...dark energy has fallen into an interdimensional rift in the fabric of space/time, can we shove the astrophysicists who insist on inventing the unobservable to fix their theories in with them Extra dimensions aren't "unobservable", insofar as they have experimentally observable consequences. Dark energy may be one of them. There are other consequences for high energy particle physics and for the short distance behavior of gravity. All of these are currently being investigated to see if the extra dimension idea holds up.
and get on with fixing whatever the error in the models really is? How do you know the error in the models is that they don't have extra dimensions?
There is nothing worse than a scientist who fixes the observation to meet their theory Are you suggesting that astronomers have faked the observational data regarding dark energy to provide evidence for extra dimensional theories? If so, you're being absurd.
On the other hand, even if these relatively large extra dimensions exist, the theorists involved like giving it a zest of "we might find evidence of this real soon" by cranking down the potential size until where is just not detectable today but will be at the LHC. AND they do this without any motivation at all. The motivation is that larger dimensions would have been seen already. There's nothing wrong with that. Eventually the size might be cranked down so far that the theory can't do the job it was invented to do, and then it would be in trouble.
A good motivation to me would be: well if we put the size to this or that we can reproduce (parts of) the standard model. Or, if we put the size to this or that we can solve dark energy?
Large extra dimension theories can already reproduce the Standard Model. The point is to explain some puzzling features that the Standard Model has (such as the hierarchy problem) and to avoid predicting things not in the Standard Model that we should have already seen. As a byproduct, they also need to predict things not in the Standard Model that we shouldn't have seen yet, but might in the future.
This analogy has always bothered me. How can extra spatial dimensions exist at different scales? The parent poster explained it. Some dimensions are infinite, and have no scale. Others are finite, and have a scale, because you can measure them. A telephone wire is essentially an infinite cylinder. One dimension has no scale. The cross-sectional dimension is circular, and has a scale: the circumference of the circle. In a universe with such a geometry, you can literally wrap a tape measure around the closed dimension and see how big it is. For the very small dimensions being discussed here, you can't construct a literal "tape measure", but you can do things like send particles around the circle and measure how they come back.
How can you have dimensions that are only apparent to objects of some fixed scale or size? The poster gave you an example. If the dimensions are so small you can't even see them, they're not going to be apparent to you. They might be apparent to an ant, though.
How can the shape of space have little curls that only affect particles, but nothing else? It affects everything, but it doesn't affect big things very much. Big things will be smeared out across the extent of the small dimensions, while small things will be more localized, and therefore the particular geometry influences their behavior more.
We solve the problem of energy we can't detect and dimensions we can't prove exist? We can detect dark energy — that's how we know it exists, because of its influence on gravitational phenomena. We just can't, currently, measure those influences well enough to narrow down the possibilities for its origin.
We can't prove anything in science, but we can find evidence to support a theory. Extra dimensions have experimental consequences; dark energy may be one of them. There are other ways that the existence these extra dimensions can be probed, especially in the case of the so-called "large" extra dimensions being discussed here. (A fraction of a millimeter is huge from a particle perspective.) It alters the behavior of high energy particles, as well as the laws of gravitation on small scales. Experiments are currently underway to test whether these effects really exist.
We tuck the one into the other and thus explain everything in a single shot. Brilliant! You're being sarcastic, but most of physics history has consisted of explaining more, with less, even when hard evidence of the proposed new physics has not yet been observed.
String Theory unfortunately has all the hallmarks of a belief system which, because we do not currently have the ability to falsify its predictions, lends itself to being entirely wrong. String theory isn't any more of a belief system than any other idea about particle physics beyond the Standard Model. Post-SM physics theories that we can't yet falsify are a dime a dozen, and are in no way limited to string theory. There always will be, given the vast gulf between what we can probe and the highest energies possible to probe. That doesn't mean that none of those theories can be tested, that they can't have experimental consequences at energy levels we can probe. There are specific string models which can and have been falsified, and some which haven't been; the same is true of non-string theories of extra dimensions, supersymmetry, unification, etc. — not to mention more mundane alternative theories to the Higgs boson and other particle physics conundrums.
