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."

Comments

Guess LIGO failed too many times

[Anonymous Coward]

See http://www.thunderbolts.info/thunderblogs/davesmith_au.htm and also http://www.thunderbolts.info/thunderblogs/guest.htm. I guess when you look for evidence of something and find absolutely nothing, it's okay not to abandon the theoretical reasons why you looked for it in the first place. Clearly you just need to use a galaxy as a detector this time. Yeah, right. How scientific. How long will it be until you guys quit defending this non-falsifiable bullshit and learn what Karl Popper tried to teach us a long time ago?

Re:Guess LIGO failed too many times

[A beautiful mind]

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.

Re:Guess LIGO failed too many times

[Anonymous Coward]

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.

Re:Guess LIGO failed too many times

[techno-vampire]

I guess when you look for evidence of something and find absolutely nothing, it's okay not to abandon the theoretical reasons why you looked for it in the first place.

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.

Re:Guess LIGO failed too many times

[Chris Burke]

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!"

Re:Guess LIGO failed too many times

[Anonymous Coward]

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.

Re:Guess LIGO failed too many times

[sadness203]

Nothing to do with iDiots. Or does it ?

Re:Guess LIGO failed too many times

[Louis Savain]

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.

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? Did you know that physicists have no clue as to what keeps a moving particle in motion? Did you know that most physicists believe that moving bodies remain in motion for no reason at all, as if by magic?

My own research, based on the application of the principle of causality to motion, has led me to conclude that we are swimming in a enormous sea of energetic particles. Having a correct causal model of motion will unleash an age of free energy and extremely fast transportation.

The Problem With Motion

Re:Guess LIGO failed too many times

[Anonymous Coward]

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.

Re:Guess LIGO failed too many times

[mbone]

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.

Re:Guess LIGO failed too many times

[John Hasler]

> 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.

Re:Guess LIGO failed too many times

[Goaway]

Is it Crackpot Hour on Slashdot tonight? First electric universe, and now free energy?

Re:Guess LIGO failed too many times

[Louis Savain]

If you got any gonads, identify yourself and be on the record. Why be ashamed of what you are? A little bit of gonads is all it takes. :-D

Re:Guess LIGO failed too many times

[Stridar]

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.

Re:Guess LIGO failed too many times

[__aasqbs9791]

I really expected that link to redirect to http://www.timecube.com/

Re:Guess LIGO failed too many times

[pavon]

No, were not. Our instruments are still not nearly sensitive enough to say that.

Re:Guess LIGO failed too many times

[Artifakt]

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.

Re:Guess LIGO failed too many times

[Artifakt]

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.

Re:Guess LIGO failed too many times

[grikdog]

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.

Re:Guess LIGO failed too many times

[Chris Burke]

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.

Re:Guess LIGO failed too many times

[NonSequor]

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.

Re:Guess LIGO failed too many times

[SlashWombat]

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.

Re:Guess LIGO failed too many times

[Anonymous Coward]

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.

Re:Guess LIGO failed too many times

[Goaway]

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?

Re:Guess LIGO failed too many times

[Anonymous Coward]

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.

Re:Guess LIGO failed too many times

[Louis Savain]

You're not even wrong.

Re:Guess LIGO failed too many times

[Anonymous Coward]

That's a rebelscience post. It's right up there with timecube on the crazy scale, but not as funny or coherent.

Re:Guess LIGO failed too many times

[maxwell demon]

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.

Re:Guess LIGO failed too many times

[Anonymous Coward]

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)

Re:Guess LIGO failed too many times

[Chris Burke]

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."

Re:Guess LIGO failed too many times

[Louis Savain]

'Not even wrong' does not do it justice. You're a gutless ass kisser on a mission. :-D

Re:Guess LIGO failed too many times

[Chris Burke]

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.

Re:Guess LIGO failed too many times

[Louis Savain]

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...

Re:Guess LIGO failed too many times

[Chris Burke]

You'd rather prove you have no stones than prove you have no clue.

Yeah, that's what I thought, bitch.

Re:Guess LIGO failed too many times

[WhoIsThePumaman]

This, ladies and gentlemen, is the exact post where Louis Savain lost the rest of his mind.

I don't get it.

[XPeter]

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.

Re:I don't get it.

[A beautiful mind]

A human landing on mars gives us pretty pictures and a bunch of cozy, warm feelings.

Understanding fundamental physics (and mathematics) gave us the computer age along with keeping Moore's "law" working for the past 40 years. What did physics ever give to you? Pretty much every major engineering invention since 1950 depends on it in some way or other.

Re:I don't get it.

[icebike]

> We spend billions on observatories, but what's the point?

Calm down. There is a depression going on.

All that money enters the economy employing everyone from astronomer to shoe-shine guys. In the mean time some science gets done.

If your tag line is to be believed, you will forgive us if we wait till you are actually OUT of your mom's basement before we task you with prioritizing our national science budget.

Re:I don't get it.

[Anonymous Coward]

Who modded this overrated? The OP has a valid point, are the mods on their periods?

Re:I don't get it.

[XPeter]

> >Calm down. There is a depression going on.

.

Exactly. So, why should we be spending money that we don't have?

Finding gravitational waves isn't going to help 99.99% of the population.

Re:I don't get it.

[Gerafix]

No it isn't, you fool. There's no Grand Scientist Bureaucracy where they dole out what every scientist is going to work on. There are many different fields and many different scientists who would like to work on many different things. Damn false dichotomies with you people, get a grip on reality for IPU sake.

Re:I don't get it.

[Gerafix]

Since when does everything science accomplish have to have immediate material benefit to humanity? Science is the advancement of Homo sapien knowledge about the universe. If you're going to complain about spending money complain about throwing trillions of dollars at the people who brought down the economy. Some people need to grow up.

Re:I don't get it.

[TheBilgeRat]

Umm...actually finding gravitational waves would help 100% of the population. That, and the weight of gravitrons. I'd like the theory holding me to the ground to become a law sometime-not too keen on drifting out of the atmosphere on a whim of disbelief...

Re:I don't get it.

[Anonymous Coward]

"Finding gravitational waves isn't going to help 99.99% of the population."
"I think there is a world market for maybe five computers."

Pray stop making bald statements which you are insufficiently experienced to understand the implications of. Or, in simpler words, shut up and let your betters talk.

Re:I don't get it.

[mcpkaaos]

He's 15 years old. It's much easier for him to understand and critique something that has been summed up than to spend the time and critical thought necessary to understand our present economy. Let's give the little bastard^Wwhippersnapper a break, he's trying.

Re:I don't get it.

[Fluffeh]

Exactly. So, why should we be spending money that we don't have?

Finding gravitational waves isn't going to help 99.99% of the population.

