New Theory of Gravity Decouples Space & Time 575
eldavojohn writes "Petr Horava, a physicist at the University of California in Berkeley, has a new theory about gravity and spacetime. At high energies, it actually snips any ties between space and time, yet at low energies devolves to equivalence with the theory of General Relativity, which binds them together. The theory is gaining popularity with physicists because it fits some observations better than Einstein's or Newton's solutions. It better predicts the movement of the planets (in an idealized case) and has a potential to create the illusion of dark matter. Another physicist calculated that under Horava Gravity, our universe would experience not a Big Bang but a Big Bounce — and the new theory reproduces the ripples from such an event in a way that matches measurements of the cosmic microwave background."
And FTL, too (Score:5, Interesting)
Special relativity, of course, forbids sending information faster than light. A theory supplanting the space-time unification of General Relativity would also supplant special relativity, and hence might not have that limitation. Here's an inteersting tidbit from the article: "Gia Dvali, a quantum gravity expert at CERN, remains cautious. A few years ago he tried a similar trick, breaking apart space and time in an attempt to explain dark energy. But he abandoned his model because it allowed information to be communicated faster than the speed of light."
I'd call that a feature, not a bug!
Re:And FTL, too (Score:5, Insightful)
Whether it's a feature or a bug depends on whether it reflects reality.
It's strange to me that Dvali would abandon his model for allowing FTL propagation of information unless he experimentally checked the conditions in question to see if information really could propagate FTL in those cases. I have to assume he did not - lacking clarification on the matter I'm left to assume that the conditions were not something simple he could test no a whim.
Without the experimental results, it's meaningless to call such an artifact in the model "good" or "bad".
Re:And FTL, too (Score:5, Funny)
I have to assume he did not - lacking clarification on the matter I'm left to assume that the conditions were not something simple he could test no a whim.
Wow. Anyone else see that? From my location, the n arrived before the o; however, the parent clearly typed them in order (o before n) in our reference frame, so I think we've just witnessed information traveling faster than light! Woohoo!
Re:And FTL, too (Score:5, Funny)
It's strange to me that Dvali would abandon his model for allowing FTL propagation of information unless he experimentally checked the conditions in question to see if information really could propagate FTL in those cases.
Sorry, my bad. I have to be the one who checks for FTL propagation, union rules. I'll get to it after I finish my "get laid" project. I'm particularly hopeful. Just the other day, I made eye contact for 1.3 seconds with what I assume to be the female of our species. I think I can get that up to 10 seconds without breaking any laws of the legal kind. It's very promising progress here.
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Whether it's a feature or a bug depends on whether it reflects reality.
Clearly with FTL travel it cannot reflect reality, so it must be false.
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I think you have the tail wagging the dog there. Whether there is an efficient way to solve NP problems is an open question. Why would the fact that a physical phenomenon would lead to such a solution method make that phenomenon invalid?
In any case, experimental evidence doesn't show us that things are impossible; it shows agreement (or disagreement) with theories (models of the world), and those models may imply that something is impossible. The GR model says that FTL information propagation is impossib
Re:And FTL, too (Score:5, Interesting)
"But he abandoned his model because it allowed information to be communicated faster than the speed of light."
I'd call that a feature, not a bug!
Exactly! "Oh no, my theory doesn't match the theory it's replacing!" Well, experiment, dummy! Did Einstein say "oh no, my theory allows light rays to bend and makes C the absolute speed!"? No! He got together with other scientists in 1919 and watched starshine bend around an eclipse.
Re:And FTL, too (Score:5, Interesting)
Actually, HE DID!
He added the cosmological constant to his general theory of relativity, because if he followed his models...it indicated that the universe was expanding.
Einstein didn't like the idea that it was expanding(because it didn't fit the current thinking), so he added the cosmological constant to his equations to make the universe "static".
so, even Einstein fell prey to conventional wisdom and thinking.