I just wanted to mention that it seems utterly ridiculous that every time something doesn't fit into the model of physics someone's trying to push, they try to "invent" something completely new to save their theory. Dark energy itself is a new theory, not an old theory being "saved". Actually, it's not even really a theory. It's just a catch-all term for "something that makes the universe's expansion accelerate". That could be the quantum zero point energy, a new kind of particle, extra dimensions, modifications to the laws of gravity, and so on. All of these ideas are being pursued; why are you so down on this particular one?
Besides, there's nothing wrong with inventing something new to preserve some theory. The neutrino was "invented" to preserve conservation of energy. Antimatter was "invented" to keep quantum theory consistent with relativity.
Despite common memes about the history of science, the vast majority of new ideas don't require tossing out the old ideas.
IE: dark matter, dark energy, string theory, etc. I think that's why we've seen theories like MOND become more popular. MOND is not by any means more popular than dark matter; indeed, the observational evidence implies that even if MOND were true, you would still need additional dark matter to fully explain the observations, with which MOND alone is inconsistent.
You're being hypocritical to boot. MOND is also an invention of something new to try to save a theory. Dark matter introduces new kinds of matter to try to save our theory of gravity. MOND introduces a whole new theory of gravity to try to save the existing particles we know about. Arguably, the former is a more conservative choice than the latter! Of course, both modifications may be necessary, but right now it looks like you can do it all with dark matter, and there are already reasons coming from particle physics, independent of any astrophysical evidence, for why those kinds of dark matter particles should exist.
There is also nothing wrong with inventing a theory of quantum gravity, such as string theory, in order to save existing theories of relativity and quantum mechanics, since both of them have enormous amounts of evidence in their favor.
Continuing on string theory, the theory has not "failed", nor do people "add more strings" to fix it; indeed, the string content of the theory is determined by the overarching M-theory and cannot be adjusted at will.
My point is we need to stop pushing stories that aggrandize theories until some serious research has been done on the issue. Serious research has been done on the issue. This story is merely reporting one of the latest proposals. This proposal is not necessarily more plausible than any of the others currently floating around, but that's why the story said it was "a sketch of an idea, that might one day become a theory". It is nevertheless interesting, and is consistent with some things we know about dark energy.
Or perhaps Lisp's garbage collector is quick, stable, with mathematically provable behavior, and Java's is not? To all the obnoxious knee-jerkers out who replied to my post: the above is not a rhetorical question, it's an actual question. I don't know anything about Lisp vs. Java garbage collection, and I don't program in either language. I was just speculating why the original poster claimed that Lisp was suitable for nuclear power plants while Java wasn't, when both languages are garbage collected. Indeed, my first guess was that the OP was simply misremembering which language it was, and that they don't use Lisp for nuclear power plants. Then it occurred to me that Lisp might have a better GC. I have no idea. Sheesh. Grow up, will you?
Or perhaps Lisp's garbage collector is quick, stable, with mathematically provable behavior, and Java's is not?
Still, I was under the impression that engineering software with critical real time constraints (which I would imagine nuclear plants to have) tends to avoid the unpredictability of GCs. Though I am sure there has been work on realtime GCs with guaranteed behavior, somewhere,...
Lisp is traditionally garbage collected. I suppose you could modify a Lisp to operate without a GC, but you could probably modify Java the same way. Perhaps you're thinking of another language?
Bush does not believe that science has demonstrated a significant human contribution or significant human risk related to global climate change, and his policies are consistent with this view. This puts him in alignment with significant percentages of both the American public and the scientific community. If you mean "significant percentages of the climate science community", that's pretty far from the truth.
The issue is unsettled, and the debate will continue for a long time I am sure. The "significant human contribution" debate has been settled within the scientific community. The "significant human risk" debate continues.
But rather than putting all money that is to be spent towards 'fighting global warming' into clean energy, I would use much of it to create international programs to help populations all over the world deal with the *effects* of global warming. Well, that is the "mitigation" vs. "adaptation" debate, and the realistic answer is that we need to do both. It's not economically feasible to cut emissions to zero, but it's reasonable to slow the rate of warming and avoid the worst case scenarios, and try to adapt to the rest of it.
