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BOINC Project to Search for Gravitational Waves
Buzz Skyline writes "Einstein@Home is a new, BOINC-based distributed computing project that will analyze data from the Laser Interferometer Gravitational wave Observatory (LIGO). The goal is to perform a whole-sky, gravitational wave survey of pulsars. Beta-test versions of the Einstein@Home screen saver should be available by the end of the summer, and final release is planned for early 2005."
Many distributed projects are coming about lately. Perhaps this is where many fields will be going within the next few years.
Disconnect and self-destruct, one bullet at a time.
Weren't the SETI@HOME people working on a next generation tool that could be used for varied data analysis/search tasks - like cancer research for example, based on plugins?
It seems to me that if you're after people donating CPU cycles something generic would be the way to go.
These posts express my own personal views, not those of my employer
Final release is planned for early 2005... in Japan!
So far, this would seem to be the 3rd BOINC project after Seti@Home and Predictor@Home.
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
Yes and that's what BOINC is, a generic framework for these types of tasks.
SETI@Home on BOINC
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
This is great to hear because it is believed that an advanced civilization would communicate not with radio waves but with gravity waves. Think about it: gravity waves fly right through anything, whereas standard EM waves are blocked by things like planets and dust clouds in space. This is why SETI@Home is a waste of time in my opinion after five years of constant computing and 3,000+ packets.
Of course, an advanced civilization using gravity waves would eventually switch over to some sort of sub-space/zero-point field communication system that could facilitate instant point-to-point communication between two points anywhere in the galaxy. Guess we'll have to wait for Subspace@Home.
Laser Interferometer Gravitational Wave Observatory? Who thought up that name? I bet he was responsible for the Illudium Q-Thirty Six Explosive Space Modulator too.
Banaaaana!
Um... BOINC _is_ the "next generation tool." SETI@Home uses it too. It's open source, and lots of projects use it.
http://www.ldolphin.org/vanFlandern/gravityspeed.h tml
If these hypothetical advanced civilization manages to find a way to communicate with gravity waves, then there you go; problem solved.
N4st0r, trixx0r h0bb1tz0rz! Th3y st0l3 0ur pr3c10uzz!
Scientific progress goes BOINC?
I was an astronaut testing a new aircraft, when I had a blow out, and the resulting crash left me with no legs, no arm, no eye... err wait...
The Kruger Dunning explains most post on
Okay, cool should've read more of the article. Just read about a specialist task and thought it was a whole new software project.
These posts express my own personal views, not those of my employer
Desktop: Seti
Laptop: PrimeNet
Boinc should open up more distributed computing projects as well, since the server/client infrastructure is mostly prewritten. Since my other Boinc projects have been sputtering and not giving me work lately, maybe I'll give this one a try. More info on Boinc Here
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
For one thing, on most of the workstations BOINC would appear to work very quickly on the data only to crash out well before the computation was created. Indeed, sometimes it would actually crash before any data was processed by the application. At other points it would work for hours and hours without actually achieving anything; closing down the workstations at the end of the day without getting one computed dataset off was quite frustrating. On the workstations that were actually computing datasets we discovered a few started to become bloated past the point of peak functionality within a few months of even casual use.
While it's possible that it's the inhouse .NET code that could be creating the problem, after several weeks of debugging we're pretty sure it's BOINC related. My suggestion is to steer clear and look for a safer and more reliable API (or roll your own).
Try not. Do or do not, there is no try.
-- Dr. Spock, stardate 2822-3.
Scientific Progress Goes BOINC.
This is one of many projects related to GriPhyN (Grid Physics Network), an organized effort by physicists to bring important data analysis tasks to the home user. Distributed data analysis for LIGO is just one of the many projects that comprise GriPhyN; others include data analysis for the Sloan Digital Sky Survey and (I believe) the Large Hadron Collider, which is nearing completion at CERN in Geneva, Switzerland. SETI@HOME definitely caught the eye of physicists who, until recently, had been stymied by the lack of funds for supercomputers. While Linux clusters have gone a long way in addressing their needs, they quickly realized that the really data intensive applications such as LIGO, LHC, and SDSS would require something more. I'm excited that I might finally be able to change my screensaver to something other than SETI@Home!