How about you look at this this way instead:

There is a lot of money going around to try to help a flailing economy. Why should that money go ONLY to those who have been bad at their business? Automakers that don't make the right cars? Banks that don't have solid lending strategies? Why NOT give some of that money that's all going to the same economy to scientists who quietly go about their business and get things done?

Re:I don't get it.

[icebike]

> Exactly. So, why should we be spending money that we don't have?

Because you can not frugally "save" your way out of a depression. That simply leads to a deeper depression.

Its cheaper to build these things (as well as other infrastructure) in a down economy than wait till everyone if fully employed and demanding big salaries.

Re:I don't get it.

[John Hasler]

> We spend billions on observatories, but what's the point?

To learn.

> I understand taking an in-depth look at our galaxy, but this is ridiculous.

Why?

> We should concentrate on landing on mars...

Well, then you and your colleagues[1] should concentrate away. Meanwhile, these people choose to concentrate on something else.

[1] I assume you have colleagues: why else do you write "we"?

Re:I don't get it.

[jfengel]

> Since when does everything science accomplish have to have immediate material benefit to humanity?

To play devil's advocate... it's not so much a matter of "what science accomplishes" as "who pays for it". One is entitled to some sort of opinion when one is paying for it, via tax dollars.

It is, as you point out, shortsighted to assume that all science must have an immediate benefit to be worth it. But it is worth considering whether money spent on basic research might be better spent elsewhere.

(Personally, I'd rather spend a lot more on basic research, but those who want to pay less for it are entitled to an opinion when it's their money.)

Re:I don't get it.

[poopdeville]

Gravitational waves are basic research. You don't get much more basic than wave propagation of a fundamental force.

Re:I don't get it.

[Foobar of Borg]

Understanding fundamental physics (and mathematics) gave us the computer age along with keeping Moore's "law" working for the past 40 years. What did physics ever give to you? Pretty much every major engineering invention since 1950 depends on it in some way or other.

The sad thing is that I've met plenty of computer geeks who basically say that physics is useless. They then go back to their beloved computers without realizing the tragic irony of what they just said. That's the pathetic thing about computer "science" majors. They think they know everything because they know how to fuck around with a computer, but they are too stupid to realize that they don't know usually what they are talking about.

Re:I don't get it.

[TropicalCoder]

"Umm...actually finding gravitational waves would help 100% of the population."

Finding gravity waves is the key to finding anti-gravity waves. You see, every particle has its anti-particle. The are electrons and positrons. The are protons and anti-protons. There are top quarks and there are bottom quarks. There are charming quarks and there are boring quarks. There are gluons and anti-gluons. Just imagine what a beam of these would do to your enemy. Leaves nothing but quarks flying in all directions! Not a pretty sight. There is the w-boson, also called the "God particle" and its opposite - the "Atheist particle." Then finally there are gravitons and there are anti-gravitons. Anti-gravitons are the basis of your common tractor beam. I hope you found this discussion illuminating.

Re:I don't get it.

[4D6963]

I know it's counter intuitive, and back when I was about your age (that's right, I'm patronising you. Feels good man.) I myself didn't get it, but basic science (the kind that seems like useless theoretical dicking around like that gravitational waves thing) is a sort of long term investment, and a great kind of investment, as you can get several times your investment back.

Think about it, what good was nuclear research in the 19th century? Yet a few decades later they probably kept us safe from an all out war against USSR, they power clean power plants, submarines, aircraft carriers, cruisers, destroyers and space probes. The research on quantum physics keeps on giving more and more, mostly as we manufacture things that keep getting smaller, like computer chips. We wouldn't have GPS if it wasn't for Einstein's relativity, and I let you guess what good did research that made transistors was good for. If you look into any technology and progress you'll find that at its root is basic research that wasn't obviously going to give that. Who would have thought that research in chemistry and fluid physics would get us to the moon?

So what do you know, maybe when you'll be older you'll owe your flying car to current research on gravitational waves.

Also, look at it this way. If we only did applied research to find things with direct applications, we wouldn't have gotten far. A good analogy is, if explorers had always only sailed within sight of a coast, we would have never discovered the Americas.

Re:I don't get it.

[giorgist]

Hang on, even better. Look at all that money being spent on womens hadbags. It's billions upon billions. What about makeup or alternative medicine with evidence that it does not work. We are now into the trillions ...

So I propose before you take a hit on science, maybe you should look at so much other usless spending and save a few kids from hunger

YEs NO ?

Re:I don't get it.

[Anonymous Coward]

do you think the bottom quarks ever want to be on top? or are they naturally sub?

Re:I don't get it.

[Anonymous Coward]

That's the pathetic thing about computer "science" majors. They think they know everything because they know how to fuck around with a computer, but they are too stupid to realize that they don't know usually what they are talking about.

Yeah, that and they think all physics majors are alike. The nerve of some people.

Re:I don't get it.

[Lorkki]

The sad thing is that I've met plenty of computer geeks who basically say that physics is useless. They then go back to their beloved computers without realizing the tragic irony of what they just said.

Still, you're making that remark using a web browser running on top of a software stack made up of at least a multi-tasking OS kernel, a dynamic linker and an assortment of userspace libraries, written in various high-level programming languages with optimising compilers. It's not as if the transistors came up with all that by themselves.

Physics in itself is important, there's just no need for most people to be physicists.

Re:I don't get it.

[Omnifarious]

I was in an academic computer lab devoted to the sciences once. The disdain for computer scientists was clearly evident. All the while they used numeric algorithms computer scientists discovered and operating systems that were the result of a lot of work by computer scientists, and any number of other artifacts of the 'science' they so disparaged.

I found it really disheartening, and it left me with a really bad taste in my mouth about scientists. Perhaps things have changed now, but at the time, 10-20 years ago or so, disrespect for the people who made the tools that made their investigations even possible was rampant.

The funny thing is, chemists respect the people who make their glassware. I imagine the construction of telescopes is a respected field for astronomers. But computer science seems not to garner any respect among scientists.

Maybe the problem is that it should just never have been named computer 'science'. I don't think it's a science any more than mathematics is.

Re:I don't get it.

[rbowles]

Sorry - couldn't help myself - if you're going to identify yourself as someone's better, ...

s/bald/hairless/; s/hairless/bold/;

Re:I don't get it.

[Anonymous Coward]

I believe the GP used the term bald in the sense of:

lacking detail; bare; plain; unadorned: a bald prose style.

Or maybe even:

open; undisguised: a bald lie.

If you are going to be a pedant, at least be familiar with the multiple definitions of a term, and maybe question whether the modern or popular definition is or is not the original definition. My guess is the latter.

It's fun to nitpick strangers, isn't it?

Re:I don't get it.

[bill_mcgonigle]

Why should that money go ONLY to those who have been bad at their business?

wait, you don't still think they were trying to fix the economy, do you?

Usefulness

[JustNiz]

>>> "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.

