The officers should be reprimanded or demoted. But fining the police department doesn't help, since you're just fining yourself (it comes out of tax money).
Well, their statements are all literally true, but nevertheless, Stanford has many relationships with drug companies, it is deeply involved in drug development, and they patent. This kind of work could easily be "freely available" in the way they describe, yet be the basis for strong patents on the results and applications. But that's the case for a lot of tax-payer funded research as well, so it's probably not worth worrying about--right now, patents and drug companies are the way society has developed drugs, and until that changes, if you want to contribute to helping find cures for diseases, you are going to support drug companies at least indirectly.
Brilliant. With that line of reasoning, the government will be able to shut down the ACLU for "aiding terrorists". You should apply for a job in the Bush administration; they need people with your way of thinking.
I have already told you that physicists DO do this, it's just not published as part of the LIGO project.
Yes, and I have already told you that it must be part of the description of such an experiment, both in the grant application and in any paper describing results; it is not sufficient for the information to exist somewhere in the literature.
That you are ignorant of this work is not a testament to the incompetence of LIGO physicists, it simply speaks to your own incompetence.
Your assumption about what I know is incorrect, but that is not relevant here. My point isn't about the possible theories that exist somewhere, my point is about the kind of information that must be supplied both as part of the preparation and as part of any presentation of a scientific experiment. You keep confirming that, not only is this information is missing in the LIGO documents, but you know so little about the scientific method that you don't even think anything is wrong.
Assuming it gets published, of course, seeing how physicists are incompetent and don't understand theories or computations; maybe the reviewers simply won't recognize your genius.
The problem with LIGO and Kopeikin isn't one of gravitational physics, the problem is one of scientific method and for procedures for using computational methods for establishing correctness of scientific theories. In that area, I am almost certainly more qualified than you, since that's my work. And these omissions are so glaring in this work that I could diagnose them even if I knew nothing about gravitational physics (I know some, but you may well know more than me).
Now your bigotry comes out. You don't have any problem with LIGO, you just have a massive chip on your shoulder against physicists.
I have a chip on my shoulder against sloppy science, in particular when it involves spending billions of dollars of tax payer money.
Look, you ass.
Insults don't make your argument any more compelling; they just reinforce the stereotype of physicists being arrogant and condescending towards other disciplines.
In real life, open source has almost always been driven by self interest; people and companies don't invest years in developing software unless there is open source. That is true even for RMS: his philosophy is the result of self-interest and bad experiences with proprietary software.
But Phipps is wrong when he generically says "there is nothing wrong with self-interest". Con-men act in self-interest, but their actions are not beneficial to society at large. And, in fact, Sun's misrepresentation of the Java licenses and the JCP are an example of how, if you fail to balance your self-interest with ethical behavior, you end up screwing your customers and hurting the community; Sun's self-interest has amounted to establishing a proprietary platform by pretending that it's open, and extracting hundreds of man-years of contributions to a proprietary platform under the false pretense that what these people are creating is "open".
As Sun's business keeps going down the toilet, you can expect more and more of this kind of spin from Schwartz, Phipps, and the other talking heads at Sun. It's clever of them to have their "open source officer" make these statements and attempt to reinforce the stereotype of open source developers as anti-capitalist dreamers. Phipps only needs to look at his company's failing business to see how much open source means business. I'm really looking forward to that company closing its doors.
and nobody ever puts up specifics and then I learn nothing
I think the problem is in how you put things. If you wrote "I believe that X is the right way of doing Y because of Z." instead of "The right way of doing X is Y, period." then (1) you come across as someone who it is worth giving feedback to, and (2) the "Z" part tells people how they can give feedback to you.
they have to collect this from everybody (including people who just want to make a phone call or backup their computer) because otherwise the artists can't stay in business.
Well, even better then; I don't want artists to be in business.
I'm curious to know how the money is divvied up among copyright holders.
Generally, it's apportioned based on the number of lobbyists each copyright holder pays for, as well as the campaign contributions of copyright holders to current holders of elected office.
The article seems to be more about exploring class libraries, not "the object system" (which would mean low-level analysis of how methods are invoked etc.).