Re: (Score:3, Interesting)
Well, I know what you mean, you might make the house of cards of our theories fall by pulling that one out, but it doesn't mean that it shouldn't be tried, as long as the impossibility of FTL information travel isn't definitely proven. For all we know, a theory might smoothly remove it without disturbing anything too much, you know, a bit like this new theory being talked about doesn't disturb too much some of the seemingly unreconcilable properties of relativity and quantum mechanics by distinguishing in t
Re:And FTL, too (Score:5, Interesting)
Actually, faster-than-light transmission of information has already been observed in science. [wikipedia.org]
It's a long way from observing and indirectly influencing quantum entanglement to a Star Trek-esque subspace communication, but the fact that Quantum Entanglement exists in the first place lends credence to the notion that c is not a hard limit, or at least, that it's not a hard limit outside of the 4 dimensions that we can observe.
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Your cited experiment seems to show entanglement by observation is FTL.
But really, what's faster than a two-year old? Therein is the true upper-end limit of c.
Re:And FTL, too (Score:4, Funny)
Re:And FTL, too (Score:5, Informative)
Actually, faster-than-light transmission of information has already been observed in science. [wikipedia.org]
Well, yes, I suppose... as long as your definition of "transmission" of information is sufficiently flexible. The quantum correlation is "transmitted" faster than light, but you can't get information out of it unless you receive the (slower than light) classical part.
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Each of the entangled particles just relies on local information that it carries with it and which was generated at the moment of entanglement.
Please see Bell's Theorem (from over forty years ago) and the experiments based on it for the reasoning as to why this is (at the very least) extremely unlikely.
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Then that wouldn't be transmitting information, now, would it?
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Precisely. FTL transmission of information is still impossible with current science, and we have good reason to believe it will stay that way. FTL transmission of something that's not information is definitely possible, and it doesn't violate any theories.
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Wait. What? I truly don't understand this. If you are transmitting something, and this something "arrives" at its destination, couldn't information have been encoded in this something?
If you can't encode information into it, are you really transmitting something? *Headache*
No, you got it. What you're transmitting is "something." It's not matter, it's not energy, and you can't encode information on it.
Re:And FTL, too (Score:5, Interesting)
You have two things quantumly entangled. You tickle either one, they both laugh. But if can only observe one at a time, if one laughs without being tickled, you don't know whether it was because the other was tickled or if it laughed spontaneously until you observe the other being tickled. There's no way to confirm the laughter as FTL information from the future unless and until you observe the future.
It may be that they only both laugh when you can observe them both. Your observation entangles them and bridges the FTL transmission classically.
I'd like to see the experiment where they're entangled, one is dropped through a black hole's event horizon, and you observe the result on the other. Time compression should have an interesting effect on the half-life of the retained entangled one until it crosses the EH.
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If you could slow down time enough and watch that laser pointers light, the light from it would likely be bending as you moved it from friend A to friend B as a function of the time it took you to move it. At all points, the laser would never go faster than light, although from your location, point C, it might seem to, but both friend A and friend B would experience the event at the speed of light and not faster. When you flick your wrist from frien
Re:And FTL, too (Score:5, Interesting)
Remember, faster than light means time travel (&, thus, causality violations), so I can understand caution. But, I bet in reality his theory had more serious problems.
If his theory is correct and space and time are decoupled then faster than light travel wouldn't allow you to travel back in time.
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I don't see how that's necessarily true. Special Relativity is based on two postulates:
1. The Principle of Relativity: The laws of physics are the same in all inertial reference frames.
2. The Law of Propagation of Light: The speed of light is a specific constant value independent of the motion of its source (and this is a "law" for purposes of postulate #1 above).
These two postulates allow you to derive the conclusion that if you send a signal from Event A to Event B such that the signal travels faster than
Re: (Score:3, Interesting)
Not to make the discussion drift off topic, but at the core people who hold religious dogmas and scientists share the same brain structure as we all do, and there are instincts in us that work the same way as when you spray chimp with cold water when they reach for the Holy Banana until quickly no one touches it, even those who were not sprayed, even when the last chimp to be sprayed left the place a long time ago.
What I mean is, we tried hard for about a century to find cracks in Einstein's theories, and
So help me out here. (Score:5, Funny)
Does this theory suck or is there some pull to it? It just seems so weighty to me.
Much more mathematical detail... (Score:4, Informative)
Re:Much more mathematical detail... (Score:5, Funny)
It's a PDF version of a PowerPoint deck, so it's not exactly easy to read.
