Stanford’s Gravity Probe B confirms two Einstein theories
After 52 years of conceiving, testing and waiting, marked by scientific advances and disappointments, one of Stanford’s and NASA’s longest-running projects comes to a close with a greater understanding of the universe.
Stanford and NASA researchers have confirmed two predictions of Albert Einstein’s general theory of relativity, concluding one of the space agency’s longest-running projects.
Known as Gravity Probe B, the experiment used four ultra-precise gyroscopes housed in a satellite to measure two aspects of Einstein’s theory about gravity. The first is the geodetic effect, or the warping of space and time around a gravitational body. The second is frame-dragging, which is the amount a spinning object pulls space and time with it as it rotates.
After 52 years of conceiving, building, testing and waiting, the science satellite has determined both effects with unprecedented precision by pointing at a single star, IM Pegasi, while in a polar orbit around Earth. If gravity did not affect space and time, Gravity Probe B’s gyroscopes would point in the same direction forever while in orbit. But in confirmation of Einstein’s general theory of relativity, the gyroscopes experienced measurable, minute changes in the direction of their spin as they were pulled by Earth’s gravity.
The findings appear online in the journal Physical Review Letters.
“Imagine the Earth as if it were immersed in honey. As the planet rotated its axis and orbited the Sun, the honey around it would warp and swirl, and it’s the same with space and time,” said Francis Everitt, a Stanford physicist and principal investigator for Gravity Probe B.
A lasting legacy
“GP-B confirmed two of the most profound predictions of Einstein’s universe, having far-reaching implications across astrophysics research,” Everitt said. “Likewise, the decades of technological innovation behind the mission will have a lasting legacy on Earth and in space.”
Stanford has been NASA’s prime contractor for the mission and was responsible for the design and integration of the science instrument and for mission operations and data analysis.
Much of the technology needed to test Einstein’s theory had not yet been invented in 1959 when Leonard Schiff, head of Stanford’s physics department, and George E. Pugh of the Defense Department independently proposed to observe the precession of a gyroscope in an Earth-orbiting satellite with respect to a distant star. Toward that end, Schiff teamed up with Stanford colleagues William Fairbank and Robert Cannon and subsequently, in 1962, recruited Everitt.
NASA came on board in 1963 with the initial funding to develop a relativity gyroscope experiment. Forty-one years later, the satellite was launched into orbit about 400 miles above Earth.
The project was soon beset by problems and disappointment when an unexpected wobble in the gyroscopes changed their orientation and interfered with the data. It took years for a team of scientists to sift through the muddy data and salvage the information they needed.
Despite the setback, Gravity Probe B’s decades of development led to groundbreaking technologies to control environmental disturbances on spacecraft, such as aerodynamic drag, magnetic fields and thermal variations. The mission’s star tracker and gyroscopes were the most precise ever designed and produced.
Played a role in developing GPS
Innovations enabled by GP-B have been used in the Global Positioning System, such as carrier-phase differential GPS, with its precision positioning that can allow an airplane to land unaided. Additional GP-B technologies were applied to NASA’s Cosmic Background Explorer mission, which determined the universe’s background radiation. That measurement is the underpinning of the “big bang theory” and led to the Nobel Prize for NASA’s John Mather.
“The mission results will have a long-term impact on the work of theoretical physicists for years to come,” said Bill Danchi, senior astrophysicist and program scientist at NASA Headquarters in Washington. “Every future challenge to Einstein’s theories of general relativity will have to seek more precise measurements than the remarkable work GP-B accomplished.”
Over the course of its mission, GP-B advanced the frontiers of knowledge and provided a practical training ground for 100 doctoral students and 15 master’s degree candidates at universities across the United States. Over 350 undergraduates and more than four dozen high school students also worked on the project, alongside leading scientists and aerospace engineers from industry and government.
Sally Ride, the first American female astronaut in space, worked on GP-B while studying at Stanford. Another was Nobel Laureate Eric Cornell, who also studied at Stanford.
NASA’s Marshall Space Flight Center in Huntsville, Ala., managed the Gravity Probe-B program for the agency. Lockheed Martin Corporation of Huntsville designed, integrated and tested the space vehicle and some of its major payload components.
