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A Galaxy-Sized Observatory For Gravitational Waves
KentuckyFC writes "Gravitational waves squash and stretch space as they travel through the universe. Current attempts to spot them involve monitoring a region of space several kilometers across on Earth for the telltale signs of this squeezing. These experiments have so far seen nothing. But by monitoring an array of pulsars throughout the galaxy, astronomers should be able to see the effects of gravitational waves passing by. They say such an array of pulsars should effectively shimmer as the gravitational waves wash over it, like a grid of buoys bobbing on the ocean. That'll create an observatory that is effectively the size of the entire galaxy. These observations should be capable of monitoring how galaxies and supermassive black holes evolve together, and shed light on the physics of the early universe. Best of all, the next generation of radio-telescope arrays should be capable of making these observations at a cost of around $66 million over ten years. That's a small fraction of the hundreds of millions that Earth-based observatories have already cost."
We spend billions on observatories, but what's the point? I understand taking an in-depth look at our galaxy, but this is ridiculous. We should concentrate on landing on mars and other planets in our solar system, then concentrate on other things.
"The difference between genius and stupidity is that genius has it's limits" - Albert Einstein
>>> "Gravitational waves squash and stretch space as they travel through the universe
Gravitational waves are very useful in the kitchen. I use them for juicing oranges.
What do you mean finding absolutely nothing? They just ruled out the higher end of the spectrum for gravitational waves. They learned a lot in building very precisely calibrated instruments to do the gravitational wave detection. They continue to lower the detection threshold.
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that is could falsify the theory? if so then go for it.
I mean, they don't have to exist, there are other theories out there.
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Physics tells us that gravity waves distort time. So, instead of setting up a billion dollar array of telescopes over several square kilometers to monitor this, why not set up an array of clocks with real time feed into a central computer that would record any temporal fluctuations?
Just wanted to point out that the pulsar timing array approach will cover a completely different frequency range (~ 10^-9 to 10^-7 Hz) to existing ground-based detectors (LIGO, Virgo and friends), which operate in the 10^1 to 10^4 Hz range. In between are projects like LISA (http://lisa.jpl.nasa.gov/).
The different frequency ranges mean different astrophysical sources of gravitational waves; generally speaking, the more massive the system, the lower the GW frequency. LISA, for instance, would see the radiation produced by the supermassive black holes at the centres of galaxies, while the other detectors would be targetting much smaller systems.
That's not how the General Public views how science works. If it doesn't immediately give them a bigger erection, bigger breasts, or a fuller head of hair it is deemed a failure and should not be funded further. Sad but true, we're surrounded by IDiots.
Will beings in larger galaxies taunt us because their gravity-wave detectors are bigger than ours?
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maybe we can create artificial gravity like in the movies without having to have big centrifuges built into the hulls.
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If there are no gravitational waves to be found? If we search the entire spectrum, and we don't find any, then I assume that falsifies the grav-wave theory (and the entire Honorverse). At that point, what is the next step/theory? In a related note, does gravity pull, or push? I think I remember reading somewhere that Einstein said gravity pushed, rather than pulled.
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That's correct. Lack of evidence isn't enough to disprove a theory; what you need is evidence that directly contradicts the theory. In the case of gravity waves, it might be observation of an event that should produce detectable gravity waves, combined with our not detecting them.
And, while I'm at it, I'd like to point out that what Popper taught us was that a theory was useless unless there's a way to falsify it, at least in theory. If you can find a way to show that any conceivable experimental results can be viewed as confirming the theory, it's useless because it can't be tested. In the case of gravity waves, they're but one of many things predicted by General Relativity, and one of the few that's not been observed as yet.
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Trolling aside -
How does this actually function like an observatory? Aren't our observatories capable of looking at stars and such... aren't these just like... a bunch of satellites floating out past earth tracking "Gravity"?
I clearly don't understand how pulsars work.
Wait, by this definition, wouldn't every observatory ever built qualify as 'galaxy-sized'?
