Are any of Einstein's theories still leading theories today?

Question

Earl Wajenberg · Accepted Answer

They’re all doing fine. General and special relativity are both undented, holding up fine to experiental test.

Einstein also contributed to the founding of quantum mechanics, though he didn’t like the implication of indeterminacy. Quantum mechanics is still gold-standard physics.

Einstein also developed the statistical mechanics of Brownian motion [ https://en.wikipedia.org/wiki/Brownian_motion#Einstein's_theory ]. That’s holding up, too.

Ken Javor · Answer

While I am not a scientist, and I don’t hold a PhD., I have no problem disagreeing with both Bridge and Nahhas. I would say that special and general relativity are still in vogue, as well as Einstein’s explanation of the photo-electric effect, for which he won the Nobel prize.

Ten or fifteen years ago, I worked on the Gravity-Probe B satellite, which was designed to test some of Einstein’s predictions in general relativity. They tested out just fine, but the real point is that hundreds of millions of dollars would not have been spent trying to prove or disprove a washed-up theory.

There is way too much government grant money, chased by way too many PhD.s trying to make a name for themselves. These types are constantly making grand pronouncements. You can rest assured that if any of Einstein’s major theories were proven wrong, you would read about it in the news. They would not have to blow their own horns.

Yousuf Khan · Answer

Yes all of his theories are still valid today. In fact they are still being proven by recent observations and experiments, such as the discovery of gravitational waves in 2015.

Although Einstein is known as a critic of quantum mechanics, he is actually one of the founders of the field! He created the theory of the photoelectric effect which initiated the entire quantum mechanics revolution!

All of his theories are now the accepted proven theories of the universe. Anything that's come afterwards are now still being proven or disproven.

Viktor T. Toth · Answer

Absolutely. Some by Einstein himself, some by his contemporaries, some by later efforts. Physics is not set in stone. Einstein’s theories are not some holy text that must be treated with reverence, not a word altered. They are important stepping stones towards an improved understanding of Nature, but they by no means represent the final step, the last word.

Take the photoelectric effect, for which Einstein received his sole Nobel prize. At the time it was proposed, most thought it was nonsense. Maxwell’s theory, quantized? Hogwash. But then… after the “modern” quantum theory was developed by the likes of Schrödinger and Heisenberg, there came the work of Dirac in the form of relativistic quantum mechanics and the Dirac equation, ultimately paving the way to quantum field theory, in particular quantum electrodynamics. A huge improvement over Einstein’s heuristic ideas half a century earlier.

And then, relativity theory. After publishing the theory in 1905 (it was not yet called “special”) Einstein spent years trying to find a more general version of the theory that would treat inertial and accelerating observers on the same footing. He was successful, the general theory was born, and the earlier version was from then on referred to as a special case of the more general theory.

But right there already, Hilbert showed a better way! While Einstein developed his field equations heuristically, Hilbert showed how the same field equations can be derived from an action principle. Then came the solutions. Einstein considered the system of ten coupled second-order differential equations an unsolvable mess, at best solved through approximations. But Schwarzschild thought otherwise, and offered an elegant analytical solution in the simplest case of a spherically symmetric, static, vacuum gravitational field. Which, incidentally, predicted a singular “horizon”, but Einstein dismissed it as a physically unachievable mathematical artifact. It took decades, lots of work by others, to comprehend that the horizon is just a “coordinate singularity” and how an astrophysical black hole actually evolves.

Meanwhile, both Einstein and others tried to come up with alternative versions of the theory. Weyl proposed an approach treating gravity (the “quadratic ground-form”) and electromagnetism (the “linear ground-form”) as a unified whole. Kaluza (with improvements by Klein) tried the same by moving the theory into five dimensions. Einstein tried a more general approach using a nonsymmetric gravitational field tensor. Later, in the late 1950s and onward, Jordan, Brans and Dicke, and others began to develop alternate theories of gravitation, eventually motivated by the “missing mass” problem in galaxy rotation curves and cosmological data. These problems remain unsolved to this day: modified gravity represents an alternative to the dark matter/dark energy paradigm, but we neither have a truly satisfactory theory nor enough observational data to know which is the right direction.

So the search continues and yes, theories are updated all the time in the light of new data or new understanding. Einstein’s theories are no exception.

Jack Fraser-Govil · Answer

No.

Nothing except abstract mathematical and logical statements has ever been proved.

You cannot prove that my name is Jack Fraser.

You cannot prove that the sun will rise tomorrow. You cannot prove that your phone will hit the floor if you drop it. You cannot prove that you're not a giant squid-robot sitting in a tank filled with Dr Pepper, buried under Nelson's Column.

What you can do is provide a boatload of evidence which suggests that the statement is plausible or not. This is not proof in the specific sense of the word — but it is the only “proof” you can get about anything that exists in this physical universe.

As for evidence that relativity is plausible — we have boatloads [1] [2] [3] [4] . I literally could fill a boat with the evidence.

But no, it is not proved — and never can or will be.

That's not how science or reality works.

And before you get all smug about how physics must be pointless then — by the exact same argument, you can't prove the squid-robot-Dr-Pepper thing. So…yeah. If physics is ‘useless’ because of this, you need to accept that you're a cephalobot.

This is you, and you can't prove otherwise.

For more on this matter, please read Can you have absolute proof of anything in physics, or is it all a case of having theories? [ https://www.quora.com/Can-you-have-absolute-proof-of-anything-in-physics-or-is-it-all-a-case-of-having-theories/answer/Jack-Fraser-Govil ]

Have we proved Relativity? No. And we can't.