===========================================================
Learn a lot more on testing Einstein’s theories here h/t Dr. Leif Svalgaard via email
I accept your explanation, Lief, that the Wikipedia chart is based on redshift observed from an object which was then at 13.2 Bly receding at sub-light speed versus recessional velocity now when the object has moved on to ~ 40 Bly. It just seems an odd hybrid convention to me to plot it in that way, and I wish the article had explained it.
Bart says:
May 7, 2011 at 2:18 pm
One more time: We cannot “see” something until the light gets here. The light traveled 13.2 Bly, not 40 Bly. It left the object 13.2 Byr ago.
One last time: the light is here from an object that now is 40 Glyrs away.
[snip] …The truth hurts doesn’t it, Anthony? But you can’t shut me up… [snip]
[Reply: No one is shutting you up, this is America. But if you want to say your piece here, you need to be a little less cranky. Posting on WUWT is a privilege, not a right. ~db stealey, mod.]
Vince Causey says:
May 6, 2011 at 5:46 am
You have articulated a question that I have often thought about. For what it’s worth, here’s my take on the warping of spacetime.
As I understand it – 3d space is not warped – that wouldn’t make sense.
Thanks for coming in here.
The presence of matter makes time run slower and therefore what is being warped is time. You have to think of 4d space-time that is being warped, and the warping is because of the time dimension, not the 3 spatial dimensions. A particle curves towards the Earth because time is running more slowly closer to the Earth. It is a rule of GR that a particle will move from one place to another so that a clock carried on it will show a longer time than it would on any other trajectory. This is a reason why the particle moves towards the Earth. If it didn’t do so, its clock would show a shorter time. From the framework of 4d spacetime, we say that the particle is following the shortest distance in spacetime – ie, a straight line through spacetime – and in doing so the particle moves in a curve through space, but the space itself isn’t warped.
Sorry, just to get this clear re time: “It is a rule of GR that a particle will move from one place to another so that a clock carried on it will show a longer time than it would on any other trajectory. This is the reason why the particle moves towards the Earth. If it didn’t do so, its clock would show a shorter time.
Could you elaborate please, I think you may be talking in a form of shorthand and I’m not getting the references. What do you mean by another trajectory? Is the first, the longer time, a set amount in space from say one planet to another? And the ‘any other trajectory’ just it travelling through space but not towards anything?
From the framework of 4d spacetime, we say that the particle is following the shortest distance in spacetime – ie, a straight line through spacetime – and in doing so the particle moves in a curve through space, but the space itself isn’t warped.
This is the when the particle gets to point B? So you’re saying it’s not the space which is creating the curved path, but the attraction somehow of matter which then slows down the time as the matter’s attraction brings it into a curve around it?
If I’ve understood that correctly. I think that’s still not time that is being warped, but only the speed of the particle.
Actually no, I don’t understand the first part. Do you mean re from one location to another, because it is moving the clock is slower? So if a clock is not in Earth’s gravitational field and not moving it is then faster?
The time link posted above: http://www.metaresearch.org/cosmology/gps-relativity.asp
“(GR) predicts that clocks in a stronger gravitational field will tick at a slower rate. (SR) predicts that moving clocks will appear to tick slower than non-moving ones. Remarkably, these two effects cancel each other for clocks located at sea level anywhere on Earth.”
That’s still just a function of matters’ attraction/distance isn’t it? It’s a heavier body slowing down another lighter something. It’s not really altering time itself, only the speed the lighter something is moving in a space. I don’t see how that is any different from the boiling point of water, say, altering at different heights. ‘Apparently’ not cancelling out above sea level a clock on a moving plane ‘will appear’ to tick slower, but the less gravity at the height wins out and it ticks faster..
