Was Einstein wrong and newton right?

[RurouniZakku]

I came across this article and was wondering should we believe this or is it all a bunch of mistakes. www.scientificamerican.com/article.cfm?id=splitting-time-from-space

It's interesting to think about it, forget the big bang if this guys right, then the worlds going to end faster than if it was the big bang.  

[Layra-chan]

That certainly isn't the first theory to try to separate time and space, although it does so differently from other modern theories. Furthermore, it doesn't go back to Newton; it merely goes back to special relativity and then heads in a completely different (and very non-Newtonian) direction for gravity.
The separation of time and space is actually a very common thread in most modern quantum gravity attempts. Quantum field theory states that under certain transformations, the observable portion of a physical system shouldn't change, just as looking at an object from a different viewpoint doesn't change what the object is.
Unfortunately, time in the general relativistic sense happens to be one of those transformations. In other words, in the naive way of quantizing general relativity, time doesn't pass in an observable fashion.
So one of the big problems in quantum gravity is how to get an observable time coordinate out of your system. This is done in various ways, sometimes by significant changes in the underlying geometry of space, sometimes just by asserting that time happens and building from there. It sounds like Horava's going the second route.

From the sound of it, Horava's theory is even less elegant than string theory. If it gets rid of the infinities, and does so in a legitimate way (renormalization is a farce) then perhaps it will have some merit, but at the moment, it sounds horrendous.  

[Mecill]

So this theory is still saying special relativity is right, it's just general relativity that they're replacing in attempt to make a better quantum field theory...?

Is the idea that all inertial frames are equivalent part of special or general relativity? Isn't the time included in that also? So if it's a part of special relativity I don't understand how they can keep that but modify general relativity.

My understanding is that general relativity makes use of special relativity along with some geometry and stuff to get a better theory of gravity... I guess the geometry is considering "space-time" and using tensors or something but it's still a bit unclear to me how this works. ^_^

In any case, classical Newtonian theory doesn't describe things very accurately on its own, so yeah, its a little misleading to say they're going back to it... Though something could still appear to follow Newtonian gravity but be non-classical (have quantum behavior)?

Also in regards to cosmology why does this mean the life of the universe will be shorter??? These kind of articles bug me because to me it sounds like they just throw some stuff together and make a drastic prediction that hasn't been confirmed, but people eat this stuff up...  

[Layra-chan]

I think they're just getting rid of general relativity. Inertial frames being equivalent is special relativity; general relativity is what you get when you wander away from inertial frames.
It is fully possible to use just special relativity without general relativity; current quantum field theory does this. It's only in the presence of Einsteinian gravitation that general relativity comes into play. In a universe where the fabric of spacetime isn't affected by the presence of energy/matter, the only relativity is special relativity.

Anyway, magazine articles aren't to be trusted. They exist to catch people's attention, not to inform. I'd recommend finding the original paper by Horava and reading that, although of course that probably requires a lot of advanced physics and mathematics background.  

[Mecill]

Oh! Maybe I will start trying to read some papers... This must be why they say such things are "advertisements about science" though. Sorry if this is slightly off topic, but do you follow any online sources of physics news that you find informative?  

[RurouniZakku]

Anyway, magazine articles aren't to be trusted. They exist to catch people's attention, not to inform. I'd recommend finding the original paper by Horava and reading that, although of course that probably requires a lot of advanced physics and mathematics background.

If you find it, please post it, I want to read it.  

[Layra-chan]

I don't follow physics news or math news (or science news at all). The news is rarely informative or correct, what with everyone in the chain trying to re/mis-interpret the results for the biggest "wow" factor. This requires reformulating the initial question into something the public can understand and then trying to connect the results to something the public cares about, neither of which are conducive to actually explaining the findings.
Similar things happen in pop-sci books; everything is dumbed down and rescaled to human interest, and as a result everything of worth is stripped away.
Physics is at a point where it is impossible to be understood by laymen; this is not a bad thing. In fact, it is a good thing. It means that physics is mature, that it isn't a child's pastime anymore. Of course, I might be biased as mathematics has been incomprehensible for centuries. But what laymen can understand and care about is terribly restrictive and looks absolutely nothing like our universe, and that means that science news for laymen looks nothing like science.
So don't read science news, and don't read pop-sci. All of that is trash.

Instead, the best thing to do is to talk to professors and researchers and read journals and papers. Well, of course, first you need to get the prerequisite math and physics down, otherwise everything you read will be nonsense. But go straight to the source. Try to find math and science journals in your libraries, or online; those will contain actual results in their pure form, not watered down and filtered by pandering to the public. This sounds like a lot of work, and it is, but that's the only way you'll get anywhere.

On that note, I looked up Horava's work on arXiv. I'm guessing the article is referring to this paper. I'm going to read it over the weekend, maybe see if I can puzzle through it, although my QFT is weak.  

[Mecill]

Ok, Thanks very much for your advice and finding that paper! I'm going to try to read a bit of it on the weekend also...

Though I disagree with what you're saying about physics being impossible for the layperson to understand. Sure they're never going to understand advanced theoretical physics, but as technology continues to progress I think it's more important to teach people physics at a higher level. Science in some places has become elitist and perhaps it's idealism to think there won't always be some element of that but pop-physics is good for the public and also has motivated me in the past. I'm just at the stage where I'm realizing it's not good for research. Which makes perfect sense.