Is relativity one of the best theories/models we've ever had? Damn right.

Is there enough evidence supporting the theory to fill a medium sized narrow boat? Yes

Is that good enough for science? Yes — until something contradictory is found.

1. Jack Fraser-Govil's answer to How do we know the speed of light (in a vacuum) is the same when observed from different inertial reference frames? It seems very unlikely to me. [ https://www.quora.com/How-do-we-know-the-speed-of-light-in-a-vacuum-is-the-same-when-observed-from-different-inertial-reference-frames-It-seems-very-unlikely-to-me/answer/Jack-Fraser-Govil ]
2. Jack Fraser-Govil's answer to Can gravity bend light? What are the events that led Einstein to prove that gravity could bend light? [ https://www.quora.com/Can-gravity-bend-light-What-are-the-events-that-led-Einstein-to-prove-that-gravity-could-bend-light/answer/Jack-Fraser-Govil ]
3. Jack Fraser-Govil's answer to What are some experiments that have confirmed General relativity? [ https://www.quora.com/What-are-some-experiments-that-have-confirmed-General-relativity/answer/Jack-Fraser-Govil ]
4. Jack Fraser-Govil's answer to Shouldn't we see Einstein rings and other figures of gravitational lensing around stars with our telescopes? [ https://www.quora.com/Shouldnt-we-see-Einstein-rings-and-other-figures-of-gravitational-lensing-around-stars-with-our-telescopes/answer/Jack-Fraser-Govil ]

Ira Clarke · Answer

Einstein theories are regarded mainly as defining or predicting the speed of propagation of light (and other EM waves) and of gravitational waves.

The age-old condundrum is not that of defining the universal value of c (in vacuo}) but what that value is measured relative to eg. in empty space.

Clearly geometrically, the speed cannot always be c relative to the Earth eg. in interstellar space or within distant galaxies.

From Einstein’s 1st postulate, EM must propagate at c within distant galaxies. If, relative to us, they are moving radially at ultrafast velocity v, starlight is then initially outbound at c±v towards us. But we also know that it arrives inbound at speed c from all stars (stellar aberration experiment).

So there must be a geometric transtion in the speed of starlight propagating en route through space towards us. That concept is not regarded as compatible with Einstein's 2nd postulate in Special Relativity.

In principle, that theory could be replaced if the experimental, logical and physical evidence is sufficiently strong - but from experience, that is up against much harsh resistance from Einstein fans.

°°°°°°°°°°°°°°

We also know now, that EM travels through space at precisely the same speed as gravitational force fields - to within 1 part in billions over millions of years (evidence from LIGO gravitational wave observations cf. a gamma ray burst, from a suddenly collapsed binary star).

We know that the gravitional force decreases non-linearly with distance. Its speed of propagation is also similarly related to neighbouring mass(es) - averaged using an appropriate inverse non-linear distance weighting.

That applies whether in intergalatic space or local to the Earth's rotating surface - with tidal effects and is measurable even for the variable mass of air above or tunnels below.

In principle, that hypothesis also seems to fit experimental evidence for EM - including classical Doppler (local and interstellar), stellar aberration, the Sagnac effect, Michelson-Morley null results, LIGO results, Hafele-Keating time-dilation observations (if re-analysed to include equatorial centripetal forces), particle half-life experiments (without relativistic pre-scaling) etc.

°°°°°°°°°°°°°°°

It would mean the disruptive demise of the Lorentz space-time, its paradoxes, unexplainable reciprocal physical contraction of space-time, sub-luminal speed limit etc.

The same issues also apply to non-inertial space-time covariant invariance - as used in General Relativity.

°°°°°°°°°°°°°°

Various of my ‘trolls’ are likely again to reply “utter nonsense”, “delusional” etc. to this reply - but rarely attempt to give justification. The evidence challenges their cherished beliefs or vested interests!

So how can this hypothesis be debated widely eg. in formal physics journals, when editors are not willing to risk possible ridicule?

°°°°°°°°°°°°°°

Modern theoretical physics, particle physics and astrophysics (including dark energy) etc. are potentially subject to significant changes.

The non-linear Lorentz space-time transform can be replaced by a modified form of the classical linear Doppler scalar factors where the prevailing speed(s) of EM propagation en route are properly accounted for - both locally and as observed by the JWST.

°°°°°°°°°°°°°°°

The two basic classical Doppler factors involve 1-v/c and 1+v/c. One applies in the receding outward red-shift case and the other to the inward blue-shift scenario where the detector is moving towards the emitter.

The two scenarios cannot apply simultaneously so cannot be combined to form any different solution(s). That includes mathematical prohibition of anything involving the product (1-v/c)(1+v/c).

So mathematically, the Lorentz space-time scale factor cannot be valid ie. γ = 1/√(1-(v/c)²).

°°°°°°°°°°°°°°°°

The temporal Lorentz space-time transform is defined by t’ = γ(t-vx/c²) where x denotes the propagation distance vector. The velocity vector is denoted v in the same direction as the x vector and in the same direction as the EM propagation velocity vector denoted by bold type-face c.

The distance vector x is zero when the observer passes by the emitter but the clock period ∆t at the emitter is predicted to be physically contracted by factor γ relative to that detected at the detector ∆t’.

It follows that that version of the twins paradox, cannot be explained by acceleration or by propagation delay or it seems, by ‘World lines’ or by different space-time projections.

°°°°°°°°°°°°°°

The distance vectors ct, ct’, c(t’-t), x, x’ and velocity vectors c and v are all co-linear. But impossibly, in the Lorentz 2nd order solution, ct, ct’ and c(t’-t) are regarded as forming a triangle.