Re:Usefulness

[A beautiful mind]

Detecting or not detecting gravitational waves validates* or invalidates part of Einstein's theory of general relativity. That's a pretty big deal. It means that we have found the first flaw in a theory whitstanding constant attacks on it since 1915 if we would not find gravitational waves.

*take "validates" in this context to mean that there is no experiment or information in disagreement with the theory, therefor going by science's falsification requirement, science considers the theory to be currently valid.

Re:Usefulness

[MillionthMonkey]

I use them to make binary neutron stars swirl into each other and explode. They remove energy from the system so you can pack those stars in there real good... and rapidly spinning black holes make great gifts for the kids.

Re:Usefulness

[TheRealMindChild]

Every time someone finds something that Einstein "may have gotten wrong", we just end up with more evidence that he was right.

Personally, I don't believe in something like gravitational waves, but I'm more inclined to trust his intelligence more than mine.

Re:Usefulness

[Anonymous Coward]

It is indeed interesting that we have yet to find evidence of gravitational waves at the same time as we have no perfect explanation for the Pioneer anomaly and the Flyby anomaly. For example, could it be that the real space-time has more properties than those that are described in General Relativity, or would that be impossible?

Re:Usefulness

[TheRealMindChild]

Or... there is a mass we don't know is there. The universe tends to be a lot simpler than we try to make it.

Re:Usefulness

[4D6963]

I feel the same way, you can bet your money on Einstein every time, but we have to test anything we can anyway to verify everything and hope to learn more.

Re:Usefulness

[blueg3]

Personally, I don't believe in something like gravitational waves

Science: You're doing it wrong.

Re:Usefulness

[eyepeepackets]

...the little goofy looking gray guys were approaching my rear portal with what may have been a probability probe. Out of desperation to appear non-plussed I casually asked, "Is that a gravity probe?"

Dead silence, but the little goofy looking gray guys (LGLGG, or Luglugs) were twitching and the approach to my posterior was delayed. Occasionally one would tweet out a tune followed by much more twitching. It occurred to me: They were laughing.

At first I suspected they might be laughing at the my soon-to-be-even-more-desperate situation but then, on a hunch, I blurted out, "A gravity detector?"

Increased twitching and tweeting from the Luglugs suggested I had found a possible escape from a most certain -- and certainly uncomfortable -- probing. A few Luglugs were obviously having problems balancing, leaning into tables whilst twitching uncontrollably. I took the shot.

"An anti-gravity generator!" Withing seconds, all the Luglugs were splayed out on the floor, a twitching and tweeting mass of Luglug hysteria.

Later upon returning me home (un-probed,) the obviously exhausted Luglugs slammed the door in my face when I offered the phrase, "I love Gravity!"

The moral of my story: When one is about to get one's ass reamed by a higher intelligence, gravity as a concept may have some value. Otherwise, not so much.

Re:Usefulness

[L4t3r4lu5]

I have a friend who doesn't believe in gravity.

I've never asked him why; I'm afraid that if he gave me the answer, I'd have to get him Sectioned.

Re:Usefulness

[Anonymous Coward]

Personally, I don't believe in something like gravitational waves

Science: You're doing it wrong.

... bitches.

Re:Usefulness

[Anonymous Coward]

http://www.thunderbolts.info/thunderblogs/thornhill.htm

The Simple Electric Universe

The big bang was not "discovered" but contrived by mathematicians following the proposal of a Belgian Roman Catholic priest and astronomer, George Lemaitre, for the origin of the universe from a "primeval atom" or "Cosmic Egg exploding at the moment of the creation." The theory defies physics principles and is unrealistic, needing most of the matter in the universe to be invisible (not even dark) and a mysterious 'dark' energy. Even galaxies must have mathematical figments (black holes) at their hearts to explain just a few of their characteristics. Hoyle believed one single, usually simple, observation could unseat a strongly established prejudice like the big bang. But when you believe in theories like the big bang, logic has no dominion and any observation can be accommodated.

The Electric Universe is developed upon plasma cosmology, which is a recognized discipline within the practical electrical engineering profession through the Institute for Electrical and Electronic Engineers (IEEE). Refereed papers on plasma cosmology are published in the IEEE Transactions on Plasma Science. The freewheeling discussion in that journal is reminiscent of the science journals of more than a century ago, not the monoculture of the big bang today. My paper on the electrical nature of supernovae and stars was published there in 2007. (It is curious that astronomers' plot stellar colors and brightness (the Hezsprung-Russell diagram) like "Alice through the Looking Glass." Left and right are reversed, which makes it difficult to see the obvious connection between the electrical power arriving at a star and the star's color, size and brightness). Unlike big bang cosmology, plasma cosmology is subject to experimental tests in the laboratory and follows the Lichtenberg experimental tradition. Any 'bangs' it creates are real and noisy. Plasma cosmology can demonstrate with simple physical principles the electrical formation and behavior of spiral galaxies and stars without recourse to hypothetical dark matter and black holes.

Almost the entire visible universe is composed of plasma - a gas where some of the atoms have lost an electron or two. However, unlike the gases we are familiar with on Earth, plasma reacts strongly to the presence of electromagnetic fields and is a better conductor than copper. Its behavior has been described as complex and "life-like." That should be a clue! The universe is principally an electrical plasma phenomenon.

Electricity exists in space. Magnetic fields detected in space can only be generated by electric currents. Radio telescopes routinely map galactic magnetic fields and their field configuration matches that found in plasma cosmology experiments. If science were the advertised open pursuit of truth, we should expect big bang cosmologists to be rushing to the plasma labs. Not a bit of it.

and so on

Is thisntest desing in such away

[geekoid]

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.

Re:Is thisntest desing in such away

[BJ_Covert_Action]

Is thisntest desing in such away

Is your title designed in such a way that could falsify your hopes of being taken seriously?

....

Yes.

Re:Is thisntest desing in such away

[rts008]

Is thisntest desing in such away that is could falsify the theory?

What language is this written in?
What does it translate to in English?

Re:Is thisntest desing in such away

[L4t3r4lu5]

Drink a few tins of hobo beer and you'll be able to understand it, no problem.

It says "GAHHHHH FUGGIN PIGEONS GET OFF MY HAT... I love you."

Re:Is thisntest desing in such away

[Anonymous Coward]

Is this test designed in such a way that it could falsify this theory?

Huh?

Re:Is thisntest desing in such away

[Jarnin]

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.

In science the word "Theory" means "the best possible explanation that hasn't been disproven". Notice the first half of the sentence. You can't have multiple "best possible explanations".

Gravity waves distort time

[Anonymous Coward]

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?

Re:Gravity waves distort time

[poopdeville]

they did. telescopes are clocks. Radiotelescopes are extremely high temporal resolution clocks.

A complementary approach

[beanyk]

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.

