The age of the universe is obtained from an analysis of the background radiation and all observers analyzing the data would obtain the same result (i.e. this is not a "special age" with respect to the earth's frame). Different observers, present at the Big Bang, would measure different "ages of the universe" — defined as elapsed time since the Big Bang according to their own clocks — depending on their state of motion.
However, in homogeneous/isotropic spacetimes, there is a preferred class of observed who singles out a unique "cosmological age" that everyone can agree is unique: those are the observes who view the universe as isotropic, or are "at rest with respect to the cosmic background radiation" (loosely speaking). The Earth is nearly such an observer (to within 0.2% of c).
But as I said above, there certainly are classes of observers who would have measured 6000 years since the Big Bang, according to their own clocks. (The Earth is not one of them.)
Unfortunately, most of what the parent post said is an incorrect application of special relativity. No, what the GP said holds in general relativity as well.
The twin "paradox" ("return to Earth...") has to do with switching reference frames, not time dilation. It has to do with both.
Also, it is spurious to apply special relativity outside of space-time. The GP did not apply special relativity "outside of space-time".
I wish I could use a single measurement like microwave radiation to tell me that nothing at all existed before 13.73 billion years ago. Why? Cosmologists don't do that. They don't even conclude that on the basis of many measurements. Is there some reason why you would prefer to reach such a conclusion?
I've heard these sweeping statements before, can anyone point out a reasonably accessible proof that overcomes basic statistical counterarguments? What basic statistical counterargument do you think you can make? You can't make any unless you know what the error bars are, which you've just admitted you don't.
Anyway, you can't prove anything in science, so I don't know what kind of a "proof" you're looking for. You can merely show that the data are highly consistent with one set of assumptions, and inconsistent with another. But it's always possible that there are a third set of assumptions with which the data are also consistent. Possible, however, does not mean plausible; as more kinds of data accumulate, it grows harder to construct alternate theories that are consistent with a growing body of evidence. Which is the point of science.
I can infer some interesting characteristics about gravity by splashing paint on my wall and studying the results from across the room, but I don't really have enough data to overcome a host of other contributing factors... The WMAP data set is quite a lot of data, actually, and "a host of other contributing factors" are studied in this analysis.
In particular, see Section 5.2.4 and Figure 19 of this paper for the assumptions made and factors considered in this conclusion.
The results in this story are based on a picture of the cosmic background radiation throughout the universe at its largest scale. That picture may be found in the NASA link in the story summary. Galaxies are invisibly small at this scale.
I did not say that MOND requires curved space. Just that it could explain MOND. There are curved spacetime theories of MOND, but their existence does not follow from what you say below.
Mass curves space-time and this curvature exerts a force, we know as gravitational force. If the space-time that makes up universe is itself curved say because of the expansion, then that curvature will itself create a force. Which will manifest itself as a force occurring without any matter. Not necessarily. Take general relativity without a cosmological constant. It admits curved, expanding spacetimes, but it can't replace dark matter. You have to make more radical changes to the dynamics of spacetime to do that. (In TeVeS theory, you need to have extra scalar and vector fields in addition to the usual tensor field of gravity.)
This force will tend to force objects into rotational motion. That doesn't follow, and indeed, is unlikely assuming local isotropy in the field equations.
The force will be negligible near large masses, as the gravitational force will dominate, That doesn't follow either, but possible if you're assuming the dynamics are some higher-order correction to GR.
You are speculating a lot about how curved spacetime can substitute for dark matter, but when you get down to details, it turns out to be quite difficult to construct a theory of gravity which can actually do so. It is impossible in general relativity itself, and modifications to GR like TeVeS are rather ad-hoc and, as far as I have seen, even more difficult to constrain observationally than dark matter.
The evidence of Bullet Cluster is a mixed bag. It does show that DM exists, in what form we don't know. We can't take WIMP's to be a given. We can't take anything as a given, but nobody's ever found another way to explain the observations, so WIMPs are likely.
Bullet Cluster also shows that the matter is moving faster than what can be achieved with normal Newtonian Gravitational force, indicating either a new force exclusively between DM particles or MOND. If you're saying that the Bullet Cluster observations are incompatible with dark matter + Newtonian gravity, I would like to see a citation for that. I've not seen any publications which reach that conclusion.
MONDian's are saying that neutrinos may provide enough DM, I really doubt that. They're too light: the move too fast to explain structure formation, and they don't have enough total mass to explain any significant portion of the rotation curves, or cosmology.
but maybe there are more forms of DM. There could be several forms of DM... plus modified gravity as well.
for the fact that MOND gives good results. But MOND doesn't give good results, except for galactic rotation curves, which are by far not the only evidence for dark matter.
DM at galactic scale would be perfectly fine if we did not have MOND work so well. DM at galactic scale is still perfectly fine, regardless of the existence of MOND or any other theory. Whether theory Y also explains observations has nothing to do with how well theory X explains those observations. (Well, unless you propose they're both true, instead of being competing.)
If all we had were galactic rotation curves, then DM and MOND would both be fine. Of course, we have more than that.
MOND and DM can both be true. Yes. But you can't have MOND explain galactic rotation curves and have dark matter explain everything else; if dark matter exists, it would have a major influence on rotation curves as well. In fact, in order to fit all of the non-rotation curve observations, it very likely has the dominant influence. (e.g., with the amount of dark matter necessary to explain the Bullet Cluster, this implies large influence on galactic rotation curves.)
I suspect that DM could be spread out nearly uniformly. That would be distinctly incompatible with observations.
