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Initial Tests Fail To Find Gravitational Waves
eldavojohn writes that though gravitational waves are "predicted to exist by Einstein's Theory of General Relativity, the initial tests run by the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration (LIGO) failed to find anything. It doesn't disprove their existence although it does rule out a subset of string theory. From the article, 'For example, some models predict the existence of cosmic strings, which are loops in space-time that may have formed in the early universe and gotten stretched to large scales along with the expansion of the universe. These objects are thought to produce bursts of gravitational waves as they oscillate. Since no large-amplitude gravitational waves were found, cosmic strings, if they exist at all, must be smaller than some models predict.' The scientists working in Washington and Louisiana (in tandem to rule out flukes) will now move on to Advanced LIGO which will analyze a volume of space 1,000 times larger. If they don't find any gravitational waves in that experiment, the results will be more than unsettling to many theorists."
Have they tried turning it off & back on again?
Meta will eat itself
That's how science works, yeah.
Gravity sucks.
"The average reporter we talk to is 27 years old......They literally know nothing." - Ben Rhodes
An experiment is only a failure if you don't learn anything from it.
Doesn't mean the gravitational waves aren't there.
Maybe they've just got the detection method wrong.
+++ Divide By Cucumber Error. Please Reinstall Universe And Reboot +++
Meta will eat itself
It should be noted that the existance of gravitational waves is pretty much certain - measurements of pulsars like the Hulse-Taylor binary match up perfectly with the predictions of GR.
What LIGO is about is trying to observe them directly, rather than just observing the effects of them.
This is obviously because gravity does not exist, but the observed effect is a result of an higher intelligence pushing things down.
http://www.theonion.com/content/node/39512
> The worst, that could happen for a physicist, would be that the observations could be explained with GR.
This kind of (extremely common) remarks strike me as frivolous. It is one thing to say that physicists enjoy being disproved, because this shows the length of the road ahead; it is another thing to say that physicists would hate to attain knowledge in one particular area or other. Science is in the business of securing truths, not in the business of idly advancing ever-refutable theories.
More like a cycle... observe, theorise, observe to check results, refine theory.
In this case, this is exactly what's happened - the observations looks like they may not fit the theory perfectly - hence, once that's been double-checked, go back and revise the theory and try to find out why.
If you don't test the theory, it's worthless. And if you posit a theory, only observation will definitively "prove" it. Science is about positing theories, observing results, and if they fit the theory - WONDERFUL... you just "predicted" part of the universe that nobody has before.
Intelligent Design has theories? What, if anything, does it predict? How could it be falsified?
This is like that Babbage quote: I am not able rightly to comprehend the kind of confusion of ideas that could provoke such a question.
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
No, there are exact gravitational radiation solutions, and you can also predict gravitational radiation from weak-field situations where the linearized approximation is very, very accurano te (the h^2 term would be less than 10^-15 for the sun's gravitational field at Earth's orbit, for example). The decay of orbits due to gravitational radiation has been observed indirectly in PSR B1913+16, and matches the theoretical prediction. If no gravitational radiation is observed at the expected amplitudes for things like that, it will throw a lot more than just string theory into question, and would raise the obvious conservation of energy question about that pulsar.
As far as I remember from my course on general relativity, gravitational waves follow from a linearization of Einstein's field equations. Thus, if they failed to find them, it wouldn't falsify the theory as a whole but only the linear approach to the field equations.
This isn't exactly right. The equations describing gravitational waves do result from a simplifying approximation of Eintstein's equations, but it's the sort of simplifying approximation that really has to be quite accurate in many circumstances. If they don't find gravitational waves of a certain magnitude then either Einstein was wrong or, more likely, the sorts of astronomical phenomena that could create the waves don't exist.
The, uh... differential manifold part...
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
We know that pulsars conserve energy because they keep turning their lights off!
Now maybe the string theorists, such as Michio Kaku, will spend a little more time back at the drawing board and a little less time pretending to be Carl Sagan crossed with Alan Alda.
I doubt it. There is no such thing as "String theory". It should be more accurately called "String Theories". It's like a multi-headed hydra that lives forever. Falsify one part of it and 3 other theories pop up to replace it.
The only thing that can really kill String Theories is a experimentally verified competing theory that's unifies quantum mechanics and general relativity. Kill the body and the head will die.