Re:A complementary approach

[TropicalCoder]

Thank you for your interpretation of the meaning behind today's article. It was a revelation for me to consider gravity waves as an analogue of electromagnetic waves. On the The North American Nanohertz Observatory for Gravitational Waves web site there is more information. They say "The timing precision of today's best measured pulsars is less than 100 ns. With improved instrumentation and signal-to-noise it is widely believed that the next decade could see a pulsar timing network of 100 pulsars each with better than 100 ns timing precision." I thought it interesting that they only get 100. Then if you did a long term integration of these signals, you may get down to pico-second timing. Such a timing base may be used to correct atomic clocks in GPS satellites and have many other uses. This is all just pure speculation by a non-physicist, so take it with a grain of salt.

Re:A complementary approach

[electrostatic]

If the pulsars under observation are, say, 100-1000 light years apart, then the time necessary to notice a gravitational wave perturbation would seem to be on the order of 100-1000 years, respectively.

IOW, because gravitational waves travel at light speed (general theory of relativity), then a "stretch and squeeze" at one pulsar would reach the more distant pulsar many years later. The observed delay is of course a function of the distance between the pulsars, the angle of the wave and the angle of them to earth.

OTOH, a gravitational wave train with a wavelength much shorter the the distance between the pulsars could also be observed if a lot of pulsars were involved -- and if the observation period was at least one cycle. The 10^-9 frequency mentioned equates to a 31.7 year period.

Re:A complementary approach

[Rakshasa Taisab]

And what do you do when the pulsar star has the 'glitch' in its rotational speed, caused by what ever it is... adjustment of the crust, startquakes, or what the theory of the month is.

Not a very good clock, now is it. ^_^

Re:A complementary approach

[Scott Ransom]

The good thing is that the pulsars which glitch are the young ones (hundreds to millions of years old). The pulsars that we are using for NANOGrav are millisecond pulsars which are hundreds of millions or billions of years old, have much smaller magnetic fields than young pulsars, and basically never glitch. They are extremely stable rotators -- much better than normal pulsars.

Re:A complementary approach

[KumquatOfSolace]

That was my first thought...but maybe they are looking for signs that the space between us and the pulsar has been distorted.

Re:A complementary approach

[Anonymous Coward]

Only one pulsar glitches at a time. If you're monitoring many of them simultaneously, you can identify and compensate for it.

Re:A complementary approach

[Kagura]

what ever it is... adjustment of the crust, startquakes, or what the theory of the month is.

The stopquakes are the ones you have to watch out for.

Re:A complementary approach

[fmackay]

With a sufficient number of pulsars there should be a pair such that a line between the two is sufficiently tangential to a gravitational wavefront to allow for coincidences to be detected in a period substantially shorter than a human lifetime.

I would be most surprised if the experiment was not designed so that this period should be less than the life expectancy of the lead researcher, less the median Nobel lag in Physics.

Galaxy envy?

[davidwr]

Will beings in larger galaxies taunt us because their gravity-wave detectors are bigger than ours?

Re:Galaxy envy?

[eviloverlordx]

I guess size really does matter.

Re:Galaxy envy?

[Anonymous Coward]

I guess we'll need a Large Hardon Collider.

This is /.

[Sybert42]

We are virgin males who are into Computer Science. We are not into astronomy.

Re:This is /.

[Anonymous Coward]

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.

Re:This is /.

[maxwell demon]

We are virgin males who are into Computer Science. We are not into astronomy.

Who is "we"?

If we learn about gravity....

[NoYob]

maybe we can create artificial gravity like in the movies without having to have big centrifuges built into the hulls.

Re:If we learn about gravity....

[imakemusic]

Or maybe we could create a gravity-powered engine for pelling space craft.

How cool would that be?

So what happens

[Xaedalus]

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.

Re:So what happens

[Ralph Spoilsport]

I think that is an excellent question. It's the classic divide between Einstein and Bohr. For Einstein, gravity is geometric, for Bohr et al, it is a product of Stuff and Stuff exists as particles, waves, and/or both.

If they don't find gravity waves in this attempt, I would suspect the following to happen:

A: One bunch, the Einsteins of the lot will say "Well, I toldja so..."

B: The Quantum types will simple demand more money for an even bigger test that will look at clusters of Galaxies or some such conglomeration of Stuff.

When that test fails, go back to step A. Rinse. Repeat.

RS

Re:So what happens

[amRadioHed]

I don't think Einstein said that gravity pushed or pulled, it just warped space-time.

Re:So what happens

[Xaedalus]

But gravity is a force. As a force - does it push, or pull? We know that it exerts a force over matter... but what are the implications if it pushes rather than pulls?

Re:So what happens

[Anonymous Coward]

Whether gravity pushes something down or pulls it down, it's still applying a downward force and accelerating it downward. What do you mean by push and pull, anyway? Normally, you push something away, or pull it towards you, so by that definition, gravity always pulls.

However, both of those definitions are simply based on which way something is moving. Are you using some definition of push and pull where there's a major difference in what sort of force you're applying?

Re:So what happens

[dido]

If gravity waves didn't exist, you'd have to find some other explanation for PSR B1913+16, which is a pulsar in orbit around another star. The pulsar and its companion are spiraling in together, losing energy in exact agreement with the phenomenon of gravitational radiation predicted by General Relativity. This binary pulsar system has been hailed as sufficiently convincing indirect evidence for the existence of gravity waves that Russell Alan Hulse and Joseph Hooton Taylor Jr. were awarded the 1993 Nobel Prize in Physics for its discovery.

No, it doesn't seem that the existence of gravitational waves is in any question here. The only thing is that there might be much yet we don't understand about gravity that is stifling our ability to observe them directly. It's obvious that General Relativity is far from being the final word on gravitation.

Re:So what happens

[Starcub]

Of course gravity is a force. F=mA, or, a force causes a certain mass to accelerate by a certain amount. IIRC, the gravitational model Einstein developed was something like a sheet being streched out across space. Objects (like those that make up our planetary solar system) rest on this 'sheet' and create 'wells'. Thus, objects that are close enough to each other will slide down the well, experiencing higher attractive, "pulling", force. However, such traditionally observed gravitational forces are not predominate on all scales. In other words, gravity seems to behave differently depending on what scale you are looking at.

It was once assumed that the universe was contracting towards some central 'big bang' point because it was assumed that this model held universally. However, we know that at the atomic level, there are grvitational forces that repel particals. Towards the opposite end of the scale, because the universe is expanding, we know that there is a point at which gravity changes from an attractive to a repulsive force as well. Thus, one could say that we exist in a 'sheet' of gravitation law.

In fact, the recent discoveries that show the universe is expanding is where the concept of "dark matter" producing "dark energy" comes from. We dont exactly know how the laws of gravity apply on different scales.

Traditionally speaking, I would think the existance of gravitational waves to be easily verifiable. I suspect that the experiments described in this article are designed to probe the limits of what we know in order to determine exactly how gravity behaves on previously unobserved scales.