The density might not be sufficient to produce much gravitational effect at galactic scales, but at larger scales, it may produce a large observable effect. That's not really possible; given say, WIMPs, it pretty much has to cluster gravitationally at galactic scales. And we know of examples of phenomena even at galactic scales which dark matter can explain but MOND can't (like the aforementioned Bullet Cluster). Dark matter is significant to galaxies both theoretically and observationally.
MOND can be explained very easily by GR, if the universe is curved. No, it can't. MOND is directly inconsistent with GR, due to its preferred acceleration scale. GR has Newtonian dynamics as its weak field limit, not Modified Newtonian dynamics. To produce a relativistic theory of MOND, you need to modify GR just as MOND modifies Newton; Bekenstein's TeVeS theory is one example.
The problem is that flatness is considered a settled question. Observationally, space is close to flat on cosmological scales. (Spacetime, of course, is not.) I don't know why you think MOND requires a curved space.
I like the Neptune-Mercury analogy a lot and use it myself.
Another analogy for dark matter is the neutrino: it was an invisible, virtually non-interacting particle introduced purely to maintain the internal consistency of the known laws of physics (the conservation laws). It was 12 years before they were actually discovered, since they interact so weakly. Dark matter also interacts weakly, but is thought to be much more massive than a neutrino, so it's difficult to produce in a particle accelerator.
Just the time dimension. You're proposing extra spatial dimensins, which is not something that "we had already accepted". String theorists like extra dimensions, but there's no evidence of them, and string theorists aren't the whole physics community. Plus, not even string theorists have managed to do what you insist is "radically simple": produce a dark matter equivalent using only the structure of higher-dimensional spacetime. Believe me, if string theory had a simple, workable alternative to dark matter, string theorists would be shouting it from the rooftops.
The usual way in which string theorists incorporate dark matter is to come up with a string vibrational mode that simulates... you guessed it... a new kind of invisible particle. In other words, string theory gives more candidates for dark matter.
There are probably brane solutions too, but you can think of branes as dark matter as well... albeit not matter made of particles.
Actually, it seems to me that the universe expanding completely uniformly in higher dimensions than what is visible would still explain all of the non-uniform expansion that dark matter was apparently invented to explain. We don't really observe non-uniform expansion... we do see random inhomogeneities left over in the current distribution of cosmic background radiation and galaxies, thought to be partly due to inflation and partly to dark matter.
Adding higher dimensions isn't going to explain that unless you postulate randomly lumpy extra dimensions; otherwise, smooth extra dimensions aren't going to project down to something random in lower dimensions.
And it's not just the expansion of space that you have to explain. It's also the orbits of stars in galaxies, and numerous other observations.
It baffles me as to why they would invent the notion of something invisible to explain anomalous observations instead of going with a no less workable and radically simpler theory. Easy for you to say. Why don't you try actually writing down a higher dimensional field theory which can explain observations of the cosmic background radiation, early universe structure formation, galactic rotation curves, galactic cluster interactions, galaxy collisions like the Bullet Cluster, etc.?
I think you will find that what you get is not "simple" (if you get anything at all, which I doubt), and almost certainly not simpler than just postulating the existence of a new kind of particle (several types of which have are already suggested from existing paricle theories for independent reasons).
And how is inventing invisible extra dimensions so superior to inventing invisible extra particles, anyway?
So far I have said anything about "what you have said" that wasn't true.
Wrong.
As I requested in the last post, please, quote me where I've insisted that "only science be done in the way I approve, on the topics I approve".
Otherwise, admit you're lying about what I have or have not "insisted".
Note: pointing out that claim X is wrong is not "insisting that science can only be done in way Y on topic Z".
Your right that I am biased. I consider it a side effect of paying attention and troll like you walking the forums to snidely correct anyone who isn't stepping in tow with your favorite position.
There you go with your prejudices again. I'm correcting people who are WRONG, on a topic I happen to know something about. Which you are. Repeatedly. Despite careful correction. If you want to present a CORRECT scientific argument in favor of your position, feel free.
And instead of taking the problem up with them, you seem content attempting to attack anyone repeating it.
Who said I'm not taking it up with them? If someone posts an argument here, I'll address it. You seem content with merely repeating other people's conclusions without even giving their arguments, and then whining about agendas when you're called on it.
How many times have you insisted in this thread that "other people" have found "alternate solutions" to the "CO2 problem", without citing any names, arguments, logic, or data? And you have the gall to accuse me of being a troll?
How about this: you drop all your paranoid bullshit about scams and political agendas and censoring the heretics, I'll stop calling you politically prejudiced, and we can talk science?
I don't think I can make one comment about the subject without you popping in to make sure everyone believe the way you do and that everyone know your way is the one true way.
Stop making false claims and people will stop correcting you. Why do you think you can post things which are wrong and expect not to be criticized for it? This is a discussion forum, not a "post whatever unfounded opinion I feel like and be immune from facts or logic" forum.
I said it doesn't have the effect being claimed and people are showing the problem is elsewhere.
And here you've given not a single argument supporting such an assertion. Curious, how devoid of science your posts on scientific topics actually are.
That's what I am saying, in order for 30% of a temperature increase to cause 70%, we would be on the other side of the curve.
No, you totally missed the point.
You are attempting to argue that ANY positive feedback from water vapor will lead to a runaway greenhouse effect: your argument IGNORES the location of the Earth's atmosphere with respect to the saturation curve. But in reality, it depends on where you are with respect to it: on one side, feedback is self-limiting, and on the other it's runaway. Thermodynamically, the ocean will generally re-equilibrate at a new, higher temperature, with the difference proportional to the water vapor feedback factor.