What do you mean finding absolutely nothing?
Judging by his links to thunderbolts.info, what I think he means is "I'm a crazy idiot who doesn't understand anything, and think this is a sound foundation to question the work of scientists everywhere. Solar wind is caused by an electric field! What do you mean it's a plasma with equal amounts of positive and negative charges, and a field can't move opposite charges in the same direction? No really, I have no idea what you're talking about because I never too physics in school! But my theories are right anyway!"
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You are marked as flamebait but I was seriously wondering why is it that everytime some story like this appears on /. there are a bunch of people going "waste of money! what's the point?"
Perhaps them being the oompa loompas of science explains it.
Gravitational waves have been confirmed in other ways. Not sure if the observations were done incorrectly or if the theory is wrong? Get a more sensitive instrument. Or at least a theory that explains the previous observations that seem to confirm gravitational wave while also predicting the failure to detect them in another way.
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"Gravitational waves squash and stretch space as they travel through the universe."
Does anyone else find these words to be a little presumptuous. It's not like they've ever detected any. Might I suggest the following wording instead:
"Gravitational waves would squash and stretch space as they travel through space, if they exist"
Nothing to do with iDiots. Or does it ?
NASA used to have a telescope aboard a C141 starlifter. I guess you could have a bigger flying telescope aboard a C5 Galaxy.
Say wasn't the Enterprise D a Galaxy class starship ?
I would love to know how fast gravity waves travel. I wonder if they travel faster than light - I know, 300,000 km/s is the Universal speed limit according to Einstein, but...? . If a black hole can keep light from escaping, that means the speed of light isn't escape velocity, and that means that gravity is getting to it faster than the speed of light?
It's NOT me! It's the meds! I'm on 1000mg of Fukitol.
I agree that we should be funding the tracking of NEOs more, but remember that the money for these two projects isn't coming from the same pool. One is a NASA sub-project, the other is an international project conducted by a variety of observatories and funded by a variety of organizations. So it's not as simple as "do this instead of that".
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was poppers idea of falsification falsifiable..?
well actually it doesn't seem to be if you think about it.
i would say that for an idea to have any usefulness in terms of science, it ought to be able to stand up to itself.
LIGO and Pulsars set limits (or could detect) gravitational waves in very different parts of their frequency spectra - periods of milli seconds versus periods of months. The sources are different, the detection physics is different, etc. It's certainly worth trying both.
Also, none of the existing detectors are good enough that you can say for certain that there are known or likely astrophysical sources bright enough that they should see them. You can't talk about falsifiability until you cross that threshold, which I would expect to see happen in a decade or so.
So, stop me if I'm way off base, but might it be impossible to detect gravity waves? If a gravity wave is a change in the gravitational constant of a finite space, then wouldn't that affect the mass, and the space-time qualities of a sensor within that space, rendering its observations relative, and useless?
Or does my thought experiment lack a certain... Knowledge?
Thanks!
> They just ruled out the higher end of the spectrum for gravitational waves.
No. They failed to detect high-frequency gravitational radiation above a certain level. Conventional theory predicts that the radiation they failed to detect should be fairly rare, so the result tends to confirm the established theory while leaving the proponents of some alternative theories with some explaining to do.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
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Is it Crackpot Hour on Slashdot tonight? First electric universe, and now free energy?
Maybe we're just skeptical and don't believe that they exist until you can prove that they do. I thought that was called science. What you are saying is that Santa Clause exists,but you just haven't seen him yet. Let me know when he shows up.
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I believe that any theory of gravity where
1. Energy is conserved
2. Gravitational information propagates at a finite speed (most theories set this speed equal to the speed of light)
will have gravitational waves of some sort.
Is there any physicist who does not believe in both 1 and 2?
Gravitational waves exit. The real problem is detecting them and interpreting the waveforms.
That's correct. Lack of evidence isn't enough to disprove a theory; what you need is evidence that directly contradicts the theory.
