the change to be reflected in the second entity of the pair whereas quantum would say that the change is instantaneous.
Incidently, I heard that a few years ago an experiment was performed on quantum pairs and, sure enough, the change was indeed instantaneous. Can anyone else corroborate this?
GMD
watch this
YESSS! In your FACE, Infinite-dimension Universe theorists! You SUCK!
Yeaaaaah! Gimme one up top, bro!
pr0n - keeping monitor glass spotless since 1981.
No, only massless objects can travel at the speed of light. Gravitons/gravity waves have no mass, therefore can travel at c. The reason objects with mass can't travel at th speed of light is that their mass increases with velocity in a parabolic manner, so the closer you get to c, the more mass you have. At c, you would have infinite mass, and require infinite energy to keep propelling you. this is why nothing w/ mass can travel at the speed of lite
"Light-speed gravity means that if the Sun suddenly disappeared from the centre of the Solar System, the Earth would remain in orbit for about 8.3 minutes"
Since gravity travels, dosn't that mean there is a possiblity that one can block gravity?
Because you don't need all those pesky unconstrained dimensions. Criminals can hide in them.
I hope everyone realizes this only provides us with an additional tool to help constrain the number of dimensions in the Universe. It would be both wrong and dangerous to assume that no more work needs to be done. We still have a long way to go. We are still living under the threat of unconstrained dimensions. Nevertheless, it is reassuring to finally see progress in this area, for a time I was very worried that we'd never be able to constrain all the dimensions. Congratulations to the scientists.
Einstein had a HUGE penis
I thought it was 9.8m/s^2
Gravity waves have been used in many stories as a FTL communication system, now that's all out of date.
Venus is a big swampy planet, eh guys ?
If we're going to generate a "gravity boom", I think we should start with a very small mass.
Ripping a nation out of the ground is one thing, splitting the whole planetary pumpkin is a more serious matter.
-kgj
The Speed of the Sound of Loneliness? Huh? Well?
Sometimes I worry that I'll develop Alzheimer's disease, but no one will notice.
When will people learn to give credit to Maxwell and HIS discovery that light has constant speed regardless the state of the observer AND that einstein was not the first that talked about relativistic motion?
Am I the only one that noticed some outrageous quoted starting salaries for some of these employers?
... and on the low side:
Employer/Starting Pay/Most common entry job
Intuit/$103,500/Software Engineer
AutoDesk/$100,000/Software Engineer
Intel/$79,249/Software Engineer
Cisco/$75,000/Software Engineer
Qualcomm/$67,000/Engineer
IBM/$66,400/Software Engineer
Adobe/$63,000/Software Engineer
FTNC/$34,000/Systems Engineering
SFC/$29,000/Programmer Analyst
Anybody from one of these companies want to chime in on whether these are for real? I doubt very much that they are.
Speed means simply distance divided by time. That distance and time don't need to fulfill any special requirement, any distance and time can be used as long as the resulting speed concept is useful. For example, with some types of waves you can talk about "group speed", which is not the speed of any material object. In fact, group speed can be above the speed of light.
About the speed of gravity, let's suppose you have two stationary particles: A and B. A experiments an attraction force directed towards B due to gravity. Now let's suppose B starts moving towards A. The gravity force experimented by A will start increasing -- but a certain time passes since B starts moving until the gravity force experimented by A starts increasing. If you divide the distance between A and B by that time, you've got the speed of gravity.
-- Repeat with me: "There is no right to profits".
I don't know much about physics, so this may not make logical sense. But is there a speed to electricity?
/There are 10 types of people in this world; those who steal sigs and those don't
Which episodes does this measurement contradict?
For instance, I could have an unconstrained dimension in my rear. Will some scientist please jam a stick into it and move me around like a little puppet? Thanks in advance.
You'll find that in the world of experimental physics nothing is ever perfect and for this kind of an experiment a 0.25c error is pretty good all things considered.
The experiment doesn't tell us that gravity travels at the speed of light, it tells us that the current theory which claims that gravity travles at c is consistant with experiment.
To quote Djikstra (more or less) "testing software can only confirm the presence of bugs, never the absence of them". In much the same way a physical experiment won't (in general) tell us that a theory is perfectly correct, only that it is wrong. This happens when an experiment returns results which do not include the predicted results.
This experiment tells us that all theories which predict the speed of g to be outside the range 0.7c - 1.2c are quite probably wrong whereas those in the vicinity of 0.95c are quite possibly right. GR predicts that g==c which is very close to the measured value, so it is in fact quite reasonable to claim that the theory has passed this particular test.
This experiment doesn't *prove* GR, it just goes to show that it is indeed a very good theory as it has shown throughout the past century.
Sonny Bono's failure to grasp rudimentary physics can be seen as yet another case of evolution in action.
But can Sonny Bono's failure to grasp rudimentary constitutional law be seen as yet another case of evolution in action?
Will I retire or break 10K?
In Newtonian physics, lots of things are assumed to happen instantaneously (like gravity) so they don't have a speed per se. But in general relativity, everything has a speed -- and that speed is no greater than the speed of light.
The only problem is that GR implicitly assumes that information is available instantaneously over great distances while denying its existence.
The reason is simple. In order for gravity to propagate at c and still result in stable planetary orbits, general relativists have to get on their heads and do a neutron dance, so to speak. They claim that information about the source velocity of body A is transmitted at c to body B. They call it "velocity-dependent interactions." This way body B can react to the actual (extrapolated, of course, from the transmitted velocity info) instantaneous position of body A. This way GR can reproduce the stable-orbit results of Newtonian gravity in weak field approximations without assuming instantaneous information at a distance.
The theory can be found in this paper by GR expert Steve Carlip.
The problem with this is that instantaneous information at a distance is implied from the start. How can body A know about its instantaneous velocity relative to body B (they could be light years apart within a galaxy)?Furthermore, if the instantaneous relative velocity is already available to both bodies, why transmit it at all?
This is the sort of nonsense that make the foundations of general relativity very suspect at best. I, for one, do not trust relativists to conduct impartial tests of GR. It's a political game and way too many people have way too much invested in GR being correct for comfort. It's like trusting Big Tobaco to tell the truth about the dangers of smoking. One man's opinion.
that theory of relativity is incorrect. Oh wait... slashdotter? common sense? proves incorrect?
Now who sounds mad?
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
- Strong
- Electromagnetic
- Weak
- Gravitational
I even fetched a URL on a whim, just in case you disagree for some reason.gravity measures YOU!
nebbian - Phd in Physics/Math = doesn't know what he's talking about.
or
slashdot + article about physics/math = idiots get modded +5
or
Stalyn - slashdot = no headache
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
I thought the speed of gravity was 9.8 M/S/S
*ducks*
(and to moderators lacking humor: it's a joke)
Go away, or I will replace you with a very small shell script.
Gravity reveals you!
...you see, it's all component forces. If you look at the free body diagram of my car travelling on the road, you'll see the normal force, force of gravity, and my velocity in the x direction. As I mentioned, one of these component forces is gravity, labelled FsubG. It was recently discovered, and posted on slashdot, that the speed of said force is 3x10^7m/s.
And THAT'S why, officer, your radar reported that I was going 60 in a 40 zone!
One important consequence of the result is that it will help constrain the number of possible dimensions in the Universe.
You're damn right. I was worried.
Dimensions running rampant without limit... what's next, violent television and people masturbating???
It's a sad, sad world. Good thing we have that dimensional problem under control!
The atomic bomb reference appears to have thrown you off.
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
His big SF series about "Honor Harrington" relied on a FTL communications system based on creating gravity waves.