It's possible with very large amounts of warming for the Earth to cross the curve and inevitably run away, as the ocean becomes permanently out of equilibrium and evaporates away. But this has not happened at any time in the Earth's history, even when the Earth was warmer than it is today: you need a much larger warming than that. (I'd have to consult the curve to work out how much warming it does take, but I'm away at a workshop for several weeks and don't have any of my textbooks with me. In the meantime, you could try a Google Scholar search on "earth runaway greenhouse" and see if that turns up the calculation.)
Obviously that didn't happen so it isn't likely that Co2 was the cause of the increase.
This conclusion doesn't even follow from your own mistaken argument, let alone from a
Yeah, don't try playing the condescension card. You don't know what the hell you're talking about.
Your image isn't detailed enough to discern a two year climate decrease, and ignores a decade of available data since 1998. Uh, no.
1. The GISTEMP record contains detailed monthly data. If you want to see a statistical analysis of it, see this companion article to the other one I linked. 2. There's not really any such thing as a "two year climate decrease" (or increase); given the observed interannual variability, it is statistically impossible to define climate trends over a period that short. (And why would a 2-year decrease matter anyway? Global warming doesn't predict that every year is monotonically warmer than the last.) 3. The GISTEMP record I linked clearly includes data up to 2007.
Sources indicating that global warming ceased in 1998 are, in part, The first link includes no data, figures, or statistical analysis.
Ditto, the second link.
Ditto the third link. It doesn't give any evidence at all that global warming ceased in 1998, it just makes an uncited reference to "a study" in the first sentence, and the rest of the article does not analyze the post-1998 warming trend.
Keep up the Googling, man. You might learn something someday.
And your insistence that only the science done in the way you approve and on the topics you approve of doesn't either. Once again, you're blatantly lying about what I've said. You have an enormous investment in portraying anyone you disagree with as biased, when you're the one who is severely prejudiced.
Please, quote me where I've insisted that "only science be done in the way I approve, on the topics I approve".
First, this has nothing to do with my political prejudices. Of course it does. You don't like the political implications, and therefore you refuse to understand the science.
SO I forgot to drop the 00 when making it a percentage. That's not the only number you've gotten wrong by orders of magnitude; you did the same thing in the post to which I originally implied. Not surprising coming from someone who is uninterested in and ignorant of the actual science.
It is still an outrageous claim. And there you go repeating the same error a THIRD time. You're truly ineducable.
Once again: the fact that CO2 is a small amount of the atmosphere does not imply that it has negligible effect on the climate.
And no, anthropogenic CO2 is not.01% of the atmosphere. Yes, it is.
While it is true that the increase is around 100 ppm (parts per million for those not in with the lingo) which seems to fluctuate 5 to 10 ppm depending on the source, not all of that is anthropogenic CO2, a good portion is released from natural syncs like the ocean and thawed permafrost lands that is attributed to the so called warming. No, the 100 ppm accumulation from pre-industrial times is due to anthropogenic sources. Natural variability is much smaller than that, on the order of a few ppm.
Or rather, more precisely: natural sources of CO2 are larger than anthropogenic sources, but until recently they were closely balanced by natural sinks of nearly equal magnitude. It's only in industrial times that additional anthropogenic sources have overweighed the natural sinks, leading to a 100 ppm accumulation of CO2 (from natural and anthropogenic sources) that would not have accumulated in the absence of anthropogenic activity.
The ocean is a net sink for CO2, not a source, by the way. And thawing permafrost has not yet become a major source of CO2, although it could become one (as well as, perhaps more importantly, a methane source) in the future when more of it thaws.
An interesting fact here is that water vapor increases have already been attributed to 70% of the warming in Europe I already pointed out in my last response that you're confused about the study, and I even linked to the study in question! It does not attribute 70% of the European warming to natural sources! It links it to increased water vapor content WHICH IS DUE TO INCREASED CO2: it is a feedback of the CO2 greenhouse effect. This is a PREDICTION of the greenhouse effect, not a refutation of it!
Why do you keep citing a study whose conclusions refute the point you're trying to make? Have you even read the abstract?
So tell me, how is 30% more warming supposed to increase water vapor enugh for it to increase warming another 70% It would appear that you would have a runaway process that wouldn't stop if that was possible. The system equilibrates at a new humidity and temperature; it doesn't produce a runaway greenhouse effect unless you're on the wrong side of the saturation curve, like Venus is. You can see nice phase diagrams of this situation in David Archer's lay book on climate.
Google "global warming ceased in 1998." You'll find yourself proven mistaken. Hardly. I'm well familiar with the GISTEMP and HADCRUT3 datasets. They indicate no such thing. Hell, just look at the data. For a detailed statistical discussion, try here.
A quick Google search on "global cooling" will also display predictions of global cooling from both former anthropogenic global warming scientists, and their opponents, and for a few decades at the least, not a few years. We were talking about predictions of future cooling due to solar trends, not past predictions of cooling based on industrial aerosol emissions. Perhaps you should get your climate science from something meatier than a "quick Google search". You might give the impression that you know what you're talking about then.
The majority of the global warming that occurred in the 20th century was pre-1950, before widespread global industrialization. No, the 1900-1950 warming is about equal to the 1950-2000 warming (about 0.4 C each). (The latter would have been larger if not for the increased industrial aerosol emissions.)
