Einstein proven right, again

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.

Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time. Image: NASA

 

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

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Simply amazing! At least someone is still doing real science.

DirkH

So, spacetime behaves a litle bit like honey? Why don’t we just call it ether?

Theo Goodwin

Wonderful post, Anthony. By the way, Aristotle’s vision of what he called the universe was very similar to the following:
‘“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.’
Oh, by the way, can someone recommend the ideal GPS device for hiking in and around the Appalachian Trail in Virginia?

Jack Savage

Einstein.
A dude.

Carl Chapman

What would Einstein have said about “scientists” who hide their data even from Freedom Of Information laws? On consensus, he said: It doesn’t take 100 signatures to prove I’m wrong. It just takes one experimental fact.

Louis Savain

There are only two nasty little problems to consider before you all get excited. First of all, time cannot change by definition and, therefore, nothing can move in spacetime. This is the reason that the great Sir Karl Popper called spacetime, “Einstein’s block universe in which nothing happens.” (source: Conjectures and Refutations).
Second, it is easy to prove that space (distance) is nothing but an illusion of perception). Surprise!
So these experiments did not prove that Einstein was right (he believed in the physical existence of a spacetime and of a time dimension!). They only proved that some of his equations were right. The interpretations of those equations, however, leave a lot to be desired.

PaulH

It’s true. GPS satellites are effected by relativity, mainly the relativistic time slowing effect due to the speed of the satellites.
http://www.metaresearch.org/cosmology/gps-relativity.asp
Cool stuff, even if the physics gets a bit deep. 🙂

RayG

I joined the staff at Stanford in 1975. Shortly thereafter, I became aware of a program that was referred to in the bureaucratese of the day as Fairbanks, Everett and DeBra or GP-B. They were Bill Fairbanks from the Physics Department, Dan DeBra from Aero and Astro and Francis Everett from the Hansen High Energy Physics Lab. They soldiered on through periods where funding was not easy to raise and challenges as to the importance of the project were periodically raised. The many successes that came about because of their work is yet another testimony to the importance of funding basic research. Bill Fairbank died in the late 1980’s while on his daily run if I remember correctly but it is great that Francis Everett and Dan DeBra were able to see the fruition of decades of world-class work.
It is sad to see the amount of research monies that are being squandered on so much of what passes as science in the climate arena today.

wayne

Those are some interesting articles Leif. The reference frame dragging was one of hardest concepts to grasp, for me anyway.
It sure seems like NASA could hire an artist that knew the basics of gravity for a story about… gravity. Neat picture but somewhat misleading if you take it too literally! Don’t look at that green-blue mesh and think that is what the real signature of Earth’s gravitational field would actually look like, well, kind of, but not correct.
At the center of the Earth there is no gravity field, zero. There should be an upside-down V-shaped dimple pointing upward in the middle from the surface inward on that grid at it’s deepest point. Maybe that article will cause some here that might not realize that fact to ‘open the books’, so to speak, and be a bit more enlightened.
Another thing I learned not too long ago is that if the Earth’s density was constant then that upside-down dimple of the gravitational field from the surface to the center of the Earth would be linear, a straight line, and not an inverse squared curve.

BarryW

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.

That bothers me.

Ray

Darn! Einstein is right again. That sucks… we will never be able to travel faster than light… at least in this space-time continuum.

Douglas DC

Gives me a bit of comfort as there still non grant grabbing ,AGW screaming ,
real scientists out there..

jorgekafkazar

“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…”
Did they use Mannian PCA? It’s very good for finding signals that you know are there.

xion III

I’d like to know what was the unexpected wobble was caused by. If there was muddy data as a result, that took years to sort, what guarantee is there that cherry picking has not occurred?

SamG

I don’t get why the warping of space time is depicted as occurring on a single plane. Is this for illustration purposes only? I would have thought a large body bends space time in every direction.

Juice

I still don’t see how you can drag space. I can see gravity warping space (can I?) but I don’t get why spinning drags it. It’s as if we have the luminous aether again.

randy

Awesome awesome science. And what an effort. Shame that AGW money is being pulled out of their funding pie.
I am a degreed physical scientist who will readily admit I have read Einstein thoroughly and proudly comprehend a little bit of it.

