Einstein's Biggest Blunder That Wasn't

jose parinas writes "The genius of Albert Einstein, who added a "cosmological constant" to his equation for the expansion of the universe but later retracted it, may be vindicated by new research. The enigmatic "dark energy" that drives the acceleration of the Universe behaves just like Einstein's famed cosmological constant, according to the Supernova Legacy Survey (SNLS). Their observations reveal that the dark energy behaves like Einstein's cosmological constant to a precision of 10%."

Comments

Re:Awesome

[OzRoy]

Einstein put in the constant as a fudge because he wanted his equation to match the data. At the time people were not aware of the exanding nature of the universe. I don't think he ever liked using the constant, and was relieved when it turned out it wasn't necessary. Everything was neat again.

Re:Still a blunder?

[EvanED]

Yeah... and it may get worse. Here's the story to the best of my knowledge:

Einstein did some calculations and stuff and came up with two potential models of the universe. (Perhaps two solutions to his equations?) One had the universe expanding, the other contracting. Einstein called up some astronomers and asked which it was. They told him to get lost, that the universe was static. So Einstein went back and added the cosmological constant so that it matched "reality." Later Hubble was like "look, y'all, the universe is expanding," and Einstein was like "my bad" and dropped the constant.

But here's the thing: the universe's expansion is accelerating. If it models something like the cosmological constant, that means that the extra force Einstein added must be repellant. This tells me that the model he picked to add the constant to was the contracting one. Which means that I don't see a correspondance to reality.

There might be something deep about why about the same force would take the contracting universe model and make it static would also take the expanding universe model and make it accelerating, but I don't see what it is.

Which means that if they turn out close, I think it's much more likely that it's just a really lucky coincidence rather than the genious of Einstein. Even if there is a deep correspondence, the fact that Einstein added it to an incorrect model to bring it to another incorrect model, and when that incorrect model was found to be incorrect renounced it, pretty much rules out the possibility that this is really an example of his genious.

This is, at least, the reaction I have whenever I read about the cosmological constant... am I totally off-base?

Hardly Einstein's biggest blunder...

[Goonie]

IIRC his biggest blunder was discounting quantum physics and spending the last half of his life trying to come up with an alternative model that didn't require the universe to be probabilistic.

Density, exactly...

[rmdyer]

That's my take on modern cosmology. That there exists this one substance, the vacum substance, the stubstance of space-time itself. It can be imagined as a drop of water, or equally as a cloud of moisture. It contains volumes within it that are "denser" than other volumes. We say that there is "more space" (or less?) within those volumes. All "material" goods are then just some kind of configuration of this "space-time" stuff. I think also that based on quantum mechanics, and the "Beckenstein bound", material within a given volume can be realized in much the same way pictures are made up of "pixels" on a computer screen. Think of it. Your computer screen resolution determines all objects that are "realizable" within its resolution. The Beckenstein bound then formulates a given volume for space-time in which objects of a given size can fit. The relationship of the "density" of space-time then should directly influence the Beckenstein bound such that, if there is "more space", then there should be the possibility of a larger number of possible quantum states within the abstract volume of space-time.

If you had a glass sphere the size of a basketball, what are all the material objects that are realizable within that space? Well, we can put car keys, pens, small animals/insects, etc. But we cannot put a house inside a basketball right? Well maybe a doll house. But how would we go about putting a real house in a volume the size of a basketball? Simple, just increase the density of space-time within that abstract volume. That will increase the number of quantum states possible just like increasing the resolution of your computer screen. But what do we mean when we say "space is dense"? Since the vacum is matters "opposite", we would probably conclude that space would be "denser" where matter is not. So we might say that within a "black-hole" there is theoretically "no space". A black hole would then indeed be a hold within space-time, a tear in the fabric of reality for example. But this may not be the case. It could be that a black hole is a place were the density of space is so high as to be exactly "solid" space-time. In this respect matter flows into a black hole and then becomes converted to "space-time", which then slowly and inexorably flows outward. Space-time is being generated by a black-hole by the conversion of matter to space-time.