It’s the ‘appears’ which is amiss here, I think. I don’t know if you’ve ever seen the demonstration of the ‘shrinking and growing Alice’, don’t know the official title, but – a viewer outside of a room has an oblong window to look through into the room, but the field of vision is restricted, he can see the ceiling and the floor of the wall opposite him which he can see from corner to corner. He sees a person in one corner normal size to the room; that person moves along the wall to the opposite corner of the same wall – and while doing so begins to grow bigger and bigger until he is squashed as his head reaches the ceiling. Even when it is explained, how this effect is achieved, one’s mind just cannot stop seeing the same effect, because it so ingrained as a learned response to the outside world, (the floor rises from one corner to the next, so the person growing is actually walking up an incline, but we still see parallel ceiling to floor), that the mind still continues to interpret it exactly as it is seeing it even though it at the same time understands what is really happening. In other words, you can’t stop seeing the man grow until he has to bend his head at the ceiling, because our learned interpretation of the world around us is that ceilings and floors are in a particular relationship to each other. Some many years ago there was a study on perception in a wild and wooly tribe somewhere in Africa. These people did not have any learned perception of square houses, they couldn’t see them. They too could be taught that a square house was a square and not a circle, but even understanding that, they still saw a round house. Perception is a learned response in childhood. All this to say, that ‘apparently’, those long haul boring plane rides must have the same effect as heavier matter/strong gravity, it completely overrides and reverses the effect of time apparently speeding up the higher one gets away from a strong gravity at sea level..
William Mason says:
May 6, 2011 at 9:45 am
I don’t think the picture is meant to be taken literally. It is drawn that way because if you draw every possible angle in 3d you would just see a sphere of ink. It is drawn in the two dimensions so you can see the shape and once understanding the concept use your mind to apply it to the 3rd dimension.
Which I did, and I got much the same result as you get, a sphere of ink.. The only difference is you’re rejecting what you’re seeing. The picture says it’s a four dimensional representation! It doesn’t even make sense in 3.
Imagine you’re jumping on a trampoline, now extend that trampoline to be a complete sphere around you and keep jumping around making big dents in the thing. The claim is that the Earth is not jumping from one point to another, but it is impinging equally on every point of the space around it. These must either cancel each other out if the Earth is truly impinging on the trampoline/stuff/inside of balloon/honey/space around it, or, it isn’t impinging at all as that diagram purports to show.
The Earth is not two dimensional, it is 3D. If, it is impinging on it’s surroundings as in the diagram then that has to extrapolated to 3D, where each of the points on the 3D Earth must impinge massively into the surrounding equally in 3D space.
Myrrh says:
May 7, 2011 at 4:20 pm
As I understand it – 3d space is not warped – that wouldn’t make sense.
You cannot separate space from time. there is only spacetime.
“(GR) predicts that clocks in a stronger gravitational field will tick at a slower rate. (SR) predicts that moving clocks will appear to tick slower than non-moving ones. Remarkably, these two effects cancel each other for clocks located at sea level anywhere on Earth.”
and this is simply not true. See e.g. here: http://www.exo.net/~pauld/physics/relativity/relativitytimefly.htm
Bart says:
May 6, 2011 at 3:27 pm
Re my: “If the mass of the Earth is warping space around it which is what is then pulling in stuff which is gravity, it can only be doing this exactly as in the diagram, on a plane. It cannot be extrapolated to three dimensions.”
Why not?
Because it has to be equally so all the way around. Which leaves no dips.
Re my: “I’m saying that can only be two dimensional, (exactly as in the diagram), because a mass will impinge itself in all directions equally, (if such a thing was happening), cancelling out all the individual impinging on all the points touching the surrounding space, in a three dimensional space.”
You need to integrate the pull over the entire mass. Gravity surrounding a spherical mass behaves externally just as though the mass were concentrated at a single point in the center.
How does it get to behave like that by the depicted scenario extrapolated to 3D?
If, the Earth is really creating such a great dent in the space around it by its mass, if it is doing so it must be equally on every point of its sphere, then there should be a layer of thick honey equally all around the Earth in a band all around at every point. The Earth the yolk of an egg, and the thick layer of stuff space/time its mass is squashing in all directions, the shell around the yolk. Is there?
Myrrh says:
May 7, 2011 at 4:45 pm
Earth must impinge massively into the surrounding equally in 3D space.
What happens is that the volume of the space inscribed by the 3D sphere is different from what you calculate for a flat space: 4pi/3*Radius^3.
Louis Savain says:
May 7, 2011 at 4:08 pm
[snip] …The truth hurts doesn’t it, Anthony? But you can’t shut me up… [snip]
[Reply: No one is shutting you up, this is America. But if you want to say your piece here, you need to be a little less cranky. Posting on WUWT is a privilege, not a right. ~db stealey, mod.]
ahahaha…
Stealy, you can kiss my you know what. WUWT commenters are calling me “troll”, “stupid” and insulting me left and right while you moderators self-righteously look the other way. And then you have the nerve to accuse me of being cranky? And all because I criticize your little god, Einstein?