Then the last quarter of the 20th century experienced mild global warming, which ceased in 1998. The warming did not cease in 1998, and the last quarter of the 20th century exhibited faster warming than any of the three previous quarters.
Now we are seeing predictions of global cooling, due to solar variability. No, on decadal time scales, CO2 forcing is likely to still outweigh solar effects; we might see slower warming, but not cooling. I don't know who you think is predicting global cooling due to the Sun, on anything longer than a few year timescale.
Ans as I have explained in the past, there are other people who have other ideas about Co2 and it's importance in the manufactured crisis of global warming. Your paranoid conspiracy theories have nothing to do with the science.
I have made the judgment that the process has been overrun by politics and if you can't understand that your insistence of their being one true way with all other research needing to stop now Stop putting words in my mouth. I'm saying that the evidence strongly supports CO2 as a dominant source of warming since the late 20th century. Nonsense about "one true way" and censoring research is your paranoid fantasy, not anything I said. It's clear that you've allowed your political prejudices to blind you to the point that you cannot honestly evaluate any science which supports AGW.
Now the question remains, is a the increase in something that is less then.0001% of the atmosphere's makeup? You seem fixated on small numbers; as I just explained to you (again), raw numerical size is not the relevant physical quantity here. (Not to mention the fact that anthropogenic CO2 is 0.01% of the atmosphere, not 0.0001%.)
And is this true considering that about 70% of th warming experienced in Europe is already being attributed to water vapor. The water vapor increase is a FEEDBACK produced by the anthropogenic greenhouse forcing; without warming induced by CO2 (or some other forcing), the water vapor wouldn't increase. Read the paper; it does not support the conclusion you're trying to draw (namely, that CO2 is of minor importance to the observed warming).
Others are working on the problem and they seem to have found other answers that don't fit the Co2 models being pushed forward. Yeah, right. Funny how every time you're pushed on the science, the "other answers" you provide come up lacking.
And yes the amount of Co2 being emitted unnaturally by humans is less then.0001% of the total green house gases. And yes, you heard that correctly, less then 1/1000 or 1 percent of the total greenhouse gases in our atmosphere at any given time. The most abundant greenhouse gas is water vapor, with an average concentration of about 0.25% by volume, or 2500 ppmv. The amount of CO2 emitted by humans over the last 150 years is about 100 ppmv (280 to 380 ppmv, a ~35% increase). So the ratio is only a factor or 25. (It would be more accurate to compare greenhouse potentials and not straight concentrations.)
However, as I've explained to you in the past, the relative concentration of greenhouse gases is not really the important issue. What matters is the change in greenhouse effect above the natural baseline. The natural greenhouse effect is something like 30 degrees C. Anthropogenic CO2 has, so far, added less than 1 C to that. The natural baseline is much larger than the anthropogenic contribution, because there are more natural greenhouse gases than anthropogenic. But the anthropogenic GHGs are still important: 1 C matters, climatically speaking. And projected CO2 emissions are likely to add several more degrees on top of that, which is the point.
The polluting power plant does have an incentive to reduce their emissions, because the total number of emissions credits is capped at some finite number (and the cap can even decrease over time, applying increasing pressure to the plants).
If plants want to pollute a lot, they can't collectively buy more credits than exist on the market, because they're finite. The limited supply drives up the price of the credits, and at some point it becomes more cost effective for an individual plant to simply reduce its emissions than to purchase emission credits. (Where that point is depends on how much the plant emits.)
When the SO2 emissions market was implemented in the U.S., the average per-plant emissions did go down. (I just went to an economics talk on this a few days ago.)
This was the subject of a short story by Greg Egan, entitled "The Moat". In it, it is discovered that an unknown group of people are genetically engineering themselves to have different DNA bases, presumably so as to be immune to all viruses. He uses the concept again in his novel Distress.
It seems that you're looking at acupuncture and determining its effectiveness based on whether or not it can treat diseases.
The original poster claimed that it was an approved treatment for several "ailments", which I interpreted to mean "diseases". I pointed out that it has not been shown to actually treat any diseases.
Furthermore, I was mainly talking not about diseases, but about pain relief, since that is the only place where acupuncture has ever shown any efficacy.
If you want to look at it from a preventive standpoint, you can, but:
Acupuncture is used to stimulate circulation in the body.
There is no evidence that it actually does so.
According to the "eastern" view of medicine, disease comes from stagnation in organs and meridians.
There is no evidence of this either (whatever "stagnation" is supposed to mean anyway), and in fact the meridian theory is demonstrably wrong when applied to pain relief (an area where acupuncturists claim that the treatment outcome is governed by meridian theory).
The big difference between "western" and "eastern" philosophies is that in the Western world we work ourselves to death and then try to deal with the effects of the diseases that develop. In the Eastern world they try to prevent the conditions that lead to diseases in the first place.
This is propaganda that one often hears in order to increase sympathy towards bogus methodologies with no physiological basis or empirical support.
(The logic goes like this: "Western medicine has bad philosophy X. I have good philosophy not-X. [Here comes the logical leap]. Therefore my treatment Y is superior to Western treatment Z." As in... "Your doctor doesn't only cares about treating symptoms. I care about preventing the problem in the first place, and your whole healthy lifestyle. Therefore, try my snake oil!" There's a big gap there.)
In reality, both Western and Eastern medicine are concerned with preventive as well as curative health. But even if I took your claim at face value, it's still irrelevant to the issue at hand: the positions of Western and Eastern medicine on preventive medicine may be interesting, but the real question is what treatments actually prevent disease, and what evidence supports those claims. It doesn't matter if Eastern doctors have the best preventive, nurturing, holistic mind-body philosophy in the world, if their techniques don't actually work as advertised. The question is: do they?