If space-time is a substance of some kind, and all matter is just some configuration of it, then that would explain why we cannot move faster than light. This would be the case if we were somehow made of configurations and vortices of "air". Since we being made of "air", we could not move faster than sound right? Of course doesn't the speed of sound vary with the density of air? Would not the speed of light vary with the density of space-time? Of course it does, this was Einsteins great find, that light travels along a space-time geodesic. The geodesic caused by the "density" of space-time.

Based on all these analogies, I don't see why we have to think about the fourth dimension at all. We just need to imagine space-time as a volume with varying densities. Within a high density of space-time, you can have more matter, and more quantum states. It is abstract I know, but for my mind it works. Is there a reason that these analogies can be viewed as "wrong"? I'm willing to take an alternate view.

Re:Density, exactly...

[rmdyer]

You are correct. The problem we have here is that these "volumes of density" are abstract. But your reasoning is exactly the problem we encounter with the Michelson-Morley Experiment right? We seem to find that light is the same speed in all directions, proving that the "ether" doesn't exist. The basic problem with the "old ether" is that ether was some kind of substance. I find this view of ether silly since space-time itself isn't a "substance" it is the opposite of substance, of matter itself...it is "space". As in, what is the volume that surrounds matter? SPACE. In my original analogy, imagine again that nothing exists except for "air". Matter then would be "configurations" of "air". Matter would be some kind of "vortices" or foldings of "air". Light then would be seen as a "vibration" in the "air". And since we, being made of "air" in this analogy, could never move faster than, vibrations in air.

So how could we "prove" this model...this analogy? Well take our original glass sphere the size of a basket ball. I said you can't put a house in a basket ball right? Well what would happen if we placed a marble sized black hole inside that basket balls volume? Assuming for the moment that the glass sphere would not be crushed by the black holes high density of space-time around it (gravity), then we should be able to put very large things in there right? The problem with this analogy is that the "glass spheres" volume would neccessarily cause it to shrink, or become more dense. If space-time actually works the way we're suggesting, then you cannot have a "rigid frame of reference" made of matter, since matter itself is made of space-time. But isn't this actually the state of affairs encountered with these experiments?

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ /mmhist.html

From this page http://en.wikipedia.org/wiki/Luminiferous_aether of the Wikipedia..."Another, completely different, attempt to save "absolute" aether was made in the Lorentz-Fitzgerald contraction hypothesis, which posited that everything was affected by travel through the aether. In this theory the reason the Michelson-Morley experiment "failed" was that it contracted in length in the direction of travel. That is, the light was being affected in the "natural" manner by its travel though the aether as predicted, but so was the experiment itself, cancelling out any difference when measured. Even Lorentz was not very happy with this suggestion, although it did neatly solve the problem. Later this idea received additional support from the Kennedy-Thorndike experiment in 1932, as Kennedy and Thorndike concluded that both a Lorentz contraction as well as time dilation occur, thus "confiming special relativity".

In order for these analogies to work, you'd have to have a "four dimensionally" rigid volume for which to measure the "density" of the 3 dimensional space-time. At least, I think. So that might mean that indeed, there is something "outside" of our own "space-time" way of measuring things.

Re:Dark matter ...

[ttsalo]

Now, if there was enough matter in the universe, the gravity between it would eventually slow it down, stop it, and finally start it contracting back together. That was a rather attractive idea -- that the big bang wasn't a one-time thing, but that we just happened to be seeing evidence of the most recent occurrence.

The problem was that our estimates of how much matter there was in the universe came out well below what was needed for there to be enough gravity to make the expansion stop and eventually reverse.

But the expansion of the universe doesn't mean that the galaxies are moving away from each other, even though this is a very, very common misconception. It means that the space itself is expanding. See 'superluminal expansion'. Yeah, I don't get it either. Why the hell would space itself be expanding and why would dark energy or matter have anything to do with it?