And what’s up with the privilege crap? You think I need to post anything on this blog? I got news for you: you don’t put food on my table. You should all be grateful to me because I taught you something that you did not know. I did you a favor by spilling the beans on the silliness and illogic of Einstein’s spacetime on this blog. I am not the one who is privileged here. You are. You are all a bunch of ingrates and ignoramuses. You don’t deserve my good graces. Ya’ll can eat shit.
PS. I dare you to publish this with no deletions, you gutless cowards. 😀
REPLY: Oh I’ll publish it, to demonstrate the sort of person you are. But it will in fact be the last comment from you here as you’ve now violated site policy. Banned. – Anthony
Myrrh says:
May 7, 2011 at 5:19 pm
because a mass will impinge itself in all directions equally
You seem to be hung up on the ‘impinging in all directions equally’. Perhaps look at this way: the impinging from all directions is stronger the closer to the mass you are than it would be if it were not for GR. In this case you can get out from under the ‘all directions equally’ fixation.
Myrrh says:
May 7, 2011 at 5:19 pm
because a mass will impinge itself in all directions equally
Perhaps this set of lectures will help:
http://asterisk.apod.com/viewforum.php?f=39
Especially the lecture on curved spaces
Louis Savain says:
May 7, 2011 at 5:32 pm
=====
We are having a discussion here, opposing opinions are encouraged, the participants of the debate rarely resort to such vile verbiage, it shows bad manners.
(and, it is an admission that they lost the argument).
Louis Savain says: “Ya’ll can eat…”
Coprophagia is how animals keep their dens clean and reduce smells that attract preditors.
Leif says May 7, 2011 at 4:53 pm
You cannot separate space from time. There is only spacetime.
There is only stuff. You can call it what you like, but that it’s “spacetime” is unproven.
Re the “GR predicts that clocks in a stronger gravitational field will tick at a slower rate. SR predicts that moving clocks will appear to tick slower than non-moving ones. Remarkably, these two effects cancel each other for clocks located at sea level anywhere on Earth.” from the http://metaresearch.org/cosmology/gps-relativity.asp
and this is simply not true. See e.g. here:
http://www.exo.net/~pauld/physics/relativity/relativitytimefly.htm
What is simply not true? I’ve read through your link, well, it’s late so maybe not so thoroughly as I should, but I can’t find what your link is saying that’s particularly different. The link I referred to was posted by PaulH I think, and I thought a very good explanation, and it appears to me, to be a better level of explanation than your link. But, anyway, please be more specific in what you’re disagreeing with, and please quote what it is that says this isn’t true from your link. Ta.
Leif says later at 5:25 pm
Re my: “Earth must impinge massively into the surrounding equally in 3D space.”
What happens is that the volume of the space inscribed by the 3D sphere is different from what you calculate for a flat space: 4pi/3*Radius^3.
I don’t know whether I’ve mentioned this specifically to you in our various exchanges, but I don’t have the maths language.. Please explain that in English if you’re making some point here.
“Inscribed” I do understand, but looked it up for geometry.. So how is that for the boundary of the Earth including boundary to this alleged eggshell of squashed space/time all around it, and then including the thickness of the squashed space/time?
Leif says: May 7, at 5:36 pm
Re my: “because a mass will impinge itself in all directions equally”
You seem to be hung up on the ‘impinging in all directions equally’. Perhaps look at this way: the impinging from all directions is stronger the closer to the mass you are than it would be if it were not for GR. In this case you can get out from under the ‘all directions equally’ fixation.
I said, “if such a thing were happening”. If you’d bother to read my post for context you’d have got that, I’ve been saying it all the way through this. The impinging in all directions equally comes from extrapolating the concept as depicted in the diagram into 3 dimensions.
Your “impinging in all directions is greater the closer to the mass you are” means what here? The alleged ‘space/time’ is immediate all around the greater mass, and the greater mass is impinging into it enough you say to alter by dramatically bending it out of shape deeply enough to create gravity.
Myrrh says:
May 7, 2011 at 6:30 pm
There is only stuff. You can call it what you like, but that it’s “spacetime” is unproven.