But yeah, thanks, because saying it your way is actually better motivation. mrgreen  

[Layra-chan]

There's a difference between needing laymen to understand physics, and making physics understandable to laymen. What we need isn't for physics to reworded so that laymen will understand, but rather for laymen to be educated so that they can understand physics. The standard for laymen needs to be raised, not the standard for physics lowered.

I understand that pop-sci gets people interested in subjects. Actually, no, that statement is blatantly false. The social sciences and interest in such suffers terribly from popular articles, because everyone says "I can do that" or "I could have told you that" and dismisses it as worthless posturing. In general, science gets so distorted by pop-sci that it comes off as either meaningless nonsense (e.g. quantum mechanics) or gets twisted around until it is meaningless (e.g. anything to do with genetics).
Does it generate interest in particular subjects? Perhaps. But it's a shallow interest, and it's a deluded interest, and while it does provide motivation to a select few, for the majority it just misinforms, and I'm not sure that the motivation provided wouldn't be encountered more purely via other channels.  

[VorpalNeko]

Yeah, I'm somewhat following this. The news article itself is overblown as usual. The full list of papers alluded to:
[1] Hořava, Petr. Quantum gravity at a Lifshitz point. Phys. Rev. D 79, 084008 (2009). arXiv:0901.3775
[2] Brandenberger, Robert. Matter bounce in Hořava-Lifshitz cosmology. Phys. Rev. D 80, 043516 (2009). arXiv:0904.2835
[3] Mukohyama, Shinji. Dark matter as integration constant in Hořava-Lifshitz gravity. Phys. Rev. D 80, 064005 (2009). arXiv:0905.3563
[4] D. Blas et al. On the extra mode and inconsistency of Hořava gravity. JHEP10(2009)029. arXiv:0906.3046.

The biggest flaw of the whole thing is it the low-energy limit doesn't actually tend to GTR as advertised.
[5] Afshordi, Niayesh. Cuscuton and low-energy limit of Hořava-Lifshitz gravity. Phys. Rev. D 80, 081502 (2009). arXiv:0907.5201.
According to which, the low-energy limit is that of gravity coupled to a kinetic quintessence field with an infinite speed of sound. The Cuscuton field is supposed to be non-dynamical and parasitic on the dynamics of whatever field it couples to (hence the name). But it's worse that it sounds; a uniform advancement of time in the preferred frame messes things up.

So no, Newton was most definitely wrong.  

[RurouniZakku]

thanks for the links  

[Mecill]

Layra-chan

There's a difference between needing laymen to understand physics, and making physics understandable to laymen. What we need isn't for physics to reworded so that laymen will understand, but rather for laymen to be educated so that they can understand physics. The standard for laymen needs to be raised, not the standard for physics lowered.

I understand that pop-sci gets people interested in subjects. Actually, no, that statement is blatantly false. The social sciences and interest in such suffers terribly from popular articles, because everyone says "I can do that" or "I could have told you that" and dismisses it as worthless posturing. In general, science gets so distorted by pop-sci that it comes off as either meaningless nonsense (e.g. quantum mechanics) or gets twisted around until it is meaningless (e.g. anything to do with genetics).
Does it generate interest in particular subjects? Perhaps. But it's a shallow interest, and it's a deluded interest, and while it does provide motivation to a select few, for the majority it just misinforms, and I'm not sure that the motivation provided wouldn't be encountered more purely via other channels.

The problem with the social sciences is also with our culture, not with the subject. Academically, social sciences are fine other than that there is a lot of posturing by undereducated people. They deal with subjects that cannot be dealt with theoretically rigorously. That can happen in physical sciences too. Also, I think it's possible that physics and math could be optimized in some ways by considering things from a layperson's -in other words more 'first principles'- perspective. Also, advertising can be valuable artistically and for optimizing learning methods. For example, if a website is more aesthetically pleasing it is easier to gain information from it. Advertising is kind of similar but on a much lower level. The reason people get misinformed is that they simply do not care enough about the subject to research in detail, but if presented in a way that it is easy to get correct information from immediately they can still learn something. However, this is a slippery slope since if our culture becomes so ADD that we have to have everything presented in such a way, less people will be able to do traditional theoretical research. But this has already happened if you compare the science and math of previous times to today's science.

/end of long spiel XD  

[RurouniZakku]

for research, you can just get books on the particular area of physics or any other math or science. I started learning physics because I read a physics of the impossible, and understood most of it. His books aren't only for physicists, most layman can understand how he does, especially sci-fi geeks.  

[Mecill]

Yeah, the difficulty with using books for lay people is that it takes a lot of dedication and time to get through the more advanced topics using proper research procedure. But it can be done with patience. One of the most valuable things one of my professors told me is that it is good to read books at all levels - ones that are easier than your level and ones that are harder.  

[Mecill]

Actually, for me it's like a puzzle to translate what those articles are saying into actual math. However, I think Layra is suggesting perhaps if I spent the time studying math instead I would have made more progress. However, sometimes I have felt the choice is between reading lite math or no math. The situation was that I reached the place where my theoretical math training ended. And then wanted to do physics. When that happens to many people they decide to become experimental physicists or astronomers, chemists, engineers, and they rely on a slightly different skill set. However, I missed the theory which is why I want to go back to studying it again.