Furthermore, there is little that is OS X specific about either the class libraries or the object system: the object system comes from Smalltalk, via Stepstone, and the class libraries come from NeXT and borrow heavily from Smalltalk and also exist in GNUStep (and, yes, people are working on porting FScript to GNUStep).
Don't be absurd. You could carpet a small moon with all the alternative theories that have been developed in the literature. See Cliff Will's book and Living Review online for a limited discussion.
Great! So, that was what my original question was about. However, it's not sufficient just to point at "a small moon" "carpeted in theories", you also need to explain how the different theories actually differ, whether they make different predictions for this experiment, and what those predictions are. Unfortunately, none of the information on LIGO that I can find does this--neither the popular news articles, nor the overview papers by project members. They all just say how nifty it would be to detect gravity waves, with no analysis of just those questions.
Computational techniques for, say, binary inspiral are up to spec.
People can't even decide whether Kopeikin's approach actually did or did not measure the speed of gravity. If computational techniques were up to spec, you'd simply do the computation and settle the question. If people can't even compute values for such a simple measurement for the standard theory, there is obviously something amiss with the state of computational gravitational physics.
I said that doing big projects is what research is all about.
Yes, and I think that's a very narrow view. Large scale experiments are almost the exclusive domain of a small subset of experimental physicists (and, very recently, a few biologists). Prior to the bomb, even most physics experiments were bench-top, but the cold war gave a small subset of physicists a lot of power to obtain large amounts of funding. Other disciplines really have not had the luxury of demanding to do a huge, expensive experiment "right now, just because we want to see what happens"--that attitude is almost unique to experimental physics.
The cold war is over, other disciplines have grown up, and other disciplines don't have an inferiority complex anymore. In the future, projects like LIGO II will have to be justified relative to other possible big funding efforts in computer science, biology, ecology, etc.; both politicians and other scientists will demand it, and, mark my words, funding for projects like LIGO II will get increasingly difficult.
But how many small research projects have to be funded so that you get one decent spin-off? A hundred? A thousand?
I think you live a rather protected life. In most disciplines other than experimental physics, you must justify your research in terms of societal and practical relevance, and they often include requirements for commercialization. That's not because those other sciences don't have fundamental questions to ask--they just don't get the funding to do it. So, in short, the answer is, that many funding agencies aim for one spin-off for every single small research grant.
And the only reason I picked up on it is that the distinction is a pet hate of mine. [...] But just to clarify for anyone else, gravity waves are fluctuations in gravity itself. Gravitational waves are a quadrupole phenomena which result from localised changes in gravity from a suitably massive source generating ripples in the background curvature of space-time (where space-time is curved due to the presence of mass).
Actually, the ambiguity that usually upsets people is that "gravity wave" in English also refers to a phenomenon in fluid dynamics. I don't think the original German papers even make the distinction that you are making.
In point of fact, it is quite likely that LIGO I will fail to observe gravitational waves: its sensitivity is borderline. This was known before the project started. It was built anyway, because only in building it could LIGO II be developed, which is the real experiment. If LIGO II doesn't see them, then you can't just attribute that to failed experiment or a misestimate of what waves should be out there: it will mean something's wrong with our theories of gravity.
But the article says something different: "Researchers are extremely confident they now have the technology to detect gravitational waves." But then, "If there is a supernova in our vicinity during the next couple of months, our chances of detecting and measuring the resulting gravitational waves are good". Overall, there seems to be a disconnect between what people believe they can achieve and how they are selling these big projects to the public.
In any case, what you have said now is a reasonable position that one could use as a starting point for arguments about cost/benefit. I still think that when everything is taken into account, these kinds of projects could easily wait for another decade or two. Gravity isn't going anywhere, and I think there is a lot more theory, engineering, and computing that can be worked out and developed with modest funding before spending the enormous amounts of money of building prototypes using current (limited) technologies.
This is a common fallacy. I heard it a lot back in the SSC days. When the SSC was cancelled, did all of that earmarked money go to other physics? No. In reality, much of the funding for these large physics experiments is created specifically for those experiments, and would not exist otherwise.