°°°°°°°°°°°°°°

Please upvote if you think that all this research should be debated more widely.

⬝ ² ± ₀ √ × γ ∆ ∂ ⨯ ℃̇ ċ ∘ ⬝

Toni Sementana · Answer

Yes, however it has been experimentally shown that string theory is at least partially wrong. The planet Mercury has been visited by a probe, called Messenger, which has been orbiting him for a few years now and has made very interesting measurements. We can easily think about a thought experiment; what would it actually be like if the Sun would change its mass? Which it does. Because we now know quite well that the Sun is a fusion reactor. Hydrogen is transformed into helium and mass is transformed into energy. This means that the Sun loses mass. And that in every second 4 million tons. In view of its total mass of 10 to the power of 30 kilograms, it is of course little. But it loses mass. Now you need an extremely accurate measuring device to measure the variations of the gravitational field, because the Sun loses mass through its radiation. That's one thing. Then it has a solar wind, which means that it also loses mass by emitting plasma from its surface. This means that the gravitational dynamics between the Sun and Mercury would simply have to change over time.

One only needs an extremely accurate measuring instrument, which measures these slight variations. And, of course, in verification with the theory. If the mass of the Sun changes - we know this without doubt - then the orbit of Mercury would also have to change. That's what Messenger measured. This change in orbit and thus also the nuclear fusion processes inside our Sun, all depend on a constant. The gravitational constant G. And it is one of the constants which, according to the great unifying field theories, such as superstring theories, should change over time. Messenger uses general relativity as an instrument, because general relativity predicts that where masses are, space-time is curved. This means that the electromagnetic radiation, which runs over the surface of this spacetime, has to enter such a spacetime depression. And then it comes out again. If, on the other hand, there is no mass at all, space-time is flat. This means that the electromagnetic radiation has a shorter path.

So we get a change in transit time; a delay in transit time due to the presence of a mass. And Messenger is a digital transmitter that constantly sends signals. Of course we can record these signals on Earth and get something like a profile map out of the delay time and can measure the gradual change of space-time in our solar system. For example, we can find out that the loss of mass of the Sun causes the Earth to move 1.5 cm away from the Sun every year. It's crazy, isn't it? So Messenger has measured for seven years and has measured something, namely next to the exact orbit measurement of Mercury, incredibly accurate, Messenger has measured that the gravitational constant obviously has not changed during these 7 years at all.

To this day, no instrument has measured the gravitational constant as accurately as Messenger. Well, now we can say that seven years is not a long period of time. However, if you make such an exact measurement for seven years, then you can extrapolate to a longer time. And then it turns out that obviously the range of fluctuation for the natural constant, which is called the gravitational constant - by the way mostly written with "G" - that this range of fluctuation is very, very small. As one must say at all, the experiments, which check whether the natural constants are really constant, all show the result, that obviously all natural constants are actually constants. How to do this? Yes, like Messenger or you look deep into space, which means you look at objects that are very far away and therefore look at radiation from ancient times. And from the properties of these radiations we can, for example, say something about how the radiation processes within atoms must have been at that time in order to produce the radiation that we measure today. And there are different variants and also all, all experiments say, the natural constants are constant within the scope of our measurement possibilities. You can even try to check this in the laboratory by measuring the radiation spectra very, very accurately in our laboratory. Nowadays, this can be done extremely accurately with lasers, and here, too, the natural constants appear to be absolutely constant. This is a catastrophe for the theories that predict the non-constancy of natural constants. Unfortunately, one must say. Perhaps we should remind ourselves that in case of doubt it is not the theory that decides, but the experiment.

The NASA MESSENGER results for further reading : Solar system expansion and strong equivalence principle as seen by the NASA MESSENGER mission [ https://www.nature.com/articles/s41467-017-02558-1 ]

Quantum Gravity: ESSENTIALS OF LOOP QUANTUM GRAVITY, Toni Sementana - Amazon.com [ https://www.amazon.com/dp/B081MY3J8Q ]

QFT: An Intuitive Approach to Quantum Field Theory, Toni Sementana - Amazon.com [ https://www.amazon.com/-/de/dp/B07YS5X48L/ref=pd_sbs_351_1/146-6191573-0579706?_encoding=UTF8&pd_rd_i=B07YS5X48L&pd_rd_r=796390be-fd41-4301-9425-e66a90fb4c12&pd_rd_w=VV2GV&pd_rd_wg=se7PU&pf_rd_p=5873ae95-9063-4a23-9b7e-eafa738c2269&pf_rd_r=7BCTN621DNAKQ5QDRP9B&psc=1&refRID=7BCTN621DNAKQ5QDRP9B ]

Henry Smith · Answer

Einstein turned out to be wrong about several things (And don’t worry, this isn’t going to descend into a conspiratorial rant). Two things come to mind.

The most famous was his insistence on a steady state universe. This was the cosmological theory most popular with physicists prior to the development of Big Bang cosmology, positing an eternal universe with no expansion.

However, it was shown that the Einstein Field Equations*, the core of Einstein’s theory of General Relativity and the foundation of cosmology, permitted an expanding universe. Einstein disagreed with this, and modified his equations to include the cosmological constant**, which would allow for a steady state universe. However, it was shown that these universes existed in an unstable equilibrium; and perturbation would lead to expansion. Then Hubble discovered physical evidence of Universal Expansion, and Einstein realized his error. He called it ‘the biggest blunder of [his] career’.