Re:So what happens

[PiSkyHi]

What's funny from my point of view, is that when I felt I understood what general relativity is about and how affects every question I ask of the universe, I had no idea people would even think to try and detect them.

Sure, observe their effects, but detect somehow implies that the detector can sit outside of spacetime - it seems that many have completely misunderstood that observing an effect like gravity which is known to change the observed path of anything with even the faintest hint of mass, including light itself - with a time dilation to match its observed frequency variation - the thing itself perceives no change in its own clock and the thing is still tied to its observer. The bending of spacetime is not something that can be avoided or even transform mass and energy - observing changes in energy are observations that require space and time to achieve and the remote energies existence maybe observed differently in different relative locations and the effect of a pulsar may not be a loss of energy, but an observed loss due to time dilations in amongst the environment of the pulsar.

I realise my post sounds a little convoluted and perhaps a little arrogant, I just wonder if most scientists see how easy it is to misunderstood the implications of general relativity.

Not interested, sorry

[Monkeedude1212]

I'm Christian.

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.

Re:Not interested, sorry

[Anonymous Coward]

carefully read the article. Then go read up about the parts you dont understand. Theres nothing magical to see here ( sorry ).

Re:Not interested, sorry

[blueg3]

The satellites are sensitive microphones to pick up and retransmit to Earth the quiet whispers of Satan.

Re:Not interested, sorry

[Anonymous Coward]

Ignorance is bliss. Shouldn't you be in church or something?

Re:Not interested, sorry

[hazah]

Why did you bother posting?

Galaxy-sized observatory?

[Anonymous Coward]

Wait, by this definition, wouldn't every observatory ever built qualify as 'galaxy-sized'?

Re:Galaxy-sized observatory?

[hansraj]

If every observatory ever built were using a galaxy as a sort of measuring instrument, then yeah. What's your point?

Re:Galaxy-sized observatory?

[Monkeedude1212]

Thats what I don't understand - how do you use the galaxy as a measuring instrument?

Re:Galaxy-sized observatory?

[Sebilrazen]

Pulsars are your measuring instruments. They feed back their measurements as a periodic electromagnetic signal. Since the period, per pulsar, is standard any deviation could indicate a measurement to be researched. Pulsars are distributed roughly equally throughout the galaxy, so in theory we can use the entire galaxy as our observatory.

Disclaimer: not an astrophysicist, I could be entirely wrong.

Comment removed

[account_deleted]

Comment removed based on user account deletion

That's a little presumptuous.

[mosb1000]

"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"

Re:That's a little presumptuous.

[nstlgc]

Technically speaking, no. They squash and stretch space by definition. If they don't exist, space obviously won't be squashed and stretched by them, but that won't change their definition. They just won't exist. It's like saying "a unicorn has wings". The fact that it allegedly doesn't exist doesn't mean it doesn't have wings when someone draws one.

Re:That's a little presumptuous.

[mosb1000]

No, the article is making a claim about space, which is real. It would be like me saying "Unicorns are eating my lawn," which is obviously not true. What I should say is "Unicorns might eat my lawn, if they exist."

Re:That's a little presumptuous.

[poopdeville]

If gravitational waves exist, they are nothing but the wave-like propagation of the gravitational force. We already know the gravitational force exists, and warps space-time.

Re:That's a little presumptuous.

[kindbud]

Space itself is a theoretical construct and gravitational waves passing through it are part of the same theory. So it is more correct to say:

"Gravitational waves, if they exist, would squash and stretch space, if it exists, as they travel, if travel is possible, through the universe, if it exists."

But that's retarded, so they don't.

Anything else I can help with, just ask.

Re:That's a little presumptuous.

[blueg3]

It's not like they've ever detected any.

If only the summary had said so! Wait...

Might I suggest the following wording instead

No, that would be presumptuous.

Perhaps the summary author assumed a level of reading comprehension. It might be presumptuous if we knew there were gravitational waves, but not what their behavior was. However, we know their behavior, but not if they exist.

Re:That's a little presumptuous.

[Anonymous Coward]

Wikipedia has the following to say about Bertrand Russell's theory of descriptions:

"One of the major complaints against Russell's theory, due originally to Strawson, is that definite descriptions do not claim that their object exists, they merely presuppose that it does."

http://en.wikipedia.org/wiki/Theory_of_descriptions

In any case, we should neither be claiming nor even presupposing that gravitational waves exist, so consider this merely a pedantic observation.

Re:That's a little presumptuous.

[photonic]

Gravitational waves are found as a 'natural solution' from Einstein's General Relativity, more or less like electro-magnetic waves are a solution to Maxwell's equations. Since GR so far seems to be solid as a rock (supported by many experiments), there is little doubt among theoreticians that GWs exist. Moreover, a binary system containing a pulsar observed by Hulse and Taylor is spinning down at exactly the rate that you would expect if the system loses energy by gravitational waves. This is not a direct observation of a GW, but it is circumstantial evidence. This observation was awarded with a Nobel prize in 1993, which would suggest that the according to the judges, the existence of GWs is more than a little presumptuous.

Re:That's a little presumptuous.

[L4t3r4lu5]

I would ask you, if you, and I, existed.

Solipsism is a bitch.

Re:That's a little presumptuous.

[Anonymous Coward]

You're confusing unicorns with pegasi, or would be if they existed.

Galaxy size observatory

[Anonymous Coward]

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 ?

This would be wonderful

[NoYob]

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?

Re:This would be wonderful

[Monkeedude1212]

No. It means the Gravity is so strong that the "force" pulling the light inwards is stronger then whatever force propels light at 300000 km/s. If you imagine space time like a blanket, and gravity from a planet like a tennis ball on the blanket, the curvature thats created in the blanket is like the effect of gravity. Thus if you propel an item along the curve, it will orbit around that tennis ball.

A black hole has been theorized to be a pea on that blanket that is so heavy that the "curve" created in space time is almost vertical or even somehow surpasses vertical - thus not letting light escape. There is a point at which light CAN escape from a black hole, a certain distance away (the horizon as they call it) - which is the point at which the force of Gravity and Light are equal and light is basically trapped there.

However, the strength of Gravity has nothing to do with its SPEED. It's speed is how fast it effects the objects around it. As in, Einstein theorized that it travels at the same speed of light, so we are orbitting around the sun, being pulled in by a force that originated 8 or so minutes before it affected Earth.

Meaning if the sun were to instantaneously disappear - we would orbit in our same path until we no longer saw any light. At least thats the theory. However Gravity could be faster, or slower, there isn't really anything concrete to suggest anything Einstein said was really right.

Re:This would be wonderful

[DarrenBaker]

The speed of light is actually the speed of energy, so if gravity waves are energy, then it will be at or slightly below the speed of light. Otherwise, if it's matter-based, then its maximum speed would be about the speed of sound. I believe.