I guess by what I wrote you can tell that I am on the fence with global warming being anthropogenic (and will be for about 10 years, or however long it will take to make sure the Sun isn't the culprit) We've already observed many solar cycles, what more is 10 years going to do? We already know that that solar variations are in dramatic disagreement with the observed climate over the last 30 years.
Every model predicts they will worsen, although some show that the degree of this "worsening" is dependent on continued output of CO2 into the atmosphere. All of them show that climate impacts depend on CO2 emissions.
But if it *will* worsen, why do I hear so much about reducing carbon footprints and so little about programs to combat the spread of malaria, etc. Because programs to combat the spread of malaria are already widespread, and because it's cheaper to reduce carbon footprints somewhat than deal with the full damages with no cutbacks at all.
Imagine what detail they would get if they had a guy in a van outside your house with a huge zoom lens, I mean they could tell if you picked your nose (yet)! You mean, like this?
Wealthy parents more likely to have boys? How does that explain Paris and Nikki Hilton? That's why they said "more likely", not "guaranteed". (Which supports your overall point... not that I am necessarily agreeing with their claims.)
From TFA:
Computer science does not need a theory of computation; it needs a comprehensive theory of process expression. Maybe it's just me, but I fail to see how "process expression" is any different from an algorithm. Or is he talking about declarative programming as opposed to procedural programming?
"A logic circuit is not a sequence of operations. A logic circuit is a sequence of operations, in its most fundamental physical form: a sequence of gates which each act upon a signal.
An operating system is not supposed to terminate, nor does it yield a singular solution. Algorithms don't have to halt, or yield singular solutions. And operating systems are supposed to terminate when you tell them to shut down.
An operating system cannot be deterministic because it must relate to uncoordinated inputs from the outside world. That doesn't mean the operating system isn't deterministic! Deterministic just means that you get the same outputs for the same inputs. The fact that in the real world, you never get exactly the same inputs twice, doesn't mean that the OS itself isn't a deterministic algorithm.
Furthermore, there are such things as nondeterministic algorithms.
Any program utilising random input to carry out its process, such...is not an algorithm." This guy is very confused about what an algorithm is.
Is he seriously arguing that this code:
scanf("%d",&n); printf("%d\n", n*n);
is neither an algorithm nor deterministic just because the user could input a random number??
I should also note that Masters has argued that the QuikSCAT funding can be used for even more important Earth observation programs. Framing his position as "Masters supports the degradation of data" is dishonest.
I'd like to believe that Weather Underground is still on the free side of things but that's something for you to prove in the face of an obvious conflict of interest. No, it's not something for me to prove. Weather Underground's words and actions have supported the free weather data of NWS. It's up to you to demonstrate otherwise. Nor is there any "conflict of interest" causing them to fail to be on the free side of things, since they themselves make use of NWS's free data services. If anything, their interests lie in supporting free NWS data, in order to keep them competitive with their closed-data competitors like AccuWeather.
Masters is siding with a smear job. You have neither established the existence of a "smear job", let alone that Masters is intentionally siding with one.
I don't know why he's doing it but it's paradoxical that he should come down on the side of a debate that would degrade weather data. None of the things he said really refutes the core argument, which is that hurricane prediction will be degraded and that will require the evacuation of larger areas. On the contrary, he has refuted the argument that the loss of QuikSCAT would "require the evacuation of larger areas". You simply choose not to believe his refutation. As for "degrading weather data", Masters has not argued for "degrading weather data". He has argued that (a) weather data will not be degraded as much as Proenza claims and that Proenza is being scientifically dishonest, (b) QuikSCAT should be replaced by a next-generation scatterometer in order to improve, not degrade, data, and (c) a short-term loss of QuikSCAT is an acceptable sacrifice if it gains us a better instrument in return. Fighting to maintain an aging satellite for an indefinite period is not arguably superior to retiring the satellite and launching a better one in a few years.
Of course, the best situation would be no loss of continuity, but the funding reality means that no money for developing a new scatterometer is going to appear while the existing one continues to incur support costs.
Even if you want to adhere to your "Weather Underground is Biased and Evil" theory, you have not explained how Weather Underground is supposed to benefit from degrading the very weather data that they themselves use.