AccountKiller
I like to see string theory crumbling as much as the next man, but err.. that :
dark matter can be explained by the evolution of advanced technological civilizations based on *known* physics (through molecular nanotechnology and extreme engineering)
If given the choice between these two propositions, I think I'll stick with string theory and its 26+ space dimensions. But kudos to you for pioneering a new approach to astrophysics that consists in claiming "space aliens did it".
You just got troll'd!
Intelligent Design has theories? What, if anything, does it predict?
That is actually the wrong criticism of ID. ID can certainly predict things. If the 'designers' are a bunch of bored aliens that like to do anal probes, you could predict that the aliens will cause changes in animals DNA such that they tend towards having ass holes. If the FSM is the designer, than you will predict that creatures will be designed towards higher spaghetti creating lifeforms. If the designer is an all powerful omnipotent god that thinks beetles totally kick ass, you will predict that there will be a crap ton of beetles (which there in fact are).
And hey, all of the above might very well be true.
If someone wants to go out and try and prove it, more power to them. The issue is that ID is nothing more than an attempt by religious nuts to try and teach about baby Jesus in the schools. If there were people that were taking the 'study' of ID seriously, they would sit around designing experiments to catch whatever the mysterious force is that manipulates DNA to force evolution and create their spiffy designed universe. Further, when they pondered what the force was, they would have to constrain themselves to theories based upon real physics. This would handily rule out 'magic' and 'god juice'. If they want to show that the force is god juice, they then need to go ahead and reinvent physics to try and explain how the force of god juice works. At no point does 'magic', 'just cause', or 'humans can't understand because they are not Jesus' acceptable.
The issue with ID is that science doesn't accept 'magic' as an answer. If you say a designer is forcing evolution, you need to go and figure out the force being used, and it either needs to conform to current theories or you need to find new ones that explain all observable events. This is what makes the ID folks nothing more than religious whack jobs. When Darwin declare that natural selection was the answer, people went to work figuring out how natural selection works and didn't just decide it was a magical force that just happens. They tore it apart by from a macroscopic level that studied how animals compete and co-opt, they tore it apart on the biological level understanding how cells reproduces, and they keep on drilling down until they are looking at atoms and figuring out how quantum affects influence evolution. At no point was anyone ever satisfied with 'magic' as the answer.
You just said what he said, but he used the language of science while you used the language of bonghits-in-a-dorm-at-a-good-college.
No, no...I was confused at his post too (wow this guy reads too much SF!) but then I realized that his first statement is not about the existence of advanced civilisations, but rather suggests that an advanced civilisation will have more of the tools and ability to solve these problems. He is suggesting that WE need to focus on such efforts as nanotechnology and such, because once we're one of those `high tech civilisations', doing physics will be easier. To an extent I think he's got a point; we can certainly do much better physics now than Gallileo (if only because of apparati), and nanotechnology may indeed allow us to build larger (or smaller) and more stable structures, which may be necessary to directly detect some of the more elusive universal secrets.
Please see the LISA mission:
http://lisa.nasa.gov/
LISA can be thought of as a giant Michelson interferometer in space. The spacecraft separation sets the range of GW frequencies LISA can observe (from 0.03 milliHertz to above 0.1 Hertz).
-- I was raised on the command line, bitch
My own "pet theory" for this was that they would never be detected because although they do exist, they perturb the measurement device to the same degree that they do everything else, ie a gravity wave may perturb one arm of a LIGO detector, but it also correspondingly perturbs the waves of the laser beam passing through it. As a result it isn't detected.
An analogy: It would be like measuring everything in a room with a ruler, then scaling the whole room including the ruler up or down. You wouldn't see a change with the same scaled ruler; you'd have to bring one in from outside.
I bounced this idea off a few physicists (including Bruce Allen who runs the Einstein@Home project on LIGO) but they don't seem to like it. :^) Maybe it will turn out to be correct, who knows. It certainly seems to be turning out to be more difficult to detect gravity waves than was initially predicted.
-- Insert witty one-liner here. --
"Gravity waves should follow the same paths as light waves, and we get plenty of light waves in out gravity well."
Which always made me wonder, how do gravity waves escape a black hole?
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
I proposed the "really tiny strings" theory long ago that said that a really tiny string is attached between the gravitational bodies like the earth and the moon. Sure, some laughed and countered with their silly "spooling paradox" argument, but sometimes it takes decades to appreciate a true genius.
I swear to God...I swear to God! That is NOT how you treat your human!
