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.
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Learn a lot more on testing Einstein’s theories here h/t Dr. Leif Svalgaard via email
Myrrh says:
May 11, 2011 at 4:41 pm
“How about attempting to answer my question about aging in space?”
Which question was that? Whatever it is, it is a confirmed fact that normal, natural processes which contribute to aging are less rapid in space compared to similar processes unfolding on the surface of the Earth. The Space environment, however, takes its own toll on the body, and the difference in rate of time is quite small, so it’s not a very effective time machine into the future.
“When I ask ‘where is time in the GR diagram?’, you come back with the repeated strange idea that mass bends time, but it’s nowhere to be found on the diagram.”
I have explained that to you repeatedly. The diagram is an analogy. It is not to be taken literally as describing the warping of space and time. I don’t know why you can’t get past this.
“How does the gyroscopes being affected by gravity prove that the Earth is warping time?”
It doesn’t. But, if it gave an answer outside reasonable error bounds from that of GR, and the difference between measured and expected performance were repeatable in other experiments, GR would require modifications. As it is, the geodetic precession result was confirmed to high accuracy. The frame dragging effect has been confirmed to lesser accuracy, and will be measured again in the near future.
“It appears that Einstein’s 43″ has now been superceded by more accurate measurements, 56″, his now being only a part of the mix.”
You appear to be looking at the wrong line. Look for the line where it says: 42.98 ±0.04.
“And I found this:”
At a glance, I saw a guy using a closed form elliptical orbit solution to describe the bending of light. Fail. The guy threw some random equations around until he came up with a formula that agreed with his already determined solution. You should be very careful of accepting just anything, just because it is written down somewhere. There are a lot of crackpots on the web.
“I think that Einstein spotted Soldner’s maths error and corrected the error…”
Incorrect. The classical formula simply does not give the right answer. This ground has been picked over for nearly a century. People who desperately wanted to discredit Einstein gave it their best shot, and failed. Because, the formula is right, and has been verified over and over again.
“Bart and Leif, and anyone else interested, this paper claims it gets Einstein’s result from Maxwell, i.e. without any need to invoke GR.”
There are many ways to formulate the problem. If you consult the Relativity Bible, you will find in Box 17.2 “Six Routes” to “Einstein’s Field Equation”. Number one is “Model geometrodynamics after electrodynamics…” Properly done, it leads back to the same spot. All roads lead to Einstein.
One last…
“Does so remind me of AGW arguments from the warmists…”
It is nothing like the AGW debate. The scientific establishment of the day was virulently against Einstein. Later, the Nazis and the Soviets, in particular, were keen to discredit him. That Einstein never even received a Nobel Prize for either Special Relativity or General Relativity should tell you something of the resistance he encountered.
He won the day because, in the end, he was right. Again, and again, and again, experiments confirmed the correctness of formulas derived from his theories. The establishment could only hold out so long before it had to give in.
AGW, on the other hand, has been accepted and promoted by the Establishment from early on, much like the theories of now discredited hacks in totalitarian countries who tried to take Einstein down. It has been around a relatively short time, and has passed no tests.
Great to see some more common sense and straight talking from Miles Mathis.
“At a glance, I saw a guy using a closed form elliptical orbit solution to describe the bending of light. “
I was hasty – the orbit equation isn’t necessarily elliptical – you forget these things when you don’t use them every day, and I haven’t bothered with hyperbolic orbits in ages. If it were, though, that would be the least of the problems with that very silly web page.
There is no closed form solution for radius as a function of time, and it does not have a semigroup property. The true anomaly (theta) is itself a function of time, and must be differentiated, too. And, so on. The page is essentially a mathematical word salad. As I said, there are a lot of crackpots on the web.
Malaga View says:
May 12, 2011 at 12:30 am
“That is horrible science, no matter how you look at it..”
It is a horrible commentary. The guy clearly knows little about the experiment beyond his preconceived notions.
Bart – will have to leave replying to you until later this weekend or beginning next. I’ve been rather shocked by what I’ve been finding and don’t have time to concentrate on it just now. Not to leave you on tenterhooks, it’s about the accusations made at the time that Einstein plagiarised the work of others.
Meanwhile enjoy: http://www-pw.physics.uiowa.edu/space-audio/sun-rings/Kronos-Lecture/gurnett2.mpg
“Not to leave you on tenterhooks…”
The anticipation is killing me…
“…it’s about the accusations made at the time that Einstein plagiarised the work of others…”
Wouldn’t that be completely moot at this point? What does it have to do with whether the theory is right or not?
“…will have to leave replying to you until later…”
I doubt I’ll be looking back. I really have no interest in any more pseudo-physics or phony muckraking websites. Hopefully, I have imparted some useful and convincing information to you and others reading along.