The stuff there is is called spacetime and have the properties specified by the special theory of relativity: that two observers moving relative to each other will disagree on the space between two event and on the timing of the events. They will, however, agree on the distance between the two events in spacetime. This is a fact. If you cannot stomach that the discussion is dead to begin with.
What is simply not true?
That the two effect cancel out exactly.
please be more specific in what you’re disagreeing with, and please quote what it is that says this isn’t true from your link. Ta.
Simply flying clocks around the Earth shows the effects do not cancel out.
Please explain that in English if you’re making some point here.
That the ‘impinging’ [which I don’t quite know what you think is] being the same from all directions is relevant. Space is simply curved equally in all directions around a mass.
So how is that for the boundary of the Earth including boundary to this alleged eggshell of squashed space/time all around it, and then including the thickness of the squashed space/time?
Not sure what you mean, but the shell can be thought of as being infinitely thin and there being infinitely many of them. The curvature of spacetime gets larger and larger the closer to the mass you are in all directions equally. In Newton’s world there is no curvature, but a mysterious force called gravity reaches out through space instantly and works at a distance [any distance from here to infinity] without any coupling, mechanism, or actor. In Einstein’s [and our] world there is no such force and no mechanism is needed. Mass just determines the curvature of spacetime locally. BTW, on very large scales [greater than galaxies] spacetime is flat [observations show this].
Myrrh says:
May 7, 2011 at 6:57 pm
the greater mass is impinging into it enough you say to alter by dramatically bending it out of shape deeply enough to create gravity.
Yes, perhaps this is the way you could understand this. Mass bends [curves] spacetime to create [the illusion of a force of] gravity. As simple as that. Sometimes, people have the hardest time understanding very simple things. Einstein fought against that attitude all this life. Only after his death was general relativity serious physics. He didn’t even get the Nobel Prize for GR.
Leif Svalgaard says:
May 7, 2011 at 3:23 pm
One last time: the light never traveled 40 Bly to reach us &_&.
Myrrh says:
May 7, 2011 at 4:20 pm
“The presence of matter makes time run slower and therefore what is being warped is time.”
Both space and time are warped about a massive object. Overall, I think a large part of the problem you are having is semantic. What do you think it means, for space and time to be “warped”? All it means is time and the dimensions of space do not maintain the same relationship to one another which they would in the absence of a massive body nearby. Which means that bodies move differently, and processes occur at different rates relative to others, than they normally would.
Louis Savain says:
May 7, 2011 at 5:32 pm
You can’t respond, but you can read. Maybe it would help your case if you could show how to design a Doppler radar, or get consistent measurements from a GPS satellite, WITHOUT using Relativity. When you are able to do so, give us a call. In the meantime, these and other properties explained by the theory can be put to many good uses.
In a way, your task is only half as difficult as it appears. Whatever you might come up with, it must have the same form as the equations derived from relativistic principles, because these have been verified repeatedly to exacting accuracies. You just have to come up with another explanation for how they come about.
Bart says:
May 7, 2011 at 8:10 pm
One last time: the light never traveled 40 Bly to reach us &_&.
Nobody is saying that. I’m saying that we are seeing [just took a photograph of it] a galaxy that is now 40 Gly away, so we can obviously see that far.
Leif – But, what we are “seeing” is not the galaxy now at 40 Bly, it is the galaxy then (13.2 Byr ago at 13.2 Bly), so we are not seeing a galaxy 40 Bly away, any more than I have seen the men and women who grew up from the boys and girls I knew in grade school, but with whom I lost touch along the way.
This discussion is a little vexing to me because it’s not what I am interested in. It appears we are asking different questions. This is mine: The article says the distance to the galaxy at the time the photons which have been collected were released is 13.2 Bly. At that time, Hubble’s relation tells me the object was receding at 0.96c. The graph at Wikipedia says that would produce a redshift of roughly unity. However, the article says the redshift is more like 10, which the graph says corresponds to a velocity of around 2c.
OK. So, my question is, did they actually measure a redshift of about 1 and extrapolate that to a redshift of about 10 for photons emitted but not yet observed based on where the object is now, or did they actually measure a redshift of 10 and the Wiki graph is plotting velocity now versus redshift of a photon emitted then? Either way, it is confusing, though conventions often can be until you get used to them.