We are approaching the point where the lack of evidence becomes evidence of non-existance. But as of yet, I know of no alternative theory.
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Eintein's theory of General Relativity (GR) predicts that gravity waves exist, and GR has already made several other verified predictions. It's a bit like a boat in the water. What we've verified with GR...
No, but my point is that every breakthrough in physics came through because people were ho hum and looking through some theory where they expected to find a result, and didn't. Once upon a time people thought Newtonian mechanics was all there was. We think 100 years of Einstein (wow!), is a long time, but just imagine 300 years of Newtonian physics. All these famous problems that lead to quantum physics - like where does the sun get its energy from, black body radiation, brownian motion, etc, are all really edge cases of newtonian physics.
Science isn't just about observing events and figuring out the cause. It's also about attempting to make predictions based on existing knowledge, and verifying those predictions with experiments.
But its not really useful, unless those predictions were wrong. That's my point. If they find gravity waves, and it confirms GR, that's all well and good but it doesn't really do anything useful as it doesn't change anything and in that sense its a waste of money. But, if there are no gravity waves, or, more spectacularly, there is no Higgs Bosun, then, really, our understanding or rather, physics understanding, of how gravity and mass works is completely wrong, and that would be as interesting as when Rutherford first aimed a beam at a gold foil and realized that the density of the gold is not uniform and got a rather surprising finding about how small atomic nuclei are relative to the size of the space around them.
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I really expected that link to redirect to http://www.timecube.com/
No, were not. Our instruments are still not nearly sensitive enough to say that.
The theoretical reasons, in this case, include General Relativity, as your first link points out. That's passed a lot of other tests, and dropping it would take some big reasons. Trouble confirming just one of many predictions? Interesting, but not excuse enough to abandon a highly successful theory, not at all. Get a competing theory that has substantially more predictive power, and makes substantially fewer untestable claims, and scientists will generally switch, but none of the electric universe models and such proposed are doing any better than GR, and in fact are generally much worse. You've read Sir Karl, but you might want to look at Thomas Kuhn, particularly about how much better a new theory has to be before scientists switch in mass.
The first page you link to characterises the next step in current research as a shift to looking at the noise, when the researchers themselves call it looking at stochastic effects. Stochastic processes must have random elements by definition, and noise, (either literal as in sound or more generally as in signal to noise ratios for all communication) has random aspects as well, but stochastic properties in data are NOT the same thing as noise in communication/observation - In this case, noise in the observations we have on the CBR is probably very different from stochastic effects that may have modulated that same CBR at the time it was emitted. Now it may be possible to prove the two are in fact inextricably linked, which would be a proof on a level with the one showing the total information contained in a black hole is directly related to its surface area. Nice if someone can actually craft the math, but last I looked, no one had succeeded. Without that, the page is too strident for the facts.
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Doesnt mean its not true...Democritus 2400 years ago proposed the existence of the atom.
He had no way testing this, he simply used logic to deduce it.
pun intended
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That position makes science itself entirely useless.
(Unless you can prove scientifically that science is the best way of determining objective truth, and neither we, nor any hypothetical beings living anywhere else in the universe, no matter how powerful their minds are, can ever invent anything better than the scientific method.).
Popper's falsification was a philosophical concept, and might be falsifiable by logic or philosophical debate, but it's not part of science itself, any more than the claim that science works better than every possible alternative could itself be science.
For more on this, try Godel. A sufficiently powerful formal system contains or generates propositions whose truth or falsity cannot be proved within the system. You have to prove some of the claims about science using something besides science itself - If that wasn't necessary, science would be insufficiently powerful to rely upon as a guide to anything important, in much the same way as you couldn't do economics with an arithmetic that didn't include fractions or negative numbers.
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Why can't our great minds that are exploring the Galaxy construct their Observatories on the Moon? Maybe on both Poles? The clarity of their images, I believe, would be fairly difficult to equal across any collections of arrays on Earth.