That's a common cop-out. In fact, there is only a limited amount of funding that can be "created"; if this funding wasn't "created" for those experiments, it could be "created" for other experiments by researchers in other areas.
Speaking as someone who has worked in gravity theory, I think LIGO is a necessary experiment, even if it comes at the expense of some theory. There is no question of "waiting for the theory or experimental technique to catch up". Theory has gone about as far as it can without additional experimental input: there are lots of alternative gravity theories lying around, they are just currently indistinguishable from GR without better data. And the technology to build a working LIGO can't be developed from thin air: the advanced LIGO (LIGO II) experiments could not have been designed without doing LIGO I first. We have the technology now: we simply can't engineer it into a working instrument without testing it for real.
OK, that's a more sensible answer than any of the other b.s. that people have posted as justification for these experiments before.
Personally, I still think it would be better to wait a couple of decades for technology to catch up with the needs of this community and to permit instruments to be built at a small fraction of the cost. Furthermore, I think theory and computational techniques also ought to catch up. I have yet to see a good, clear formulation of alternative theories to Einstein, and computational techniques seem to be weak and ad-hoc.
And aside from this, you need to have reasons to investigate (and therefore invest) in these technologies - this is an example of a large scale project which has the potential for practical and tangible gains in (as I posted before) laser technologies, control systems, material science and computational anaylsis. These are tangible scientific results in their own right with several industrial applications and assorted spin-off tech companies.
To the degree that the spin-off applications are valuable, the spin-off applications themselves will drive the development of the technologies, which can then (in a few decades) be used to conduct the physics experiments at a much lower cost. If the potential spin-offs don't justify investment in the technologies, then your justification that these are economically valuable is bogus.
As to how many billions of dollars it takes - quite a lot. But the practical outcomes I've listed are what you get. Along with international co-operation - many countries working together for a common goal.
Strange as that may be for you to believe, but people don't just collaborate internationally on big physics projects, and useful spin-off technology doesn't just come from big physics projects (and I suspect that dollar-for-dollar, large scale physics projects are one of the least productive projects when it comes to valuable spin-offs).
So, compared to this experiment, many other projects that could be funded with this money not only yield all the practical benefits you list, but in addition have a clear, predictable, and demonstrable scientific benefit no matter what the outcome of the experiment.
Large scale experiments are what research is all about.
I guess according to you, the the millions of researchers in the world that make do with small budgets just aren't doing real research; it's only when you have figured out how to milk the taxpayers out of a few billion dollars for a single experiment that you graduate to real research, right?
There comes a point in research where a table-top experiment just won't do.
We have funded these kinds of experiments for decades, all with negative outcomes. So, there also comes a point at which investing ever more in the same kind of large-scale experiment that yield no results won't do anymore. It seems to me that we have reached this point when it comes to direct detection of gravity waves.
Therefore, again, my question: what's the justification for doing this particular experiment, where previous experiments have failed? Simply saying "it has more sensitivity" isn't good enough--you need to explain why this level of sensitivity should be good enough when the same kind of experimentalists previously argued that the previous level of sensitivity ought to have been good enough then.
And another thing. It's gravitational wave detection. Not gravity wave detection, which is something completely different.
I think you're smart enough to figure out which of the two (valid) senses of "gravity wave" I'm using (and if you have ever bothered to read the original papers, you'll understand why this ambiguity is unlikely to go away even in English).
Yes, let's be absolutely sure we're correct before testing a hypothesis. After all, what are hypotheses for?
What I'm saying is: when we invest a lot of money in an experiment, let's be sure we understand how the experiment and its possible outcomes relate to the hypothesis, and why similar previous experiments have failed. Just doing open-ended experiments without a prior understanding of what the possible outcomes mean is not doing science, it's voodoo or alchemy.
Until such time as it looks like 2) is the case, there's no basis for exploring alternative hypotheses,
"The equipment is wrong" is an alternative hypothesis, albeit not a fully formulated one.
What is happening right now is that, after a number of these experiments have been done in the past and failed to demonstrate the existence of gravity waves, the people involved just say "hey, it didn't work, maybe our equipment wasn't sensitive enough/faulty, so we're just going to try again".