ID it not a theory, it is a religious/political ideology being presented as a theory that aims to explain the perceived weaknesses of science in order to advance the interests of certain groups and individuals.
- This beautiful, complex interaction could not have possibly arisen spontaneously, therefore God's will.
- This makes no apparent sense/has no apparent purpose, therefore descent from God's will.
- You cannot explain something neatly, therefore God's will or the descent from it.
That's not a theory. The aim of a theory is to predict something that you can then test for. ID doesn't predict anything, there is no empirical test for God and deciding arbitrarily whether things are as God intended or not does not increase our understanding of them - it's merely a reactionary attitude advanced by old men who are afraid of change and what it means for their status.
Besides, even if you believe in God the creator, the ID advocacy of ignorance still seems bogus; God gave you all these wonderful cognitive capabilities, so why not use them to try to fully appreciate his grand work? You would be wasting God's gifts if you didn't. :p
Even as you read this, your pants are strangling your loins! Aaa!
Yep. OK, enough with ID vs evolution, let's move on to the other battlefront of the science vs faith war. Climate change!
Global warming, schmobal schmwarming! Temperatures have gone done for the last 10 years (facts here [wikipedia.org]), so everything is just fine, it's just evil liberals who hate our benevolent oil companies because they're in the pocket of Big Ethanol. Discuss.
You just got troll'd!
Hey, I'm having a party tonight and I want to make sure it wraps up by 1 o'clock. Could you stop by at about 12:55 and bore everyone out of the place for me?
. Science is in the business of securing truths, not in the business of idly advancing ever-refutable theories.
I'm sorry, science is in the business of proving theories wrong. All current scientific theories are merely those that have yet to be proved wrong. They are extremely valuable in that they can be used to predict future behavior of the universe to a significant degree of confidence. However, scientific theories cannot be proven true, they can only be proven false.
The great weakness of science is that people have a tendency to view theories that have been around for a long time and not proven false to be true. All it really means is that they are reliable predictors of the behavior of the universe insofar as our technology allows us to observer the behavior of the universe. Sometimes this means that they are good theories that are very useful (say General Relativity), other times it merely means that our technology has not yet reached the point where we can reliably test any of the theory's predictions (say the various String Theories).
The truth is that all men having power ought to be mistrusted. James Madison
That is actually the wrong criticism of ID. ID can certainly predict things.
Quite correct, that is the wrong criticism. Unfortunately, yours is, too. The argument that "science doesn't accept 'magic' as an answer", and therefore ID isn't science is a circular one. ie, if ID is magic, then science doesn't accept magic, therefore ID isn't science. Well, yeah, duh, no kidding. Heck, technically, I think that might actually be "begging the question".
No, the *real* problem with ID is that it isn't *falsifiable*. And this is specifically because any attempt to falsify the theory, by providing evidence which contradicts any "predictions", could easily be reinterpreted under the lens of "god did that, too". And if a theory can't be falsified, it simply isn't science.
Of course Einstein was wrong.
He was, at best, as right as any human could have been given the evidence available at the time. If he was as true a scientist as the world portrays him, then he expected to have his model refined over time as new evidence comes to light, eventually being completely replaced by something much more accurate.
Whatever new theory we build based on this new evidence will also be wrong, for the exact same reasons.
But it will be right enough to be useful as a stepping-stone to an even righter theory. That is how science works, and that is also why find science zealots to be even more annoying than religious zealots...science zealots have accepted as absolute truth a model that is just a stepping-stone, in direct contradiction of the very methods that they proclaim to be the ultimate determiners of truth.
and why do we think we can detect them this deep inside a Gravity well?
honestly, looking for something like that needs to be outside the gravity well of the sun.
There's a pebble on top of Mount Everest. Using my trusty ruler, I measure the pebble as being 1.3 inches tall.
"Aha!", says my colleague. "Now we know that the top of the pebble is exactly 6 miles, 1.3 inches high!"
"No, silly!", says my other colleague. "The only way that we can measure the height of the pebble precisely is by bringing it down to sea level! Being on a mountaintop confounds any precision measurement!"
Oddly enough, the pebble turns out to be 1.3 inches tall. A most remarkable coincidence, I'm sure.
~Idarubicin
Well played sir. I'd mod you funny but I'm a little pissed off about the coffee dribbling down my screen.