My GR training ended after the standard three elementary solutions for the metric external to a massive body (Schwarzschild, Reissner-Nordstrom, Kerr), and a very brief overview of cosmology, so I do not know the conventions someone in the field would use, or what a typical redshift is versus distance to the source.
Bart says:
May 8, 2011 at 12:12 am
what we are “seeing” is not the galaxy now at 40 Bly, it is the galaxy then (13.2 Byr ago at 13.2 Bly), so we are not seeing a galaxy 40 Bly away
We are seeing a galaxy that now is 40 Gly away.
The article says the distance to the galaxy at the time the photons which have been collected were released is 13.2 Bly. At that time, Hubble’s relation tells me the object was receding at 0.96c.
Perhaps you are confusing light years and parsecs….
did they actually measure a redshift of 10
The measured redshift is ~10.
>>
Bart says:
May 6, 2011 at 3:27 pm
Jim Masterson says:
May 5, 2011 at 1:23 am
“It’s harder to show mathematically, but a ring can’t orbit around a star either (as in Ringworld).”
But, it can remain steadily oriented in space through gyroscopic stiffness, and its CG will move approximately with the Star’s CG. Some stationkeeping may be needed to deal with stray forces which act differently on the Star and the ring.
<<
We’re talking about a structure (made of metal? silicon? Niven, of course, made up some fantasy-super-strong material to build the ring with.) that is two astronomical units across and about a million miles wide. I doubt seriously that such a structure would be rigid enough to rotate with “gyroscopic stiffness.” The “station-keeping” would be quite a feat by itself.
But let’s do some calculations. The Earth must travel fast enough to orbit the Sun in one year. (We can assume the orbit is circular to simplify the calculation.) This gives us an average orbital speed of 2*pi*AU/year-in-seconds = 29.79 km/sec.
To compare, the escape velocity from the Earth is 25,000 miles/hour or 11.2 km/sec. So the Earth is orbiting the Sun at more than 2.5 times the fastest speed that man has yet traveled (escape velocity was required to reach the Moon).
Ringworld rotated fast enough to create about 1 g. Let’s try to calculate that. Centripetal acceleration is: a = v^2/r where a is 1 g or 9.8 m/sec^2 and r is 1 AU or 149,597,870.691 km. Solving for v we get 1210.8 km/sec. This is about 40 times the velocity required to counteract the Sun’s gravitational force. The ring would make one rotation in about 9 days. I doubt that such a structure could withstand the centrifugal force and would fly apart.
Jim
Leif says:
May 7, 2011 at 7:08
Re my: “There is only stuff. You can call it what you like, but that it’s “spacetime” is unproven.”
The stuff there is called spacetime and have the properties specified by the special theory of relativity: that two observers moving relative to each other will disagree on the space between two events and on the timing of the events. They will, however, agree on the distance between the two events in spacetime. This is a fact. If you cannot stomach that the discussion is dead to begin with.
What you’re not dealing with here is that “spacetime” is still unproven. These things may well happen, I don’t have the time to go into more complicated effects witnessed in our world, but you still haven’t proved that it is your “spacetime” that is doing this, that it even exists, that the method claimed is warping it is even possible!
So, as I originally asked, first prove that such a warping exists of the space around the Earth, is even possible, in 3D, before invoking time.
There is nothing in that diagram that shows Time being warped or that it is even involved. Claiming it is a representation of 4 dimensions is nonsense. It represents a claimed scenario in simple 3D, of the body with mass affecting the space around it.
From now on I shall try to remember to refer to this space stuff as honey stuff or space honey, to root it firmly into the 3D problem that this diagram is actually representing and rooting it firmly into the description of it from the experimenters. When I forget I’ll revert to space or stuff.
Re my: “What is simply not true?”
that the two effects cancel out exactly.
Still can’t find it. Please point it out.
Re my: “please be more specific in what you’re disagreeing with, and please quote what it is that says this isn’t true from you link. Ta.”
Simply flying clocks around the Earth shows the effects do not cancel out.
Still can’t find it saying that. It does however say that it is not dealing with General Relativity on that web page – are you confusing this because you haven’t taken that into account?
Re my “Please explain that in English if you’re making some point here.”