Just think, that tree will have 95 more rings before Sonny's copyrights expire.
I asked my physics teacher the very same exact question- "if the sun disappeared, would the earth fly off from its orbit instantly, or would it take about 8 minutes?" He goes "it would be like snipping a cord- instantaneous". Discouraged, I went into the slashdot-posting, linux compiling netadmin that I am today, never knowing the true path of lab coats, leather gauntlets, and welding glasses that is physics- How dare you Stockwell! You stole my life with an assumption and I want my five years back!!!
slashdot: where everyone yells sarcastic metaphors to themselves to understand the issue
I remember, back when I was even more ignorant about physics than I am now, envisioning a communications device that worked instantaneously over long distances. I assumed that gravity traveled instantaneously throughout the universe, so all you needed was a significantly large mass that you could perturb in a predictable (to the receiver) way, and a vastly more sensitive perturbation detector than we have now.
Oh well. It was a cool idea, anyway. I wonder if gravity travels at a uniform speed under different space-time conditions, that is, if I perturb a mass on Earth, does the effect travel at the same speed as when 1km from a black hole? Thoughts? Random speculations like this?
If your bitterest enemies are people who hack the heads off civilians, then I would say you're doing something right.
For *starting* pay, I'd say that anything up to the $80K range may be believeable. A good software engineer with experience should be able to command $80K (depending on experience). Now, $100K... with a master's or PhD, or some really good experience... yeah, I could see it.
Now from Intuit or AutoDesk..I dunno. But, realistically, if a medical company was looking for a software engineer for designing products that are qualified for medical use (i.e., its not going to pull an X-files and the MRI isn't going to microwave you while you are in it), and the guy has experience and graduated from MIT... yeah, I think he might command $100K no problem.
Why do you think gravity ONLY affects mass? It does not. It also effects energy, mainly, it causes redshifts (from the outside observer's POV) Most of the time gravity is too weak to change it much, but in the case of blackholes, its enough to infinitely redshift, which is why no light escapes them.
Do a google search on 'do photons have mass' and learn something.
-
Star trek doesn't need this to be loaded with bad science. Here's a nice gravity related one, in "generations" they alter the course of the nexus by blowing up a star that would have influenced it gravitationally. Unfortunatly they miss the fact that even if the star blows up, the mass is all still there, just spread out, and its center of mass is still in the same place, the path of the nexus wouldn't have changed.
Correct, although the usual way to say this is that photons have mass, but no rest mass. This is a pretty important distinction since special relativity says that an object with rest mass can never travel at the speed of light (or at least it's mass-energy would have to be infinite, which seems kind of stupid to most people).
If anybody wants to know, the energy of a photon is given by
E = h f
where E is energy in J, h is Planck's constant (roughly 6.626E-34 J s) and f is frequency in Hz
From there it's pretty easy to rearrange E = mc^2 to get:
m = E / c^2 = h f / c^2
where m is mass in kg and c is the speed of light in a vacuum (roughly 2.998E8 m/s)
While we think of mass and momentum being related by speed, energy and momentum are related by FREQUENCY.
Here's some equations if you want to wrap your head around them: equations
-
So being the smarty pants scientist i am, i substitute jupiters mass in and speed into the equation and looky here, it says gravity travels at the speed of light. No i am going to publish a paper on the subject and get ridiculed by smart people
Come on wake up! the only reliable way to test any theory about how fast gravity travels would have to be done in the abscene of it. But assuming einstien was correct and gravity waves do travel at the speed of light, then several things spring to mind. First off there has to be a method of spontaneous generating gravity waves, why you ask, well we do have ways of spontaneous generating light. But this brings up a larger point if you can generate gravity this way, what is stoping you from generating antigravity. Could this be the Unnacounted for "dark energy/mass" that scientists can't find? Maybe the (anti)gravity generated by and an object isn't just related to speed and mass? Is the amount of light generated by an object relative to mass/speed?
Sorry just sort of ranting, please feel free to postulate some more.
A Fatal OE Exception has occurred, Sig will now reboot.
Actually, the Earth's orbit wouldn't be affected at all. If it split into two pieces of equal mass traveling at an equal but opposite velocity perpendicular to the plane, there would be no change in the gravitational pull. We could still treat it as a point object.
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
the slightly longer answer is "because in the sun's inertial reference frame (i am going to leave gen.rel out of this) the sun still has the same mass."
if you don't understand what I just said, read more about special relativity, kay?
My life in the land of the rising sun.
I gaurantee you that when we unlock the absolute secrets of life - that is, the what, how, when, where and why - a comet is going to smack right into earth and obliterate us.
--LordKaT
Now, I'm not physics whiz, but I was always taught that acceleration of an object due to gravity was -9.81m/s/s^2. Is this incorrect now?
Also, if gravity's speed is the same as the speed of light, wouldn't an object have to travel at the speed of light to break the earth's gravitational pull?
I think maybe I'm confusing the speed of gravity with the force gravity exerts on an object, but I don't understand how gravity itself could have speed. Is this a measure of the latentcy before gravity takes effect or something?
Like I said, IANAPW (I am not a physics whiz)
So, who's right?
You are not alone. This is not normal. None of this is normal.
First off, one must remember that a single instance is far from sufficient to confirm anything, unless of course, you're not a scientist...
With that thought out of the way, I'd like to point to previous experimental data. I've found a previous publication some time ago by one Tom Van Flandern, called The Speed of Gravity - What the Experiments Say. You will probably find the bibliography just as interesting.
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
Watching South Park can screw with your brain...
Ok, so science has proven that the effect of gravity travels at the speed of light. Again, the speed is relative to the frame of reference of the observer... if gravity is wave-like, then it can be compressed by accellerating the object. So, take a Jupiter-sized object, and fling it. The mass of the object generates gravity waves in the forward direction of movement, but wouldn't they be compressed (blue-shifted of sorts) outside of the the time-compressed reference? Does that mean that the effect of gravity can be time-adjusted, or does the compression increase the amplitude of the gravity wave...
Einstein has also hypothesized the existance of wormholes, shortcuts in space but not time. Suppose that you have a star, and you put one end of the wormhole close to the gravity source... do gravity waves propogate through the hole? If yes, then is mass at the other end of the wormhole attracted towards the mouth of the hole (gravity waves spewing like water out of a hose), or towards the original location of the star in 3-space? Since the ends of a wormhole are linked, does the wave "resonate" the other end of the hole? If gravity does not pass through the hole, is gravity attracting the near end of the hole and moving it in 3-space? And what about an object that is accellerated into a wormhole by the gravity of the star?
So you're saying the Sun couldn't disappear and then, as a more believable alternative you suggest that it could instantly accelerate to the speed of light? Are you a scientist?
Been in the inventory for *years*...
As everyone knows, when a king dies, his son instantaneously becomes king, no matter how far away he is. This proves that the royalty particle (the royalon, monarchon or kingon) does travel faster than light. It's not regicide; it's physics.
Actually there would have to be a change in the orbit. The masses are both moving away from you, so the force exerted by both of them is decreasing. Imagine the situation when the two halves of the sun are many light years away.
What won't change is the direction of that slowly diminishing force. It'll always point at the same spot that the sun was before it broke into two.
Now, the effect on our orbit would be the following: since the force is always pointing "inwards," and decreasing, the earth is going to spiral outwards from its current orbit. The degree of the spiral depends on the speed of the halves of the sun. I put "inwards" in quotes because inwards doesn't really have a precise meaning for a spiral. But you get my point.
