Albert Einstein's general theory of relativity is about to celebrate its 100th anniversary, and his revolutionary hypothesis has withstood the test of time, despite numerous expert attempts to find flaws.

"Einstein changed the way we think about the most basic things, which are space and time. And that opened our eyes to the universe, and how the most interesting things in it work, like black holes," said David Kaiser, professor of the history of science, technology and society at the Massachusetts Institute of Technology (MIT).

Einstein, a celebrated German-born theoretical physicist who spent the final years of his life at Princeton University in the northeastern United States, presented his theory on November 25, 1915 before the Prussian Academy of Science.

The document was published in March 1916 in a journal called Annalen der Physik.

The general theory of relativity was among the most revolutionary in history; it marked a major leap from the law of universal gravitation put forth by Sir Isaac Newton in 1687.

Einstein believed that "space and time are not fixed, which was what others had thought, but are flexible, dynamic phenomena like other processes of the universe," said Michael Turner, director of the Kavli Institute for Cosmological Physics.

"So space bends and time warps, and it was a whole new way at looking at gravity."

Einstein had put forth a more restrained version of his theory in 1905, the special theory of relativity, which left out gravity but described the relationship between space and time. It held that the speed of light is the same in a vacuum, and the laws of physics do not change regarding inert objects.

**Precursor to GPS**

He also came up with his famous equation, E=mc2, which says that energy equals mass times the speed of light in a vacuum, squared. In other words, mass and energy are the same but in different forms.

Ten years later, the general theory of relativity offered a larger and more explanatory vision, adding gravity's role in the space-time continuum.

Therefore, time would move more slowly in proximity to a powerful gravitational field, such as that of a planet in the void of space.

This relationship has been verified by comparing two atomic clocks, one on Earth and the other in a high-altitude airplane where it shows a slight delay.

Global positioning systems (GPS) are an application of this phenomenon.

Satellites have clocks that are precisely adjusted to account for this time difference, otherwise GPS would not be able to function.

According to the theory of general relativity, light is also warped by powerful gravitational fields, which British astronomer Arthur Eddington confirmed with his observations on the deflections of starlight by the Sun in 1919.

Einstein also predicted that stars at the end of their lives would collapse under their own gravity.

Their external envelope would explode in a supernova while their heart would form a very dense object known as a neutron star, or a rapidly spinning pulsar.

They could also transform into a black hole, which such a huge gravitational field that space and time could not escape.

According to Einstein, these celestial bodies, given their masses, should provoke waves in space time much like a thrown stone causes ripples in water.

These are the gravitational waves that astronomers hope to observe first-hand.

**String theory**

This would "confirm one of the last great but as yet untested predictions from Einstein, equation that space and time are not really dynamical but they can ripple, like the surface of a pond," said Kaiser.

Instruments have been designed to capture this phenomenon, including the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States and VIRGO, a gravitational wave detector in Italy in Europe.

An enormous challenge remains—to reconcile the general theory of relativity with quantum physics, the two big pillars of modern physics.

Quantum physics, contrary to relativity, perfectly describes phenomena on an atomic level and has numerous applications, from transistors to computers.

Turner said the most popular theory for reconciling the two is string theory, which holds that particles are not the fundamental building blocks of matter but are elastic strings that vibrate at different frequencies.

"String theory might answer that deep question of what space and time are," Turner told AFP.

"It suggests it could be extra dimensions and that the number of dimensions of space and time could change," he added.

"And if you take the most extravagant view of that, maybe space and time did not exist and they emerged from something else."

Turner described string theory as an "empty vessel," and added: "the great thing about an empty vessel is that we can put our hopes and dreams in it."

"We are now ready for the next Einstein to open our eyes a little more."

**Explore further:**
How Einstein could help unlock the mysteries of space travel

## vlaaing peerd

"Phys.org-posters - debunking science myths and frauds since phys.org"

## docile

Oct 20, 2015## SuperThunder

## antialias_physorg

It would mean that there is a difference between gravitational and inertial mass. (If you can find a link where you got this idea from I'd be interested. At least wikipedia says "Although inertial mass, passive gravitational mass and active gravitational mass are conceptually distinct, no experiment has ever unambiguously demonstrated any difference between them.")

If such a difference existed we could establish an absolute frame of reference (which would nix Relativity)

## vlaaing peerd

This relationship has been verified by comparing two atomic clocks, one on Earth and the other in a high-altitude airplane where it shows a slight delay."

Then the clock in high altitude wouldn't show a delay but instead would tick a little faster, wouldn't it?