Think of it this way - what if the theory is correct, and there simply *isn't* any "reasonable and plausible alternative hypothesis"
I believe gravity waves exist, but people have failed to detect them in previous experiments. So, that means that either the previous experiments were insufficient to test the theory, or people don't understand the theory enough to make testable predictions. Either way, either people screwed up on the previous experiments, or they screwed up on the theory. The point is that until people have figured out which of the two is the reason previous experiments came up negative, it is difficult to justify funding expensive experiments.
Therefore my question: what are the alternative hypotheses? Another way of putting it is: how do you account for the fact that previous experiments designed to test for the existence of gravity waves didn't find them? Or, more succinctly: before we fund any more of this, we need to know how previous experimenters screwed up.
I note that nobody in this thread has given a satisfactory answer; everybody just waves their hands about how nice it would be to find them, and how it is important to identify them, both of which I agree with. But those are not sufficient reasons to conduct this experiment in light of what we already have done and what we know.
And a null result is easy. All you need is the absence of gravity waves when you observe an event (like a collision of stars or black holes) that should produce them.
Unfortunately, it isn't easy. We have had multiple experiments like this, all quite expensive, and all of them failed to demonstrate gravity waves. Physicists still believe that gravity waves exist but we just need a bit more sensitivity to detect them. That's a reasonable belief, but the question is whether that kind of belief should be enough to finance these kinds of experiments right now, or whether we should simply wait until either theory or experimental techniques have caught up.
It's not like this would be the first experimental confirmation of general relativity.
You can't confirm hypotheses, you can simply fail to disprove them. General relativity has survived a number of experimental tests, but so have an infinite number of alternative hypotheses.
Why does there need to be an alternative hypothesis if there's a chance the first hypothesis is correct?
Because otherwise you can't interpret the results. As I was saying, there have been attempts to detect gravity waves, and they failed to measure them. So, without an alternative hypothesis, you simply don't know: is this because they don't exist? Are they too weak? Are there other possibilities?
None of that matters if you're talking about cheap table-top experiments. But these kinds of experiments are expensive, and other science isn't getting done because these experiments are getting funding.
The difference is that the photoelectric effect didn't take multi-million dollar installations to demonstrate.
The question is and remains whether this particular experiment is a sensible use of scarce research dollars at this time, in particular since the same kind of experiment with the same promises has been carried out multiple times before.
Not to mention the gains in laser technologies, control systems, material science and computational analysis that such a project brings.
Those gains would be even greater if we invested directly in those areas.
if the outcome is negative, then we can set an upper limit (i.e. the waves must be of lower magnitude than X at frequency Y)
We have had half a dozen experiments trying to detect gravity waves, all with negative or indeterminate outcomes. And I note that neither you nor anybody else in this thread has provided a compelling argument why this experiment should be any different. How many billions of dollars are to be sunk into these kinds of fishing expeditions?
The potential gains in knowledge of astronomy, astrophysics and even particle physics are vast.
Until physicists get their house in order, I think large scale experimental physics like this (gravity wave detectors, particle physics, fusion) should get defunded. There are enough areas, both within physics and outside physics, that have yielded far more tangible scientific (not to mention, practical) results and that would use funding far more effectively.
Your argument is predicated on the assumption that we learn something from this experiment, but I don't think we do.
If the outcome is positive, it just confirms all existing theories (but likely won't be compelling enough to do so beyond reasonable doubt), and if the outcome is negative, we simply assume that the detection threshold wasn't good enough.
So, I agree that confirmatory experiments are important, but this one just doesn't seem to be a good one.
MM was an experiment to measure a specific quantity, and it was clear that the quantity could be measured with that apparatus. As soon as the measurement was performed, there was no issue of detection thresholds: whether the measured speed was 0 or 10^-3 m/s, either way presented a problem for the classical theories.
Gravity wave detection is not at all analogous to that, since a negative outcome in this experiment still doesn't really tell you anything.
Slashdot Mirror
The officers should be reprimanded or demoted. But fining the police department doesn't help, since you're just fining yourself (it comes out of tax money).
I live in NH too... I moved here (along with many others) to fight for Freedom.
Well, looks like you got what you wanted, since it seems like you have your work cut out for you.