A second error was his interpretation of quantum mechanics. He was never comfortable with the probabilistic nature of quantum mechanics; he believed that there was some yet-to-be discovered hidden variable theory that preserved locality and was deterministic rather than probabilistic. This was shown to be false however, with Bell’s theorem showing that there was no local, deterministic theory. However, he never doubted the ability of quantum mechanical theories to make accurate predictions; he fully accepted them as accurate theories of nature, but viewed them as incomplete.

*Original Einstein Field Equations:

[math]R_{\mu
u}-\frac{1}{2}R=\frac{8\pi G}{c^4}T_{\mu
u}[/math]

**Einstein Field Equations with Cosmological Constant:

[math]R_{\mu
u}-\frac{1}{2}R+\Lambda g_{\mu
u}=\frac{8\pi G}{c^4}T_{\mu
u}[/math]

Note that their is nothing mathematically incorrect about adding the cosmological constant, and most cosmological theories include it as necessary to describe the acceleration of the expansion of the universe.

EDIT:

Got a crackpot comment on this answer. Really self-obsessed. Naturally when he comment-then-blocked me after I pointed out how self-obsessed he was, I deleted his comments.

EDIT:
Got another crackpot comment-and-block. Naturally, deleted.

Dimitri Ken · Answer

I’ll start by saying that Einstein is arguably the greatest scientist in history. Not only was he prolific (like many others), but his creativity and his multiple influences on physics and math are second to none. Among his achievements:

* Special relativity theory
 * Photoelectric effect
 * General relativity
 * Lasers’ theoritical description (and prediction)
 * Bose-Einstein condensate
 * Differential geometry
But there are two things in which the German-American was pretty much wrong. Let’s explore them.

1- The cosmological constant

After releasing the general relativity’s equations, Einstein realized the implication of one of their results: the universe was in expansion. Yes, he reached this result 10 years before George Lemaitre’s theory. The problem was that the paradigm at the time was that the universe was static.

So, contrarily to what he had demonstrated before, showing boldness in redefining space-time, gravity and demonstrating the non-existence of ether, he decided to go along with the status quo instead of challenging it.

He added Λ, to represent a constant which would result in a static universe. In 1929, Lemaitre and Hubble demonstrated the motion of the universe and in 1931, Einstein removed Λ, calling it his “biggest blunder”. (Gamow, 1956)[1]

Fun fact: the constant has be reinstated in 1998, after astronomers realized that the universe in an accelerated expansion. But that’s a story for another day.

2- The hidden-variable theory

- Niels Bohr and Albert Einstein, 1925

Following the quantum philosophy initiated by the Danish physicist Niels Bohr, numerous of his coleagues begged to differ. For instance, Erwing Schrödinger imagined that famous thought experiment with a cat, to mock the quantum superposition.

https://www.newscientist.com/definition/schrodingers-cat/
Albert was among these dissidents. Famously telling in one of his letters: “God does not play dices” (1971) [2], in reference to the probabilistic nature of quantum mechanics. Also, with Boris Podolsky and Nathan Rosen, he wrote a publication now called the EPR paradox, criticizing the phenomenon of quantum entanglement. (SEP, 2004) [3]

So Enstein espoused the hidden-variable theory. Which, to put it simply, is a deterministic description of quantum mechanics. But this time, he didn’t aknowledge any mistake. And it was in 1982, 27 years after his death, that an experiment which follows the falsifiability principle [ https://en.wikipedia.org/wiki/Falsifiability ] could be made. Using Bell’s theorem, it has shown to this day that such hidden variables just cannot exist. (Bell, 1987) [4]

Citations

[1] Gamow, G. (1956). "The evolutionary universe". Scientific American. 195 (3): 136–156.

[2] The Born–Einstein letters: correspondence between Albert Einstein and Max and Hedwig Born from 1916–1955, with commentaries by Max Born. Macmillan. 1971. p. 91.

[3] Stanford Encyclopedia of Philosophy (2004), The Einstein-Podolsky-Rosen Argument in Quantum Theory.

[4] Bell, John S. (1987). Speakable and Unspeakable in Quantum Mechanics. Cambridge University Press. p. 65

Eric Baird · Answer

Re: the first part of the question, Einstein’s general theory is internally inconsistent.

The general principle of relativity (“GPoR”) says that acceleration and rotation are relative, rather than absolute. This means that the gee-forces that we feel when we accelerate or rotate can be blamed on the relative acceleration or rotation of background matter. Accelerating the outside universe relative to a body, or spinning the background shell of stars around a body, causes the body to experience what appears to it to be gravitational fields.

These used to be referred to as “ficticious forces”, but under a general theory they are considered to be real, and since there’s nothing special about the matter making up the background stars, if we accelerate or spin any mass, or artificially force it to move along a curved path when it doesn’t want to, a general theory predicts that the relative motion of that body ought in turn to cause gravitational fields as seen by a background observer. It’s a “mutuality” thing: if the relative acceleration of B affects A, then the relative acceleration of A must also affect B.

So GR will say that, when we orbit a satellite around the Earth, the Earth’s rotation causes a drag on the satellite (see: Gravity Probe B). This accelerative or rotational drag is referred to as a form of gravitomagnetism, “GM” (=the additional gravitational field due to the motion of a mass)

So far, so good.

Unfortunately, accelerative and rotational GM can’t exist unless there’s also an underlying velocity-dependent GM effect. Which, if it exists, must be universal, invalidating special relativity. According to special relativity, bodies can move however they like without warping the lightbeam geometry. This “flatness” is a direct consequence of the SR Doppler relationships, so GM can’t be retrofitted onto an SR-based model. SR and GR can’t coexist.