Re:This would be wonderful

[John Hasler]

> I would love to know how fast gravity waves travel.

At the speed of light.

> 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?

Gravitational radiation does not come from inside a black hole any more than electromagnetic radiation comes from inside an electron.

Re:This would be wonderful

[Anti_Climax]

I seem to recall an experimental observation in the last few years involving Jupiter, through which they verified with about 90% certainty that the speed at which gravity propagates through space/time is equal to the speed of light.

A little googling turned this up:
http://www.nrao.edu/pr/2003/gravity/index-p.shtml

Re:This would be wonderful

[Anonymous Coward]

Otherwise, if it's matter-based, then its maximum speed would be about the speed of sound.

*WOOOSH*

Re:This would be wonderful

[Anonymous Coward]

The speed of sound in vacuum? WTF! Gravity waves can travel in a vacuum, therefore they must be non-material.

Re:This would be wonderful

[Anonymous Coward]

Uh, no, it is a limit that represents the resistence of movement through spacetime continnum. In other words, its a measurement of viscosity of the sapcetime foam.

Re:This would be wonderful

[blueg3]

Hmm. Please do not explain physics in the future. :-(

Not that relativity is particularly easy, but... just no.

Re:This would be wonderful

[DarrenBaker]

Vacuums contain material, dude. My Dyson is almost full.

Re:This would be wonderful

[DarrenBaker]

The Universe has a foamy head?

Re:This would be wonderful

[ThePeices]

No, not quite.

Remeber that mass causes a curvature in spacetime ( General Relativity ), so inside the event horizion, spacetime is curved in on itself so much that light cannot escape, as all possible directions inside the event horizion point towards the center. While a 'calculated' escape velocity inside the event horizion may turn out to be a speed higher than lightspeed, no matter can ever reach that speed.

As far as we can tell, gravity moves at the speed of light, so therefore gravitational waves will have a speed limit of lightspeed.

Re:This would be wonderful

[imakemusic]

...........*BOOM*

surely?

Re:This would be wonderful

[Anonymous Coward]

Vacuums contain material, dude.

A vacuum containing matter is not really a vacuum, dude.

My Dyson is almost full.

Oh, well, this really sucks ...

Re:This would be wonderful

[Anonymous Coward]

Those claims were based on a misinterpretation of general relativity, as shown by Cliff Will, Steve Carlip, and others. (Sadly, the Wikipedia entry on the speed of gravity dances around admitting that, based on the fact that the authors later published another mistaken paper that nobody bothered to correct the second time around.)

Observations of Jupiter can't resolve the speed of gravity in the way those scientists claim. On the other hand, observations of pulsars can, and the 1993 Nobel Prize in Physics was awarded for that work. They show that the speed of gravitational waves is the speed of light to within the precision of the experiment.

Re:This would be wonderful

[DarrenBaker]

From the Wikipedia article on 'Vacuum':

a perfect vacuum with gaseous pressure of exactly zero is only a philosophical concept and never is observed in practice.

also:

Upright designs usually employ a rotating brushroll or beater bar, which removes dirt through a combination of sweeping and vibration.

Re:This would be wonderful

[Anonymous Coward]

I am not a physicist, merely an engineer, so take this with appropriate caution, but I think you will find that changes in the gravitational field cannot propagate faster than the speed of light. But to the light trying to escape from a black hole, the gravitational field is not changing, it is already there. Analogies are dangerous, but think of it like a cyclist starting at the bottom of a hill...the hill is already there. The slope could change, but only at some rate. Eg an earthquake could change the slope but no faster than the speeds at which the P and S waves can travel in the rock. Or we could add material, but the rate of doing that is limited, ultimately to the speed of light although practically to a lot less.

Re:And yet we spend only 1.6 million on tracking N

[Chris Burke]

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".

Any armchair physicists here?

[DarrenBaker]

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!

Re:Any armchair physicists here?

[Anonymous Coward]

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?

Possibly. But if the sensor is not within that space where the wave passes, then it could be detected. Alternatively, if the sensor resides in, but detects something that is not within that space, it could work, too, if these waves exist.

By "space" I don't mean the general term of space, but rather vicinity, of course.

Re:Any armchair physicists here?

[John Hasler]

> So, stop me if I'm way off base, but might it be impossible to detect gravity
> waves?

Proving that they cannot be detected would be exactly the same as proving that they do not exist.

Re:Any armchair physicists here?

[Anti_Climax]

A gravity wave, as derived from the theory of relativity, doesn't specify that the gravitational constant would oscillate - simply that the shifting of large masses, like co-orbital black holes and such, will distort spacetime in wavelike manner. Those perturbations of spacetime would travel from their origin outward at the speed of light.

It's best to think of it in terms of the bowling-ball-on-a-rubber-sheet analogy of space-time. If you take a large mass like a bowling ball and set it in the middle of a large rubber sheet, it will depress deeply nearby and taper off the further away from it you go on that sheet. If that bowling ball magically disappeared, there would be a wave that travelled across that sheet as well as if you had 2 bowling balls spinning around each other.

The way we've been trying to detect gravity waves so far (LIGO) uses lasers set up at right angles so if space were to compress or stretch in one dimension, the beams the were previously in phase would shift apart. This can detect a stretching of spacetime equal to a fraction of the wavelength of light used in the lasers.

In actuality, it is the change in the behavior of spacetime that lets us measure in that manner, but if the wave were to stretch spacetime in all dimensions, LIGO couldn't work. Hope that explains it.

Re:Any armchair physicists here?

[superluminique]

DarrenBaker, a gravity wave is not a change in the gravitational constant; it is a deformation of the space-time fabric itself. So it doesn't change the gravitational (attractive) force between masses but simply moves the "fabric" on which they lie.

Imagine a stretchy, rubber fabric that you pull/push or move upward/downward from one side such that a wave propagates through. Then two masses lying on this fabric, link ping pong balls that you would stick on, would move closer/further apart. That's basically the effect that people are trying to measure. Of course, if these "test" objects are perfect in such that they're infinitely small, everything behaves in a trivial way. The catch is when your object is not "perfect" anymore and possesses some finite size. This seems to be concept that you worry about and you are right. Because of it's finite size, the object itself would change size. However, it does not matter at all because this change is not significant. Here's why:

The amplitude of a gravity wave is express in a weird unit expressing the ratio of the spatial compression in one direction to the stretching in the orthogonal direction (see the nice animation here). A typical gravity wave would have an amplitude of 10^-20., which basically mean that any object would change size by this fraction. So this is practically undetectable unless you consider something really big like the "arms" of the LIGO gravity wave detectors or this pulsar timing array. The other thing to take into account is the fact that what you are trying to detect acts like a wave. Waves that this pulsar array is after have frequencies of nanohertz, or wavelengths of 3*10^17 meters (this is about 32 light-year!). For LIGO, frequencies are the order of 1 hertz, so 300 000 km. Hence if your object, the pulsar for the pulsar array, or the mirror/detector for LIGO is much smaller that the wavelength that you attempt to detect, it really doesn't have any effect on what you are trying to measure.