## docile

Oct 20, 2015## someone11235813

Never write science articles while drunk.

## SuperThunder

Once again google is useless to my memory of anything at all. Teeth grindingly infuriating, because it blew my mind and I had no one to talk to about it.

## docile

Oct 20, 2015## SuperThunder

## bluehigh

## SuperThunder

I'm done ranting.

## bluehigh

## arom

While waiting for the fruitful from the MAGIC of string theory; maybe this understandable idea (with the familiar particles of the building blocks of matter, normal space and time without extra dimensions) could help to visualize ….

http://www.vacuum...=9〈=en

## Doug_Huffman

In infinite time all possibilities are realized, only in this causal *u*niverse is this not so.

## bluehigh

Theoretically from a math point of view there's arguments against its validity.

Eg:

http://www.journa...6/Lo.pdf

"It is interesting to note that the earliest experimental support of Einstein's equivalence principle would be the Michelson- Morley experiment."

also more doubt here ... http://arxiv.org/...3083.pdf

Experimental evidence article still not found. I give up. Lost the plot.

## docile

Oct 20, 2015## antialias_physorg

Try google scholar

https://scholar.google.de

## bluehigh

Piqued my curiosity. Please explain.

## Benni

It isn't just DM that is not attracted to the center of "massive bodies", that is the point where there is the least mass & therefore the least gravity of any body of mass. The gravity field of all bodies of mass are maximum at the surface, any point above or below the surface is subject to the Inverse Square Law in which gravity diminishes based upon the distance it is measured from the surface.

## Hat1208

So things weigh less underground or in an airplane.

## billpress11

While it is almost universally accepted that nothing violates relativity I think there is room to question whether that is true or not. The Sagnac Effect and the CBR both seem to indicate there just might be a fixed frame of reference.

An interesting experiment that I would like to see carried out would be the test the one way velocity of light in opposite directions and compare those results to the velocity relative to the CBR. With today's atomic clocks we should be able to do this in space.

## rossim22

This entire article is simply an appeal to authority.

## antialias_physorg

"Gods do not exist" is the null hypothesis. Until someone comes up with a proof that shows that the null hypothesis isn't valid there's no reason to believe in any gods.

If someone is asking you to "disprove god" it just shows that they haven't understood the scientific process (in more ways than one)

## docile

Oct 20, 2015## shavera

Let's say I'm in a car, and a cop clocks me as going 15 over the speed limit. I can say "no officer, I was at rest" or "Officer, I was travelling against the Earth's rotation, so you were really going faster than me" or a number of other arguments about reference frames.

But we choose, as a *convenient* rest frame for this measurement, that the surface of the Earth we are at is (more-or-less) at rest and partially inertial (neglecting gravitation for the moment).

The CBR is the same. It's convenient, in that all observers throughout the universe should be able to measure their velocity w.r.t the CBR, and in so doing can compare their velocities directly to each other, but it's no more "fixed" than the surface of the Earth is a "fixed" reference frame.

## shavera

I don't know if there's a "fallacy of appealing to the wrong fallacy" but plenty of people are guilty of getting 'appeal to authority' totally wrong. If the 'authority' was totally speaking without argument to defend their statement, then it's an appeal to authority.

But in this case, a *host* of experiments have supported the 'authority's' position on relativity. We see gravity deflect light, we see gravity shift light's frequency, we see objects in motion live longer and shrink along the axis of their motion, we see clocks run at different rates when subject to different speeds and different gravitational conditions, we see relativistic beaming. And so on and so on.

So it's not an appeal to authority when the authority has a ton of evidence to support their position.

## shavera

What GR does not tell us is "what is the stuff in our universe." GR doesn't care whether matter is baryonic or not, its mass will bend light all the same. GR doesn't care whether we've labelled all the kinds of energy in our universe or not, energy will drive expansion of the universe.

So when you hear scientists speak of 'dark' matter and energy, all they're saying is "we don't know everything yet."

## billpress11

## SuperThunder

Anyway, to commemorate the anniversary, here is for everyone to read "Relativity" by the kind old Time Lord himself. This is one of my favorite books, as a critical thinker and a philosopher of life.

http://www.bartleby.com/173/

## arnold_townsend

First, "inert object"? Did you mean "inertial reference frame"? I doubt "inert object" has become a suitable synonym for "inertial reference frame" and there is a very big difference in what the two concepts convey. You really flubbed this one and it gives someone not familiar with relativity a very bad start.