In a field of grain, you can grow wheat, barley, rye or oats. It's still a field. ID is still an area that people study. It's a field. You may not agree with it. I may or may not agree with things that come out of it. That's fine. It's still a field of study. Get over it.
sudo mount --milk --sugar
Here's the part that I find interesting. The whole gravity/space-time curvature is merely an abstraction of gravity into a new dimension.
Ancient people's idea of gravity was simple. Stuff goes down.
Then people figured out that the earth's surface is curved, and "down" didn't work anymore. The new theory of gravity said that stuff moves toward other stuff, and the earth is a big blob of stuff that all our little stuff moves toward. Kinda simple, but you don't have the nice, straight, linear sort of system. You've got a radial one, and other planets and stars have their own gravity fields that pull stuff toward them, and it's a bit more complex.
So, with this notion of mass curving the surface of space/time in some higher dimension, we envision space/time as a sort of elastic surface. Mass sinks into the surface, and smaller mass will "roll" into the depression caused by the larger mass. Why does the "mass" roll downhill? Well, there's the kicker: this higher dimension apparently has its own sort of gravity, and, like the ancients' theory, it's nice and straight: it always goes down!
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
> Which always made me wonder, how do gravity waves escape a black hole?
They don't. While systems involving black holes may emit gravitational waves, the waves don't come from inside the hole.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
In a field of grain, you can grow wheat, barley, rye or oats.
That's very true, of course. But you can't grow wheat, barley, and Ford Pintos. I'm arguing that physics, philosophy, and automobile repair are fields of study, while ID is not. It is a platform. An agenda. It's like saying the people paid by the tobacco companies to falsify studies on the effects of tobacco smoke are conducting science. Apples to orangutans.
Disclaimer: I don't work on LIGO, but I work with people who do.
LIGO didn't expect to see a signal above the noise here. What it has done, is largely rule out a lot of 'exotic' sources - sources with equations of state that don't fit the normal matter we see, but some of the more ambitious parts of string theory thought might be possible. What they have achieved is a phenomenal reduction in their 'noise curve' - the background above which a signal must register to be considered real. So far it's only been a one-way test - just ruling out exotic sources, but nothing that we think should necessarily be there.
LIGO primer and vast oversimplification:
LIGO is an interferometer. The way it works is that a laser is split into two parts, each of which goes down an equal length tunnel, at right angles to one another. If the light went the same distance, when it is reflected back, it should still be in phase, and should interfere constructively (think back to intro physics and the way waves on a string add). If a gravitational wave which had the right polarization passed through the region in the time of detection, one tunnel will have been 'shorter' due to the contracting geometry caused by the wave, and hence the beams will no longer be in phase when they return, so will not interfere constructively in the same way.
So why is it so hard to see waves? Well, all kinds of things (drilling, trucks going by, someone sneezing!) can cause a minute wobbling of any part of the equipment and thus will cause the waves to interfere in the wrong way. What LIGO looks for is a specific 'signature' measured at three sites concurrently, the signature being the waves predicted to occur from certain galactic events (two black holes spiraling into one another, for example). They do some pretty impressive data processing to look for this, but so far have only found that they can't see anything above the noise. We've ruled out some of the less likely things that could be going on - types of matter that some string theories allow, but certainly aren't predicted to exist by established theories (like GR).
However, over time with a few additions to 'advanced' LIGO, or the amazing LISA project we should have a two-way test: Either we'll see the wave that GR predicts to exist from standard black hole collisions, or theoretical physicists have a lot of explaining to do.
Here you have just given away that you start with the philosophical assumption of naturalism: that is, everything that is (or everything that affects the universe) happens inside the universe. There is not, cannot be, any supernatural. That's not a proof you have, it's an assumption that you start with. And that's fine, we all make assumptions (e.g., logic works), but it's better if you're honest about it.
Let's try an analogy. Computers operate by rules, right? Everything in the computer can be defined by the state of its memory, registers, and disk (toss in whatever extra motherboard or micro-architectural state you want). How it transitions from one state to another depends only on what the state before it was, and any inputs into the system. The vast majority of those state transitions are 100% deterministic. (I know, I did my PhD thesis on this stuff.) Only a relatively small amount of input when you boot up determines whether you're playing Quake with friends or writing posts on Slashdot. In fact, for a running system overall, the less input needed to make the whole run smoothly the better designed it was.
Now, suppose there were a self-aware program living in your computer, looking at the state of the system, and trying to determine if there were such things as these mysterious "users", and if so, how they affected the state of the system. All you know is "data"; you can't see the physical world. Since these mysterious "users" don't live in data, to you they're essentially super-natural. Now ask your question: How is it that these "users" affect data?