Re:Any armchair physicists here?

[mbone]

A gravity wave will change the distance to objects at right angles to its direction of propagation. This effect is biggest when the distance to an object is order the wavelength of the wave, or longer. (Since they travel at the speed of light, the relation between wavelength and frequency is the same as for light.) Likewise, the sensitivity is biggest when the period of the wave is between the frequency of measurement and the total duration of observations. So, pulsars are sensitive to waves with periods between about a day (they are not observed continuously) and some decades (the length of data).

Some waves are sinusoidal (distant objects appear to move closer and further away periodically), while impulsive gravitational radiation can have "memory" - i.e., the distance after the burst goes by will be permanently changed.

All of the above assumes we know the correct theory of gravity, which we won't be sure about until we actually get to study them.

Re:Any armchair physicists here?

[Migraineman]

You, I, and the lasers are inside the three-space being acted upon by the gravitational wave. How the hell are we supposed to measure this phenomenon from the "inside?"

Re:Any armchair physicists here?

[Anti_Climax]

Like I mentioned in the last sentence, it relies on the expectation that a gravity wave passing through an area would stretch one dimension of space while contracting another perpendicular to it.
 
If it causes all dimensions (including time) to expand and contract simultaneously, it can't work.
 
Of course, I have to defer my understanding of gravity waves to those who study this stuff for a living and have experimentally verified a large body of the predictions made by general relativity.

Re:Any armchair physicists here?

[Velex]

You, I, and the lasers are inside the three-space being acted upon by the gravitational wave. How the hell are we supposed to measure this phenomenon from the "inside?"

Same way we'd measure the surface of a sphere changing if we were on the surface of the sphere. Just add an extra dimension.

Re:Any armchair physicists here?

[Migraineman]

Doesn't that require a reference that's outside the space-time reference frame we occupy? I'm not aware of us having that capability yet.

Huh?!? WTF?!? OMG!?! PINK PONIES?!?

[gbutler69]

You FAIL! Unicorns don't have WINGS!!!!!

They have HUGE PENISES!

That's dumb

[tjstork]

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.

Re:That's dumb

[A beautiful mind]

Gravitational waves are a consequence of general relativity, so IF gravitational waves don't exist then GR is at least partly wrong. That's a bit stronger than believing in Santa Claus I'd think.

Re:That's dumb

[Profane MuthaFucka]

The guy you're responding to, tjstork, is an idiot, not worth your time. He's also a conservative, but I repeate myself. The only reason it's relevant is that his opinions come from his ideology. In his mind, you are already wrong because you like science, and science is paid for in large part by public dollars. This makes science the enemy to him.

He'll stick to his scientifically ignorant position, and you will fail to educate him.

Just a heads up.

Re:That's dumb

[Fallen Seraph]

No, you really, really, don't get it. It's not like someone one day decided there are gravity waves, and conned people into spending millions on tests for them.

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 already is that the boat displaces water, this is the distortion that objects with mass cause to occur on spacetime. Gravity waves would be the wake the boat leaves behind as it moves through the water.

This is expected to be most evident in binary star systems, as the stars rotating around one another have a relatively high angular momentum, as well as the large masses required to make gravity waves easier to detect.


Now, your analogy to Santa Claus is pretty bad, what with Santa being based on myth and all, but if we ignore that for a second and ran with it, it'd be saying something like this:
We can see a flying sled, pulled by reindeer in the sky between December 24th and 25th. Also, any house this sled visits finds mysteriously delivered presents under their Christmas tree, which no one in the house placed there. We haven't seen anyone in the sled, but we believe that the sled is related to the presents appearing on that particular night. So now we're looking for the little man in the sled (maybe it's an elf, maybe it's Santa, maybe it's Jack Skellington for all we know) that we believe is dropping off the presents. For the last experiment, we looked for things at eye level, but saw no one. Therefore, if there is someone coming into the house from the sled, they must be shorter than 6', thereby ruling out Jack Skellington. We have now developed a new tests that will look two foot above, and two foot below our eye level.



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.

PS - Wow, that analogy was painful to continue running with <.<

Re:That's dumb

[tjstork]

He'll stick to his scientifically ignorant position, and you will fail to educate him.

Oh look at you, the same old lying liberal pig as ever. All you talk about is learning with one hand while on the other you ban owning chemistry sets, get rid of electricity experiments in schools, forbid kids from flying rockets in fields, or planes, or working with any sort of mechanical thing in the name of safety.

You can talk about how much you love science and point your crooked and greedy finger at religion as the supposed enemy of man, but the fact is, science is even more the enemy of you communists, because you sick and subhuman traitors are not interested in humanity advancing as much as you are in every human being the exact same thing. You ban altering the earth in every conceivable way, all the while laughing at people caught up in your lies of environmentalism and safety.

Yet, the truth is really simple, you evil bastard. You can't learn about biology unless you cut the animal open first. You can't learn about the earth unless you dig inside it. You can't learn about the sky unless you fly in it. You can't learn about chemicals until you mix them. The more you block people from doing it, the more you spread ignorance throughout humanity.

And the thing is, your side is doing it deliberately, because at the end of the day, you want to hoard knowledge, not share it.

Re:That's dumb

[tjstork]

Gravitational waves are a consequence of general relativity, so IF gravitational waves don't exist then GR is at least partly wrong. That's a bit stronger than believing in Santa Claus I'd think

Well, if GR was wrong on that score, don't you think physics would suddenly get a lot more interesting? I mean, seriously, its the prospect of Santa Claus popping up and gravity waves not being there that really, fundamentally, the human force that drives science. People want to be surprised by the experiments that they do.

Re:That's dumb

[Profane MuthaFucka]

Awesome! Please continue.

Re:That's dumb

[Artifakt]

I'm really starting to hate the Santa Claus metaphor. There really was a historical person, Nicholas of Cusa, who was Bishop Nicholas in life but became known after his death as Saint Nicolas. That title got shortened and linguistically shifted to Santa Claus.* So technically, there was a Santa Claus, and its just some of the claims made, like his continuing to live today, having flying reindeer or residing at the north pole, that are contra-factuals. Some of the claims, such as his giving a great deal to many people, are facts. Some others, such as giving to the nice and not the naughty as best he could determine, may be factual as well.

* Copernicus never spelled his own name that way, it's a translation to some sort of approximate Latinate/English. The same goes for Christopher Columbus, So if you want to argue that technically Santa Claus never existed under that exact name, fine, but you can do the same for all the other people who are referred to historically by a nick-name.

Jack Skellington is an entirely fictional character, as are Frodo Baggins, Moll Flanders, and the Easter Bunny. Saint Nicholas is a historical person who has simply had more myths and legends attach themselves to him than has George Washington, also still a historical person despite the Cherry Tree and Dollar across the Potommac stories.