OK Bart, I just checked back to see if you replied. So you know all about the details of Einstein’s plagiarism? Though clearly you haven’t noticed or ignore that these go back to the original sources who were not publishing from any kind of racist angle. This is what disheartened me, having to go into that world, but, thinking about it yesterday I was struck by the fact that often the pertinent facts to the truth of something are kept in record when no longer in general consciousness by the energy of those who are angry/hate for one reason or another, regardless of the reason. Like this site for example, it’s existence as it has developed is fuelled by the anger/hate at the manipulations of science by world powers and corrupt co-operation of scientists, and all with layers of manipulation by vested interests according to ideology. Doesn’t make the information exchanged here as to the truth in the origins and reach of AGW tentacles a lie. That’s the warmists accusation against this site.
Anyway, it is still known, that, for examples, what Newton said about matter and energy, that experiments were already being done before the turn of the beginning of the last century showing and utilising e=mc2, that the equation so expressed was being used and published by the Italian Olinto De Pretto for several years previous to Einstein claiming his amazing ‘intellectual revelation out of nowhere’, Einstein spent time in Italy and could read Italian. None of which background he credited, he couldn’t, because he came up with nothing new from his own thinking building on concepts which had existed previous to him or being published from long work around him, he simply took them. And he really didn’t understand what he had taken, that’s why he kept producing and endorsing garbled statements about it all and getting caught up in his own lies about what he had or not read previous to his appearance as the new brilliant science genius of the age.
I’m just so disappointed. I was amused to find it possible that he had spotted a mistake and turned it to his advantage, because I thought he was a genuine scientist and this was a lapse all too human nature couldn’t then admit to after all the lauding and praise, but it’s far murkier than that and so no longer funny.
So too complicated for my time constraints to go into to rebut the rebuttals, it’s for Science itself to clean out its own stable and work out how far that has set back general scientific knowledge by taking it into fantasy land of a blank vacuum Space/Time around us which can be warped but has no mechanical or kinetic energy yet somehow miraculously influences us and creates gravity.. With the state of Science as we see it now in the Global Warming scam, there may not be enough number left in any discipline who care to give credit where it is due.
So point taken, this has nothing to do with the whether the theory is right or not.
Back to General Relativity. It has not been proven and physically can’t be, as in the sentence in last para, it’s base premise is utterly stupid so not surprisingly its method to show its workings is equally, though now it has grown like topsy to even more absurdly, so.
I doubt I’ll be looking back. I really have no interest in any more pseudo-physics or phony muckraking websites. Hopefully, I have imparted some useful and convincing information to you and others reading along.
Whether or not you come back to read this reply, I can only speak for myself here, but you have not provided any convincing information to me.
When you can show how a mass like Earth can bend space/time all around it to create gravity as depicted, I’ll be convinced.
Until then it stands nonsense. From its base premise of Einstein’s aether it will take more than using common or garden real 3D science, as has this Gravity B project, to fudge that you can’t supply any information on it, let alone convincing.
The very description of it claiming 3D science is absurd, a body cannot exert pressure in all directions simultaneously without it expending a great deal of energy doing so, or any one movement of warping as a heavy ball on a rubber mat will cancel out if the effect could be in every direction, remaining as a entity in that space as in suspension and which means the greater energy being from its surroundings acting on it, not it acting on its surroundings. The Earth is expanding like a balloon is it, creating gravity all around it? We hadn’t noticed.
To not be able to think through to the 3D representation of this 2D diagram in our physical universe is a drawback, I would think, for a scientist in this field. And, ‘explanations’, which are no more than constant repetition of the claim, based on an unproven theory about a physical concept of the space around us unknown in example to science in the real 3D world, shouldn’t convince any scientist.
I’d found this yesterday which I thought you might appreciate better than my maths language free explanations, through exploration here into the concepts (before I got disheartened by the foray into Einstein’s history): http://scienc1.wordpress.com/2008/10/27/mercurys-perihelion-and-einsteins-general-relativity/
I couldn’t follow the maths, but was interested to see that he was saying that all the explanations from Einstein’s 4th Dimension people are unable to provide a 4D maths to go with it. Which is why I now suppose they keep screwing with the 3D as in this discussion re Gravity B claiming 3D effects prove it, I loved the duh, and particularly in your and Leif’s comments, by claiming it ‘is an analogy’ relating to some higher level of learning that I’m incapable of understanding because I’m obviously too uneducated in the finer points, if not downright thick..
..and yet I keep finding that the most basic science questions I pose of some who call themselves experts here go unanswered, either by misdirection or ad hominem the usual response upon asking for clarification. Still can’t find any proof let alone explanation that blue light from the Sun heats the water in our oceans, not anywhere on any science pages I’ve looked through, and I’ve looked and looked, (sigh), it must be out there somewhere.