You can't try to understand tai chi, acupuncture, qigong, meditation and a healthy diet in a vacuum where they are seperate from each other.
Sure you can; that's the whole point of a control group. You take a bunch of people who have similar diet, exercise practices, etc., but in addition you give some of them acupuncture and withhold it from the others. Then you can see how much of an effect occurs from the acupuncture, and how much of it is due to the other factors.
If you were very interested in interactions between treatments, you'd use at least four groups (the "no Eastern practices, no dietary changes" control group, the "tai chi+qigong+meditation+improved diet" control group, and then those two groups plus acupuncture as the experimental groups). You'd find out what adding acupuncture does to either a "Western" or an "Eastern" lifestyle, and this is directly informative regarding decisions about whether to add acupuncture treatments to one's own lifestyle, be it Western or Eastern.
I don't know of any acupuncture studies that were that elaborate, and done in a long term longitudinal study from the perspective of preventive outcomes, but it can be done at least in principle.
That kind of thinking comes from the Western, "Take pill X for symptom Y for Z amount of time." way of dealing with the body.
That's nonsense. Certainly a lifestyle which is healthy in all areas is a go
if medicine restricted itself ONLY to what is thoroughly vetted and understood by scientific rigor, then medicine would have its hands tied when it came to actually treating people. No, it wouldn't. There are vast numbers of treatments for which scientific evidence of their efficacy exists. Even when not all of the mechanisms are understood (and frequently they are understood), you can at least scientifically show that they work. (For instance, there are commonly used medicines whose biochemical basis is not yet understood scientifically, but it can be shown scientifically that the medicines do help.)
However, there is still a lot of room for complimentary therapies out there, especially as a replacement for high-side-effect drug usage. IMHO, there isn't any room for "complementary" techniques unless there is scientific evidence that they actually work... and if there is, then they're not "complementary" medicine anymore, they're just medicine.
Take herbal remedies, for instance. Herbs have been used as medicines for millennia. Some of them work — indeed, many existing synthetic drugs are based on chemicals found in plants. Many of them don't. The ones which have been shown to work become accepted medical practice. The ones which don't, live on in the complementary/alternative medicine community, unencumbered by evidence, surviving by personal anecdote and appeals to open mindedness or wishful thinking.
The difference between standard and alternative medicine is not really that standard medicine rules out treatments which have not been explained scientifically. Rather, it is that standard medicine rules out treatments which were not successful in controlled trials or observational studies. (Well, at least that's true of good modern medicine. There are still cases of treatments that individual doctors promote which have not been tested, and that's no better than untested Eastern medicine.)
This is the point of evidence based medicine. They don't say, "We're going to ignore this treatment because it sounds bogus and comes from the wrong part of the world." They say, "This treatment doesn't have evidence supporting it. If someone shows that it works, using appropriate scientific methodology to rule out spurious explanations, then we'll use it."
It gets trickier outside of the scientific method, absolutely. That doesn't mean there is nothing of value out there though. There may be untested therapies of value out there, but until they have been tested, there is no reason to believe they are any better than snake oil or bloodletting. Simply having been around for a long time, with testimonials from the recipients, is not evidence that they work. There are plenty of treatments which have been around for a long time, with testimonials from the recipients, which upon closer inspection demonstrably do not work.
Slashdot Mirror
However, in homogeneous/isotropic spacetimes, there is a preferred class of observed who singles out a unique "cosmological age" that everyone can agree is unique: those are the observes who view the universe as isotropic, or are "at rest with respect to the cosmic background radiation" (loosely speaking). The Earth is nearly such an observer (to within 0.2% of c).
But as I said above, there certainly are classes of observers who would have measured 6000 years since the Big Bang, according to their own clocks. (The Earth is not one of them.) Unfortunately, most of what the parent post said is an incorrect application of special relativity. No, what the GP said holds in general relativity as well. The twin "paradox" ("return to Earth...") has to do with switching reference frames, not time dilation. It has to do with both. Also, it is spurious to apply special relativity outside of space-time. The GP did not apply special relativity "outside of space-time".
Anyway, you can't prove anything in science, so I don't know what kind of a "proof" you're looking for. You can merely show that the data are highly consistent with one set of assumptions, and inconsistent with another. But it's always possible that there are a third set of assumptions with which the data are also consistent. Possible, however, does not mean plausible; as more kinds of data accumulate, it grows harder to construct alternate theories that are consistent with a growing body of evidence. Which is the point of science. I can infer some interesting characteristics about gravity by splashing paint on my wall and studying the results from across the room, but I don't really have enough data to overcome a host of other contributing factors... The WMAP data set is quite a lot of data, actually, and "a host of other contributing factors" are studied in this analysis.
In particular, see Section 5.2.4 and Figure 19 of this paper for the assumptions made and factors considered in this conclusion.
The results in this story are based on a picture of the cosmic background radiation throughout the universe at its largest scale. That picture may be found in the NASA link in the story summary. Galaxies are invisibly small at this scale.
"Spacetime is flat to within a 2% error margin."
No, space is flat to within 2% (on cosmological scales, according to WMAP Year 5). Spacetime is curved, as per general relativity.