So:

* If the GPoR is correct, then gravitomagnetic effects must be real, and SR must have the wrong Doppler shift equations. Or,
 * If the SR equations are correct, then gravitomagnetic effects cannot exist, and we cannot have a general theory of relativity.
Either way, Einstein’s general theory of relativity, which requires BOTH gravitomagnetism to exist, AND the SR equations to be correct, is impossible. Einstein’s definitions can’t be implemented as geometry, because they contradict each other.

Re: the second part of the question, why has nobody come up with anything better … The only way to fix general relativity is to rewrite it to eliminate the SR content, at which point it’s no longer Einstein’s general theory.

This means, essentially, throwing special relativity under a bus.

The relativity community isn’t prepared to do this, because they’ve just spent the better part of a century hyping special relativity as being something that can’t be wrong, and physicists have been trained to believe that anyone who questions special relativity must be mad, bad, or educationally subnormal. Anyone in the community who questions the validity of SR is considered to be committing “career suicide” … they are liable to be put onto a list of “physics crackpots”, and pro-orthodoxy activists working from those lists are then liable to suggest to the person’s employers that perhaps they may like to rethink whether they should be hiring this person, as it might bring their organisation into disrepute.

So if you are a relativity theorist, and you are good at your job, and you understand the arguments above and try to put them (or something similar) into print, then you have to be prepared to risk losing your beloved job in academia, and/or not being able to get another one.

The problem is social rather than technical: we know how to fix general relativity and its conflict with QM, but special relativity has become something of a fundamentalist religion, and suggesting to most relativity folks that they should consider dropping SR is like suggesting to Texans that we should consider limiting the number of guns in circulation.

Adam Stoddard · Answer

None that I'm aware of. If it had “proven” one of Einstein's theories incorrect , that would mean there was an independent back up experiment to agree with the results of this new theory. I'm really not sure how you silence something like that.

Unless of course you are using the same twisted logic that the Flat Earth Society uses. Those folks also insist that peer review science is silencing the truth as they see it. With modern communication and media, There is always someone on a soapbox claiming to have discovered the secret of the universe. Mainstream science is about growth and learning. Quack science is about controlling masses with misinformation.

Dale Gray · Answer

One was his first prediction of the amount of bending of starlight grazing the edge of the sun. In a paper “On the Influence of Gravitation on the Propagation of Light,” published in 1911, Einstein predicted the amount of deflection to be .83 seconds of arc. There were plans for Erwin Freundlich to lead a team of astronomers to Crimea to test this during the solar eclipse of August 21, 1914. However, while Freundlich was in Russia, World War I broke out and he was imprisoned for a few days and missed the opportunity to make observations. Later, with the completed version of General Relativity, Einstein gave a revised approximation doubling the amount of the deflection, which was verified in 1919 by Sir Arthur Eddington.

In 1917 Einstein applied General Relativity to cosmology, finding that the universe should expand or contract. This was prior to Edwin Hubble’s observation of the cosmological redshift and the associated interpretation of an expanding universe. Einstein introduced the cosmological constant as a modification of the field equations of General Relativity to produce a static (though unstable) cosmology, in accord with what was known at the time. After Hubble’s discovery, Einstein removed the cosmological constant, calling its introduction the biggest blunder of his life. At present the evidence that the expansion of the universe is accelerating, calls into question whether rejection of the cosmological constant was not the biggest blunder Einstein made!

Einstein began an unsuccessful attempt in the nineteen twenties, and lasting the rest of his life, to find a unified theory of gravitation and electromagnetism. In 1938 he wrote, after many failed attempts at unification, “Most of my intellectual offspring end up very young in the graveyard of disappointed hopes.” This Month in Physics History [ https://www.aps.org/publications/apsnews/200512/history.cfm ] At the time Einstein began working on unification of gravitation and electromagnetism, there was no field theory for the weak interaction and the strong nuclear force, so it is understandable that Einstein did not attempt to include these in his search for unification. With the development of the quantum field theoretic understanding of these interactions, and the successful unification of the weak interaction and electromagnetism of the nineteen sixties, a quest for unification of the four fundamental interactions became a mainstream endeavor in physics research.

Einstein had many “false starts” and incompletions, but he had a great nose for where the fruitful ideas in physics were located and a dogged determination in their pursuit. Although the question asked here is about Einstein’s failed theories, it is good to keep in mind his successes, which were spectacular. See my answer to “What was Einstein famous for?” on Quora.

Dale Gray [ https://www.quora.com/profile/Dale-Gray-17 ]

AstroKevin92 · Answer

OK let’s first clarify that theories aren’t proven. Proof is the domain of mathematics, not science.

Theories are detailed proposals or explanations of how (some aspect of) nature works. So (for example) you might have Newton’s theory of universal gravitation that proposes that we can understand why things fall down, and why planets orbit the Sun by assuming that all matter exerts a mysterious, invisible gravitational pull on all other matter according to Newton’s familiar formula.

With theories, you (usually) can’t prove those explanations are the right ones, but you can perform lots of experiments to check whether the theories correctly predict the results of those experiments, in which case the theory becomes trustworthy / dependable.

The theories of Special and General Relativity were developed in the early 20th Century to explain some curious results that were seen in experiments performed in the late 19th Century, that didn’t seem to fit with Newton’s ideas of absolute space and time. Through relativity, Einstein gave us a radically different understanding of the relationship between space and time, and even though it seemed bizarre and counterintuitive at the time (and since!), it worked exceedingly well, quickly surpassing Newton’s theories.