If gravity waves distort space-time, then how can you extricate the observer from her own deformable frame of reference long enough to make a measurement? Shouldn't there be a quantum effect, like teleportation, if a distortion is detected? Since the effect would probably be small, it would probably show up as weird stuff like unexplained cold or miniscule loss of mass in a reference object.
``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
This is precisely this type of condescending, we-are-am-smater-than-you attitude that turns people off on science and scientists. Maybe physicists should concentrate on the foundational issues (e.g., the true nature of motion) first before they go chasing after gravity waves. You folks are not as smart as you think you are.
But of course you are as smart as you think, which is smarter than every other physicist alive or dead (while so pointedly stating that you aren't one), so this is the kind of condescending attitude we need. LOL.
Did you know that over 90% of physicists believe that matter can move in spacetime even though it is known that spacetime is frozen from the infinite past to the infinite future?
Spacetime isn't frozen. It's warped by mass and constantly expanding. "Did you know" indeed. :)
Did you know that most physicists believe that moving bodies remain in motion for no reason at all, as if by magic?
They also believe that bodies at rest remain at rest for no reason at all, as if by magic! This is no more mysterious.
Well, magic, and that and for it to do otherwise in either case would require an expenditure of energy and a transfer of momentum.
I'll admit, I bit and read the blog, and it was highly amusing. It was very humorous reading about how you agree with Aristotle* that there must be a "force" to make an object move at a constant velocity, and the object should instantly stop as soon as that "force" is removed. And therefore there must be "energy" around us to make this happen. As if "force" and "energy" are vague, mysterious entities, like a sci-fi writer referring to a "mysterious force" or "a being of pure energy".
But actually, force is a change in momentum. If there was a net force acting on a moving object, it would accelerate (or decelerate). If there's no force on an object, it can't accelerate or decelerate, i.e. its velocity must be constant. If the speed of the object changes, then there was a transfer of energy. Energy, by the way, is the principle Newton was looking for. It's the transfer and storage of energy in various forms that explains how objects can begin moving, and continue moving. Conservation of energy was formulated not too long after Newton's conservation of momentum and fills in what Newton couldn't.
The problem with upending physics is that you have to understand it first. This has been the case for all the great physicists, and it's the case today. And you don't understand causality. An object changing its speed, going from motion to no motion, is the effect, and for this to happen there must be a measurable cause, specifically a transfer of momentum and energy. So, please, Conservation of Energy demands an answer: in the absence of any outside force, why would an object moving at a constant velocity stop?
* Great thinker but lousy physicist -- thought his ideas were so good they didn't need testing**! Must be why you're drawn to him. ;)
** Maybe if he had, he would have realized that he was close but off on his idea of an object's natural state in the absence of interference being one of rest, when it's really one of constancy, and we would have Aristotle's Laws of Motion.
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The lack of positive results in gravitational wave detection and the Higgs search reminds me of the Michelson-Morley experiment. Sure I know that we're only scraping the bottom/top of the possible ranges for these phenomena, but I wonder if we aren't just killing time until the next Einstein comes along to explain that there is no luminous aether.
My only political goal is to see to it that no political party achieves its goals.
...well, OK, not in terms of energy consumption, but still thinking big! See http://en.wikipedia.org/wiki/Kardashev_scale
The problem with all this is that the original claims for the LIGO detector were that it would detect something ... Remember, LIGO's predecessor was a huge iridium bar that also detected nothing. Furthermore, LIGO was significantly improved during its operation, and yet it still found nothing. Now the scientists involved claim they never expected it to find anything? Sounds like the multibillion we have poured into the cure for cancer ... still haven't got that! Take another several billion for the next 10 years.
Perhaps gravity doesn't work exactly the way they think? If so, might explain a lot of questions regarding dark matter/energy.
So what do you know, maybe when you'll be older you'll owe your flying car to current research on gravitational waves.
And gravity-defying breast implants for your wife...