The best way to predict the future is to invent it.
http://www.what-is-the-speed-of-light.com/roemer-s peed-of-light.html
burris
Star trek doesn't need this to be loaded with bad science. Here's a nice gravity related one, in "generations" they alter the course of the nexus by blowing up a star that would have influenced it gravitationally. Unfortunatly they miss the fact that even if the star blows up, the mass is all still there, just spread out, and its center of mass is still in the same place, the path of the nexus wouldn't have changed.
This is hillarious. I am not a Star Trek fan, but the fact that they don't even operate on high school level of physical understanding leaves me in stitches!
To perform the experiment, numerous (probably several thousand) measurements are taken, but due to imprecision in the process of taking the measurements (imperfect measuring equipment, human error, etc) you get a variety of results. These answers could vary from well below c to well above it. If Einstein was right and nothing propogates faster than c, the higher results could only be attributed to imprecise measuremements, but you can't throw those measurements out if you are trying to be objective.
At the end of the process, you have something vaguely resembling a normal bell curve, where the height of the curve at a point along the x axis (velocity) is a measurement of the relative frequency with which that speed of gravity was obtained as a measurement. The total area under the curve will be exactly 1. In many cases, the curve may not be symmetric, but for an experiment such as this, you are unlikely to obtain an assymetric curve (Central limit theorem of statistics, or some such thing). A line right down the middle of the curve shows the measured average result (.95c).
A confidence interval is then picked (it is a shame that this interval is not mentioned in the article, but it is almost assuredly at least 95%, probably even 99%, or 99.9%). This percentage is converted to decimal (95%=.95, 99%=.99, etc), and a symmetric region around the average score with that area is blocked off. This blocked off area has a minimum X component of .7125c, and a maximum X component of 1.1875c, the difference between each of these and the average measured velocity being .2375c, which is 25% of .95c.
And that's where the 25% margin of error comes from -- for their desired level of confidence, the variance in measured results was off by no more than 25% of the value that was actually obtained as the mean.
Since the value of 'c' lies WELL within the bounds of the margin of error of the experiment, and pre-existing theories support the speed of gravity being c, this experiment supports those theories. It is important to note that this experiment did not prove anything, it only failed to disprove that the speed of gravity is anything other than something very close to c.
File under 'M' for 'Manic ranting'
If the gravity is limited to propagating at the speed of light, then consider a pair of neutron stars closely orbiting each other at, say, 1/3 C. Each would be pulled by gravity in the direction that the other used to be, and the differential between the direction of the pull of gravity and the current position of the object would be around 2/3 of a radian. How can this work with the conservation of mass-energy? Wouldn't that just make them spin faster and faster? Wouldn't limiting gravity to the speed of light destroy the reciprocity of forces, especially with respect to torque?
Repeal the DMCA!
If gravity goes at c, does this impact our understanding of the expansion of the universe? The universe expanded at speed > c for a period, so is it possible that gravity from the matter on one side of the universe hasnt reached the other side?
Ahh right, anvils from Acme Anvil Company ... like in the Roadrunner cartoons.
-kgj
Incorrect. If the sun were to explode in an expanding shell then we would be able to treat it as a point source, in which case the Earth's orbit would not be affected by the explosion until the expanding shell passed said orbit (at which point it would be as if the sun was exerting zero gravity on the Earth; interesting transition.)
If the sun exploded into two equal masses that headed off in opposite directions we would experience a falling-off of the Sun's gravity; to understand this, imagine that the two halves of the sun had reached an infinite distance. The center of mass is still in the same location, but clearly the inverse-square law shows that we would not experience any garvitational attraction at all.
um... I dought that is starting pay, im sure if I worked for some company for long enough I could make over 60k to.
Selling software wont make you money, selling a service will.
What, though, if you use one as a qubit in a quantum computer? Something akin to how a quantum fast Forier (sp?) transform is used in Shor's algorithm to boost the probability that the final, classical read operation will produce a factor of the input.
If you can shift the wavefunction's state vector at all then it would seem that you can send information with some nonzero probability faster than light. As long as your ECC has greater corrective abilities than the probability of corruption, why isn't this an FTL information conduit?
Oh, though there still remains the problem of getting the entangled qubits to the ends of the communication channel... well, presumably you could do that at 2c by putting the transmitter in the middle.
--Knots;
Anarchy$ dd if=/dev/random of=~/.signature bs=120 count=1
Then you'll really like the part where the rocket launches up, visually less than FTL, and the sun explodes in about 15 seconds... instead of the 6-12 minutes one might expect, even *at* lightspeed.
Gravity bends YOU!
Space-time bends YOU!
Humm, what about this
please tell me that they aren't really claiming to have measured the speed of gravity...with a 0.25 margin of error!? correct me if i'm wrong, but that means that they could be off by up to 46,500 m/s!
It all depends on what the meaning of 'gravity' is.
Strange, 20 years ago I was taught other people had experimental evidence agreeing with a prediction that the effects of gravity move at light speed:
In 1882 Simon Newcomb observed an excessive perturbation in precession of the orbit of mercury, to the tune of 43 seconds of arc per century. In 1915, Albert Einstein showed this could be explained by the propogation of gravitic wave effects at the speed of light...
But thanks for playing.....
Energy, as far as we know, does not generate gravity (perhaps it generates the elusive dark energy? well thats just idle speculation...don't take my word on it). Without gravity, it would not collapse in on itself. Even if it did have gravity, it most certainly would not be a 'black hole' as we think of them now.
Black holes as we know of them now are stages in atomic collapse - right on past neutron degeneracy into the realm of the currently unknown. Since photons have nothing in common with atomic particles, it definately wouldn't be a black hole.
-
"Remember the Unified Field Theory? Well, forget it. Physicists have pretty much thrown in the towel on unifying gravity with the other elemental forces, so now we have the Standard Model, which says that everything works together in intricate harmony except gravity, which is on holiday in Tasmania and need not concern us further."
- Jon Carroll on the Higgs Boson
Nerd: Derogatory term typically directed at anybody with a lower Slashdot ID than you.
This isn't interesting. This is an example of stupidity/ignorance. I'd explain why but I've already explained it once (search up for topic 'Welcome to Physics').
He reformulated the equations in a way which lent themselves kindly to experiment and then performed the experiment to obtain a result.
The "proof" (or more accurately lack of disproof) was in the experiment, not the equation mangling.
IIRC, can't light could be slowed down by passing it through particular chemicals?
However, I don't think any similar studies have succeeded in slowing down the speed of gravity. So maybe it's not that nothing moves faster than the speed of light, but rather that nothing moves faster than the speed of gravity--it's just taken us longer to get around to measuring that.
It may seem like rubish to most people, but his theroys make a lot more sence that these ones. Like gravity is the speed of light? Next they will be saying that gravity is always the speed of light. Wait, doesn't that mean that when light is in a gravitational pull it goes slower, so gravity goes slower in gravity? Pretty stupid, doncha think? But that is where astromony is going today.
This view is a lot more senseble in my position:
The Speed of gravity, and more! (MetaResearch.org)
The EXP theroy there is plausable, but only if you stop to think and join it with another theory going around lately. I don't recall the name, but it goes around to state that the planets core may be Unranium, or the like. Makes for an interesting catalsyt.
Sig
"The secret to flying is to throw yourself at the ground, and miss." - Douglas Adams.
Nice...
Imagine that you wanted to shine a laser on the Sun from the Earth's surface. Where would you point it considering that it takes 8 1/2 minutes for the light to travel from the Earth to the Sun? Why, you'd point it right at the Sun, of course. The Sun isn't moving.
So basically you're missing [2. ???] in order to reach [3. Profit]. Welcome to the club.