You are speculating a lot about how curved spacetime can substitute for dark matter, but when you get down to details, it turns out to be quite difficult to construct a theory of gravity which can actually do so. It is impossible in general relativity itself, and modifications to GR like TeVeS are rather ad-hoc and, as far as I have seen, even more difficult to constrain observationally than dark matter. The evidence of Bullet Cluster is a mixed bag. It does show that DM exists, in what form we don't know. We can't take WIMP's to be a given. We can't take anything as a given, but nobody's ever found another way to explain the observations, so WIMPs are likely. Bullet Cluster also shows that the matter is moving faster than what can be achieved with normal Newtonian Gravitational force, indicating either a new force exclusively between DM particles or MOND. If you're saying that the Bullet Cluster observations are incompatible with dark matter + Newtonian gravity, I would like to see a citation for that. I've not seen any publications which reach that conclusion. MONDian's are saying that neutrinos may provide enough DM, I really doubt that. They're too light: the move too fast to explain structure formation, and they don't have enough total mass to explain any significant portion of the rotation curves, or cosmology. but maybe there are more forms of DM. There could be several forms of DM
String theory is a quantum theory of gravity. We don't know if it's a correct theory or not, but it is, at least, a theory.
If all we had were galactic rotation curves, then DM and MOND would both be fine. Of course, we have more than that. MOND and DM can both be true. Yes. But you can't have MOND explain galactic rotation curves and have dark matter explain everything else; if dark matter exists, it would have a major influence on rotation curves as well. In fact, in order to fit all of the non-rotation curve observations, it very likely has the dominant influence. (e.g., with the amount of dark matter necessary to explain the Bullet Cluster, this implies large influence on galactic rotation curves.) I suspect that DM could be spread out nearly uniformly. That would be distinctly incompatible with observations. The density might not be sufficient to produce much gravitational effect at galactic scales, but at larger scales, it may produce a large observable effect. That's not really possible; given say, WIMPs, it pretty much has to cluster gravitationally at galactic scales. And we know of examples of phenomena even at galactic scales which dark matter can explain but MOND can't (like the aforementioned Bullet Cluster). Dark matter is significant to galaxies both theoretically and observationally. MOND can be explained very easily by GR, if the universe is curved. No, it can't. MOND is directly inconsistent with GR, due to its preferred acceleration scale. GR has Newtonian dynamics as its weak field limit, not Modified Newtonian dynamics. To produce a relativistic theory of MOND, you need to modify GR just as MOND modifies Newton; Bekenstein's TeVeS theory is one example. The problem is that flatness is considered a settled question. Observationally, space is close to flat on cosmological scales. (Spacetime, of course, is not.) I don't know why you think MOND requires a curved space.
I like the Neptune-Mercury analogy a lot and use it myself.
Another analogy for dark matter is the neutrino: it was an invisible, virtually non-interacting particle introduced purely to maintain the internal consistency of the known laws of physics (the conservation laws). It was 12 years before they were actually discovered, since they interact so weakly. Dark matter also interacts weakly, but is thought to be much more massive than a neutrino, so it's difficult to produce in a particle accelerator.
Just the time dimension. You're proposing extra spatial dimensins, which is not something that "we had already accepted". String theorists like extra dimensions, but there's no evidence of them, and string theorists aren't the whole physics community. Plus, not even string theorists have managed to do what you insist is "radically simple": produce a dark matter equivalent using only the structure of higher-dimensional spacetime. Believe me, if string theory had a simple, workable alternative to dark matter, string theorists would be shouting it from the rooftops.
... you guessed it ... a new kind of invisible particle. In other words, string theory gives more candidates for dark matter.
... albeit not matter made of particles.
The usual way in which string theorists incorporate dark matter is to come up with a string vibrational mode that simulates
There are probably brane solutions too, but you can think of branes as dark matter as well
Adding higher dimensions isn't going to explain that unless you postulate randomly lumpy extra dimensions; otherwise, smooth extra dimensions aren't going to project down to something random in lower dimensions.
And it's not just the expansion of space that you have to explain. It's also the orbits of stars in galaxies, and numerous other observations. It baffles me as to why they would invent the notion of something invisible to explain anomalous observations instead of going with a no less workable and radically simpler theory. Easy for you to say. Why don't you try actually writing down a higher dimensional field theory which can explain observations of the cosmic background radiation, early universe structure formation, galactic rotation curves, galactic cluster interactions, galaxy collisions like the Bullet Cluster, etc.?
I think you will find that what you get is not "simple" (if you get anything at all, which I doubt), and almost certainly not simpler than just postulating the existence of a new kind of particle (several types of which have are already suggested from existing paricle theories for independent reasons).
And how is inventing invisible extra dimensions so superior to inventing invisible extra particles, anyway?
So far I have said anything about "what you have said" that wasn't true.
Wrong.
As I requested in the last post, please, quote me where I've insisted that "only science be done in the way I approve, on the topics I approve".
Otherwise, admit you're lying about what I have or have not "insisted".
Note: pointing out that claim X is wrong is not "insisting that science can only be done in way Y on topic Z".
Your right that I am biased. I consider it a side effect of paying attention and troll like you walking the forums to snidely correct anyone who isn't stepping in tow with your favorite position.
There you go with your prejudices again. I'm correcting people who are WRONG, on a topic I happen to know something about. Which you are. Repeatedly. Despite careful correction. If you want to present a CORRECT scientific argument in favor of your position, feel free.
And instead of taking the problem up with them, you seem content attempting to attack anyone repeating it.
Who said I'm not taking it up with them? If someone posts an argument here, I'll address it. You seem content with merely repeating other people's conclusions without even giving their arguments, and then whining about agendas when you're called on it.