If you do, you'll see that in this case "magic" (meaning, "something not described in the rules of the system") is an acceptable answer; in fact, "magic" is by definition the only answer. Users create the input from the keyboard, mouse, network, &c that feed into the system. Users really can decide which processes live and die; but what does that look like to a program? Some random data came in on a certain line which fed into a program, which when certain data hits inside a certain area on the screen (the "X" button on the upper right-hand-side of a window), the program sends a signal to another program which sends a signal to another program which tells it to exit. An atheist program might say those inputs were random, like states in quantum physics. Furthermore, really technical humans may have even more control: They can use in-circuit-emulators to directly change state on the CPU and use PCI bus devices hidden from the cpu to directly read and write memory. They can rewrite the register after an ADD instruction to make it look like it added 2 and 2 and got 5.
People who believe in the Judeo-Christian God believes that God has that kind of access to the universe. If he can feed 5000 people from five loaves of bread and 2 fishes, turn water into wine, and come back from the dead, surely he can twiddle some DNA at key points in history. By definition, a "miracle" is a temporary suspension or contravention of the normal laws of the universe. And thus, by definition, the "force being used" may not be detectable or describable under the laws of physics, any more than changes a programmer makes using an in-circuit-emulator would be detectable or describable by a program inside the computer trying to determine if the universe consisted only of data, or if there was a "supernatural" outside of the data.
Note that my point is not to defend any particular ID theories or people who promote them. I have a lot of biologist friends who are Christians, and think that the evidence pretty clearly supports the current scientific understanding of the development of life here on Earth. Believing that God can intervene in the natural world doesn't mean that you can't believe in and shouldn't look for natural laws and natural explanations for things. But your logic of "ID is bad because it will accept a supernatural explanation (i.e., magic)" isn't sound.
TCP: Why the Internet is full of SYN.
Science studies that which is not "magic". A supernatural explanation may be true and it would still not be science. This is a necessary limit of science.
However, even if the answer is "God did it", if God chooses to do things according to some set of rules (as most religions would have us believe), then those rules should be apparant from the patterns observable in the universe, and science should be able to deduce those rules.
That is the point of science: to observe the patterns than events in our universe follow, and produce a set of rules -- a predictive model -- that explain those patterns. This approach only fails if there are effects in our observable universe with an arbitrary or random cause outside of it. Only a God who actually behaved in an arbitrary and random way would affect the predictive success of scientific models.
Socialism: a lie told by totalitarians and believed by fools.
Well, it's easy to explain: It conveys the wrong message. While the curvature of space is indeed similar to the curvature of a rubber hose when a mass is on it, the image you get is wrong at quite a lot of counts:
I hope those explanations did help a bit.
The Tao of math: The numbers you can count are not the real numbers.
That isn't a valid argument. You could say the same thing about any subject. Such as:
At many levels, Mathematics is an agenda as well. Why else would there be such a push to have it taught in schools?
The simple answer is because evolutionism is actually based on scientific evidence. ID is simply a religion that is trying to make itself look scientific so it can be lobbied to be taught in public schools.
The visualization is sound, for a 3d representation. The problem is that space/time involves the 4th dimension, and we are 3rd demensional beings. It is impossible for us to visualize anything in the 4th dimension in a literal sense - we have no frame of reference.
We can think about it abstractly, in ways we can somewhat understand. That is what the "rubber sheet" model is. Space/time is obviously not a 2d plane in a 3d world, it's a 3d plane in a 4d world. What is actually happening is that rubbersheet exists in every direction - forward, backward, up and down. It's not many sheets, it's not a sphere surrounding everything, it is a plane that exists in all three dimensions. It's a difficult abstraction to make, and it is impossible to accurately and literally conceptualize because we have no 4d frame of reference.
For a good explanation of why that is, check out Carl Sagan's explanation, it's rather enlightening. He steps it down to a 3d object interacting with a 2d world, so that we have a frame of reference to understand what is happening.
You won't come out understanding the 4th dimension, you'll come out understanding why you can't understand the 4th dimension, and since Space/Time is a 4th dimensional concept, why the explanations don't make sense.
Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller
Citation please.
After reading this post a couple of times, I've decided that the first line is not referring to the parent, but is rather an abstract of the remainder of the post. It all makes sense now.
...Just in case anyone else was wondering.