RMN
~~~
The Taylor and Hulse binary pulsar experiments (1993 Nobel Prize) which found indirect evidence for gravitational waves, also found indirect evidence for the speed of those waves -- the speed of light, to within 1%. The results being discussed here on Slashdot are merely a more recent, and less accurate, indirect measurement. Direct measurement will have to wait until the direct detection of gravitational waves (by LIGO or other experiments), when we can actually measure how long it takes a change in the gravitational field to propagate from one observatory to another.
Bearden says that a photon is just mass rotated along the time dimension. http://www.cheniere.org/books/excalibur/raindrop%2 0model.htm
Also relevant are Low's and Carlip's papers on the theory regarding the speed of gravity.
That is not what he's saying. There's no such thing as free energy. It has to come from somewhere (maybe you can get enery out of nowhere but then you also get some anti-energy, and would have a lot of trouble keeping them apart).
It is possible to convert matter into energy with great eficiency. Fireflies do it all the time. With a bit of work, it would probably even be possible to convert all matter into pure energy. The main problem would be converting that energy back to exactly the same matter that it originally was. Probably, the only way to do it would be to send extra energy with information about the original matter's properties.
But the whole process is a bit silly.
If you have the technology to create the matter you want (from "raw" energy), there's no need to convert the original matter to energy in the first place. This would be a bit like converting your hard disk into energy so that it could be sent over the network wires and rebuilt at the other end. It's simpler to transfer just the information necessary to reconstruct the disk, and when the (perfect) copy has been created, you destroy the original one (or keep it, if you prefer). The two problems here are a) how do you determine the exact structure of the original disk and b) how to you build a new disc that matches that structure perfectly. It's easy when you're dealing with abstract entities such as bits and sectors, but not when you need every single particle to match the original one.
I suspect we (humans) will get there, eventually. But I doubt it'll be before Duke Nukem Forever and Team Fortress 2 are actually released.
RMN
~~~
Looks like it's back to the good ol' entangled particles, then.
RMN
~~~
There are also theories of spelling, punctuation and grammar. They're not as fast as light, buy apparently you're slower than them.
"You can't go faster than the speed of light."
"Of course not. That's why scientists changed the speed of light in 2208."
EPR paradox...
So, basically, what we KNOW influences what we SEE.
Sounds plausible.
... in fact, light is travelling at the speed of gravity.
Truely nifty stuff. I've never learned much about the weapons architecture for thermonucleogenics, and thought of this as enlightening. Other forms a fusion (the "desktop fusion" of however long ago that was and the "fusor" of a couple weeks ago) seem not to rely on the fission at all, something I like to refer to as "the increasing niftiness factor."
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
If Gravity's speed is equal to that of the speed of Light, then how do you explain the pull descrepencies between blackholes and low graivty environments? Go to the moon, you'll notice that the gravitational pull there is much lower than that of Earth's. And Earth's is far far less then a blackhole's gravitational pull.
:)
So how can one say that Gravity's pull is as fast as the speed of Light when Gravity itself doesn't stay constant in different environments? I never heard light not traveling the "speed of light" so it's a bit confusing.
Ao, from what I gather, blackholes have so much gravitational pull that even light can't escape. Which suggests to me that Gravtiy is stronger than light. It would also suggest to me that gravity is is faster than light because of this. I don't have any sources to back this up, all of this is just my train of thought in words here.
I'd appreciate a simple-as-possible answer as to why my train of thinking is wrong, as i said, i'm no scientist, but this topic is interesting none the less
A Penny for my thoughts? Here's my two cents. I got ripped off!
So, basically, what we KNOW influences what we SEE.
Sounds plausible. Think of the ramifications on probability, and the general direction of the events which unfold both on the quantum and physical realities. The events we witness (even in real life) that lead to changes in what we are about to experience; the signs we miss that an event is about to occur, even though thinking back we had a nagging suspicion that the said event was about to occur, etc. etc.
Cause and effect, really. It's the filtering of a string of 'cause and effect's to really get down to what the primal cause was, based on our OBSERVATIONS, and only what we see. So a primal cause as seen by us was actually an effect caused by another effect, since the true primal cause is so far out of our understanding that we can't discern it.
Hence the generalization. We only SEE what we KNOW.
Actually, you got the order wrong.
:).
Strong, Electromagnetic, Weak, Gravitational
This depends strongly on the distance you choose to measure the force at. At a distance of 1m, as opposed to 1e-15m, the original ordering may be correct.
And as long as we're being nit-picky, I'll point out that human-observable phenomena tend to be larger than 1e-15m
If this experiment had come out differently, it would have been earth-shattering, and because it was cheap to do, it was therefore worth doing. But the way it did come out wasn't a "win" for Einstein, nor was it a "loss" for Einstein, it was simply almost completely uninformative.
It's like buying a lottery ticket when the jackpot is really large: the expected win from the lottery ticket is more than you paid for it, so it may be rational for you to participate, but if you don't win the jackpot, your modest investment is still lost.
I found this link in some blog somewhere:
Albert Einstein's Theory of Relativity In Words of Four Letters or Less
Even I was able to understand most of that explanation!
From the article , a way of measuring speed of gravity is to measure the gravitational ripples caused by accelerating bodies, but no-one has managed to do this.
Shouldnt this be an easier thing to do? I suppose all bodies going round in circles have centrifugal/petal acceleration? There are huge galaxies spinning all the time, so they all are causing ripples all the time? Cant we just measure it? Can some body explain why it is so difficult? Sorry Im not too good with relativity and cant figure it out myself.
.ACMD setaloiv siht gnidaeR
It's hard because gravity is so weak. The strongest sources of gravitational waves are colliding black holes, but even those are just barely at our current technological capability of detection.
Here is how you can use relativity and electricity to "explain" magnetism:
Say we have two wires separated by a certain distance, each carrying a parallel current. There will then be a magnetic force between the wires pulling them together. Where does it come from?
The actual current in the wire is traveling at a very low speed- about a few cm/sec. (Wires transmit electrical impulses very quickly, so usually people are surprised to learn that the actual electric current itself moves very slowly, slower than water through a pipe.)
Look at the situation from the perspective of a test charge, a conduction electron in one of the wires. Although individually it is bouncing around in random directions at thermal velocities, its drift velocity is that of the current in the wire- a few cm/sec, or 10^-13 of the speed of light. And of course, we all learn in school that relativity only becomes important at velocities approaching the speed of light!
From the perspective of this test charge, the negative conduction electrons in the other wire are standing still. But the positive charge in the wire is moving, and shrinking in the direction of its motion. What is its Lorentz length contraction? It's absurdly low, 1 part in 10^26. But this means the linear charge density of the positive charges becomes that much larger than that of the negative charges in the wire, and the test charge feels an attraction to it. How much? It must be tiny. But remember, the positive and negative charge densities in the wire are huge even though they are closely balanced. A gram of copper contains 1500 coulombs of conduction electrons. If you do the math you will find that the predicted electrical force expected from the Lorentz contraction is equal to the ordinary magnetic force we would normally expect between the wires! If the currents in the two wires are antiparallel instead of parallel, it turns into a repulsive force. So that is what magnetism "really is". Except not really, because you can also use magnetism to explain away electricity if no charges are present.
You could (recklessly) extend the analogy to gravity, and consider water in two parallel pipes. Running water "shrinks" in the direction of its motion, so the gravitational field surrounding a pipe increases when the water is running. Except here the pipes have to carry water in opposite directions for this force between them to increase. So you would expect gravimagentism to work in a way that's opposite to how magnetism behaves.
French physicist Alain Aspect performed this experiment in 1982, confirming Bell's Theorem ( which in 1964 proved mathmatically that the EPR thought experiment refuting predictions of quantum theory was, in fact, what DOES happen).