Second, Einstein did not "predict" black holes -- they were a consequence of certain solutions to GR's field equations. Schwarzchild worked out one solution to the GR (GR's field equations are differential equations) which contained what later became known as the "event horizon". While Einstein seemed to enjoy theoretical explorations of exotic solutions to his field equations (see wormholes etc), he did not personally believe a "black hole" was an actual, physical thing.

## docile

Oct 20, 2015## Returners

Headline:

4th grade science experiment proves Lorentz transformation wrong for at least some situations. Einstein's abstract mass over-simplistic.

in one reference frame, visile light appears to pass through the prism.

in the other reference frame (according to lorentz transformation) the wavelength of the light is infrared, and should get bounced off the glass of the prism....which is an absurd contradiction.

The only reason Relativity hasn't been disproven is because the physics community bans people like me, who point out obvious was to disprove it, which have never been tested.

I was able to show another scenario where the speed of light postulate in one reference frame, combined with the Lorentz transformation, forces the speed of light in another reference frame to be infinite, which contradicts the original postulate.

## bschott

SuperThunder - Check out Einstein's "The evolution of Physics", he was always on the right track...the Mainstream just didn't like his chosen direction later in his career.

## docile

Oct 20, 2015## docile

Oct 20, 2015## Captain Stumpy

@SuperT

also try https://duckduckgo.com/

you may also be able to still use Lycos and Bigfoot, and try to cross references your results, which might actually be fruitful as you narrow the search parameters?

when you actually run across those type articles, you should consider posting the address/link in an *.rtf or other doc on your HD

or open a thread in a protected place like Sapo's Joint or SciForums (where moderators can delete the moon-howlers)

## Hyperfuzzy

## Hyperfuzzy

## Benni

.......apply the Inverse Square Law exactly as I described.

## SuperThunder

## Benni

Applying the Inverse Square Law to the Einstein Field Equations & you would be correct, they would tick faster in accordingly.

## SkyLy

## Hat1208

There is something I will probably never see in the same sentence again, "clarification" and "Benni and Zeph".

## bschott

Arnold and Benni are the same poster? Neat.

From years of reading Zeph's posts, he has more clever insights and fundamentally correct observations than most of the posters. He also has completely off the wall ideas sometimes but he's human just like the rest of us, at least he never proposed 4/5 of the matter in the universe is undetectable other than generating gravity exactly where it is needed just so the math of AWT could still work.

Imagine the lambasting if he did though.....I mean if someone else hadn't proposed it already and garnered a - - -different reaction.

## swordsman

## Benni

Yep "neat". At least there's more than just a couple of us posting to this site who have actually studied the mathematical derivations Einstein undertook in coming up with General Relativity & his Field Equations.

## Hat1208

There is quite a difference between study and understand.

## Benni

Actually "study & comprehend" is a better way of stating it.

## Hat1208

There is nothing better about it. Understand and comprehend are synonyms.

## Benni

............"comprehend" carries a deeper meaning.

## Captain Stumpy

lets examine that

comprehend http://dictionary.reference.com/browse/comprehend

understand http://dictionary.reference.com/browse/understand

lets see: they both use EACH OTHER in the definition, thus, by that very definition and use, we can state that they are synonymous

but that's not all!

http://www.thesau...tand?s=t

http://www.thesau...hend?s=t

the very first synonym for each word is the OTHER

WOW... never before have i seen more gibberish than your "interpretations" of reality based upon your claims of authority and higher education (see also: https://en.wikipe...r_effect )

Thanks for demonstrating this over and over

## Hat1208

Thanks for the comprehension and for understanding.

## Hyperfuzzy

Correct, the universal constant is not constant, it's a function of the center of "mass", I prefer +&- charge centers; also 420 is more fun.

## TimLong2001

## SuperThunder

## SuperThunder

## Uncle Ira

I took your advisement and started trying to learn to do these differential equation things you are so fond of pretending you know about. But can you tell how this thing here cyphers out? I am stumped, but I am not the nuclear engineer like you aren't either.

D(ư) ≡ 0 where D ≡ λ/λ(x1) + λ/λ(x2) ·

## Hyperfuzzy

Since we are on Dr. E's nonsense, consider the time derivative of m*r, or better yet, with m = mo/sqrt(1-v^2/c^2) then define momentum or force. Note the integral of force used to be momentum. Or start from the bottom up. What is d(mr)/dt, something foolish? Newton would get mdr/dt, what does Dr. E get that is not nonsensical or a need to redefine Newton's calculus, or momentum and conservation!?