How many times have you insisted in this thread that "other people" have found "alternate solutions" to the "CO2 problem", without citing any names, arguments, logic, or data? And you have the gall to accuse me of being a troll?
How about this: you drop all your paranoid bullshit about scams and political agendas and censoring the heretics, I'll stop calling you politically prejudiced, and we can talk science?
I don't think I can make one comment about the subject without you popping in to make sure everyone believe the way you do and that everyone know your way is the one true way.
Stop making false claims and people will stop correcting you. Why do you think you can post things which are wrong and expect not to be criticized for it? This is a discussion forum, not a "post whatever unfounded opinion I feel like and be immune from facts or logic" forum.
I said it doesn't have the effect being claimed and people are showing the problem is elsewhere.
And here you've given not a single argument supporting such an assertion. Curious, how devoid of science your posts on scientific topics actually are.
That's what I am saying, in order for 30% of a temperature increase to cause 70%, we would be on the other side of the curve.
No, you totally missed the point.
You are attempting to argue that ANY positive feedback from water vapor will lead to a runaway greenhouse effect: your argument IGNORES the location of the Earth's atmosphere with respect to the saturation curve. But in reality, it depends on where you are with respect to it: on one side, feedback is self-limiting, and on the other it's runaway. Thermodynamically, the ocean will generally re-equilibrate at a new, higher temperature, with the difference proportional to the water vapor feedback factor.
It's possible with very large amounts of warming for the Earth to cross the curve and inevitably run away, as the ocean becomes permanently out of equilibrium and evaporates away. But this has not happened at any time in the Earth's history, even when the Earth was warmer than it is today: you need a much larger warming than that. (I'd have to consult the curve to work out how much warming it does take, but I'm away at a workshop for several weeks and don't have any of my textbooks with me. In the meantime, you could try a Google Scholar search on "earth runaway greenhouse" and see if that turns up the calculation.)
Obviously that didn't happen so it isn't likely that Co2 was the cause of the increase.
This conclusion doesn't even follow from your own mistaken argument, let alone from a
1. The GISTEMP record contains detailed monthly data. If you want to see a statistical analysis of it, see this companion article to the other one I linked.
2. There's not really any such thing as a "two year climate decrease" (or increase); given the observed interannual variability, it is statistically impossible to define climate trends over a period that short. (And why would a 2-year decrease matter anyway? Global warming doesn't predict that every year is monotonically warmer than the last.)
3. The GISTEMP record I linked clearly includes data up to 2007. Sources indicating that global warming ceased in 1998 are, in part, The first link includes no data, figures, or statistical analysis.
Ditto, the second link.
Ditto the third link. It doesn't give any evidence at all that global warming ceased in 1998, it just makes an uncited reference to "a study" in the first sentence, and the rest of the article does not analyze the post-1998 warming trend.
Keep up the Googling, man. You might learn something someday.
Please, quote me where I've insisted that "only science be done in the way I approve, on the topics I approve". First, this has nothing to do with my political prejudices. Of course it does. You don't like the political implications, and therefore you refuse to understand the science. SO I forgot to drop the 00 when making it a percentage. That's not the only number you've gotten wrong by orders of magnitude; you did the same thing in the post to which I originally implied. Not surprising coming from someone who is uninterested in and ignorant of the actual science. It is still an outrageous claim. And there you go repeating the same error a THIRD time. You're truly ineducable.
Once again: the fact that CO2 is a small amount of the atmosphere does not imply that it has negligible effect on the climate. And no, anthropogenic CO2 is not
Or rather, more precisely: natural sources of CO2 are larger than anthropogenic sources, but until recently they were closely balanced by natural sinks of nearly equal magnitude. It's only in industrial times that additional anthropogenic sources have overweighed the natural sinks, leading to a 100 ppm accumulation of CO2 (from natural and anthropogenic sources) that would not have accumulated in the absence of anthropogenic activity.
The ocean is a net sink for CO2, not a source, by the way. And thawing permafrost has not yet become a major source of CO2, although it could become one (as well as, perhaps more importantly, a methane source) in the future when more of it thaws. An interesting fact here is that water vapor increases have already been attributed to 70% of the warming in Europe I already pointed out in my last response that you're confused about the study, and I even linked to the study in question! It does not attribute 70% of the European warming to natural sources! It links it to increased water vapor content WHICH IS DUE TO INCREASED CO2: it is a feedback of the CO2 greenhouse effect. This is a PREDICTION of the greenhouse effect, not a refutation of it!
Why do you keep citing a study whose conclusions refute the point you're trying to make? Have you even read the abstract? So tell me, how is 30% more warming supposed to increase water vapor enugh for it to increase warming another 70% It would appear that you would have a runaway process that wouldn't stop if that was possible. The system equilibrates at a new humidity and temperature; it doesn't produce a runaway greenhouse effect unless you're on the wrong side of the saturation curve, like Venus is. You can see nice phase diagrams of this situation in David Archer's lay book on climate.
You might find it somewhere in Wikipedia's computer generated music article.
However, as I've explained to you in the past, the relative concentration of greenhouse gases is not really the important issue. What matters is the change in greenhouse effect above the natural baseline. The natural greenhouse effect is something like 30 degrees C. Anthropogenic CO2 has, so far, added less than 1 C to that. The natural baseline is much larger than the anthropogenic contribution, because there are more natural greenhouse gases than anthropogenic. But the anthropogenic GHGs are still important: 1 C matters, climatically speaking. And projected CO2 emissions are likely to add several more degrees on top of that, which is the point.