Well, that makes sense. If you believe that the universe is "everything"," then putting strange forces into a local inflation is a good way to rectify the math. Chaotic inflation is not a "way to rectify the math" and was not invented merely to explain the origins of the universe; it is a consequence of generic inflationary physics, which itself has a number of experimental justifications.
Hey, our universe just continually inflates. Why? Who knows? It's the "universe," it just inflates. The universe naturally inflates when it rolls down the inflaton particle's potential hill. Inflatons, in turn, are natural particles implied by most theories beyond the Standard Model, including string theory and grand unified theories.
Just because you don't understand any physics behind inflation doesn't mean that no one does.
I prefer to believe that the universe is not "everything." A universe itself requires a universe to exist in. That's not an argument of physics, it is one of semantics, and has no bearing on the validity of inflationary physics.
Everyone can be manipulated, in principle. However, you have given no justification for your claim that anything Jeff Masters says should be automatically "suspect", other than simple paranoia. You certainly have given no justification for your claim that Weather Underground tried to cripple free updates from the NWS. That's pretty much libel.
Are you really too dense to tell the difference between a scientific theory accepted by scientific experts on the basis of research and evidence, and the acceptance of an opinion regarding fictional characters accepted by science fiction fans?
Was Weather Underground involved in the weather service scandal? I thought it was just AccuWeather and CWSA? My understanding is that Weather Underground relies heavily on NWS's free data and is a strong supporter of the NWS. Am I mistaken?
Your list fails to distinguish failed pronouncements by members of the academic community from failed pronouncements by a large portion of the academic community. If some random scientist says something and is wrong, do you blame the scientist as untrustworthy, or do you blame yourself for taking the word of a single scientist with a preliminary theory, instead waiting for followup confirmatory research, debate, and widespread acceptance among scientists?
Note too that a scientist who says something and is wrong is not necessarily oversensationalizing or distorting anything.
Your list also fails to distinguish sensationalism perpetrated by scientists from sensationalism perpetrated by the media. If the headlines say that an asteroid will hit us any second, but the scientists say it's unlikely to happen in this century, do you blame the scientists as untrustworthy, or do you blame the media for exaggerating the risk? Or yourself for getting your science from the media instead of from scientific publications?
In short, I see little connection between "the sky is falling" arguments and oversensationalizing on the part of the scientific community.
I don't think it was ever quite as hysterical (for want of a better description) as the current global warming carry-on, but global cooling was being promoted by several apparently prominent people in much the same was that global warming is being promoted now. A new theory "being promoted by several apparently prominent people" is a far cry from "being promoted by the vast majority of the climate science community after decades of research", which is how global warming is being "promoted" now.
Despite the media scare, global cooling was never a widely accepted hypothesis, and those who proposed a new ice age cycle would start didn't claim that it was going to start in anything less than hundreds or thousands of years. Those who believed in global cooling via atmospheric pollutants also admitted that they didn't know enough about emissions to tell whether they would be outweighed by CO2 warming. (More here and here.)
This is in stark contrast to the current state of research of global warming, which has been studied intensively for more than 30 years and is now almost universally accepted within the climatological community (more here).
I found a similarity between my semantic dislike of LQG (i.e. it doesn't make sense) Whether it "makes sense" to you is irrelevant to its physical correctness. If you're going to object to it, you should object to it on legitimate grounds. There is nothing physically wrong with the concept of time as we know it originating at the Big Bang, when the very structure of spacetime itself can be quantum mechancially uncertain and admit no classical description. That is not one of the problems with LQG. Certainly M-theory admits solutions which cannot be described in classical terms of "space" and "time", either.
and your dislikes (on specific grounds). There is no similarity; your objections to LQG have nothing to do with mine.
Discover had an article on "branes." They posited that the Big Bang was a collision of extra-dimensional objects. The brane theory accounts for "acceleration," much like a car crash where the cars are still plowing into each other. It's certainly easy to understand, but that too has nothing to do with its correctness. No one knows what M-theory actually is (the theory has not yet been written down!), there is no experimental evidence for it or for branes, nor can one derive within M-theory that the brane scenario is likely to occur. Indeed, no one can derive within string theory the possibility that any universe remotely like ours is likely to occur — the notorious landscape problem. There are a number of competing proposals within M-theory itself, other than braneworlds, for how the Big Bang happened, and the proposal perhaps most accepted by cosmologists (chaotic/eternal inflation) isn't intrinsically an M-theory scenario at all.