It doesn't make sense to permit video recording and prohibit audio recording, since you can recover what was said quite reliably from video alone.
Well, their statements are all literally true, but nevertheless, Stanford has many relationships with drug companies, it is deeply involved in drug development, and they patent. This kind of work could easily be "freely available" in the way they describe, yet be the basis for strong patents on the results and applications. But that's the case for a lot of tax-payer funded research as well, so it's probably not worth worrying about--right now, patents and drug companies are the way society has developed drugs, and until that changes, if you want to contribute to helping find cures for diseases, you are going to support drug companies at least indirectly.
Brilliant. With that line of reasoning, the government will be able to shut down the ACLU for "aiding terrorists". You should apply for a job in the Bush administration; they need people with your way of thinking.
I have already told you that physicists DO do this, it's just not published as part of the LIGO project.
Yes, and I have already told you that it must be part of the description of such an experiment, both in the grant application and in any paper describing results; it is not sufficient for the information to exist somewhere in the literature.
That you are ignorant of this work is not a testament to the incompetence of LIGO physicists, it simply speaks to your own incompetence.
Your assumption about what I know is incorrect, but that is not relevant here. My point isn't about the possible theories that exist somewhere, my point is about the kind of information that must be supplied both as part of the preparation and as part of any presentation of a scientific experiment. You keep confirming that, not only is this information is missing in the LIGO documents, but you know so little about the scientific method that you don't even think anything is wrong.
Assuming it gets published, of course, seeing how physicists are incompetent and don't understand theories or computations; maybe the reviewers simply won't recognize your genius.
The problem with LIGO and Kopeikin isn't one of gravitational physics, the problem is one of scientific method and for procedures for using computational methods for establishing correctness of scientific theories. In that area, I am almost certainly more qualified than you, since that's my work. And these omissions are so glaring in this work that I could diagnose them even if I knew nothing about gravitational physics (I know some, but you may well know more than me).
Now your bigotry comes out. You don't have any problem with LIGO, you just have a massive chip on your shoulder against physicists.
I have a chip on my shoulder against sloppy science, in particular when it involves spending billions of dollars of tax payer money.
Look, you ass.
Insults don't make your argument any more compelling; they just reinforce the stereotype of physicists being arrogant and condescending towards other disciplines.
In real life, open source has almost always been driven by self interest; people and companies don't invest years in developing software unless there is open source. That is true even for RMS: his philosophy is the result of self-interest and bad experiences with proprietary software.
But Phipps is wrong when he generically says "there is nothing wrong with self-interest". Con-men act in self-interest, but their actions are not beneficial to society at large. And, in fact, Sun's misrepresentation of the Java licenses and the JCP are an example of how, if you fail to balance your self-interest with ethical behavior, you end up screwing your customers and hurting the community; Sun's self-interest has amounted to establishing a proprietary platform by pretending that it's open, and extracting hundreds of man-years of contributions to a proprietary platform under the false pretense that what these people are creating is "open".
As Sun's business keeps going down the toilet, you can expect more and more of this kind of spin from Schwartz, Phipps, and the other talking heads at Sun. It's clever of them to have their "open source officer" make these statements and attempt to reinforce the stereotype of open source developers as anti-capitalist dreamers. Phipps only needs to look at his company's failing business to see how much open source means business. I'm really looking forward to that company closing its doors.
and nobody ever puts up specifics and then I learn nothing
I think the problem is in how you put things. If you wrote "I believe that X is the right way of doing Y because of Z." instead of "The right way of doing X is Y, period." then (1) you come across as someone who it is worth giving feedback to, and (2) the "Z" part tells people how they can give feedback to you.
It better not be called "X11"...
Unless they actually mean it...
they have to collect this from everybody (including people who just want to make a phone call or backup their computer) because otherwise the artists can't stay in business.
Well, even better then; I don't want artists to be in business.
I'm curious to know how the money is divvied up among copyright holders.
Generally, it's apportioned based on the number of lobbyists each copyright holder pays for, as well as the campaign contributions of copyright holders to current holders of elected office.
The article seems to be more about exploring class libraries, not "the object system" (which would mean low-level analysis of how methods are invoked etc.).