Those who can make you believe absurdities can make you commit atrocities. - Voltaire
That made absolutely no sense. There is nothing to gain from trying to falsify an axiom, moron. The entire "idea of falsification" applies to scientific models and hypotheses. Trying to use it on itself (which is more a philosophy than a scientific theory) is completely pointless.
It takes you literally a single mouse click to find out who I am, but I guess that would take a little bit of marbles, huh?
Are we fish in the ocean, trying to detect pressure waves in the water ?
What a depressingly stupid machine.
good effort, but how do you come to the conclusion that "The entire "idea of falsification"" is an axiom and thus doesn't need to be tested...? very convenient!
it doesn't cut it to apply different labels to what are meant to be ideas, that are either true or false.
what is completely pointless is to call something a philosophy as a get out, and of course they don't need to be testable do they.
either you're a hypocrite or you don't know what you're talking about. probably the latter.
the truth is that poppers ideas are vestiges of an outdated understanding of what science should be, a C19 model that has outlived its usefulness.
That's a rebelscience post. It's right up there with timecube on the crazy scale, but not as funny or coherent.
was poppers idea of falsification falsifiable..?
well actually it doesn't seem to be if you think about it.
i would say that for an idea to have any usefulness in terms of science, it ought to be able to stand up to itself.
I think the claim that the way of falsification is the best way to determine the truth is indeed falsifiable.
An experiment could be as follows:
You set up a truth to discover (say, in form of a computer game where you have to find out how some in-game machinery works). Now you get people to find out the truth, either with the method of falsification, or with some other method to be tested against it. If the other method consistently turns up to be more effective, then falsification as best method to find the truth is falsified.
The Tao of math: The numbers you can count are not the real numbers.
Skimming through everything, I'm surprised no one has mentioned the short story "Standard Candles" by Jack McDevitt. In it, the presence of certain star types suggests a massive extraterrestrial beacon system. While certainly a bit farfetched, why not throw out that the presence of pulsars themselves is simply a trans-galactic gravity wave testing system?
We are virgin males who are into Computer Science. We are not into astronomy.
Who is "we"?
The Tao of math: The numbers you can count are not the real numbers.
er...that approach might be considered to lack validity; it's a fake test - its set up- and off the top of my head this would mean that it misses out on criterion validity apart from anything else.
its a moot point, but how could you approach your investigations on the basis that knowledge doesn't have to be falsified?
how would that affect the way that you conduct your investigations (as a participant)?
can you think of any valid way in which you might be able to demonstrate that falsification is a principle that should be adhered to when it comes to science (big clue - there isn't any)
No, I'm "not even" wrong, I'm experimentally verifiably right.
And you on the other hand are experimentally verifiably wrong.
It's sad that you think Newton endorses your viewpoint, because you don't understand that he's explaining a simple problem that the only force that the Laws of Motion define is the reactive force, so in a system with no initial movement, how is movement then imparted. The answer is that there must be some other force outside the Laws of Motion, and there is. Gravity, for instance. That's why Newton didn't spend a lot of time on the issue. You're just confused and ignorant enough that you misinterpret him horribly.
As Wolfgang Pauli would say "Who is this idiot quoting me in support of his crackpot theory? Hey kid: Take a real physics class, you might learn something."
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On a mission to refute ignorant crack-pottery, in the hopes that onlookers won't be bamboozled by bullshit, even if it is just an elaborate troll. But gutless? Please, bitch. You're the one dodging. Answer the Conservation of Energy question or shut the fuck up forever. May your rampant auto-fellation result in asphyxia.
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ahahaha... I see that the usual politically correct Slashdot gang is hard at work, as ususal, supressing free expression. Did I mention that you people were stupid as fuck? ahahaha... AHAHAHA... ahahaha...
You'd rather prove you have no stones than prove you have no clue.
Yeah, that's what I thought, bitch.
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This, ladies and gentlemen, is the exact post where Louis Savain lost the rest of his mind.