The experiment has not only been repeatedly confirmed, but has been done so at greater and greater distances. I believe they're now up to a seperation of 15 km.
Anyone who wants to understand this stuff should read Nick Herbert's book "Quantum Reality." It is the *ONLY* "popular" book that explains quantum theory properly. Let me repeat that, it is the *ONLY* popular book that explains quantum theory properly, so put that copy of "Alice in Quantumland" back on the shelf where it belongs.
For anyone who wants to understand the differences between, and attempts to integrate quantum theory and general relativity Steven Weinberg's "Dreams of a Final Theory" is the clear choice.
Yes, I am a physicist, and no, I will not fix your Mr. Fusion.
KFG
..about these results. He's been telling everyone that the real speed of gravity is many orders of magnitude greater than that of light !! For those that don't know, his web site is here ..
http://www.metaresearch.org/cosmology/speed_of_gra vity.asp
Here's what bugs me about "extra dimensions rolled up really small".
If you turn and go in that Nth direction, any distance you go just carries you all the way around the universe in that direction and deposits you back where you are.
So how can they be said to have "dimension" when nothing that traverses them gets anywhere?
--Blair
The mass of photons is very real. Try this experiment, which a professor did at one of my Engineering Physics classes:
Take a relatively large gong. Make sure it is reasonably well polished.
Next, take a professional-class camera flash and set the intensity to "fry".
Third, fire the flash at the gong. As the photons bounce off the (polished) gong, it will resound as if having been struck with a solid object.
This was a very awakening demonstration to me...
You would not worry about such trivial things. All you need to know about gravity is that when gravity pulls the apple to the ground you pick it up, put it in your basket and shut the hell up.
Ben
Work Safe Porn
Confusing chalk with sodium is a little dangerous. But don't fear that this guy was about put the sun's pedal to the metal thinking it would only nova.
Stupid name for a car, too, in any language.
so i fall into a black hole for no particular reason. forgive me if my understanding of the thery of relitivity is wrong but once im in that black hole im crushed into nothingness, light stops, time stops, but what about that gravity? i supose it stops having an effect now but that does me no good because time has alredy stoped and im smashed into oblivian. ;)
this is hurting my head i should stop thinking
The information you gain from an experiment is related to the change in the probabilities you assign to different hypotheses. In particular, what that means is that, unless you have a plausible alternative hypothesis, experiments that agree with your hypothesis tell you essentially nothing.
Physicists regularly disregard this simple principle; they pick one hypothesis, elevate it to dogma, and then carry out lots of experiments. And when everything is said and done, they say "hey, see, the hypothesis survived thousands of experimental tests". But none of those tests may have tested against a logically plausible (or possible) hypothesis, or the tests may not have been independent of each other.
More specifically, unless you can come up with a logically consistent alternative to GR, something that makes experimentally testable predictions, there isn't really much point in spending a lot of time and money on experiments. Shots in the dark like this one are only worth it if they are cheap (as this one was), but when the result is as expected, you didn't learn anything from it.
It is actually possible for, say, an electron to move in water faster than light moves in water. In addition, speed of light in water depends on the wavelength. It's hard to tell what happens with the speed of gravity.
in short, no
if you could do this, then you would be world famous - therefore I am pretty sure that you can't
if you have a pair of entanged electrons and you collapse one, then a random eigenstate will pop out. Same with the other. No information is passed, because it was random.
I think that what you are saying is that you want to set up one of the particles as a quantum register after transmitting the other. And that you want the other particle to be a quantum register too? How can you do that?
As for you last paragraph, I don't understand what you are saying, but perhaps you are not taking Special Relativity into account for something, as c is the limit for nonrandom stuff.
A Usenet Troll Triumphs on Slashdot
Gravitational waves measure YOU.
Gravtiy is stronger than light. It would also suggest to me that gravity is is faster than light
Well, it doesn't suggest that to me.
My Karma: ran over your Dogma
StrawberryFrog
Yes it's possible.
It's not often that I get the chance but when I accrue enough holiday leave to make a long voyage possible I normally use a polarized black hole highway for my interstellar travel.
A polarized black hole is one that creates an asymmetric gravitational pull. There are dotted paths of polarized black hole highways that connect most of the densely populated regions of the milky way.
Spacecraft typically accelerate towards the event horizon of the nearest black hole in the highway, obviously effectively having their mass reduced by the gravitational pull.
Then as long as the black hole highway is synchronized correctly, the asymmetric gravitational field will distort in the appropriate way to transform the surface of the event horizon such that the craft will pass by it and be attracted by the next black hole in the highway.
If there's interest in a setting up a highway to earth then you can picky up asymmetric black hole factories for reasonable prices at Orion's belt.
I just wish that the intergalactic trips were as simple.
i need coffee...
During my A-Levels in physics, when studying gravity we were taught that gravity is an instantanious force. What if it works in the same way as an electric current. Popping an electron into one end of the wire kicks one out the other end, at the speed of light, but the electron actually moves much slower. In this case, gravity is working instantly, but an actual 'graviton' would take far longer.
?
What do you guys rekon
Kopeikin's results:
0 links/press/ SOG-Kopeikin.asp
http://xxx.lanl.gov/abs/gr-qc/0212121
And already one harsh criticism by one of his opponents:
http://metaresearch.org/media%20and%2
Unfortunately I could not find Asada's comments on this. As one of the creators of the theory of brane worlds, it would be very interesting to see what he thinks about this.
gravity sucks!
considering speed is measured in distance/time how do you place gravity in such a measure considering that it warps space as well as the passage of time. it's hard to cleanly measure and catagorize something that changes the rules.
Gravity is itself the warping of space. The best way to explain is by imagining a 2 dimensional world instead of a 3 dimensional world (spacial dimensions). Imagine a 2-D surface like the top of a soft bed. Objects on the bed that are 3D are simply 2D objects with mass (gravity field). Place a bowling ball in the middle of the bed, and it will warp the surface of the bed into another 3rd dimension (down = force of gravity in this universe). Anything nearby that bowling ball on the bed will be drawn towards the bowling ball (gravity in 2D) if it is nearby. Assume you were to roll a ball in a straight line across the bed, and it came across the pit in the bed made by the bowling ball... the ball's path would curve due to being near the bowling ball... this is what happens to light usually near gravity. Light bends, but it THINKS it's going in a straight line b/c it is space itself that is curved (bed's surface). Imagine a ball travelling in a circle around the bowling ball within the pit formed by the bowling ball on the bed. If it's located at a very specific point, travelling with enough speed, the ball will remain spinning in a circle around the bowling ball forever (assuming no friction). This is how planets stay in orbit and how light can become trapped at the event horizon of a black hole. Many things that are closer or not traveling at the correct speed and direction will be sucked in.
Take this analogy and think about it in our 3D world, and you'll see that gravity is another dimension in which space itself is warped. The "speed" of the warping of space is simply how quickly a change in gravity would affect objects and light nearby. Theoretically, the only known way to shift gravity is to shift the mass of an object, and since matter and energy are restricted to the speed of light, gravity should also be limited to the speed of light. Also, the warping of light from an outside source by jupiter's mass (gravity), should not instantaneously warp the light, but warp it at the speed of light as well.
That's all well and good, but they have yet to determine the smell of gravity!
bius sig file. This is a moebius sig file. This is a moe
In case anyone is interested, you can find an abstract link to the original paper that predicts the quasar deflection caused the Sept 8th close approach, here. The paper was published in the Astrophysical Journal in 2001 by S. M. Kopeikin. Interestingly, this theory paper has listed only two citations but the citation rate is sure to climb now that the observations have been made.