Furthermore, there is little that is OS X specific about either the class libraries or the object system: the object system comes from Smalltalk, via Stepstone, and the class libraries come from NeXT and borrow heavily from Smalltalk and also exist in GNUStep (and, yes, people are working on porting FScript to GNUStep).
Don't be absurd. You could carpet a small moon with all the alternative theories that have been developed in the literature. See Cliff Will's book and Living Review online for a limited discussion.
Great! So, that was what my original question was about. However, it's not sufficient just to point at "a small moon" "carpeted in theories", you also need to explain how the different theories actually differ, whether they make different predictions for this experiment, and what those predictions are. Unfortunately, none of the information on LIGO that I can find does this--neither the popular news articles, nor the overview papers by project members. They all just say how nifty it would be to detect gravity waves, with no analysis of just those questions.
Computational techniques for, say, binary inspiral are up to spec.
People can't even decide whether Kopeikin's approach actually did or did not measure the speed of gravity. If computational techniques were up to spec, you'd simply do the computation and settle the question. If people can't even compute values for such a simple measurement for the standard theory, there is obviously something amiss with the state of computational gravitational physics.
I said that doing big projects is what research is all about.
Yes, and I think that's a very narrow view. Large scale experiments are almost the exclusive domain of a small subset of experimental physicists (and, very recently, a few biologists). Prior to the bomb, even most physics experiments were bench-top, but the cold war gave a small subset of physicists a lot of power to obtain large amounts of funding. Other disciplines really have not had the luxury of demanding to do a huge, expensive experiment "right now, just because we want to see what happens"--that attitude is almost unique to experimental physics.
The cold war is over, other disciplines have grown up, and other disciplines don't have an inferiority complex anymore. In the future, projects like LIGO II will have to be justified relative to other possible big funding efforts in computer science, biology, ecology, etc.; both politicians and other scientists will demand it, and, mark my words, funding for projects like LIGO II will get increasingly difficult.
But how many small research projects have to be funded so that you get one decent spin-off? A hundred? A thousand?
I think you live a rather protected life. In most disciplines other than experimental physics, you must justify your research in terms of societal and practical relevance, and they often include requirements for commercialization. That's not because those other sciences don't have fundamental questions to ask--they just don't get the funding to do it. So, in short, the answer is, that many funding agencies aim for one spin-off for every single small research grant.
And the only reason I picked up on it is that the distinction is a pet hate of mine. [...] But just to clarify for anyone else, gravity waves are fluctuations in gravity itself. Gravitational waves are a quadrupole phenomena which result from localised changes in gravity from a suitably massive source generating ripples in the background curvature of space-time (where space-time is curved due to the presence of mass).
Actually, the ambiguity that usually upsets people is that "gravity wave" in English also refers to a phenomenon in fluid dynamics. I don't think the original German papers even make the distinction that you are making.
In point of fact, it is quite likely that LIGO I will fail to observe gravitational waves: its sensitivity is borderline. This was known before the project started. It was built anyway, because only in building it could LIGO II be developed, which is the real experiment. If LIGO II doesn't see them, then you can't just attribute that to failed experiment or a misestimate of what waves should be out there: it will mean something's wrong with our theories of gravity.
But the article says something different: "Researchers are extremely confident they now have the technology to detect gravitational waves." But then, "If there is a supernova in our vicinity during the next couple of months, our chances of detecting and measuring the resulting gravitational waves are good". Overall, there seems to be a disconnect between what people believe they can achieve and how they are selling these big projects to the public.
In any case, what you have said now is a reasonable position that one could use as a starting point for arguments about cost/benefit. I still think that when everything is taken into account, these kinds of projects could easily wait for another decade or two. Gravity isn't going anywhere, and I think there is a lot more theory, engineering, and computing that can be worked out and developed with modest funding before spending the enormous amounts of money of building prototypes using current (limited) technologies.
This is a common fallacy. I heard it a lot back in the SSC days. When the SSC was cancelled, did all of that earmarked money go to other physics? No. In reality, much of the funding for these large physics experiments is created specifically for those experiments, and would not exist otherwise.