Relativity has since been the subject of hundreds of experiments over a very wide range of circumstances - from particle physics to astrophysics and cosmology and has never been demonstrated to be wrong. It predicts the time dilation of clocks, the precession of Mercury’s orbit, the existence of black holes, gravitational lensing, gravitational waves, frame dragging, and even the expansion of the universe, all of which have been found to be real.

So yes, relativity has been demonstrated to be correct, hundreds of times. And if it wasn’t, then the Sun wouldn’t shine, particle colliders (like those at CERN or Fermilab) wouldn’t work, and neither would your GPS system.

So it’s not proven, but it is very well-tested, and works exceedingly well.

Jason St. Pierre · Answer

None of them were.

Look, whether you want to admit it or not, Einstein’s theories have been remarkably robust and have held up to every single experimental test they’ve been subjected to for the past century. Special relativity has been experimentally verified. General relativity has been experimentally verified. Photons have been experimentally verified. Wave-particle duality has been experimentally verified. His explanation of the photoelectric effect has stood up. His explanation for Brownian motion has stood up. Bose-Einstein statistics hold up. The only times his theories have been discarded have been when they were proven wrong - Einstein himself was forced to abandon the idea of a static universe when Hubble and Lemaître showed he was wrong - or when there’s no way to verify them, such as his work on wormholes.

That said, Einstein was not a god and scientists don’t treat his work as if it’s holy writ. Every physicist in the world dreams of finding a problem in his work because they want the fame and glory that would come from making such a massive breakthrough. That’s why there are hundreds of physicists out there trying to replace general relativity as we speak. We know that theory is flawed but so far nobody has been able to find a quantum theory of gravity to replace it.

However, scientists aren’t going to blindly follow anybody simply because they say they have a better option. Anyone who proposes a theory that contradicts Einstein is going to have to be able to defend their work. Other scientists are going to go through their data, look at the experimental evidence, and make sure that this new theory is right before they accept it. People have tried. For instance, we’re starting to get evidence that there may be a problem with the equivalence principle - Einstein’s argument that free fall is an inertial reference frame - and there’s some interesting work out there that suggests Einstein may have been wrong. That work has only just gotten started so it will be a while before we know where it leads.

But suggesting that there was some kind of conspiracy to silence Einstein’s critics? That’s just childish.

Gali Weinstein · Answer

In 2012 two physicists – James Hill and Barry Cox from the University of Adelaide in Australia – showed that Einstein's special theory of relativity can be logically extended to allow for faster-than-light motion. They were quick to point out that their finding in no way contradicts the original theory, but simply provides a new aspect of it.

https://phys.org/news/2012-10-physicists-special-relativity.html

James M. Hill, Barry J. Cox (2012). "Einstein's special relativity beyond the speed of light." Proc. of the Royal Society A, 468, 4174– 4192.

Almost immediately afterwards a group of scientists from Hungary showed that the transformations J. M. Hill and B. J. Cox introduced "between inertial observers moving faster than light with respect to each other are consistent with Einstein's principle of relativity only if the spacetime is two dimensional".

http://rspa.royalsocietypublishing.org/content/royprsa/469/2154/20120672.full.pdf

And in 2013 scientists from India found that "with the proposed Hill and Cox formulation for superluminal velocities … if an observer A in [inertial system] k moves back and forth on the x axis, observers in [inertial system] k' would interpret this as A is moving from past to present and present to past freely at will. Further, the Hill and Cox transformations do not maintain the constancy of the speed of light in directions other than the line of relative motion".

https://aijcrnet.com/journals/Vol_3_No_5_May_2013/4.pdf

And so scientists found major flaws in the Hill and Cox formulation and Einstein was proven "right" again.

In 2011 physicists from the CERN laboratory in Geneva officially announced that subatomic particles called neutrinos might be travelling at a velocity faster than light.

https://arxiv.org/abs/1109.4897

If confirmed, this discovery could invalidate Einstein's special relativity and cause great chaos in physics because according to Einstein's special theory of relativity, nothing can travel faster than the speed of light.

So the obvious conclusion to be drawn: either the measurements are incorrect, or physicists must revise special relativity.

https://arxiv.org/abs/1110.2685

Journals reported the finding in sensational way. Universe Today wrote: "Oh, yeah. Moving faster than the speed of light has been the hot topic in the news and OPERA has been the key player. In case you didn't know, the experiment unleashed some particles at CERN, close to Geneva. It wasn't the production that caused the buzz, it was the revelation they arrived at the Gran Sasso Laboratory in Italy around 60 nanoseconds sooner than they should have. Sooner than the speed of light allows! Since the announcement, the physics world has been on fire, producing more than 80 papers – each with their own opinion. While some tried to explain the effect, others discredited it. The overpowering consensus was the OPERA team simply must have forgotten one critical element".

https://www.universetoday.com/89933/special-relativity-may-answer-faster-than-light-neutrino-mystery/

Indeed they did, the results were flawed. The claim that neutrinos can travel faster than light has been given a knock by an independent experiment.