Flintstones (Hanna Barbera): Sep 30 1960 (ABC)
Road-runner (Warner Bros.): 1949
Every substance has a dielectric and magnetic constant. These constants tell us how much slower the wave propagates through a medium. Does this apply for gravity too?
Weak Force is too week to hold together anything at all!
I wonder how your CRT works, then. Electrons hitting phosphors at 2 meters per hour? This is bright.
acceleration of gravity on earth: 9.8 m/s^2
speed of gravity (in general): 299792458 m/s
This gives ut the age of gravity ~30591067.14 (or just above 354 days).
Light, like most other waves that get propigated throught space and times, probably needs a medium to be propigated in. Perhaps the gravitational field produced by an object is light's medium. This might also explain why something cannot travel faster than the speed of light. Much like the sonic boom associated with traveling past the speed of sound, something similar might occur with traveling past the speed of light. Since all objects have some gravitational force (albiet a small one), a particle moving at the speed of light would probably develope a large gravitational wall in front of it. Tidal forces, much like those associated with a black hole, could strecth the object, most likely destroying it. Or, perhaps, the surge of gravity in front of the object would create some kind of black hole or worm hole entrance, allowing an object to warp through space and time.
SIGFAULT
"Isaac Newton thought the influence of gravity was instantaneous, but Einstein
assumed it traveled at the speed of light and built this into his 1915
general theory of relativity"
"Kopeikin found another way. He reworked the equations of general relativity
to express the gravitational field of a moving body in terms of its mass,
velocity and the speed of gravity. If you could measure the gravitational
field of Jupiter, while knowing its mass and velocity, you could work out
the speed of gravity."
assumption that gravity was the speed of light, therefore if he re-works these
equations to take the known mass and velocity and give a number equaling the
speed of gravity it SHOULD come out as the speed of light, not because that's
the right answer, but because that's the value the original equation was
based on??
Your name doesn't happen to be Dan Bowen, does it?
What's this Submit thingy do?
supposed to exist?? I recall researching this subject only a short while back and it was theorized that gravity traveled much much faster than light, somewhere like 10^8 * C! One of the ideas here was that if it took gravity that long to work, orbits of objects like planets and whatnot would be destabilized. They would not maintain a smooth orbit like we see.
Yes, but it's an extremely important linebreak.
If it were possible to exceed the speed of light, would we also therefore escape all gravitational influences?
I wouldn't take their word for it.
This paper gives a good case for gravity traveling faster than light and I'm pretty sure all the working Newtonian gravity calculations assume instantaneous gravity:
"Standard experimental techniques exist to determine the propagation speed of forces. When we apply these techniques to gravity, they all yield propagation speeds too great to measure, substantially faster than lightspeed. This is because gravity, in contrast to light, has no detectable aberration or propagation delay for its action, even for cases (such as binary pulsars) where sources of gravity accelerate significantly during the light time from source to target"
OddManIn: A Game of guns and game theory.
I like your water pond and rubber sheet analogy. Gravity as we see it mostly works like the rubber sheet, put a planet on it and it will funnel the sheet to a kind of point. But what if something was to dissapear from space time? Would it be like plonking a pebble into a pond? Would there be ripples of gravity waves created that moves everything around it to and fro?
The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.
Gravity does travel much faster than the speed of light.
/ pr ess/SOG-Kopeikin.asp
http://www.metaresearch.org/media%20and%20links
Galaxy collision simulations treat the speed of gravity as instantaneous. Looks like a few astronomers have some more papers to publish.
The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.
Maybe light is traveling at the speed of gravity instead.
When I first heard about this I went and dug up some articles on google. One argued from indirect evidence that the speed of gravity >= 2 * 10^10 * c. (man, I wish I everyone had MathML...). This meant that a gravity drive could theoretically go faster than c. Soooo... I'm wondering if the whole gravity drive thing is bunk now.
-l
Help cure AIDS, cancer, and more. Donate your unused computer time to worldcommunitygrid.org. Join Team Slashdot!
It's much more likely the ringing comes from the air right next to the polished gong surface suddenly heating up.
There's a similar confusion about what drives those "solar radiometer" things - you know, a little black-and-white paddlewheel inside an evacuated glass ball that spins when you shine a light on it? People often say the reason they run is photon momentum, when the actual explanation is that the black sides of the paddles are hotter than the white sides, so when the few gas molecules left inside the ball hit the paddles, they leave the black sides going faster than the white sides.
The proof of this is the direction the paddlewheel turns - it turns white-side-first, and a photon-mass explanation would have the paddle turning black-side-first. If you put a paddlewheel inside a REAL hard vacuum, with a REAL low friction bearing, and REALLY isplate it from outside vibration, it turns the right way. See here for a more coherent and complete explanation.
To a Lisp hacker, XML is S-expressions in drag.
So then does "anti-mass" (ie anti-matter) experience anti-gravity? Would anti-matter repel other anti-matter or repel matter? Is this why we don't get much anti-matter casually passing by?
End of Line.
For reference see:
http://www.hrvg.org/project/erminmink/reactor/ce renkov.htm
This is possible when light is travelling through some medium like water, where the speed of light is lower than light in a vacuum. The charged massed particles excite the atoms of the medium and the excited particles return to their normal state by emitting a photon. This is the effect that causes reactor cores to glow. I don't beleive that it is a direct analogy to a sonic boom, but I thought it may be interesting none the less. Percontor
After all, the Newtonian model assumes infinite speed of propagation for gravity. So, limiting it to something finite, and within spitting distance of c, does accomplish something significant.
Now, if they had found a speed between 1.1 c and 1.4 c, physicists around the world would be racing to replicate the result. If it held up, that 30 Hz thumping you hear in the background would be Albert Einstein, spinning in his grave...
To a Lisp hacker, XML is S-expressions in drag.
I wonder if it's possible to simulate an interference pattern in gravity, such as the double-slit experiment with light.
As I recall, If two narrow slits are parallel and near each other, the resulting diffraction patterns will interfere with each other causing hi/lo super-positioned wave patterns. I remember this demonstrated in physics class with a tank of water and slits made in small bulkhead in an aquarium tank. The wave on water would diffract in the two slits and the resulting interference pattern would make a series of hi/low areas that seem to radiate from the area between the slits. The patterns would change with frequency of the wave.
See http://homepages.ihug.com.au/~flavios/diffrac.htm
How could one change the frequency of a gravity wave? I guess the frequency of gravity waves would change proportional to the change in gravitational fields?
What affect would the sudden disappearance of mass (fission) have on gravity? I wonder if during a-bomb testing there was ever any observation for change in gravitational field?
Perhaps these gravity patterns already exist as unexplained anomolies but are actually interference patterns?
If light waves diffract upon passing through a narrow slit, I wonder what kind of 'gravity slit' may exist to cause gravitational diffraction? Black holes, large mass objects, or sudden appearance/dissapearance of mass as in nuclear fusion/fission.
Suncoast Linux - Sarasota, FL
I mean, there are so many astronometric techniques that involve measuring things by inference using gravitational influence.
But now, according to this nothing is orbiting the center of mass of a system, it's orbitting where that center of mass WAS (time) ago. And the center of mass of a system isn't between to gravitational points, it's between where they were (time).
What impact does this have on the age of the universe calculations or the rate of cosmic expansion, since the distant quasars etc that we're detecting at the far limit of our instruments are trailing their gravitational effects like a wake?
So what happens if two gravitational sources are travelling at significant fractions of the speed of light, in parallel? Does D=.5AT^2 then become a sliding scale, dependent on the (absolute/relative) velocities of their gravitational centers?