It's somewhat philosophical, but, I looked for a flaw and could not find one. Theories like LQG are more easily flawed imo. What you consider to be a flaw does not appear to be an actual flaw. The flaws in LQG lie elsewhere.
I didn't say that determinism implied the subjectivity of time. I did say that it does make the flow of time seem subjective. I can't see how. Our perception of time is the same in quantum or classical mechanics, since macroscopic bodies such as ourselves exist in the classical limit of a quantum universe; it's only on the Planck scale that there can be any significant differences between the two.
If God knew everything that would ever happen, I'm sure a philosopher could still point out that time might still flow, but I can't imagine why I would care. Whether or not you care has nothing to do with whether time is, or even "seems", subjective.
However, if quantum mechanical measurement changes the universe in an irreversible way, I have trouble seeing how this wouldn't impose a causality that everybody has to agree on It's quite the opposite; a deterministic spacetime has a well defined causal structure. This may or may not be the case with a non-deterministic spacetime in which the causal structure itself may be uncertain (in the quantum mechanical Heisenberg sense).
Slashdot Mirror
...dark energy has fallen into an interdimensional rift in the fabric of space/time, can we shove the astrophysicists who insist on inventing the unobservable to fix their theories in with them Extra dimensions aren't "unobservable", insofar as they have experimentally observable consequences. Dark energy may be one of them. There are other consequences for high energy particle physics and for the short distance behavior of gravity. All of these are currently being investigated to see if the extra dimension idea holds up. and get on with fixing whatever the error in the models really is? How do you know the error in the models is that they don't have extra dimensions? There is nothing worse than a scientist who fixes the observation to meet their theory Are you suggesting that astronomers have faked the observational data regarding dark energy to provide evidence for extra dimensional theories? If so, you're being absurd.Large extra dimension theories can already reproduce the Standard Model. The point is to explain some puzzling features that the Standard Model has (such as the hierarchy problem) and to avoid predicting things not in the Standard Model that we should have already seen. As a byproduct, they also need to predict things not in the Standard Model that we shouldn't have seen yet, but might in the future.
We can't prove anything in science, but we can find evidence to support a theory. Extra dimensions have experimental consequences; dark energy may be one of them. There are other ways that the existence these extra dimensions can be probed, especially in the case of the so-called "large" extra dimensions being discussed here. (A fraction of a millimeter is huge from a particle perspective.) It alters the behavior of high energy particles, as well as the laws of gravitation on small scales. Experiments are currently underway to test whether these effects really exist. We tuck the one into the other and thus explain everything in a single shot. Brilliant! You're being sarcastic, but most of physics history has consisted of explaining more, with less, even when hard evidence of the proposed new physics has not yet been observed.
Besides, there's nothing wrong with inventing something new to preserve some theory. The neutrino was "invented" to preserve conservation of energy. Antimatter was "invented" to keep quantum theory consistent with relativity.
Despite common memes about the history of science, the vast majority of new ideas don't require tossing out the old ideas. IE: dark matter, dark energy, string theory, etc. I think that's why we've seen theories like MOND become more popular. MOND is not by any means more popular than dark matter; indeed, the observational evidence implies that even if MOND were true, you would still need additional dark matter to fully explain the observations, with which MOND alone is inconsistent.
You're being hypocritical to boot. MOND is also an invention of something new to try to save a theory. Dark matter introduces new kinds of matter to try to save our theory of gravity. MOND introduces a whole new theory of gravity to try to save the existing particles we know about. Arguably, the former is a more conservative choice than the latter! Of course, both modifications may be necessary, but right now it looks like you can do it all with dark matter, and there are already reasons coming from particle physics, independent of any astrophysical evidence, for why those kinds of dark matter particles should exist.