Two physicists, Cohen and Glashow, have demonstrated that "such superluminal neutrinos would lose energy rapidly [… by producing] electron-positron pairs (ν→ν+e−+e+). For the claimed superluminal neutrino velocity and at the stated mean neutrino energy, we find that most of the neutrinos would have suffered several pair emissions en route, causing the beam to be depleted of higher energy neutrinos. Thus we refute the superluminal interpretation of the OPERA result".

https://www.nature.com/news/2011/111020/full/news.2011.605.html

https://arxiv.org/abs/1109.6562

https://arxiv.org/abs/1110.3763

Nathan Coppedge · Answer

I have hypothesized a few theories about Einstein’s final theory. Maybe these would be foundational for contemporary philosophy of science:

NOTES ON EINSTEIN’S THEORY OF EVERYTHING

The Einstein Conjectures [ https://hypercubics.blogspot.com/2019/09/the-einstein-conjectures.html?m=1 ] (Sept 4, 2019)

Introducing the amazing concept of gravito-electromagnetism [ https://cosmosmagazine.com/mathematics/the-amazing-concept-of-gravito-electromagnetism ] (Sept 5, 2019)

%3E “Infinity exists, although not absolutely.” —Does ultimate dimension exist? [ https://www.quora.com/Does-ultimate-dimension-exist/answer/Nathan-Coppedge ]
Einsteins Time Theory [ https://emporium.quora.com/Einsteins-Time-Theory ]

Einsteins Dimensional Theory [ https://emporium.quora.com/Einsteins-Dimensional-Theory ]

Impossible Space Theory [ https://emporium.quora.com/Impossible-Space-Theory ]

“When considering material politics, if neutrality (such as homogeneity) emerges from an exception (such as exponential efficiency), then neutrals can be exceptional. In other words, deviation may occur invisibly. [italics added]” —Nathan Coppedge, General Mergence Theory [ https://emporium.quora.com/General-Mergence-Theory ]

Inside-Outside System [ https://emporium.quora.com/Inside-Outside-System ]

Universal Matter Theory [ https://emporium.quora.com/Universal-Matter-Theory ] (theory by Coppedge, June 2020)

Time-Strand Theory [ https://emporium.quora.com/Time-Strand-Theory ]

Rarity Wave Theory [ https://emporium.quora.com/Rarity-Wave-Theory ]

Warren D Smith · Answer

I had earlier commented refuting the massively false “answer” by “Toni Sementana, PhD Physics, University of Milano” in which he claimed the Messenger Mercury spaceprobe had “proven string theory is at least partially wrong.” But TS then removed my comments. Therefore I am going to write my own answer here (1) refuting his and (2) responding to original question.

TS completely-falsely claimed that “The gravitational constant G... according to the great unifying field theories, such as superstring theories, should change over time.” Actually string theory in principle predicts every constant of physics in Planck units. None change in either time or space. This is approximately the most basic fact there is about string theory so that anybody who gets this wrong, is essentially totally ignorant of the area.

TS then continued “‘By how much does string theory predict these constants to vary over time?’ By so much that you would be able to see the variation in an highly accurate experiment like [the ‘Messenger’ spaceprobe].” That again is completely and utterly false.

TS then falsely claimed “to this day, no instrument has measured the gravitational constant as accurately as Messenger.” In fact, Messenger never even measured G at all. And Measurements of the gravitational constant using two independent methods [ https://www.nature.com/articles/s41586-018-0431-5 ] is one of the most accurate determinations of G, obtaining G = 6.6743(3)*10^(-11) cubic metres per kilogram per second squared (Qing et al, Nature, 2018).

But Messenger did obtain good bounds in the time variation of G, namely it claimed that |(d/dt) ln(G)| %3C 5*10^(-14) / year. But an old argument by Edward Teller requiring no instruments at all had already shown a bound of order 5*10^(-10) / year, and astronomical observations, for example using the laser reflectors placed on the moon by the apollo missions, had yielded 10^(-12)/year.

But this all has no impact whatsoever against string theory, and in fact to the extent it does have any impact it supports string theory.

In view of both these massive errors, and his response to their refutations, I recommend not trusting any statement by “Toni Sementana, PhD Physics, University of Milano” about physics, until you check it out for yourself. He plainly is neither competent, responsible, nor ethical.

Now to return to the original question of whether string theory is “still in the running,” the consensus is that the topmost problem it faces is “supersymmetry” aka “SUSY.” It was widely claimed that by now we would have gotten evidence of SUSY, e.g. “If we understand supersymmetry and its implications correctly, direct experimental evidence for supersymmetry will be found in the next few years." — Gordon L. Kane, pages 2-3 of his book “Supersymmetry: Unveiling The Ultimate Laws Of Nature” (Perseus 2000).

“[If after a few years of operation of a 2 TeV accelerator, no supersymmetric-partner particles have been found, then] most SUSY protagonists have agreed to abandon the theory in a public ceremony in which they break all their wooden pencils." — [Nobel laureate in this area] Leon M. Lederman p.365 in his book “The god particle” (Dell 1993). But in fact, there still is no experimental evidence for SUSY even as of 2019 prompting such articles as

Why Supersymmetry May Be The Greatest Failed Prediction In Particle Physics History [ https://www.forbes.com/sites/startswithabang/2019/02/12/why-supersymmetry-may-be-the-greatest-failed-prediction-in-particle-physics-history/ ] (2019), Supersymmetry Bet Settled With Cognac | Quanta Magazine [ https://www.quantamagazine.org/supersymmetry-bet-settled-with-cognac-20160822/ ] (2016), https://www.scientificamerican.com/article/is-supersymmetry-dead [ https://www.scientificamerican.com/article/is-supersymmetry-dead/ ] Is Supersymmetry Dead? (2012), and The truth hurts: LHC breaks supersymmetry's beauty [ https://www.newscientist.com/article/mg21228421-400-the-truth-hurts-lhc-breaks-supersymmetrys-beauty/ ] (2011).

And if SUSY is false, then superstring theory and supergravity both automatically are false, and indeed completely irrecoverably dead.

Mark · Answer

None of Einstein‘s theories were ever proven incorrect, quite the opposite, they are regarded as scientific fact. But he was not right about everything. Here’s the story.