Indeed, informative link but I think your signature should be at the start of your post. I was doing pretty good right up until they plugged the ansatz into the Horava’s action to produce the reduced Lagrangian.
Re:Much more mathematical detail... (Score:5, Funny)
... until they plugged the ansatz into the Horava’s action to produce the reduced Lagrangian.
Huh. I didn't get that far. And I'm pretty sure that whatever it that is, it's illegal in Texas.
Re:Much more mathematical detail... (Score:5, Insightful)
String Theory (Score:5, Interesting)
Re:String Theory (Score:4, Informative)
"String theory" is actually a collection of several competing theories and this theory appears to be another version. I can't really say for sure as the presentation on the theory seemed to me to be rather limited.
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I think it is an alternative to string theory.
From http://www.physicsforums.com/showthread.php?t=313565 [physicsforums.com] :
Compared to string theory - much simpler and works in 3+1 dimensions
Compared to LQG - the classical limit is not a problem
Here's the actual article (Score:3, Informative)
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Bullshit.
I just pressed "Preview" on this comment and it took 18 seconds to display.
I'm not posting anonymously.
The second time pressing it takes 1 second.
ZZZTTT ! (Score:4, Informative)
it fits some observations better than Einstein's or Newton's solutions. It better predicts the movement of the planets (in an idealized case)
Oh. In an idealized case. Imaginary physics. Of course, in the actual case, it does not (it requires patching to allow for non-spherical planets).
At any rate, there are at present no known relativistic measurements that are not consistent with General Relativity, so I am not clear where the "better than" comes from.
And, from the standpoint of a General Relativist, the stubborn desire of the particle physicists to have a flat spacetime at high enough energies, no matter what, seems, well, quaint.
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It isn't the expectation of a flat space-time at quantum scales that is the problem, it is the infinities and negative probabilities that are the trouble. Relativity is wrong at some level; this much is pretty well established. The real tricky part is welding our understanding of space-time with quantum physics in a signle theory without breaking everything.
some modest hypotheses (Score:4, Funny)
2. I don't think time, as in "time lines" or some kind of unidirectional movement through a medium exists. Now exists, hypostatized out of a past (which stops existing when it stops being now) and which in turn hypostatizes the future (which does not exist.)
3. Electromagnetism is the dominant force in the heavens as it is on Earth.
4. Stars are organisms and they reproduce through fission.
5. Galaxies are powered by vast electric circuits; beads on a string.
Theory or Hypothesis? (Score:4, Interesting)
Sounds to me like this is just an hypothesis as there doesn't appear to much experimental evidence supporting it. This is an extraordinary claim and so need extraordinary proof.
And, the interchanging of hypothesis and theory by scientific magazines is a bad thing. If scientists, science fans, and science writers do not use the words correctly how are we to defend the difference when creationists come around misusing the words?
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The theory of special relativity and of general relativity existed before there was any experimental proof.
I think when you are dealing with theoretical physics, if you can get a mathematical model to "work," then it is a theory. Like String Theory.
Just wondering out loud... (Score:3, Interesting)
Sounds like this guy's saying "Let us assume the speed of light is not necessarily the fastest anything can travel. If we assume this, then..."
The reason for Einstein's initial assumption is that we have never to date observed anything which has moved faster than light. Then again, would we know such a thing if we observed it, and have we actively looked for such a thing? If so, how have we looked?
Re:Just wondering out loud... (Score:5, Informative)
Wrong.
Special relativity is built on two principles:
(actually, if you take Maxwell's equation into account, the first is just a special case of the second). Especially it does not postulate that there's nothing faster than light. Rather,
However, you can describe hypothetical faster-than-light particles in SRT (so-called tachyons; those cannot be decelerated to below the speed of light), and AFAIK there have been experiments to look for them. Note however that as soon as you add quantum mechanics to the picture, even with tachyons no information can be transmitted faster than light (local disturbances in he quantum tachyon field only propagate with light speed).
General relativity adds the equivalence principle (locally you cannot distinguish between gravitation and acceleration) and the demand of general covariance (the equations must look the same regardless of choice of coordinates, even if those don't correspond to an inertial system).
Re:Just wondering out loud... (Score:5, Informative)
Then we need a new theory.