There is also nothing wrong with inventing a theory of quantum gravity, such as string theory, in order to save existing theories of relativity and quantum mechanics, since both of them have enormous amounts of evidence in their favor.
Continuing on string theory, the theory has not "failed", nor do people "add more strings" to fix it; indeed, the string content of the theory is determined by the overarching M-theory and cannot be adjusted at will. My point is we need to stop pushing stories that aggrandize theories until some serious research has been done on the issue. Serious research has been done on the issue. This story is merely reporting one of the latest proposals. This proposal is not necessarily more plausible than any of the others currently floating around, but that's why the story said it was "a sketch of an idea, that might one day become a theory". It is nevertheless interesting, and is consistent with some things we know about dark energy.
Or perhaps Lisp's garbage collector is quick, stable, with mathematically provable behavior, and Java's is not?
...
Still, I was under the impression that engineering software with critical real time constraints (which I would imagine nuclear plants to have) tends to avoid the unpredictability of GCs. Though I am sure there has been work on realtime GCs with guaranteed behavior, somewhere,
Lisp is traditionally garbage collected. I suppose you could modify a Lisp to operate without a GC, but you could probably modify Java the same way. Perhaps you're thinking of another language?
Furthermore, there are such things as nondeterministic algorithms. Any program utilising random input to carry out its process, such...is not an algorithm." This guy is very confused about what an algorithm is.
Is he seriously arguing that this code: is neither an algorithm nor deterministic just because the user could input a random number??
"Help me out of this box, I can't breathe in here! Help, let me out!"
I should also note that Masters has argued that the QuikSCAT funding can be used for even more important Earth observation programs. Framing his position as "Masters supports the degradation of data" is dishonest.
Of course, the best situation would be no loss of continuity, but the funding reality means that no money for developing a new scatterometer is going to appear while the existing one continues to incur support costs.
Even if you want to adhere to your "Weather Underground is Biased and Evil" theory, you have not explained how Weather Underground is supposed to benefit from degrading the very weather data that they themselves use.
Just because you don't understand any physics behind inflation doesn't mean that no one does. I prefer to believe that the universe is not "everything." A universe itself requires a universe to exist in. That's not an argument of physics, it is one of semantics, and has no bearing on the validity of inflationary physics.
Everyone can be manipulated, in principle. However, you have given no justification for your claim that anything Jeff Masters says should be automatically "suspect", other than simple paranoia. You certainly have given no justification for your claim that Weather Underground tried to cripple free updates from the NWS. That's pretty much libel.
Are you really too dense to tell the difference between a scientific theory accepted by scientific experts on the basis of research and evidence, and the acceptance of an opinion regarding fictional characters accepted by science fiction fans?
Was Weather Underground involved in the weather service scandal? I thought it was just AccuWeather and CWSA? My understanding is that Weather Underground relies heavily on NWS's free data and is a strong supporter of the NWS. Am I mistaken?
Your list fails to distinguish failed pronouncements by members of the academic community from failed pronouncements by a large portion of the academic community. If some random scientist says something and is wrong, do you blame the scientist as untrustworthy, or do you blame yourself for taking the word of a single scientist with a preliminary theory, instead waiting for followup confirmatory research, debate, and widespread acceptance among scientists?
Note too that a scientist who says something and is wrong is not necessarily oversensationalizing or distorting anything.
Your list also fails to distinguish sensationalism perpetrated by scientists from sensationalism perpetrated by the media. If the headlines say that an asteroid will hit us any second, but the scientists say it's unlikely to happen in this century, do you blame the scientists as untrustworthy, or do you blame the media for exaggerating the risk? Or yourself for getting your science from the media instead of from scientific publications?
In short, I see little connection between "the sky is falling" arguments and oversensationalizing on the part of the scientific community.
Despite the media scare, global cooling was never a widely accepted hypothesis, and those who proposed a new ice age cycle would start didn't claim that it was going to start in anything less than hundreds or thousands of years. Those who believed in global cooling via atmospheric pollutants also admitted that they didn't know enough about emissions to tell whether they would be outweighed by CO2 warming. (More here and here.)
This is in stark contrast to the current state of research of global warming, which has been studied intensively for more than 30 years and is now almost universally accepted within the climatological community (more here).