Zeke

From NASA: “According to calculations, the twisted space-time around Earth should cause the axes of the gyros to drift merely 0.041 arcseconds over a year. An arcsecond is 1/3600th of a degree. To measure this angle reasonably well, GP-B needed a fantastic precision of 0.0005 arcseconds. It’s like measuring the thickness of a sheet of paper held edge-on 100 miles away.
Pulling off the experiment was an exceptional challenge. But after a year of data-taking and nearly five years of analysis, the GP-B scientists appear to have done it.
“We measured a geodetic precession of 6.600 plus or minus 0.017 arcseconds and a frame dragging effect of 0.039 plus or minus 0.007 arcseconds,” says Everitt.”
I am glad they were able to sift through the “problems and disappointment when an unexpected wobble in the gyroscopes changed their orientation and interfered with the data.” Good thing the scientists were able to take…”years to sift through the muddy data and salvage the information they needed.”

slow to follow

“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,”
Does anybody have a reference that discusses this “honey swirling” effect for the atmosphere? TIA

Zeke

More from NASA: “Time and space, according to Einstein’s theories of relativity, are woven together, forming a four-dimensional fabric called “space-time.” The mass of Earth dimples this fabric, much like a heavy person sitting in the middle of a trampoline. Gravity, says Einstein, is simply the motion of objects following the curvaceous lines of the dimple.”
That is a handy image, using gravity to illustrate…gravity. 😀

Jimbo

Should Warmists pay any heed to Einstein’s sayings?

“Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.”
“The important thing is not to stop questioning. Curiosity has its own reason for existing.”
“To defeat relativity one did not need the word of 100 scientists, just one fact.”
Einstein

Theo Goodwin

RayG says:
May 4, 2011 at 4:15 pm
“They soldiered on through periods where funding was not easy to raise and challenges as to the importance of the project were periodically raised.”
Old School Scientists. The science was what motivated them. No doubt they made significant personal sacrifices to practice their science. God Bless them and all like them.

Theo Goodwin

xion III says:
May 4, 2011 at 4:43 pm
“I’d like to know what was the unexpected wobble was caused by. If there was muddy data as a result, that took years to sort, what guarantee is there that cherry picking has not occurred?”
There is no guarantee. However, the huge difference between this case and that of Climategaters is that these physicists had physical hypotheses (a huge set of them) that actually specify the data. Climategaters have no physical hypotheses at all, except the few they borrowed from poor old Arrhenius. Michael Mann has never created a physical hypothesis. All he has done is organize proxy data. That kind of fundamental science has to be done, but the very fact that Mann can be tenured and honored as a scientist-without-portfolio drives me up the wall.

Greg Cavanagh

The project was soon beset by problems and disappointment when an unexpected wobble in the gyroscopes changed their orientation and interfered with the data.
The mission’s star tracker and gyroscopes were the most precise ever designed and produced.
I’m having difficulty reconciling these two statements.

1DandyTroll

To warp space and time or to perceive space and time getting “warped”. O_0

CRS, Dr.P.H.

Now, THAT’S how NASA should spend precious money (vs. Gavin’s budget?)!!
Nice stuff, thanks for posting!
On an Einstein tangent, Fermilab’s director, Dr. Pier Oddone, was just elected to the National Academy of Sciences, joining past luminaries including Einstein. This is an incredible honor and well deserved.
Pier’s an excellent chap and runs a great ship at Fermilab, wish him the best!
http://fnal.gov/pub/today/

Darren Parker

This is old news to anyone taht has studied Eastern Mysticism. Anyone interested should research ‘Akasa’ (sometimes called Akasha)

Dave Worley

Good to know the old station wagon has finally caught up to an early 20th century scientist.
Can we put the pedal to the metal and get a base on the moon now, or does Obama have to stop and take a leak?

Allen63

Its true. The AGW debacle has made me “skeptical” of certain types of scientific claims.
There were, perhaps honest, “errors” made by those professing AGW — simply because they’re human and humans tend to see what they expect to see. Still, the fallacies would have been easy to correct by a qualified, objective member of the team. That they were not, is an indictment of “Big Government Funded Science” — and the desire to keep the funds coming.
Now, I am hesitant to “believe” the above results (which are the result of a big government funded science project) without seeing the data in detail and, maybe, doing some of the math myself.
Sad it has come to this, but true. Fool me once, as they say.