That's a common cop-out. In fact, there is only a limited amount of funding that can be "created"; if this funding wasn't "created" for those experiments, it could be "created" for other experiments by researchers in other areas.
Speaking as someone who has worked in gravity theory, I think LIGO is a necessary experiment, even if it comes at the expense of some theory. There is no question of "waiting for the theory or experimental technique to catch up". Theory has gone about as far as it can without additional experimental input: there are lots of alternative gravity theories lying around, they are just currently indistinguishable from GR without better data. And the technology to build a working LIGO can't be developed from thin air: the advanced LIGO (LIGO II) experiments could not have been designed without doing LIGO I first. We have the technology now: we simply can't engineer it into a working instrument without testing it for real.
OK, that's a more sensible answer than any of the other b.s. that people have posted as justification for these experiments before.
Personally, I still think it would be better to wait a couple of decades for technology to catch up with the needs of this community and to permit instruments to be built at a small fraction of the cost. Furthermore, I think theory and computational techniques also ought to catch up. I have yet to see a good, clear formulation of alternative theories to Einstein, and computational techniques seem to be weak and ad-hoc.
And aside from this, you need to have reasons to investigate (and therefore invest) in these technologies - this is an example of a large scale project which has the potential for practical and tangible gains in (as I posted before) laser technologies, control systems, material science and computational anaylsis. These are tangible scientific results in their own right with several industrial applications and assorted spin-off tech companies.
To the degree that the spin-off applications are valuable, the spin-off applications themselves will drive the development of the technologies, which can then (in a few decades) be used to conduct the physics experiments at a much lower cost. If the potential spin-offs don't justify investment in the technologies, then your justification that these are economically valuable is bogus.
As to how many billions of dollars it takes - quite a lot. But the practical outcomes I've listed are what you get. Along with international co-operation - many countries working together for a common goal.
Strange as that may be for you to believe, but people don't just collaborate internationally on big physics projects, and useful spin-off technology doesn't just come from big physics projects (and I suspect that dollar-for-dollar, large scale physics projects are one of the least productive projects when it comes to valuable spin-offs).
So, compared to this experiment, many other projects that could be funded with this money not only yield all the practical benefits you list, but in addition have a clear, predictable, and demonstrable scientific benefit no matter what the outcome of the experiment.
Large scale experiments are what research is all about.
I guess according to you, the the millions of researchers in the world that make do with small budgets just aren't doing real research; it's only when you have figured out how to milk the taxpayers out of a few billion dollars for a single experiment that you graduate to real research, right?
There comes a point in research where a table-top experiment just won't do.
We have funded these kinds of experiments for decades, all with negative outcomes. So, there also comes a point at which investing ever more in the same kind of large-scale experiment that yield no results won't do anymore. It seems to me that we have reached this point when it comes to direct detection of gravity waves.
Therefore, again, my question: what's the justification for doing this particular experiment, where previous experiments have failed? Simply saying "it has more sensitivity" isn't good enough--you need to explain why this level of sensitivity should be good enough when the same kind of experimentalists previously argued that the previous level of sensitivity ought to have been good enough then.
And another thing. It's gravitational wave detection. Not gravity wave detection, which is something completely different.
I think you're smart enough to figure out which of the two (valid) senses of "gravity wave" I'm using (and if you have ever bothered to read the original papers, you'll understand why this ambiguity is unlikely to go away even in English).
Yes, let's be absolutely sure we're correct before testing a hypothesis. After all, what are hypotheses for?
What I'm saying is: when we invest a lot of money in an experiment, let's be sure we understand how the experiment and its possible outcomes relate to the hypothesis, and why similar previous experiments have failed. Just doing open-ended experiments without a prior understanding of what the possible outcomes mean is not doing science, it's voodoo or alchemy.
Until such time as it looks like 2) is the case, there's no basis for exploring alternative hypotheses,
"The equipment is wrong" is an alternative hypothesis, albeit not a fully formulated one.
What is happening right now is that, after a number of these experiments have been done in the past and failed to demonstrate the existence of gravity waves, the people involved just say "hey, it didn't work, maybe our equipment wasn't sensitive enough/faulty, so we're just going to try again".