Um

[TallMatthew]

The cosmological constant balanced out equations that assume a static universe. It wasn't based on anything observed; Einstein just knew he was missing something because he couldn't get his observations to follow his math.

If you take a snapshot of the universe, if you discount its expansion, then the existence of dark energy, remnant of the big bang, is requisite to explain certain phenomena and balance out equations.

Why is it weird these two are similar?

Reminded me of the TARDIS.

[Hitman_Frost]

Using density as an analogy, as you have in your post, I couldn't help be reminded of the old TARDIS. By increasing the effective density of space-time within a police-box, you could possibly fit enough inside it to resemble that famous timeship.

Who knows - perhaps the travelling in time and the density of space-time have further connections, even?

Not exactly brilliant science is it?

[n54]

On topic:

Fudge factor (Einstein) == fudge factor (dark energy/matter)

What exactly is surprising about this? They were/are both added to represent something unknown, a pure speculation which is likely to fall (or be changed to the extreme) by Occams razor as science and knowledge progresses.

http://www.astronomycafe.net/anthol/fudge.html

Einstein retracted his fudge while still alive and I have a suspicion those championing dark matter/energy will have to as well :)

Slightly off topic:

Hmm was this the first valid and correct reference to Occams razor on Slashdot ever? Probably the first time here it wasn't used in a faulty manner applying it with anti-religious or ideological/political arguments (one would think people would get a clue from the fact that Occams razor was created by a Franciscan friar).

religion != science
Occams razor = intended for scientific theories (given two equally predictive theories, choose the simpler)
Occams razor != rational to apply to religion

*doesn't even need a flameretardant suit*

Re:Not exactly brilliant science is it?

[Chemicalscum]

Einstein retracted his fudge while still alive and I have a suspicion those championing dark matter/energy will have to as well :)

Prior to the experimental (observational) discovery of the increasing rate of expansion of the observable universe (part of the multiverse ?) many physicists regarded the cosmological as essential to general relativity. Coleman for one asked the question why is the cosmological constant zero and proposed a hypothesis based on wormholes between universes to explain why it should be zero. Inflationary big bang theories suggest a very high vacuuum energy (dark energy) which manifests itself as a cosmological constant. This vacuum energy arises from quantum theory rather than GR, or at any rate as a result of the uneasy coexistance of QT and GR in inflationary theories.

The result is that the expectation value of the vacuum energy should be much greater than required by the observational data for the increasing rate of expansion of the observable univese. Weinberg has proposed that selection on the basis of the weak anthopic principle from a multiverse composed of universes with the full range of possible values of the cosmological constant 9as a result of quantum uncertainty during the big bang) to explain why the value of the cosmological constant we observe.

IANAP but I am a chemist who suffers from physics envy (as Niles Eldredge put it) who occasionally consults the original papers coming out on arXiv.org to try to undertand what is going on in cosmology.

Re:Dark matter ...

[OlsonSchmolson]

I get tired of this description of the Big Bang as an explosion in the usual terms, as in things flying apart out into something, "matter flying off in all directions". It's popular science, and most people wouldn't know what the heck you were talking about if you described it any other way. But, it ought to be restated...

It's an expansion of space, everything that is in space is just going along for the ride.

A visual way to clarify that is to shoot down the idea people have that things cannot recede faster than light. That gets their attention, they all know about Einstein and c. Things cannot move through space faster than light, but space itself puts a distance between things that C can never outpace.

Re:Ohh yeah...

[phoenix.bam!]

You might only be joking but the quote about God throwing dice is interesting. The idea that something can be truely random was absurd to Einstiein and he might be right. Eventually it might be possible to completely predict object intereaction in a closed system with enough variables. Or crazily, matter/energy interaction anywhere in the galaxy.