RandomReal[]

Congrats to Dr Everitt and his team. To overcome the technical and engineering challenges is quite an achievement. With regard to the unexpected wobble, this is the kind of problem that earth-bound experimenters face, but the difference is that Everitt et al. could not fly up there and fix things. To get usable data, I assume that they first had to figure out the source(s) of the wobbles, and then, carefully correct for them. I am sure the paper will describe these things in detail. You can build the most sophisticated equipment, but then you put it on a devise that does a controlled explosion to shoot it into space (Ouch!). I am amazed that anything to works properly.
There are some other interesting tests of GR. The Harvard Physics department has a video by Robert Pound called “Weighing Photons — The Story of an Experiment” from 1991.
http://www.physics.harvard.edu/about/video.html
You will find it on the main page with other interesting lectures (Sydney Coleman’s “Quantum mechanics in your face” is especially enjoyable)
— I love the internet!
Kudos to the physics community for putting cutting edge science from colloquia/seminars/meetings on the web. I only wish that other disciplines and departments follow suit.

Louis Savain says:
May 4, 2011 at 4:03 pm
There are only two nasty little problems to consider before you all get excited. […] They only proved that some of his equations were right. The interpretations of those equations, however, leave a lot to be desired.
I also noted in my email, that this was bound to stir up some General Relativity Deniers. BTW, General relativity is described by just one equation.

R. Gates

Interestingly, these results are still valid even if time actually is NOT a fourth dimension as it is so often thought of. This was a concept that Einstein actually embraced, as he saw time really as nothing more than the ordering of events, but the popular view of time as a actual fourth dimension has proven hard to shake. This article makes an excellent overview of this:
http://www.physorg.com/news/2011-04-scientists-spacetime-dimension.html
Neither the geodetic effect nor frame dragging actually require time as an actual dimension as they are effects on the 3D fabric of space caused by gravitational fields.

Louis Savain

Svalgaard wrote:
I also noted in my email, that this was bound to stir up some General Relativity Deniers. BTW, General relativity is described by just one equation.
Leif, are you denying that time cannot change by definition and that, as a result, there can be no motion in spacetime? If so, let us see your explanation of how time can change. On second thought, don’t bother. I know you have no explanation.
In the meantime, let me explain to the rest of us why time cannot change. A change in position implies a velocity (rate of change) that is expressed as v = dx/dt. A change in time also implies a rate of change which is given as dt/dt, which is, of course, nonsense.
It is that simple, folks. This is the reason that there can be no time dimension, Einstein and a billion relativists claim otherwise notwithstanding. But don’t take my word for it. And don’t take the relativist’s word either. Do your own thinking. Figure it out on your own.

Fernando (in Brazil)

In a way. I expect a comment from Lubos

Jenn Oates

I love science…
/sighs happily
(even when it’s being done at Stanford, booooo)

etudiant

Kudos to the researchers who soldiered on through the decades that it took to build, launch and then evaluate this mission.
It is too bad that the error levels of the results are so wide. They appear to encompass the expected values, so the results are consistent with expectations.
Ideally the results would have shown a discrepancy, something to spur new efforts to improve our understanding.

rbateman

Is that the ‘missing mass’? The gravity of a galaxy wrapping up space around it as it spins?
Now that brings up another question:
If the spin of the Galaxy is wrapping up space around it and dragging it, where does the energy to continue spinning come from (resisting the friction)?
I want to say Dark Energy keeps the Galaxies from slowing down, but now I’m in over my head in honey.

AusieDan

So it seems that I too am of a skeptical disposition.
This was a hughly expensive experiment, consuming imense amounts of scarse resources.
Just what did it demonstrate?
Does it show anything more than moving a body through a gravitational field will influence the movement of that body?
Warped time? Warped space?
Just what is time made of?
What are the constitutes of space?
Pretty artifacts of complex equations.
Anything more?