Think of it this way - what if the theory is correct, and there simply *isn't* any "reasonable and plausible alternative hypothesis"
I believe gravity waves exist, but people have failed to detect them in previous experiments. So, that means that either the previous experiments were insufficient to test the theory, or people don't understand the theory enough to make testable predictions. Either way, either people screwed up on the previous experiments, or they screwed up on the theory. The point is that until people have figured out which of the two is the reason previous experiments came up negative, it is difficult to justify funding expensive experiments.
Therefore my question: what are the alternative hypotheses? Another way of putting it is: how do you account for the fact that previous experiments designed to test for the existence of gravity waves didn't find them? Or, more succinctly: before we fund any more of this, we need to know how previous experimenters screwed up.
I note that nobody in this thread has given a satisfactory answer; everybody just waves their hands about how nice it would be to find them, and how it is important to identify them, both of which I agree with. But those are not sufficient reasons to conduct this experiment in light of what we already have done and what we know.
And a null result is easy. All you need is the absence of gravity waves when you observe an event (like a collision of stars or black holes) that should produce them.
Unfortunately, it isn't easy. We have had multiple experiments like this, all quite expensive, and all of them failed to demonstrate gravity waves. Physicists still believe that gravity waves exist but we just need a bit more sensitivity to detect them. That's a reasonable belief, but the question is whether that kind of belief should be enough to finance these kinds of experiments right now, or whether we should simply wait until either theory or experimental techniques have caught up.
It's not like this would be the first experimental confirmation of general relativity.
You can't confirm hypotheses, you can simply fail to disprove them. General relativity has survived a number of experimental tests, but so have an infinite number of alternative hypotheses.
Why does there need to be an alternative hypothesis if there's a chance the first hypothesis is correct?
Because otherwise you can't interpret the results. As I was saying, there have been attempts to detect gravity waves, and they failed to measure them. So, without an alternative hypothesis, you simply don't know: is this because they don't exist? Are they too weak? Are there other possibilities?
None of that matters if you're talking about cheap table-top experiments. But these kinds of experiments are expensive, and other science isn't getting done because these experiments are getting funding.
The difference is that the photoelectric effect didn't take multi-million dollar installations to demonstrate.
The question is and remains whether this particular experiment is a sensible use of scarce research dollars at this time, in particular since the same kind of experiment with the same promises has been carried out multiple times before.
Not to mention the gains in laser technologies, control systems, material science and computational analysis that such a project brings.
Those gains would be even greater if we invested directly in those areas.
if the outcome is negative, then we can set an upper limit (i.e. the waves must be of lower magnitude than X at frequency Y)
We have had half a dozen experiments trying to detect gravity waves, all with negative or indeterminate outcomes. And I note that neither you nor anybody else in this thread has provided a compelling argument why this experiment should be any different. How many billions of dollars are to be sunk into these kinds of fishing expeditions?
The potential gains in knowledge of astronomy, astrophysics and even particle physics are vast.
Until physicists get their house in order, I think large scale experimental physics like this (gravity wave detectors, particle physics, fusion) should get defunded. There are enough areas, both within physics and outside physics, that have yielded far more tangible scientific (not to mention, practical) results and that would use funding far more effectively.
Your argument is predicated on the assumption that we learn something from this experiment, but I don't think we do.
If the outcome is positive, it just confirms all existing theories (but likely won't be compelling enough to do so beyond reasonable doubt), and if the outcome is negative, we simply assume that the detection threshold wasn't good enough.
So, I agree that confirmatory experiments are important, but this one just doesn't seem to be a good one.
MM was an experiment to measure a specific quantity, and it was clear that the quantity could be measured with that apparatus. As soon as the measurement was performed, there was no issue of detection thresholds: whether the measured speed was 0 or 10^-3 m/s, either way presented a problem for the classical theories.
Gravity wave detection is not at all analogous to that, since a negative outcome in this experiment still doesn't really tell you anything.
In all seriousness, there are many homeless folks in this world not all of them have the opportunity to get back on their feet.
No, but the Internet gives more of them an opportunity they previously didn't have, and that's a good thing.
Also, by recognizing this possibility, people who work with the homeless can present them additional options.