Well, "the same in all systems" in the post above didn't refer to "at different places in the universe", but "as seen/described by different observers in the same part of the universe".
That doesn't mean we don't also assume that the laws of nature are always and everywhere the same. Indeed, that's basically always assumed.
By applying the laws we found locally to observations of distant objects, and seeing if they fit. For example, we can look at the spectra of distant stars and look if we get the same atomic spectral lines as on earth. This works great; so we know that atomic physics obviously works the same in distant stars. Also we can observe the 21cm hydrogen line everywhere in space, so atomic physics seems to apply also in between the stars.
Where we do have some problems is with large scale gravitation (what we describe with dark matter and dark energy). However, the local effects of those deviations are small enough that we couldn't measure them directly anyway, so it's also no evidence that the local laws of physics are different than the distant ones, even if those effects are to be described with modified theories.
No, it's much too small for that. To be an indication for different physics "outside" it would have to be such a large deviation that we would have to have detected the difference if it applied to Earth.
Re:Just wondering out loud... (Score:4, Informative)
Ow! (Score:4, Insightful)
Ow! My brain hurts.
Apparent contradiction (Score:3, Interesting)
From the linked article, it seems the theory both predicts the heat death of the universe (continued accelerated expansion) and that our universe started from a "Big Crunch" scenario (gravity had pulled everything back again). This seems quite strange (although of course nature can be quite strange at times). Anyone know this theory any better and can provide some enlightenment?
How about the Big Smack? (Score:3, Interesting)
Gosh darnit. Two guys I'd like to do my PhD under (Score:3, Funny)
I have a hypothesis about gravity. (Score:4, Funny)
My hypothesis about gravity:
Everything is growing. We can't see anything growing, because our rulers and tapemesures and everything is growing. That's gravity: Just the growing earth pushing against your growing feet. Gravity at a distance is just objects growing towards each others (the void doesn't grow). Come to think of it. It's probably a bad hypothesis. It couldn't explain a slingshot effect, could it? Nevermind.
But does it also predict (Score:4, Funny)
Looks like a step in the right direction (Score:3, Interesting)
Gia Dvali, a quantum gravity expert at CERN, remains cautious. A few years ago he tried a similar trick, breaking apart space and time in an attempt to explain dark energy. But he abandoned his model because it allowed information to be communicated faster than the speed of light.
How do we know for sure that it's impossible? How can we test against it to conclude it's definitely an impossibility? We surely haven't found any way to achieve that, but given that all theories are still in the balance, how do we know for sure there's no way we possibly could?
This being said, nice to see a theory that's more intuitive than usual, that attempts to explain dark matter and dark energy by revising how things work rather than claiming there's a bunch of invisible mysterious things at work, and that does so without adding a bucketload of new unperceptible dimensions and weird vibrating strings that no one can prove. Ah, and give an alternative to the ailing theory of Big Bang.
And nice to see that it took SciAm's commenters less time than Slashdot users to make the discussion drift into some crap about religion. Maybe we're not that bad after all.
Rather than viewing this as overturning Einstein (Score:3, Insightful)
Remember the saying that science proceeds by successive approximation to the truth.
YOU ARE ALL WRONG. (Score:3, Funny)
Re:Not again (Score:5, Insightful)
Behold, science.
The catch is, eventually one will be right, and explain things that are out of the scope of Einstein's theories or more accurately explain in-scope things.
Or do you believe we are at the pinnacle of the field, and can achieve no more?
Re:Not again (Score:5, Funny)
We have reached enlightenment. We shall now call ourselves Q.
(huuummmm)
Man this is dull.
Re:Not again (Score:5, Funny)
Re:Not again (Score:5, Funny)
Then I shall be Fah Q 2!
Re:Not again (Score:5, Funny)
Well Fah Q both then
Re: (Score:3, Funny)
To differentiate myself from the lot of you bores I shall take a first name: Fah. From this point on I am Fah Q! :)
Just curious, do you own a horse?...
Re:Not again (Score:5, Funny)
Re:Not again (Score:5, Funny)
Re:Not again (Score:5, Funny)
I believe they will all be right, but it will only be from the perspective of the observer/believer which is right at the moment. However when it isn't being observed it will be both right and wrong until observed again. Therefore there are multiple pinnacles and it won't matter which are right or highest. Just have your towel ready because on top of the pinnacle is a little man who is only going to apologize for the inconvenience.