AusieDan

Just what is time made of?
You cannot warp nothing.
So time must have a physical constitution.
Or Einstein was still mired in 19th century mysticism.
Do you want some “ether” with your fries?
I’ll take mine plain, thank you very much.

ferdberple

“Darn! Einstein is right again. That sucks… we will never be able to travel faster than light… at least in this space-time continuum.”
That only applies to the observer. According to Einstein, a spaceship with a constant 1 G acceleration can travel to the edge of the visible universe. 13 billion light years and the occupants of the space ship will only age about 60 years.
From the point of view of the folks onboard the spaceship, they have travelled much faster than light. Much. However, the folks back on earth will have aged a little bit more than 13 billion years during this time, so it will appear to them that you never exceeded the speed of light.
So, except for the problem of generating enough energy to maintain 1 G acceleration, human beings have the ability to visit anywhere in the universe within 1 lifetime.

Louis Savain says:
May 4, 2011 at 7:52 pm
Leif, are you denying that time cannot change by definition and that, as a result, there can be no motion in spacetime?
Yes, I’m a time-cannot-change denier. This experiment was called Gravity Probe B, because there was a Gravity Probe A long ago. In GP-A one atomic clock was sent into space while two clocks remained on Earth. Relativity predicts that the one that was sent aloft would run slower than the two on the ground, and sure enough it did, and by just the amount predicted. http://en.wikipedia.org/wiki/Gravity_Probe_A
End of discussion.

davidmhoffer

Louis Savain;
In the meantime, let me explain to the rest of us why time cannot change.>>>
Is there some genetic mutation out there that compels people to spew nonsense spattered with some randomly chosen math symbols related to nothing at all, just dribbled in a row in the paragraph? Is there some specific gene that makes people spew such drivel despite experimental evidence confirming the theory? One of the very first experiments NASA did in this regard was to put highly accurate atomic clocks in orbit in order to compare how they travelled in time compared to identical clocks on earth surface. The difference confirmed Einstein. Sorry Louis, but that was decades ago, and there have been more experiments since then, and they keep on confirming Einstein. Either he got it right or there have been an awfull lot of experiments that just coincidentally produced results matching Einstein’s equations to a rediculous number of decimal places. What pleasure or value you get out of announcing that dt/dt disproves him is beyond me.

So, the flow of time depends on the presence or absence of a large mass in vicinity.
Why this is never taken into account when they talk about red shift?

Leif Svalgaard says:
May 4, 2011 at 9:23 pm
Relativity predicts that the one that was sent aloft would run slower than the two on the ground
Grrr, faster, of course. High gravity slows down time.

““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.”
Or…
Stick with me here, this is going to be complicated.
Imagine the Earth as if it were surrounded by a gaseous cloud and a thin layer of liquid.
Well, I guess his description is way better than mine, it has fantasy going for it.
So, exactly how does this disprove the idea that space is really a medium through which everything moves?

Alexander Feht says:
May 4, 2011 at 9:27 pm
So, the flow of time depends on the presence or absence of a large mass in vicinity.
Why this is never taken into account when they talk about red shift?

It is: http://en.wikipedia.org/wiki/Gravitational_redshift
The cosmological red shift is something else, completely, and have nothing to do with time slowing, but with space expanding. Note that the galaxies are almost stationary in space and do not move away from us or each other. Space is just getting bigger.

Larry in Texas

My God, R. Gates actually said something that made sense to me, and that I agreed with. And he actually cited a piece that seemed a genuine observation! Has the world gone mad? /sarc and laughter

Anthony Watts says:
May 4, 2011 at 9:44 pm
So Leif, if gravity continues to rise….will time stop?
Yes, if you are falling into a black hole we would observe that your time [e.g. as shown on a clock dial carried with you and visible to us] will slow to a crawl and eventually stop. You, on the other hand, would not detect anything unusual, except that you’ll eventually be shredded to long skinny threads.
Sounds like the next crisis. Eat less, lose mass, save time. 😉

Anthony Watts says:
May 4, 2011 at 9:44 pm
So Leif, if gravity continues to rise….will time stop?
Sounds like the next crisis. Eat less, lose mass, save time. 😉

Skinny threads are what you’ll become…
http://en.wikipedia.org/wiki/Black_hole

Curt

It was my privilege to study under Robert Cannon and Dan DeBra many years ago. Both their knowledge and their passion inspired me.
I wonder what Lubos Motl thinks of this announcement. He was very dubious about the project not long ago…
http://motls.blogspot.com/2010/03/tamino-5-sigma-and-frame-dragging.html