Re:That's dumb

[uninformedLuddite]

I suspect that the gravitational waves are obscured by the dark matter

Re:That's dumb

[xouumalperxe]

Saint Nicholas is a historical person who has simply had more myths and legends attach themselves to him than has George Washington, also still a historical person despite the Cherry Tree and Dollar across the Potommac stories.

The myth of Santa Claus has taken such a scale that, though Saint Nicholas might be a historical person, it's fair to say that Santa Claus is a separate entity, a myth based on a historical figure.

Re:That's dumb

[Anonymous Coward]

He'll stick to his scientifically ignorant position, and you will fail to educate him.

Yeah, I feel your pain. I've run into the same problem recently...

Gettin' my drift?

mod doWn

[Anonymous Coward]

formed his own eerors. Future I OF AMERICA irc fun to be again. Lay down paper Get how people ca8 argued by Eric are inherently

Well I never thought of that - n/t

[TropicalCoder]

This space intentionally left blank.

Gravitational Waves Exist

[rotenberry]

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.

Re:Gravitational Waves Exist

[mbone]

The really interesting thing is that General Relativity predicts two and only two polarizations, while other theories (that cannot be distinguished from G.R. in the usual solar system tests) have more polarizations. If and when we get a good, high SNR, detection of gravitational radiation, a profound test of gravity should follow in short order.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Better there are no gravity waves.

[tjstork]

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.

Re:Better there are no gravity waves.

[dougisfunny]

So you want all experiments to show something contra to the hypothesis, which suggests some new hypothesis? That's what it sounds like. What do you want to happen when they try to test the secondary hypothesis? Do you want that experiment to fail and sugest something else? If no hypothesis are proven, what's the point of experimenting?

Re:Better there are no gravity waves.

[tjstork]

So you want all experiments to show something contra to the hypothesis, which suggests some new hypothesis? That's what it sounds like

Oh, don't be so sith-like. The situation at hand is that physics has been in confirmation mode for a good long time and it would be fun to see things shaken up a bit.

Re:Better there are no gravity waves.

[Fallen Seraph]

I'm going to reply to your previous post with this too.

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.

Oh god, wow, where to begin. First of all, you have your dates wrong. Philosophiæ Naturalis Principia Mathematica was published in 1687, so by the time GR surpassed it, it'd only been around for ~230 years or so, not 300 (so you're off by like 23%, which is a significant margin of error :P). I'll call your dates on GR close enough though, since it's only a little over a decade off.

Second, every major breakthrough was NOT "because people were ho hum and looking through some theory where they expected to find a result, and didn't." Most breakthroughs, especially in the earlier years, were due to people observing phenomenon that the current models had no explanation for, and could not account for. Hubble's expanding universe is one such phenomenon, as is GR itself, since Newtonian motion fails to account for different points of observation entirely, and is based on a static observer.

Also, in what way, exactly, is the thermonuclear fusion reaction in the sun an "edge case of newtonian physics", or even blalckbody radiation for that matter? You realize that newtonian physics says pretty much nothing about either of these, right?

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.

No, again, you really, REALLY don't get it. Being proven wrong just rules out a theory, it does not necessarily make new ones, as Rutherford's experiment did. Finding gravity waves would help confirm GR, confirm that out understanding of gravity is solid, at least for now, and give us more data to work with in mathematical models as well as allowing us to make more potential observations. Quite the contrary to what you say actually, being proven wrong doesn't do anything useful, as it only leaves us back at square one. No gravity waves means either GR is incorrect, that we're measuring them in a bad way, again, or, that there's some weird exception that prevents them from forming. If in the case that GR is proven wrong, well, then what? There's no other theory that even comes close to rivaling it's explanations for phenomenon which we have observed, and the explanation for what gravity really is, according to GR, is pretty damned elegant if you actually understand it.

You realize that for physics to be in "confirmation mode" is a good thing right? That means we're on the right track, and that we haven't been "wasting money" at all, quite the contrary, it means we've been using it effectively to learn more about the universe. That is the end goal. Not to "shake up science" or to "make breakthroughs," but to actually learn something.

Re:Better there are no gravity waves.

[Deosyne]

Fair enough. Simply convince the scientific community that they need to stop focusing on trying to develop an understanding of the way that the universe works and change the priority to having fun instead.

Just because a theory cant be tested

[voss]

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.

Re:Just because a theory cant be tested

[Anonymous Coward]

If a theory cannot be tested, it is as useful as not making one.
For example: There is no way to prove the "God" theory is true or "not true". People can use logic to deduce its existence but at the end of the day, saying there is a God is as useful as saying nothing at all.

An untested theory is philosophy, not science.

Re:Just because a theory cant be tested

[volpe]

Bear in mind that there's a big difference between a theory which cannot be tested in principle, and one which cannot currently be tested in practice due to limited technology. Actually, it's not even appropriate to use the word "theory" in this context. In the latter case, it's a hypothesis. In the former, it's metaphysics.

Re:Just because a theory cant be tested

[JohnFluxx]

He might not have thought about, but there's actually a fairly simply way to measure the size of an atom.

Take an oil drop and measure its weight. Then drop it on the surface of a very still lake, and leave it to spread it out. It will spread to be about 1 atom thick. Then you can simply look to see how big it spread out, divide by the volume by the area, and the result is the size of the atom.

This gives a result to within an order, which amazing given its simplicity.

Re:Just because a theory cant be tested

[Anonymous Coward]

You are correct in that an untestable theory need not be incorrect. But if a theory can not be tested, then it can not be falsified either. Since that is crucial to the scientific method, it's bordering philosophy rather than science.

OTOH, in the future there may be new methods that can validate/invalidate the "wild" theories put forth today. 2400 years ago they didn't have the tools we have today.

As for logic, Democritus could probably have proposed the existence of the unicorn as well. Logic only works as well as the statements used.

Re:Just because a theory cant be tested

[Kagura]

But that requires knowledge that oil spreads out to about one atom worth of thickness, which requires previously knowledge of atoms. And a non-atom model (if that were the universe we lived in) could surely replicate such a phenomenon.

Re:Just because a theory cant be tested

[JohnFluxx]

Why would there be a limit in the non-atom model to how thin it spreads out?

adds a whole new dimension to "surf's up"

[vaporland]

pun intended

A Suggestion for 2 New Observatories

[LifesABeach]

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.

A Kardashev type III observatory?

[deoxyribonucleose]

...well, OK, not in terms of energy consumption, but still thinking big! See http://en.wikipedia.org/wiki/Kardashev_scale

Physics = Useful inventions

[AliasMarlowe]

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...

I don't have a car analogy, but...

[vegiVamp]

Are we fish in the ocean, trying to detect pressure waves in the water ?

standard candles

[eleuthero]

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?