That the ‘impinging’ [which I don’t quite know what you think is] being the same from all directions is relevant. Space is simply curved equally in all directions around a mass.
The impinging as in the diagram. That the mass of the Earth is sinking into the honey space is it impinging on it. As the general description of this gives it, take a rubber sheet and put a heavy round ball in the middle of it, and the weight of the ball distorts the rubber sheet – it impinges on it, impacts upon it. (COD) impinge – v.t. and t. (Cause to) make impact (on, upon); hence ~ment n.
Re my: “So how is that for the boundary of the Earth including boundary to this alledged eggshell of squashed space/time all around it, and then including the thickness of the squashed space/time?”
Not sure what you mean, but the shell can be thought of as being infinitely thin and there being infinitely many of them. The curvature of spacetime gets larger and larger the closer to the mass you are in all directions equally.
[So you agree that it is equally in all directions, therefore making it a simple 3D model as the diagram is extrapolated all around equally.] By the shell I mean at the deepest point of each impingement/impact of the heavy body into the spacehoney surrounding it, which then extrapolated all around the body equally would create a shell around it, the edge between the unwarped honeyspace and the warped at every point of the deepest effect of the mass impacting/impinging on it. As in the diagram. Because the Earth is distorting a something there is a squashed area at the deepest point beyond which the distortion doesn’t go, while the honeyspace around that point is slipping around the weight distorting it into less curvature. The Earth then has this shell of more compacted honeyspace directly at each point as the mass impacts it.
Which is what you are also saying in the “the shell can be thought of … there being infinitely many of them, and “the curvature of spacetime gets larger and larger the closer to the mass you are in all directions equally”.
So, the further away the more honeyspace’s distortion becomes less, the curvature straightening out until it is just honeyspace undistorted by the mass of the body. By boundaries I mean the beginning of the outside edge point which is the shell at the last moment of greatest distortion into the honey space, to when the weight/mass of the body is no longer capable of distorting it and it reverts to undistorted; the beginning and end of the shell which is the amount of the distortion the body creates by its impact at its deepest effect. In the diagram the beginning of the space between the earth and the furthest point of the reach of its effect on the space honey it is distorting. So, the Earth is completely enclosed by this shell, there is no more opening on the other side of Earth to the point at which its mass is distorting the space on its opposite point. No open curvature spiralling in anywhere on the shell to capture anything supposedly travelling in a straight line and claiming this is gravity. It has all been cancelled out. Even if you could show that this was a one way street and the honey stuff was merely being acted on and not also acting on the body distorting it, there is no warp. There’s nothing happening from the distortion created by the mass because it’s the same all the way around.
So, what we’re left with is the normal 3D effect of a body suspended in a fluid.
And all the experimenters have found, is that the spin of the Earth is moving this fluid space honey.
Now, if you want a vortex out of that then perhaps you should look to the movement of fluids on Earth. Down the plug hole with different spins in each hemisphere. So not some mythical “space/time” invisibly channeling in something travelling in a straight line which just happens to get caught at the top of a helterskelter, but the Earth extending its reach into the honey stuff all around it and sucking that in, taking with it whatever has been caught in the fluid… Where’s it all going?! Hmm, the Earth must be recycling it somehow. Earth is the Honey Monster..
Anyway, the Earth is also moving as well as spinning, and at the boundary layer of a body moving fast in a fluid we have well understood science too: http://hkprogolf.com/dimples.html
[Air is a gas, Air and Water are fluids.]
From which about a golf ball travelling at around 120 miles an hour:
So, at the surface of the Earth moving around the Sun in a fluid honey space stuff which you call space/time, the fluid space is still, and in the boundary layer it is just slurping along creating wild whipping whirlpools as the fluid space tumbles behind the speeding Earth, and just above that, the fluid space is rushing past the much slower moving slurpy honey stuff.
So, the spinning Earth in the fluid space stuff around it like a golf ball with a spin on it travelling at speed through the fluid gas Air. We know the effects of this, as described above and continued on that page. Normal Science can work out the drag, the low pressure formed behind the Earth taking into account its speed and size and so on.
Your scenario, of a static bending of space stuff around the Earth, has no means of capturing anything because all it creates is a closed boundary layer, of a ball suspended in a bath of water. Not even taking into account that such a ball is also being acted upon by the water surrounding it.
