100 years ago, the way we viewed our Universe was vastly different than the way we view it now. The night sky, with stars, planets, comets, asteroids, nebulae, and the Milky Way, was viewed to make up the entire contents of the Universe.
The Universe was static, governed by two laws only: Newton's Gravity and Maxwell's Electromagnetism. There were the first hints that the Universe was made up of quantum particles, such as the photoelectric effect, Rutherford's first hints at the existence of the nucleus, and Planck's view that energy was quantized. But other than that -- and Einstein's new Theory of Special Relativity, there were very few mysteries about the Universe in 1909. But one of them would change our view of the Universe forever.
You see, there was a tiny, tiny problem with the planet Mercury. Its orbit just wasn't quite right. Kepler's Laws (which can be derived from Newton's Gravity) said that all the planets should move in ellipses around the Sun. But Mercury (above) doesn't quite do that. Mercury makes an ellipse that precesses -- or rotates -- ever so slightly. Specifically, it precessed at a rate of 1.555 degrees per century. A greatly exaggerated example of precession is shown below:
Now, physicists and astronomers have always been very detail-oriented people. So they calculated what the effects of the Earth's equinoxes precessing were, and were able to account for 1.396 of those degrees. They realized that there were seven other major planets (and the asteroids) acting on Mercury, and that was able to account for another 0.148 degrees. That left them with only 0.011 degrees per century that was different between their theoretical predictions and their observations. But this minuscule difference was significant enough that it led some to consider that Newton's Law of Universal Gravitation might be wrong.
Newton said that mass and separation distance was what determined gravity. There was a force that he called "action at a distance" that made everything attract. But during the time from 1909-1916, a new theory came about.
The same guy who discovered the photoelectric effect, special relativity, and E=mc^2 came up with a new theory of gravity. Instead of an "action at a distance" due to mass, this new theory said that space gets bent by energy, and causes everything -- even massless things -- to bend beneath what we see as gravity.
Now this new theory was very interesting for a few reasons. First off, it accounted for those 0.011 degrees that Newton's Gravity did not. Second, it predicted -- as a simple solution -- the existence of black holes. And third, it predicted that something very exciting and testable would happen: that light would be bent by gravity.
Big deal, said Newton's advocates. If I take E=mc^2, and I know that light has energy, I can just substitute E/c^2 for mass in Newton's equations, and get a prediction that Newton's gravity would bend light, too. It just so happened that Einstein's bending was predicted to be twice as much as Newton's bending, and that there was a total Solar Eclipse coming up in 1919. The stage was set for the most dramatic test of gravity ever.
The director of Cambridge Observatory, Sir Arthur Eddington, led an expedition to observe the total solar eclipse of May 29, 1919. During an eclipse, the sky gets dark enough that you can see stars, even close to the Sun. So Eddington set out to map the position of the stars when they were close to the Sun, and see how the Sun bent the light. Would it match up with Einstein's prediction, Newton's prediction, or would it not bend at all?
(Image credit: American Institute of Physics.)
Lo and behold, Einstein's prediction was spot on. Just like that, Newton's theory of Universal Gravitation, the most solid foundation in all of physics -- unchallenged for over 200 years -- was obsolete. All of this was done in the years 1909-1919, and it was just the start of changing how we view the Universe.
And (FYI) so far, in the 90 years since, every single prediction of Einstein's gravity that's ever been tested -- from gravitational lensing to binary pulsar decay to time dilation in a gravitational field -- have confirmed General Relativity as the most successful physical theory of all-time.
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Comments
This is soooo cooool, thank you very much for doing this !
Posted by: RF | June 11, 2009 4:37 PM
That last picture of the eclipse, what exactly are those rings? Stars that are being gravitationally lensed?
Posted by: Matt | June 11, 2009 8:25 PM
And best of all, this continued the simplification of the motions of the planets. From complicated spirals orchestrated by the hands of Gods, to elipses (admittedly more complicated than the circles which closely predated them) to straight lines! And all due to the simple fact that time doesn't progress at all places the same way so that space as a result is not a flat and empty stage for other forces, but is instead locally directional! What a grand discovery about the workings of things!
BUT I have read several times before that QED is even more accurate to experimental evidence than the General Theory. I suppose there isn't much of a reason to compare apples to oranges though, especially considering the problems in mathematically rectifying the two.
Posted by: Raimund | June 12, 2009 1:18 AM
Matt, for one of the actual 1919 eclipse images see here. The stars are between the pairs of horizontal marker lines. They are much smaller than in the above picture.
Posted by: Tristram Brelstaff | June 12, 2009 2:44 AM
"QED is even more accurate to experimental evidence than the General Theory." -- so what? We don't have a Grand Unified Theory that reconciles the two scientific paradigms.
We have clues, but they have mostly been eliminating suspects.
QED breaks down at a small enough scale. So does General Relativity. Unfortunately, the physical universe, so far as we know, exists and operates with no complaints at that scale.
This is a grand challenge for the 21st century. If not completed as classwork in this century, take this away as homework, due in the 22nd century...
Posted by: Jonathan Vos Post | June 12, 2009 11:14 AM
Einstein himself was not surprised at all by this finding, his theory is simply mathematically more "beaufiful" than Newtons gravity equation.
Posted by: TOEfan | June 12, 2009 11:23 AM
Thank you for using the proper Einstein picture for this. As Harry Kroto says, it's important that all these important - groundbreaking - discoveries (you left out Brownian motion - the final confirmation of Atomic Theory) weren't made by that old geezer with the crazy hair.
Isn't there talk that Eddington's results weren't all that clear and that he may have suffered from some degree of confirmation bias (like all those people repeating Millikan's experiment).
Posted by: Sili
| June 12, 2009 12:16 PM
Interesting! Nice to read.