I guess it makes logical sense to say that gravity has speed, but I see that it would complicate a lot of things not to simply assume it was instantaneous.
-Styopa
and had a look at this. It's an interesting but rather flawed book, at least from the perspective of grasping quantum theory. You'ld be better off with Gribben, and Gribben's merely "ok."
I'll stick with my earlier claim.
By the way, if you haven't read it, Leon Lederman's "The God Particle: If the Universe is the Answer, What is the Question?" is an excellent first person look into the lives and interests of *experimental* physicists.
KFG
You must mean The Coyote & Roadrunner!
</OFFTOPIC>
Can I get an eye poke?
Dog House Forum
I thought that the speed of light was recently found to not be a constant, and that this would imply that maybe the speed of gravity isn't either. Could they be speaking loosely here, or maybe I misunderstood the "speed-of-light-not-constant" discovery also?
The "cue the foo posts in 3, 2, 1..." posts will commence with no subsequent foo posts in 3, 2, 1...
There was another poster that also claimed this would have been due to the air heating up near the gong.
However, this professor continued his demonstration with sooting the gong heavily (taking it from polished to near-black), and then firing the flash again. The sound was significantly softer, noticable by all attendees (around 120), and he explained this by the photon package having been absorbed instead of bouncing (the gong only got half the impulse from before).
In a scenario where heat was the cause of the sound, sooting the gong would have caused a significantly louder sound as the light was absorbed, instead of (as happened) as softer one.
Ok, does this mean that the classic sci-fi "warp drive", where a black hole is projected in front of the ship, which accelerates toward it, which moves the projected hole forward etc, etc, is not possible?
(Makeing the assumption, of course, that it is possible to generate gravity other than the old-fashioned way.)
grnbrg
What about Korea. Why is it we're soooo concerned about Iraq (OIL), when all reports indicate they are decades away from producing Nukes (OIL), yet N. Korea can build all the fucking Nukes they want? I'll tell you why, Iraq is about OIL. N. Korea doesn't have oil, they have rice. We already have rice, we want oil.
If that's not simple enough, consider that N. Korea has a big brother that a. we don't want to piss off, and b. provides American businesses with 3 billion consumers.
If you want to war monger, try this approach- "China has 3 billion people that in 5, 10, x (your choice) many years will single handedly eat all the food the earth can produce and drink all the water the earth can produce, and in 10, 15, x (again, your choice) will deplete the earth entirely of all it's food and water. Therefore we need to kill them all to save ourselves."
It's equally absurd, and is very evil, but at least it's a little scarier than the "Iraq will nuke the US" threat.
I for one am totally sick that my friends and family are going to risk their lives to fight in this family fued. I'll hold bush, his fucking father, and the entire oil industry personally responsible for every friend I lose. ANd people like you should go to their f*cking funerals and try to explain to their lifeless bodies why it's a good war.
(by the way, I don't think most of this relates to your comment, but I'm off topic anyway, so what the hell. cheers.)
because I have been enjoined by this Holy Office to abandon the false opinion which maintains that the Sun is the centre
Ohh..again. Another fight back from conservative scientists who wrote their Phd based on Einshtain. Don't they used a photo film with a micron grain again?. I hope not. Goverments around the world spend bilions on gravity research and nothing. But now someone from university finally calculated it with radio telescope. Gigantic shaft were drilled. Super sensitive equipment were installed. Billions of dollars waisted. Well everything they came up with a earth quake sensors!. Now this professor is draggin dead horse again.
This just hit me, if both light and gravity travel at about the same speed then there must be some commonality. There must be some force or reason that they cannot exceed that limit, and if we are able to define and discover what is prohibiting faster speed limits then we, as in humans, should be able to create a device to enable faster than light (FTL) travel. Maybe that's where warping space might come into play, it's been seen that science fiction becomes science fact.
Just my $0.02.
I don't know about you folks, but the older I get, the faster gravity seems to travel.
What if gravity has different properties from a long way away, such as intergalactic distances?
I've often wondered lately if perhaps gravity is both a repulsive and an attractive force. For local (i.e. interstellar) distances, the attractive force prevails. But for really vast (intergalactic) distances, it might act as a repulsive force. This could partly explain why the galaxies are accelerating away from each other.
Physicists don't have much of an idea what dark energy is... maybe it's just gravity, and Newton's law needs an amendment.
I've never heard this idea proposed, but it would make a certain kind of sense to me if it turned out to be the case.
WWJD? JWRTFA!
As a professional photographer who owns several flashes that can fry, I can tell you from experience that you actually hear the flash go off even if it is in a light absorbing bag. There is sound eminating from the unit and that is what caused you gong to reflect sound.
My guess (can anyone help?) is that the sound is from the huge capacitor dumping.
For instance, it assumes that electrons are point-particles with no mass, yet have a charge in many equations. This is impossible. The electron is known to have mass, and the best model for electrons is a donut-shaped spinning ring. This accounts for it's moment, spin (up or down), charge, etc. and it's the most accurate model for predicting electron shells in atoms. Quanta (packets) are just ways to approximate and estimate energy and matter, yet they are about as accurate as assuming a horse is a sphere for mathematical simplicity... lol.
Gravitons are a ficticious creation to try to quantize gravity distortions in space-time. They essentially said "hey, this works with light, so let's try gravity" and it doesn't add up. In order for gravitons to exist, you'd have to have these particles with no mass jumping from every object in the universe to every other object in the universe at infinite speed, yet not accumulating on any object for long enough to crush it, just to put pressure on it and keep it in place. There's no explanation in the world of quantum mechanics that fits gravitons with known reality. Even light "particles" can't travel faster than the speed of light, and now that gravity has been measured to be about or equal to the speed of light as well, gravitons are lookin' like a even less of a possibility of being reality.
Another major flaw of quantum mechanics is the belief that something can exist in multiple states at once or even many PLACES at once! Simply because the MATH says that there is a probability of a particle being in a certain state or position, does not mean that it is or isn't in that state. Quantum Physicists routinely treat unknowns as being in a state of flux until measured, when in reality they are either one or the other... you just don't know until they check. I actually heard physicists saying things such as "the moon isn't really there until you look at it" and garbage like that. Let's say you have a truly random function that pics a number between 0 and 1, a quantum physicist would tell you that the output is essentially every possible number between 0 and 1 at the same time until you look at the answer. They believe simply because the probability of something can be expressed as a wave function, that the object IS a wave, therefore it exists in all possible states at once. This is beyond illogical to stupidity... and though they claim to have created small quantum computers which work on the logic of 0, 1, and some state which includes both 0 and 1, they also say that "there is no way to decode the information at this point... just to compute it... theoretically". In other words, they did the math and think the darned thing is working how they thought it should, but have no real way to check it.
In order to buy into this stuff, you have to believe in alternate universes, many multiple dimensions, and that all matter and energy exist as waves. (vibrating strings in string theory). While I believe the math is useful for many purposes, it is akin to how astronomers once placed earth in the center of the solar system and devised many circular tracks for the sun, moon, and other planets to revolve around the earth in a manner which matched what was observable in the sky. The math works in a lot of situations to determine outcomes, but analyzing the math to determine the structure of the universe and creating imaginary particles is beyond theoretical physics and into plain old science fiction and fantasy. I think we're in for another paradigm shift away from quantum physics in the next 20-50 years. Most physics professors I know think gravitons are fictitious & think string theory is just about to give itself enough rope to hang itself. lol. lata
If I remember correctly, Bell's theorem showed conclusively that information can be transmitted instantaneously (independent of the frame of reference) via interactions with particle pairs.