Albert Einstein‘s contributions to science are almost unbelievable. That one person could have made such an impact is astonishing. His explanation of the photo electric effect, which basically proves that light, while traveling as waves, can also be viewed as being quantized by a force carrier particle called the photon, would have secured his place in history without any other accomplishments. In fact he won the Nobel prize for that work. But he is best known for his relativity theories. The theories of general and special relativity are basically scientific fact. They revolutionized physics. So where did Einstein go wrong? What was it that he was incorrect about? Well I can tell you that it had nothing to do with relativity!

It was not that Albert Einstein proposed a theory which was later proven incorrect. Rather, there were aspects of quantum theory that he was very uncomfortable with. Understand that Einstein’s work, his explanation of the photo electric effect, were pioneering efforts that helped create quantum theory. But quantum physics has certain aspects of it that are rather random, and we can only predict certain probabilities rather than knowing something specifically about a given system. Einstein was very uncomfortable with this, believing that a theory was incomplete until it could completely predict the process. Heisenberg‘s uncertainty principle embodies the concept of this randomness, and explains that we cannot know everything about a system. Einstein had a problem with that, but it ended up being demonstrated that the uncertainty principle is a law of physics, that cannot be subverted.

Einstein was also uncomfortable with another aspect of quantum physics, quantum entanglement. The simplest explanation of entanglement can be viewed when a particle, let us say it is a photon of light, is sent into a system where the photon is split into two separate photons of 1/2 the energy of the original. In experiments, no matter how far apart these two sibling particles travel away from one another, when a measurement is performed on one of them, the other particle will provide a reciprocal measurement which indicates the attachment between the two. The agreement in measurement between the two happens instantly, which violates the limitation of anything, or any information traveling at faster than light. Einstein and his two colleagues, Rosen and Podolsky, argued that the reason this happened was that the two particles possessed intrinsic properties, or “hidden variables”, which eliminates the need for the transfer of information between the two particles. It was later demonstrated undeniably however, cthat no such hidden variables exist and that some kind of instant agreement occurs between the two widely separated, sibling particles.

Even though Einstein objected to these aspects of quantum physics, his objections were brilliant, and stimulated the research necessary to bring out the truth. It is a great example of how the scientific method works.

So Einstein‘s contributions come from his brilliant theories, but also from his disagreements about certain things. Einstein did not live long enough to see some of his ideas overturned, but if he had, he would have been more than happy to admit that he was incorrect, and would have reveled in the acquisition of the new knowledge, which is after all the motivation of science.

Jamie Oglethorpe · Answer

His theory cannot be proved. It is not a mathematical theorem to be proved from accepted axioms. It is a theory of nature and it can be disproved, if somebody can demonstrate a situation where its predictions are wrong. After half a century of trying really hard scientists have failed to find any such discrepancies. This has raised the stature of the theory tremendously.

However, there is another theory of space, Quantum Mechanics, that gives quite different answers. Einstein spent the last years of his life trying to reconcile the two. The two are very difficult to test against each other, because General Relativity deals with the very large, and Quantum Mechanics the very small. General Relativity has been tested with falling atoms, but cannot be tested with charged particles because of its weakness, nor can it be tested with more exotic particles because they don’t last long enough.

A “theory of everything” combining GR and QM is needed, because neither has anything to say about the singularities in GR: the instant of the big bang, and the heart of a black hole where gravity appears to overwhelm QM. QM has a lot to say about the tiniest fraction of a second after the big bang. The theories also come together at the event horizon of black holes in ways that suggest things about a TOE.

Dark matter is a possible clue that GR needs to be changed. In essence galaxies rotate too fast for the matter seen in them, and galaxies in clusters move too fast for the mass seen in them. Matter that cannot be observed and only feels gravity is proposed to make GR work. Many physicists are unhappy with this, and are trying to get the same answers by proposing alternative theories to explain the observations without dark matter.

The recent observation of gravity waves from the merging neutron stars has shown that gravity and light travel at the same speed, ruling out theories that predicted the contrary.

Edit: Unfinished sentence

Jack Fraser-Govil · Answer

Sure - there are a fair few:

EPR “paradox”

The EPR (Einstein–Rosen–Podolsky) Paradox supposedly shows that quantum theory is incomplete—they wanted a local realist theory (which quantum theory isn't)

However, this is because they didn't (at the time) understand the concept of entanglement

This is now considered an elementary part of physics—you can normally refute the EPR paradox as an undergraduate.

Bell’s inequalities came along in the 1960s and Bell test experiments showed that a local realist theory is impossible. A theory can either be local, or realist—but not both.

Introduction of the cosmological constant

His relativistic field equations initially implied an expanding universe.

He fudged a constant (Λ) in to his equations to stop this expansion—when Hubble later proved the universe was expanding he called this “my greatest blunder”.

We have later reintroduced the cosmological constant, in order to account for “dark energy”—rather than making the universe stay the same size, we flipped the sign, and now it makes the rate of expansion increase, in accordance with observer evidence.

Initially dismissed the idea of gravitational lensing as insignificant

He thought it would be too small to see (it’s not)

He initially disproved the existence of gravitational waves

Einstein very nearly published this result. When peer review caught a mistake in his work, he angrily withdrew his paper, and never published in Physical Review again.

Gravitational waves were detected indirectly in 1973, and directly in late 2015. (Oops)

Black holes

Einstein never accepted the idea of black holes (even though his maths definitely predicts them), saying instead that angular momentum would prevent the collapse.

There are a few more ones I will probably remember and add in.

Einstein was a clever guy—but he made his fair share of mistakes and blunders. And even his mistakes are an interesting subject!