Always have a towell ready.
Re:Not again (Score:4, Interesting)
There are really 42 quarks. [angryflower.com]The LHC should probably be able to test this... [angryflower.com]
(God but I love that guy's cartoons!)
Re: (Score:3, Insightful)
The catch is, eventually one will be right,
This is, perhaps, a minor quibble with wording. (Depending on what you meant.) But no, neither is likely to be right. One will be shown to be wrong before the other, however. Or, if you prefer, one will probably be more accurate.
Re:Correction: (Score:5, Funny)
Or maybe you actually meant the theory would be better than 'Reletivity'. That could work.
Re:Not again (Score:4, Funny)
It's always interesting how quick some people without deeper knowledge of the matter are with labeling something as nonsense.
I have 3 dark PhD's, and I say it's bunk!
Re:Not again (Score:5, Insightful)
Yeah: http://yfrog.com/b9sciencevsfaithbigp [yfrog.com]
This sentiment is rather old, I'm sure before and when Einstein came about, people were saying the same thing about Newtonian physics. Skepticism about new theories are fine, but I'm sure the science will come to a point where we do discover something better than Einstein's formulas in some areas.
BTW, my physics is really rusty, doesn't one of Einstein's equations devolve into a newtonian equation at slow speed? Which just shows that things are truly built on top of one another.
Re:Not again (Score:5, Insightful)
BTW, my physics is really rusty, doesn't one of Einstein's equations devolve into a newtonian equation at slow speed?
Wouldn't be correct if it didn't. Newton wasn't *wrong*, he just didn't specify the parts he couldn't see. Same with Einstein, same with this.
Re:Not again (Score:4, Insightful)
Re:Not again (Score:5, Interesting)
Recently, paradigms in physics have been interesting in this respect as the new perfectly subsume the prior in their limits. I am not sure that this is a tautology of science, but it is an elegant means of progression.
Re:Not again (Score:5, Informative)
Same thing in Quantum Mechanics. They devolve into classical equations, if you set Planck's Constant to 0.
Re: (Score:3, Funny)
Same as with the Highlander. But I digress.
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Yes, and our current problem in physics is that we have two forks of Newtonian Physics. In one branch, we fixed the description of gravitation, in the other branch we fixed the description of subatomic particles. Both branches are very successful in their respective area. Now we try to merge those branches, however it turns out that the patches are not compatible, and we don't know what is the right way to combine them.
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The difference between science and faith is whether the statement could possibly be disproved. If it can, it's science. If it can't, it's faith.
That's a tiny difference in length of description. But the difference between what can be disproved and what can't is a very big difference. While faith statements could be the most important if true, like a diety, afterlife, consequences of pure morals, without proof or disproof those statements are the most unreliable to be true.
Re: (Score:3, Interesting)
Religions, which is what you're talking about when you say faith, are software that runs in a cluster of human beings. They mutate all the time... you turn your head, there's another one popping up, the bastard stepchild of a few predecessors. Some religions will destroy the hardware they run on before they ever propagate. The Davidians, for example. Others will propagate through a population quickly, but lead that population to extinction in a few generations. A few will endure, supporting their popul
Re:Not again (Score:4, Insightful)
All faith is blind.
'Faith - Belief that does not rest on logical proof or material evidence.'
And just because some may swing one way or the other within either group doesn't show anything. At its root religions are unchanging, or at least the Judeo-Christian ones are meant to be. At sciences base we strive for changing, evolving viewpoints.
No, that is a stupid terrible meme. First off the axioms of science are things like 'a + b = b + a', compared to there is a God and history as described in a multiple 1000page book. Not the % of which is axiom, In fact the whole christian belief system IS a huge axiom, individuals get to add theories on top that's all.
As well, science is made of 'best guesses so far'. That 'so far' stipulation means you don't actually have faith in anything merely knowledge of a best guess. Scientists/Philosophers haven't proven with any great certainty that we can know anything so all we CAN do is make guesses. The only absolute proofs we make do use givens, so we can prove things withing certain constructs. Like, we can PROVE things in math, but it is an artificial device. That isn't the same as universal truths. All we get there are good guesses.