Oops, link missing energy – http://science1.wordpress.com/2008/10/27/mercurys-perihelion-and-einsteins-general-relativity/
Since it came up in the accusation of ‘racist’ sites promoting anti-Einstein information.
On looking for who else had Jon Bjerknes’s book I found the Armenians had it. I know about the Armenian massacre by the Turks and I’d no reason, I hadn’t explored further, to think it wasn’t the particular Muslim faction anti Christians who then used the standard Sharia law applicable to those of dhimmi status, of death to those who objected to their rule, when the Armenians appealed for help to the British. I’m not directly putting up what I learned, but more detail about this history can be found on some links here: http://hayq.blogspot.com/2007/09/blog-post_7815.html
I think most of us ‘skeptics’ about AGW have been shocked to discover the ideology driving some to promote it, this has nothing to do with ‘racism’, but like all such ideas, from an aberration in human character which is by default co-operative in nature. And therein lies its strength in changing human history for the worse, in co-opting that nature of some by the few easily turned to ‘permission’ to create an immense amount of heartache for the many. Reasons to justify such the only thing that differentiates one movement from another through our world’s long history.
For myself, whenever I step into these worlds past or present I first recall what someone said who had survived existence under Lenin and Stalin and being starved and abused as slave labour in Hitler’s camps. After recounting the history in Germany and being told the listener hated the Germans for what they had done, said: “There are good and bad in every nation”, and continued with stories of her own nations’s atrocities to others. It helps me to retain balance whenever I find as I’ve done in exploring AGW, that there a people in the world with power and no sense of worth of the other whatever the names of the ideologies which they use as excuses to bolster their lack of self-worth. Doesn’t mean we have to be like them in trying to stop what they’re doing.
Finally. Re speed of light. One of the things that has puzzled me in the discussions on Solar energy heating the Earth in the AGW arguments is the emphasis placed on the ‘highly energetic’ photons of Visible light from the Sun, as if that automatically means that they are therefore more capable of ‘doing stuff’, because, it takes a lot of heat to produce these and it seems to me then that the real ‘high energy’ is in the heat, and so like in an ordinary light bulb where 95% of the energy is given off as Heat energy to the 5% Light energy, it would follow that the high energy capability of doing stuff is still with the heat, (therefore, in the AGW arguments, the Thermal IR given off by the Sun radiating to Earth and not the Visible light radiation). I decided that this was a confusion between ‘highly energetic’ and ‘high energy’, the former merely means that it is moving faster in the same length of space, not that it is more powerful as a ‘force’.
The Visible light from the Sun, especially the shorter more energetic wavelengths of blue light, are actually very weak, they are very easily scattered all over the place by the molecules of oxygen and nitrogen in the air and we have a blue sky, and by water molecules in the oceans they pass through to reach deeper levels than the longer wavelengths of visible . And then there’s led’s… Anyway, that nothing travels faster than light is a premise of SR and as I was packing away some windows I still had up when looking for info on it, I had this:
http://www.awesomelibrary.org/Classroom/Science/Physics/Particle_Physics/Lorentz_Symmetry.html
2. Lorentz Symmetry Violations and Constraints (Physics.McGill.ca)
“The idea of Coleman and Glashow is the following. Suppose that Loretnz symmetry is not a true symmetry of nature. This open up the possibility that the limiting speeds (the highest speed which can be attained) of different particles, are different from each other. Suppose in particular that the speed of light (of electromagnetic radiation) and the limiting speed of a proton were not the same, and that the speed of a proton were higher. Then it turns out that the proton would lose energy to electromagnetic radiation, until its speed was the same as the speed of light.”
“The way this works is the following. Since the proton is electrically charged, it carries around an electromagnetic field. When the proton moves, the electromagnetic field of the the proton must move with it. The emission of electromagnetic radiation (light) can be understood as that electromagnetic field continuing to propagate, when the proton’s motion is changed by some external force; so every time a proton changes its speed or direction of motion, some of the electromagnetic field accompanying it continues in the old direction and becomes radiation. If a proton were moving faster than the speed of light, then it would ‘outrun’ its own electromagnetic field; without any acceleration being necessary, the electromagnetic field of the proton would get stripped away from the proton and propagate away as photons (electromagnetic radiation). Since the proton is charged, it would continuously regenerate electromagnetic field; but this field would continuously fall behind the proton and be lost as radiation, until the proton slowed down to the speed of light, whereupon the electromagnetic field could keep up with it. This is what happens when a medium, such as water, a crystal, or the air, modifies the speed that light travels; charged particles which travel faster radiate ‘Cherenkov’ light.”
Make of it what you will.
The geometry of space and time that we experience is created by light and is not the same as mathematical geometry,our measurement of space and time changes as we approach the speed of light?