Posted by: Xiara | June 12, 2009 1:00 PM
Very nice post. It is really amazing to watch the progress of scientific thought and the evolution of theories as time goes by.
Posted by: Lefteris | June 12, 2009 4:10 PM
"...have confirmed General Relativity as the most successful physical theory of all-time."
Them's fightin' words! Successful? Successful at what? 'Splainin your namby-pamby telescope observations?
It's clear to me that quantum mechanics is the most successful theory of all time! QED's the most successful at cranking out digits of precision, nonrelativistic quantum is the most successful at explaining the structure of the matter around us in everyday life, and Bell's inequality is the most successful with the ladies, if you know what I mean.
Posted by: Anonymous Coward | June 12, 2009 5:59 PM
This story just proves that scientists are always wrong about everything, and we must trust our gut instincts and/or preferred holy books for answers. Or something. Nah.
Posted by: Naked Bunny with a Whip
| June 13, 2009 6:02 AM
Well done. I'd like to see a history of how quantum mechanics has shattered Einstein's theory of relativity.
Posted by: Rich Gallen | June 15, 2009 12:03 AM
Interesting story. Einstein was so smart!
Posted by: Gratis geld | June 15, 2009 3:21 AM
Thanks for another fun post.
I recall reading something saying that Newton knew his theory of gravity needed a correction. Something, maybe from an Einstein biography, where he was impressed by how Newton himself was aware of this issue. Has anyone else seen that? If so could you remind me where it came from?
Posted by: Bruce | June 15, 2009 5:36 AM
Showdown again SM vs GR tickets available!
"nonrelativistic quantum is the most successful at explaining the structure of the matter around us" Hah? You can't formulate a consistent theory of Quantum Electrodynamics let alone QCD without relativity. You MUST have it or something equivalent. It is built into QM. Special Relativity that is.
Rich Gallen - We all would like to see a history of how QM shattered GR. Unfortunately it has never happened. As was said EVERY single possible observation we have ever made that could be applied has supported GR. With some reservations this is also true of the Standard Model. They don't predict the same things. Anything they do predict differently or break down on we can't test right now.
Posted by: Markk | June 17, 2009 8:17 AM
"time doesn't progress at all places the same way"
Nitpick: I don't think you can compare clocks in different places at all (hence you could say they progress the same as measured by clocks), but compare in inertial (SR) or even accelerating (GR) frames.
Posted by: Torbjörn Larsson, OM | June 23, 2009 9:49 AM
Well done. I'd like to see a history of how quantum mechanics has shattered Einstein's theory of relativity. louboutin
Posted by: louboutin | August 4, 2009 4:43 PM
Einstein himself was not surprised at all by this finding, his theory is simply mathematically more "beaufiful" than Newtons gravity equation. Christian Louboutin
Posted by: Christian Louboutin | September 12, 2009 2:13 PM
New research has imaged gravity field forcons by solving the correlation function for mapping the set of virtual force photons onto the spacetime manifold of the atom's 5/2 kT J heat capacity energy cloud. This system uses spacons and chronons for strict quantized relativity.
The atom's RQT (relative quantum topological) data point imaging function is built by combination of the relativistic Einstein-Lorenz transform functions for time, mass, and energy with the workon quantized electromagnetic wave equations for frequency and wavelength. The atom labeled psi (Z) pulsates at the frequency {Nhu=e/h} by cycles of {e=m(c^2)} transformation of nuclear surface mass to forcons with joule values, followed by nuclear force absorption. This radiation process is limited only by spacetime boundaries of {Gravity-Time}, where gravity is the force binding space to psi, forming the GT integral atomic wavefunction. The expression is defined as the series expansion differential of nuclear output rates with quantum symmetry numbers assigned along the progression to give topology to the solutions.
Next, the correlation function for the manifold of internal heat capacity particle 3D functions condensed due to radial force dilution is extracted; by rearranging the total internal momentum function to the photon gain rule and integrating it for GT limits. This produces a series of 26 topological waveparticle functions of five classes; {+Positron, Workon, Thermon, -Electromagneton, Magnemedon}, each the 3D data image of a type of energy intermedon of the 5/2 kT J internal energy cloud, accounting for all of them.
Those values intersect the sizes of the fundamental physical constants: h, h-bar, delta, nuclear magneton, beta magneton, k (series). They quantize nuclear dynamics by acting as fulcrum particles. The result is the picoyoctometric, 3D, interactive video atomic model data imaging function, responsive to keyboard input of virtual photon gain events by relativistic, quantized shifts of electron, force, and energy field states and positions.
Images of the h-bar magnetic energy waveparticle of ~175 picoyoctometers are available online at http://www.symmecon.com with the complete RQT atomic modeling guide titled The Crystalon Door, copyright TXu1-266-788. TCD conforms to the unopposed motion of disclosure in U.S. District (NM) Court of 04/02/2001 titled The Solution to the Equation of Schrodinger.
(C) 2009, Dale B. Ritter, B.A.
Posted by: Dale B. Ritter, B.A. | October 1, 2009 6:43 AM
Interesting story. Einstein was very smart! kitchen cabinet knobs
Posted by: Thomas D. | October 19, 2009 9:23 AM
Interesting story. Einstein was very smart! kitchen cabinet knobs
Posted by: Thomas D. | October 19, 2009 9:31 AM
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@ Bruce | June 15, 2009 5:36 AM
I wish I could help you, but I don't remember where it is either, though I also read that somewhere. That's how I got here, trying to Google it, and it picked up your comment.
Posted by: yonason | November 29, 2009 6:39 AM
Is it true that Eddington made Einstein Famous?
Posted by: david | December 15, 2009 9:44 AM
Einstein is really famous today and the future...
Posted by: Education Essays | December 23, 2009 4:07 AM