Do we act on those guesses? Certainly, much like you'd call a friend's cell before his house. You don't KNOW he is there, simply that is the best educated guess you can make at the moment. The idea that people EVER need to make a leap of faith is total BS.
Re: (Score:3, Insightful)
The problem with faith is when it becomes blind faith.
No, the problem with faith is that it is always blind. Faith is a strong belief in the absence of evidence, but without evidence, you are utterly and completely blind.
Faith will always be there for the things we do not have the tools to understand.
There are better words for the things we do not have the tools to understand. "Ignorance" is a pretty good one, for instance.
If you notice, there are "science" folk in here mocking this new theory because it contradicts the old one. Think about this next time you want to take a swing at someone who holds faith.
Criticizing new theories is part of what "science folk" do, you know.
Re:Not again (Score:4, Insightful)
Re:Not again (Score:5, Insightful)
Not so. You cannot prove that repeatedly making a measurement in the past is any indication that it will hold in the future. Pointing out that it's worked before is just begging the question, and therefore reproducing the results doesn't help, for it does not mean you'll reproduce the results *again*.
You *must* presuppose that the future is relevantly like the past for empiricism to have any meaning in any context; it's pretty much an irreducible problem.
With that said, such "faith" is, I would argue, essentially to daily living and doesn't really deserve to be categorized as "faith" except in the most pedantic of senses. Without acting under this presupposition, you cannot learn. Anything. I suspect that biologically this presupposition cannot be unlearned since it appears to be intrinsic to learning even in some of the stupider members of the animal kingdom.
Re:Not again (Score:5, Insightful)
"You cannot prove that repeatedly making a measurement in the past is any indication that it will hold in the future."
Flip side, you can't prove that it won't hold true in the future either. In essence, your argument is a case of argumentum ad ignorantiam.
The bottom line is that you're engaging in fancy footwork trying to get to him to use the word "faith", in which case you then have a basis for moving on to a discussion of "true faith", a belief in God or some such. Faith is belief without proof.
But... if you have proof then you don't need faith. Past personal observation, history, science, math, and orbital mechanics all say that the sun will come up tomorrow. Faith is not needed.
Re:Not again (Score:5, Insightful)
Belief without evidence is called blind faith, science rests on the faith that the universe is ultimately predictable and will continue to exist even if we don't (in other words it believes that the proverbial tree in a forest does indeed make a noise).
There is no way to "prove" that the universe behaves like this but rational people take it as an indisputable fact because the evidence of ones own perceptions is very difficult to ignore particularly when they match the perceptions of other humans. So yes, science is based on faith as is all knowledge that goes further than "I think therfore I am".
"The bottom line is that you're engaging in fancy footwork trying to get to him to use the word "faith"
No he is not, the "bottom line" is that basic scientific philosophy confuses the hell out of people who subscribe to the popular but incorrect notion that science is in the bussiness of "proof". We wouldn't even be having this discussion if epistemology [wikipedia.org] was taught in modern high schools.
Re: (Score:3, Interesting)
You *must* presuppose that the future is relevantly like the past for empiricism to have any meaning in any context; it's pretty much an irreducible problem.
Who must what?
That is, you--who who exist and are persistent in time with a unique personal identity and live in a causal world that is persistent in time and full of a diversity of phenomena that are identifiable by you and persistent in time--must, to engage in the act of disagreeing with the self-consistency and sturdiness of the logical foundations
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Yes, with science there is a certain amount of established expectation based on observation. Do something, see what happens, expec
Not faith - belief (Score:4, Informative)
You do NOT need faith to believe that the universe is anything. Ordered, structured, causal, etc. A good scientist believes these things because there is evidence of order, causality, etc.
To not have faith is to not believe in something for which there is no evidence.
One does not need faith to look forward to the future doing something chaotic because of the belief (through prior observation) that those kind of things (earth turning into a carnivore butterfly) just does not happen.
Science and faith are NOT intrinsically linked. Science and belief ARE. Science and faith are two completely separate things.
Re: (Score:3, Interesting)
BTW, my physics is really rusty, doesn't one of Einstein's equations devolve into a newtonian equation at slow speed? Which just shows that things are truly built on top of one another.