Bell's theorem evolved from experiments by Einstien, Podolsky, and Rosen IIRC.
What is this g-r-a-v-i-t-y you speak of?
If the gong is reflective, the air near it gets heated both by the incoming light and by the reflected light. If the gong is sooted, only the incoming light heats the air.
At least, this seems logical to me. A way to test it would be to put a vibration sensor on the gong, and try it both in air, and in a vacuum. If you're right, the sensor should read the same, if I'm right the impact in vacuum should be much less.
To a Lisp hacker, XML is S-expressions in drag.
One argument holds that gravity's speed must be at least 10^15th times faster than light.
Consider the Earth's orbit around the Sun. It takes light about 8 minutes to travel the distance. If gravity takes that long, then the Earth should feel the tug of gravity not where the Sun is, but where it was 8 minutes ago. This should cause gravitational drag. Though this is small over short time scales, over a 5 billion (10^9) year time scale, the Earth's orbit isn't stable.
The argument continues that since the Earth's orbit appears to be stable, gravity must move faster.
I haven't heard a really good counter argument.
If gravity really is this fast, it's going to be really hard to measure, so it's going to be really hard to use it for high speed communication.
-- Stephen.
Electromagnetic
Weak
Gravitational
There is no strong force. It's a myth. Just like Neutrons are a myth. No, I'm not joking. Anytime you extract a neutron from an atom, it breaks into a proton and an electron (hydrogen). A Neutron is not a true particle, it's simply a compressed proton and electron. Although scientists say it has the same mass as a proton, it actually is a proton with an electron paired with it (electrons have a very small mass... so small, in fact, that quantum physicists usually say it has no mass) The "strong" force is the force atomic physicists had to invent in order to explain how protons and neutrons would sit together so tightly packed while the protons repelled each other (and the neutrons simply needed a reason to be stuck next to anything at all). The truth is, electrons exist at the center of an atom holding protons together. They form shells which link protons and bind them tightly. This cancels out the positive charge of many (thus the many so-called neutrons), and leaves many protons unpaired within the nucleus which gives the nucleus a net positive charge allowing electrons to orbit the nucleus.
Ever noticed that you won't find any nuclei other than hydrogen without a neutron??? Noticed that the larger the atom, the higher the neutron to proton ratio?? The strong force is supposed to be exactly 100 times stronger than the electromagnetic force, which would allow for nuclei of atoms to reach about 100 protons, thus those beyond that are highly radioactive. (means that once there are 100 positively charged protons, their repelling forces would overcome the strong force and shoot them out of the atom). BUT, the best model of atomic nuclei structure shows rings of electrons supporting ever-larger numbers of protons, thus there is no strong force needed. The positive protons are cancelled out by negative electrons, and thus a spherical crystal-lattice type structure is created within the Atom's nucleus. The unusual shape of this crystal only allows about 300 or so protons within the nucleus before the crystal becomes too densely packed and unorganized that it's insanely radio-active. There is a theory that if the structure were re-organized, there could be an island of stability beyond that point, however, I seriously doubt it. Wow... wouldn't it be awesome to have a noble solid??? *grins*
Energy released in matter/antimatter anhilation:
E=m(matter)c^2 + m(antimatter)c^2
Thus, with equal mass pairs - positron/electron or proton/anti-proton:
E=2mc^2
If antimatter had antimass then the equation would be:
E=mc^2-mc^2=0 and NO energy would be released.
Again, antimatter has mass, not anti-mass.
-T
I do think there are a few too many conservation laws being broken there.
You actually agree with the premise that antimatter repulses matter?
Antimatter has _mass_. Not anti-mass, not negative-mass.
Additionally, even if there were some magical uber-repulsor like grandparent claims, that still wouldn't accelerate you past c - force required to accelerate increases to infinity as you approach c. Thus, no passing light speed unless you have a force able to provide infinite acceleration. In which case, you're smoking crack.
-T
The speed at which fields propagate is governed by the causal structure of spacetime (determined by the spacetime geometry). So in a sense, the speed of gravity is the most fundamental, because gravity is the geometry of spacetime, and other fields have to travel at its speed because they all exist within spacetime.
Since the gravity from an object like the moon is actually pulling objects towards where it was however many seconds ago that light takes to travel between the two objects... and on orbital scales, there are very significant numbers involved here... maybe leading to one of the reasons that orbital calculations don't tend to hold up well over years of time???
There are dangers inherent in believing the first thing that turns up on a Google search. You -- and many others in this thread -- found van Flandern's erroneous aberration calculation.
Does anyone know if this invalidates the Alcubierre drive?
s /abstracts/miguel94a.html
http://www.astro.cf.ac.uk/groups/relativity/paper
The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.
There is no strong force. It's a myth. Just like Neutrons are a myth. No, I'm not joking. Anytime you extract a neutron from an atom, it breaks into a proton and an electron (hydrogen). A Neutron is not a true particle, it's simply a compressed proton and electron.
First of all, you're still going to have an interesting time explaining how all of those nice, positively-charged protons are bound into an incredibly tiny space without the strong force holding them together.
Secondly, the production and decay of neutrons is mediated by the weak force, not the strong force.
Thirdly, your model fails to explain mesons and the zoo of other particles that can be produced even in relatively low-energy accelerators, while the quark model explains it nicely.
Protons become neutrons when an electron and an "up" quark interact to produce a "down" quark and an electron neutrino. The inverse process - decay of neutrons into protons and electrons - happens when a "down" quark decays into an "up" quark, emitting an electron antineutrino and an electron.
The neutrino emitted during the decay has significant momentum. Its existence can be shown - and was originally inferred - by tracking the charged particles emitted when a neutron decays into a proton and an electron. In many cases, both of the charged particles are going in the same direction. To conserve momentum, something else had to be fired off in the opposite direction during the decay. That "something" is the neutrino. If a neutron was a bound proton/electron pair, there would be no third particle to explain the momentum discrepancy.
You're also overlooking the fact that a bound system has less energy than an unbound one. Which would mean that in your proposed scenario, _neutrons_ should be the stable nucleon, which is at odds with observations.
Or, you may have written that post as sarcasm. Either way, moderators have been falling for it.
The rest of your post is even sillier, so I'm not going to bother with it.
In summary, your proposed model is demonstrably incorrect.
Speed of Light .... Flying Colours....
Was that an intended pun...?
Now, now children.
Don't you know that arguing on the internet is like running in the special olympics? Even if you do manage to win, you're still a retard.
I read about this in Stephen Hawking's "A brief History of Time" over 10 years ago. It didn't really seem to be up for debate. Is it only exciting now because it's the first actual observation of it, or something?
In 1825, Laplace determined that the minimum speed of gravity consistent with observations was at least 10 million times the speed of light, c.
r ess/SOG-Kopeikin.asp
Modern, high-precision solar system observations show that the direction from which the Sun's light comes, and the direction toward which the Sun's gravity pulls us, are not the same. The former is retarded by the time it takes light to travel from Sun to Earth, 8.3 minutes; and the latter is not retarded by any detectible amount.
Eclipses of the Sun by the Moon occur about 40 seconds before the time of the Sun's maximum gravitational pull on the Moon. The delay indicates that light and gravity do not have the same propagation speed.
A 1997 laboratory experiment by Walker & Dual showed that gravitational signals propagated much faster than light signals.
Binary pulsars (with large masses and speeds) show that the speed of gravity must be at least 20 billion times the speed of light.
For a detailed critique of the reported results of measuring the "speed of gravity", see http://www.metaresearch.org/media%20and%20links/p