Well, the idea is presumably to reduce the CO2 in the atmosphere back down to pre-industrial levels, not to suck all of it out of the air.
The polluting power plant does have an incentive to reduce their emissions, because the total number of emissions credits is capped at some finite number (and the cap can even decrease over time, applying increasing pressure to the plants).
If plants want to pollute a lot, they can't collectively buy more credits than exist on the market, because they're finite. The limited supply drives up the price of the credits, and at some point it becomes more cost effective for an individual plant to simply reduce its emissions than to purchase emission credits. (Where that point is depends on how much the plant emits.)
When the SO2 emissions market was implemented in the U.S., the average per-plant emissions did go down. (I just went to an economics talk on this a few days ago.)
This was the subject of a short story by Greg Egan, entitled "The Moat". In it, it is discovered that an unknown group of people are genetically engineering themselves to have different DNA bases, presumably so as to be immune to all viruses. He uses the concept again in his novel Distress.
"Engineer's Syndrome" reminds me of the Salem hypothesis.
It seems that you're looking at acupuncture and determining its effectiveness based on whether or not it can treat diseases.
The original poster claimed that it was an approved treatment for several "ailments", which I interpreted to mean "diseases". I pointed out that it has not been shown to actually treat any diseases.
Furthermore, I was mainly talking not about diseases, but about pain relief, since that is the only place where acupuncture has ever shown any efficacy.
If you want to look at it from a preventive standpoint, you can, but:
Acupuncture is used to stimulate circulation in the body.
There is no evidence that it actually does so.
According to the "eastern" view of medicine, disease comes from stagnation in organs and meridians.
There is no evidence of this either (whatever "stagnation" is supposed to mean anyway), and in fact the meridian theory is demonstrably wrong when applied to pain relief (an area where acupuncturists claim that the treatment outcome is governed by meridian theory).
The big difference between "western" and "eastern" philosophies is that in the Western world we work ourselves to death and then try to deal with the effects of the diseases that develop. In the Eastern world they try to prevent the conditions that lead to diseases in the first place.
This is propaganda that one often hears in order to increase sympathy towards bogus methodologies with no physiological basis or empirical support.
... "Your doctor doesn't only cares about treating symptoms. I care about preventing the problem in the first place, and your whole healthy lifestyle. Therefore, try my snake oil!" There's a big gap there.)
(The logic goes like this: "Western medicine has bad philosophy X. I have good philosophy not-X. [Here comes the logical leap]. Therefore my treatment Y is superior to Western treatment Z." As in
In reality, both Western and Eastern medicine are concerned with preventive as well as curative health. But even if I took your claim at face value, it's still irrelevant to the issue at hand: the positions of Western and Eastern medicine on preventive medicine may be interesting, but the real question is what treatments actually prevent disease, and what evidence supports those claims. It doesn't matter if Eastern doctors have the best preventive, nurturing, holistic mind-body philosophy in the world, if their techniques don't actually work as advertised. The question is: do they?
You can't try to understand tai chi, acupuncture, qigong, meditation and a healthy diet in a vacuum where they are seperate from each other.
Sure you can; that's the whole point of a control group. You take a bunch of people who have similar diet, exercise practices, etc., but in addition you give some of them acupuncture and withhold it from the others. Then you can see how much of an effect occurs from the acupuncture, and how much of it is due to the other factors.
If you were very interested in interactions between treatments, you'd use at least four groups (the "no Eastern practices, no dietary changes" control group, the "tai chi+qigong+meditation+improved diet" control group, and then those two groups plus acupuncture as the experimental groups). You'd find out what adding acupuncture does to either a "Western" or an "Eastern" lifestyle, and this is directly informative regarding decisions about whether to add acupuncture treatments to one's own lifestyle, be it Western or Eastern.
I don't know of any acupuncture studies that were that elaborate, and done in a long term longitudinal study from the perspective of preventive outcomes, but it can be done at least in principle.
That kind of thinking comes from the Western, "Take pill X for symptom Y for Z amount of time." way of dealing with the body.
That's nonsense. Certainly a lifestyle which is healthy in all areas is a go
Take herbal remedies, for instance. Herbs have been used as medicines for millennia. Some of them work — indeed, many existing synthetic drugs are based on chemicals found in plants. Many of them don't. The ones which have been shown to work become accepted medical practice. The ones which don't, live on in the complementary/alternative medicine community, unencumbered by evidence, surviving by personal anecdote and appeals to open mindedness or wishful thinking.
The difference between standard and alternative medicine is not really that standard medicine rules out treatments which have not been explained scientifically. Rather, it is that standard medicine rules out treatments which were not successful in controlled trials or observational studies. (Well, at least that's true of good modern medicine. There are still cases of treatments that individual doctors promote which have not been tested, and that's no better than untested Eastern medicine.)
This is the point of evidence based medicine. They don't say, "We're going to ignore this treatment because it sounds bogus and comes from the wrong part of the world." They say, "This treatment doesn't have evidence supporting it. If someone shows that it works, using appropriate scientific methodology to rule out spurious explanations, then we'll use it." It gets trickier outside of the scientific method, absolutely. That doesn't mean there is nothing of value out there though. There may be untested therapies of value out there, but until they have been tested, there is no reason to believe they are any better than snake oil or bloodletting. Simply having been around for a long time, with testimonials from the recipients, is not evidence that they work. There are plenty of treatments which have been around for a long time, with testimonials from the recipients, which upon closer inspection demonstrably do not work.