It's easy to get Newtonian physics from Relativity. The hard part was to get Relativity knowing just Newtonian physics. Ergo, things are not just built on top of one another, but it's more like building beneath of what you don't know.
Re:Not again (Score:5, Insightful)
This is healthy. Science can only progress if we accept that thinking outside the box is admissable. If the idea works ehen it will be testable.
Re:Not again (Score:5, Insightful)
Re:Not again (Score:5, Insightful)
Can you send me an example where Jesus accurately predicts known experimental results?
(I'm not sure if your stay on rejection was genuine or troll-bait, but it's caught momentum and I thought I'd provide an honest response rather than leave the question hanging.)
There's the golden rule, for starters. He didn't invent it, but he was instrumental in the widespread use of its positive statement ("Do unto others as you would have them do unto you" as opposed to "Do not to your neighbor what you would take ill from him"). And the result of following that rule, the rule of initiating kindness, you are statistically more likely to be treated kindly in return. Common sense and anecdotal evidence bear this out as well.
Then there's a bunch of other stuff he said, including things about the Kingdom of Heaven being here and now, forgiveness, faith, and love, that has unfortunately been so steadily downplayed and cloaked in tradition and dogma that it gets lost in the "war" to "win souls" for God. I think the historical Jesus would get along just fine with good-hearted atheists, Muslims, Hindus, Krishnas, Christians, Buddhists, and followers of most any other creed that you can imagine--and he probably had more in common with the Buddhists than we tend to think. He might not agree with all of the beliefs in those various systems, but he was more interested in disciples, people who would emulate his way of living, than converts to his religion, which didn't even exist during his lifetime. In other words, I think he'd be an excellent person to discuss philosophy and religion with, and he'd probably be the first to quell any budding flame wars.
This is of course only my understanding of Jesus. I've put a lot of thought and a decent amount of study into it, so I have a nuanced view not shared by most Christians, but I prefer to simply act in a manner I think he would approve of than to talk about it. It's more challenging and more effective to act, and I lack the agenda to convert people so dislike being perceived as having it. It is still disheartening to see his teachings rejected out-of-hand because of the centuries of stupid, un-Christlike actions of his followers, not to mention the (in my opinion) corruption of his words within the Bible. I hope to change that by trying to live up to the way I think he did. Even if most people who learn from me never find out my source, it is a good way to live.
It is also not a complete and consistent theory (Score:5, Insightful)
Horavec's formulation works for certain (perfectly spherical) cases of the stress-energy tensor, not in other cases. In fact it produces some wildly inaccurate results in more realistic cases. Nor is he the first to try this kind of thing. Still, it sounds interesting and further refinements could produce a fully consistent theory which can match observation. When and if that happens then it will be a really major advance. It certainly seems like we're edging closer to something.
Cows are fractal . . . (Score:3, Interesting)
Re:Oh no... (Score:5, Funny)
If you reverse the polarity, inject some chroniton particles, and rub Patrick Stewart's head for good luck, it'll still work.
Excellence: Biography of Petr Hoava (Score:4, Informative)
Yet, who is Petr Hoava? He maintains a Web page [berkeley.edu] that offers the following biography.
"Petr Horava received his Ph.D. in 1991 at the Institute of Physics of the Czech Academy of Sciences in Prague. He was awarded the Robert McCormick Research Fellowship at the Enrico Fermi Institute at the University of Chicago, worked as a Research Associate at Princeton University, and won a Sherman Fairchild Senior Research Fellowship at Caltech, before joining the New High Energy Theory Center at Rutgers University in 2000 as an Associate Professor. In 1997, he was awarded the Junior Prize of the Czech Learned Society, and in 1999 he appeared on the list of top three scientists of the Czech Republic of the 90's. He joined the Physics Department at UC Berkeley in 2001."
The liberation of Eastern Europe in 1989 has unleashed an intellectual force that will advance human knowledge by leaps and bounds. 2009 is the 20th anniversary of that liberation.
Buddha bless the Eastern Europeans.
Re:Excellence: Biography of Petr Hoava (Score:5, Funny)
Re: (Score:3, Informative)
Einstein was an Eastern European. As were most of the other scientists coming up with what Einstein brought together in Relativity. Soviet physicists were mostly Eastern European, and came up with quite a lot of advances in physics.