Stupid Question

[miyako]

I realize that this is probably a stupid question. I haven't had the math or physics yet to really understand probably all the reasons it's a stupid question, so I'll put it out there and see what people have to say on this (slightly) off-topic issue.
Why is it not possible that the universe is simultaneously expanding and contracting?
One question I've had for a while is, why couldn't the universe be shaped in such a way that the force causing accelleration on the expansion of the universe is actually the gravitational force of the universe contracting.
To sort of illustrate my point, think of the game Asteroids. If you fly out of the top of the screen, you appear back on the bottom, and if you fly out the left side of the screen, you appear on the right side. Why couldn't there be some n-dimensional version of that concept in the universe such that as it expands it's actually approaching an earlier state?
Anyway, if this is just the stupidist thing ever, please be kind in saying so. IAONAP (I Am Obviously Not A Physisist).

Re:Stupid Question

[bjorniac]

Not a stupid question at all.

It is possible to have the universe expand and contract in different directions at the same time. However, this isn't what we observe. Two of the basic ideas about the universe we assume to be broadly true (yes, not exactly but to a good approximation) are

1) It is homogeneous. This is math speak for it's the same at every point
2) It is isotropic. Math speak for looks the same in every direction.

Now, this clearly isn't exactly true - if it were there would be no difference between the earth and an empty vacuum of the same size. However, on a very very large scale (where galaxies appear like point particles because they are so small) this appears to be true. We get this from the Cosmic Microwave Background - a set of rays that fly towards us from all around the universe in a fairly uniform manner. Also when you look at the "Redshift" of galaxies (like the doppler shift of sound makes a siren sound higher when an ambulance approaches and lower when it moves away) it looks like all galaxies are moving apart from one another in equivalent directions. So we guess that the universe is largely isotropic and homogeneous, make a broad model and then do corrections (perturbations about the solutions to the equations) for the bits that aren't.

So given the idea that it's isotropic and homogeneous we get that it must expand at the same rate in all directions etc. However, there's nothing in the everyday physics to say that it necessarily is - just the observations of some cosmic phenomena.

The asteroids thing is kind of a side point - that's more to do with the topology of the universe. Asteroids is like a torus (or donut with a hole) shape - you go one way for a while you end up back where you started. Some models of the universe have the universe be a 3-torus (an extension of the donut in another dimension, cue Homer drool). However, the universe is broadly thought to be either flat (just like regular space looks) a 3-sphere (like a ball but with another dimension again) or a hyperboloid (hard to explain, but like the inverse of the sphere). This all depends on the matter in the universe and the cosmological constant in a fairly complex way.

Although if you mean that the universe could cycle, that again is possible - it could expand, contract, expand again indefinitely. If you look at the works of Bojowald, for example, on Loop Quantum Gravity he seems to think that the big bang could be just part of a cycle of expansion and contraction.

Re:Dark Matter; whatever..

[Anonymous Coward]

There is no proof for the existance of Dark Matter or Dark Energy. They were both created to explain-away the shortcomings of some popular theories.

There is never "proof" of anything in science. For dark energy, there is good evidence that the acceleration of the universe is expanding, and the cause of that expansion has been dubbed "dark energy", whatever it is. For dark matter, there are a lot of independent lines evidence which consistently indicate there is a great deal of unseen matter in the universe, and we even have some pretty good ideas on what it could be.

Coincidentally, there is no proof that the universe is expanding. Most people don't know this because the 'bangers' (big-bangers, specifically) have been loudy shouting out their theory for so long..

There is no "proof" of anything in physics, but the expansion of the universe has been extremely well established in by observations.

Google 'no big bang' or 'compton effect'.

Yeah, Google 'compton effect' (and here and here).

Sorry, but there are no existing alternatives to the expansion of the universe. If you had a modicum of physics education, you'd understand why. That is not to say that no such alternative can exist -- see "there is no proof in physics" -- but the evidence in favor of expansion is quite strong and you have to go through far more contortions to get an alternative to work than the current crop of naive crackpot models.