This is only a cursory view. But I guess, with Dr. E's logic, this should be ignored as well as the deviations upon the measurements of G. When m is not a constant, the rocket equation would yield mdr/dt + r dm/dt = P, mass released by the rocket as a rate.

## Uncle Ira

Was that what you just wrote meant to come to me? Or are you asking Bennie-Skippy for some help too with your homework like I was?

Maybe you can help me, so maybe you would take a lookie-loo at what I wrote for Bennie-Skippy. I am trying to get to the 2nd derivative and the 3rd derivative too.

## Uncle Ira

Newton-Skippy did what he could with what he could see and experience when he was alive. The Einstein-Skippy had a lot more information and stuffs to work with that Newton did not have.

If Newton-Skippy came along at the same time as Einstein-Skippy maybe he would be the person getting talked about here. All the smart monies is on Einstein taking things a little more complete than Newton, not that Newton was wrong, he just have not yet seen and measured the things Einstein's podnas were seeing and measuring.

Bet smart or not is your choice.

## Benni

Were it not for Copy & Paste, he would never have anything to post. Hey, El Stumpo, give a try for the Differential Equations that are found within the topic under discussion here, Einstein's General Relativity.

You who have never seen a Differential Equation you could solve, supposing you provide us with some thoughtful insight as to why Einstein used so many Partial Differential Equations for developing his thesis on General Relativity, after all GR is the topic under discussion here. Or maybe you didn't realize that? Most likely you didn't realize it, you're too Partial to name calling.

When should we expect a dissertation of your comprehension of this level of science & math? When you present it, just remember words like "troll", "moron", and body part nether regions do not appear in Einstein's GR, but of course how would you know that because you've never read it, much less studied any of it.

## Captain Stumpy

as a gentleman i've always said "Ladies first" so you get first crack in demonstrating your prowess in math here... but i hope you do better than your attempts in the following threads:

in here, you couldn't do ODE's at all & didn't speak the math lingo

http://phys.org/n...ood.html

in here, you couldn't even do basic math or figure out ANY astronomy terminology, easily researched

http://phys.org/n...als.html

Ira caught you too

http://phys.org/n...sts.html

http://phys.org/n...ial.html

and furlong

http://phys.org/n...ate.html

so, when are you going to demonstrate anything but stupidity?

## Captain Stumpy

when will you PROVE you know what they mean? right after you prove yourself

but i doubt that will happen, because it will require you to demonstrate knowledge you haven't shown at least i can actually read English and comprehend what is being written (see above)

you've yet to be able ot offer ANY cogent remarks other than "ROC" or whining about ODE's... which, again, you've never been able to demonstrate knowledge of

thanks for playing, ms benji

## docile

Oct 22, 2015## PhysicsMatter

You may read here a brief story of SR and GRT:

https://questforn...ativity/

## Egleton

It is unsupported by the empirical evidence.

http://www.newton...ion.html

## my2cts

Experience shows that there is no way to talk sense into, or get rid of, whatever lurks behind the alias "Benni".

Stop feeding the troll, put "Benni" on ignore and discuss physics.

In that context, what is this article about ? Einstein is mentioned in the title to attract the trolls, but what news is reported?

## my2cts

Well ... It nicely explains Mercury's orbital precession and correctly predicts the bending of light by gravity, the slowing down of time in a gravitational field.

If YOU can do better than that, publish and get a Noble prize.

Ach so, you can not? Then remove your posts.

## Mimath224

## Mimath224

## Captain Stumpy

yep. i don't respond as much to B as you think. just like to remind people occasionally that for all his big talk, he still has yet to produce anything here but a claim: including his abject failures at math

Thanks for the reminder though rhetorical, right?

SR/GR is heavily tested and proven, and fits best with observations, but in all honesty, like Mimath, i am a mite concerned with String theory.

Mostly because of the whole testing and validation thing... https://en.wikipe...g_theory

sure, it can be powerful in explaining things, but it's still not tested, AFAIK

(feel free to link some evidence if i am wrong, i appreciate it)

I don't know of any tests which validate it: but i don't search out it's tests/studies, either

just offered IMHO, anyway

@Mimath:

posting problems?

## Hyperfuzzy

Try common sense. The mathematical and physical errors within SR/GR & the Standard Model are obvious. But if you don't know Formal logic and Topology, I understand. By the way, sense Newtons mass is simply a constant formed empirically to satisfy "falling apples", do you think physicists have gone too far?

## SuperThunder

https://www.youtu...lBIcHre0

## Mimath224