No he wasn't - Western Germany/Italy/Switzerland are hardly 'Eastern Europe'. Nor were the others: Poincaré (France), Planck (Germany), Bohr (Denmark), Lorenz (Netherlands), Schwarzschild (Germany), Lemaitre (Belgium)... (Not that Eastern Europeans weren't well represented in sciences, they just have very little to do with the early history of relativity.)
Re:Excellent! (Score:4, Interesting)
i read that some of the theory used math from helium super-fluids.
As I'm no math nerd, perhaps someone who is can explain why infinity is disallowed? I finally figured out why you can't divide by zero; 10/2=5, 5/2=2.5, but if you use numbers smaller than one it is reversed; 1/.5=2, 1/.05=20, so anything divided by zero would be infinity. Is the universe infinite? If so, how can it be studied mathematically?
I found this intrigueing:
I'm no physicist, but that occurred to me when I first herd of the big band theory. If so, would it bounce an infinite number of times?
Re:Excellent! (Score:4, Informative)
The problem isn't so much with the infinities, those are perfectly allowable in math and in physics.
The gravitational pull as you approach a black hole approaches infinity
The limit of the graph 1/x as x->0 is infinite.
The problem is that other theories of quantum gravity result in infinities where we do NOT observe these infinities to exist. As a simple example (quantum mechanics is beyond me, but this gives the flavor), one of the classic theories of electrostatics states that the electric field of a point charge is inversely proportionate to the square of the distance from that charge.
However, from a quantum-mechanical standpoint, and electron has no size...it is a point particle.
This causes an issue if we take both of these results together...as you approach an electron, the electric field should approach infinity.
We know that this doesn't happen, so one of the two theories must be incomplete.
Re: (Score:3, Interesting)
Uh, because that would be incorrect? One infinity is not necessarily equal to another, not to mention infinity isn't a number, nor is it a constant or variable. It's a concept, and you can't add, subtract, multiple or divide concepts, so you can't do anything like that to infinity.
There's a calculus theory whose name escapes me that allows you to solve for what X/Y equals when X and Y are both infinite functions using their derivatives. I remember taking tests where we basically had lim (x->oo, y->oo)
Re: (Score:3, Informative)
No, but I did get a Bachelor's degree in math what seems like an infinity ago....here's what I remember.
You can add infinity to the number system just fine. In doing so you would want to preserve rules of the standard number system (e.g. a+b = b+a, (ab)c = a(bc)).
This has already been done. Hyperreal numbers make up a branch of mathematics called nonstandard analysis.
Nonstandard analysis has been used occasionally in studies of quantum physics, but it doesn't help with th
Re: (Score:3, Funny)
In my home reality, we had machines to jump into parallel dimensions, but baguettes were outlawed when Palin took the U.S. presidency and invaded France.
I hadn't heard of the croaking bird dimension though. I'll have to visit.
Re:Spooky action at a distance? (Score:5, Interesting)
Spooky action at a distance doesn't need any finagling to get around lightspeed, because spooky action at a distance doesn't involve any communication. It's already compatible with general relativity (at least, insofar as any quantum theory is compatible with relativity).
A flawed, but illustrative example that should explain why this is so: imagine you have a friend who is flipping a coin... if it comes up heads, he writes an X on two sheets of paper, if it comes up tails, he writes a checkmark on both instead. Both are immediately sealed inside envelopes and mailed to opposites sides of the planet. If you open one letter and see an X, you instantly know the other has an X also. That doesn't require any communication.
A slightly less flawed, and still illustrative extension: Now instead of a coin flip, you have a machine do it based on the decay of a mass of cesium, and you have a perfect envelope which protects against quantum decoherence. The same situation applies, as soon as you open one envelope you know what is contained in the other. The only difference this time is that the letters were entangled and in a superposition of states. However, it's the same mechanism, and no communication is required.
Re: (Score:3, Funny)
The Jatravartid People of Viltvodle Six firmly believe that the entire universe was sneezed out of the nose of a being called The Great Green Arkleseizure. They live in perpetual fear of the time they call The Coming Of The Great White Handkerchief.