Your scenario is incapable of explaining 3D space around it, and yet you claim this also includes Time…
And lastly, from http://www.docstoc.com/docs/6077410/Gravitational_field
Hmm, seems to me that ‘the ether’ is just what this honey is, and the Earth moving in it and spinning it around fully capable of being explained by bog standard science of 3D reality as the golf ball is explained.
Does this experiment then, prove the Ether theory?
Myrrh says:
May 8, 2011 at 10:39 am
Dealing with here is that “spacetime” is still unproven. These things may well happen, I don’t have the time to go into more complicated effects witnessed in our world, but you still haven’t proved that it is your “spacetime” that is doing this, that it even exists, that the method claimed is warping it is even possible!
All my links have not had any effect, it seems. Spacetime is one of the best supported fact of all of science.
It represents a claimed scenario in simple 3D, of the body with mass affecting the space around it.
spacetime is curved.
Re my: “What is simply not true?”
that the two effects cancel out exactly.
Still can’t find it. Please point it out.
Myrrh says:
May 7, 2011 at 4:20 pm
“Remarkably, these two effects cancel each other for clocks located at sea level anywhere on Earth.”
and this is simply not true.
Because the Earth is distorting a something there is a squashed area at the deepest point
Not a squashed area, but a squashed spacetime
And all the experimenters have found, is that the spin of the Earth is moving this fluid space honey.
Not only that, but also that the dragging is just what is predicted from GR’s warping of spacetime.
we have well understood science too: http://hkprogolf.com/dimples.html
Relativity is very well understood science, and has survived every experimental test it has been carried out over the last 100 years.
[Air is a gas, Air and Water are fluids.]
From which about a golf ball travelling at around 120 miles an hour:
So, the spinning Earth in the fluid space stuff around it like a golf ball with a spin on it travelling at speed through the fluid gas Air. We know the effects of this, as described above and continued on that page. Normal Science can work out the drag, the low pressure formed behind the Earth taking into account its speed and size and so on.
Relativity is Normal Science and does indeed account [quantitatively] for the observed effects.
“The detection of gravitational waves bears directly on the question of whether there is any such thing as a “gravitational field”, which can act as an independent entity. ..this fundamental field hypthesis has been generally accepted without observational support. Such credulity among scientists occurs only in relation to the deepest and most fundamental hypotheses for which they lack the facility to think differently in a comparably detailed and consistent way. In the nineteenth century a similar attitude led to a general acceptance of the ether..”
The pulses from binary pulsars are slowed down by their issuance of gravitational waves, e.g. http://en.wikipedia.org/wiki/Gravitational_wave Detectors are being constructed both on Earth and in Space and we are approaching the sensitivity needed to detect the waves directly.
Does this experiment then, prove the Ether theory?
In a sense, yes. In another sense, no [not the classical Ether theory]: http://redshift.vif.com/BookBlurbs/PIRTVol1.htm
Bart says:
May 7, 2011 at 8:10 pm
Myrrh says: May 7, 2011 at 4:20 pm
“The presence of matter makes time run slower and therefore what is being warped is time.”
Not me, I was quoting Vince Causey, who first said that he agrees it is not space being warped, but thinks matter is warping time (so the discussion on moving objects apparently slowing down time etc.
So to Vince’s statement thinking it mine you reply:
Both space and time are warped about a massive object. Overall, I think a large part of the problem you are having is semantic. What do you think it means for space and time to “warped”? All it means is time and the dimensions of space do not maintain the same relationship to one another which they would in the absence of a massive body nearby. Which means that bodies move differently, and processes occur at different rates relative to others, than they normally would.
What I mean by space and time to be “warped” is exactly as it is presented by you, generic, in the diagram which begins this discussion. That is what I am describing and commenting on.
The rest of your paragraph continuing “All it means..”, is hypothetical. I’m saying that you can’t even make that diagram work in 3D reality, so how the heck do you think you can establish that any kind of difference exists between your hypothetical measurements invoking Time relating to Space with a massive body nearby when your concept of Time and Space without a massive body nearby isn’t proven to exist and when your concept of a massive body distorting ‘space/time’ all around it creates a simple ball suspended in a bath of still water, at best?
See my last post to Leif.