With the average home computer advancing to higher levels, how long will it be until you can rent out your computer? I can imagine that it would be extreemly profitable to credit say $1.50 per hour of time running in the background of a program. Actually, paying for time is bad, paying for packets is better. Now I am not a trained professional in any way or form (I'll be a senior in HS next year) but I believe that paying people to compute should be cheaper then doing your own processing - and alot faster.
:-)
Most office computers in offices that I have been working in have relativly decent power and word processing doesn't take up much of their resources. Offices could make extra cash by running software in the backgrounds on their computers, if not during the day, then at night or after hours. Hrm, interesting possibilities
In nature, there are neither rewards or punishments, there are only consequences.
One of my colleagues likes to tease our students by referring to this volunteer grid stuff as "H-bomb@home". "Sure, your SW says it's doing gravity-wave calculations. I claim that USDoD is using it to do H-bomb (or bioweapon, or whatever) design simulations for free on your computer. Go ahead, prove me wrong."
IMHO it's an interesting point.
(Note that this -isn't- "Scientific American". "American Scientist" is a bimonthly journal with articles aimed at a multidisciplinary scientist audience, whereas SA is aimed at a lay audience. AS's articles are of the depth and quality that SA had twenty years ago.)
You can't read the article online, but your local li-berry may have it. Worth a trip.
Wasn't that the name of a Calvin & Hobbes collection? "Scientific Progess goes BOINC."
LIGO Hanfod is a very cool facility. I got to go on a tour of it several years ago while they were in the calibration phase. At the time they were working on mapping the background vibration in the area. Trucks hitting a bump on a highway over 10 miles away left a consistent detectable spike. It was impressive the work that went into identifying every vibration they felt and then setting up monitoring and periodic average noise maps in order to help filter out the background noise to focus on the vibrations from space. LIGO is the king of siesmographs.
:P, got to love America's fear of nuclear power.
Its interesting that LIGO Livingston seems to be the more PR focused one. Go figure the one in a worse location for this work, but not on a nuclear site gets the PR
If I remember right, there are 5 other international LIGOs, all collaborating on this. It's amazing the expense getting put into verifying this prediction by Einstein. It's never been clear to me why peopel care enough to go to such great lengths to verify this prediction. Anyone have insite in this? Please no philosophical boiler-plate answers...real impact-on-physics answers are what I am looking for.
Sort of like saying what is the speed of time?
distance/time=speed
anything/0=undefined
weirdness.
Our instruments are anchored in time, so how can we measure a wave that warps it?
We really are stuck in a cave looking at the shadows on the walls.
If voting were effective, it would be illegal by now.
Whenever distributed computing is discussed, people forget one thing: their electricity bill. A P4 running BOINC will consume 50 to 100 Watts more then one with Boinc turned off. Get a hold of your last electricity bill and figure out how much 24 hours of BOINC will cost you. Scientist will have to make very attactive offers indeed if they want to let you make a profit.
10 ?"Hello World" life was simple then
While scanning the einstein@home site I noticed a picture that looked a lot like something I had overflown at Hanford. Blew my mind to see that in fact it is the same facility.
I cannot overstate the alien devastation that is at the Hanford site. It is by far the most bizarre and scary thing I have ever seen. Nothing in my experience prepared me for what I saw, nor can I describe it to you. The most heinous depictions in movies and games only begin to capture the horror.
When I first heard of a 300 million dollar proposal to clean up Hanford, I thot it was just pork, but now I think that would just be a bandaid.
There is no doubt in my mind that that site was designed by insane people.
Thus, I would not be surprised at all that if the hanford lab is involved, its probably unsavory.
Yet another version of AMOR... Talk about number of choices. For those who do not know: AMOR stands for Amusing Misuse Of Resources, its one of the toys for KDE.
"Listen If Gravity Occurs"
It's called that because, every time a graviton strikes the sensors, it makes the noise "boink!"
The detection of large gravitational wave fluctuations preceeds the eventual welcoming of our new giant,space folding Overlords...In Japan.
No. You'd have the effect before the cause would be visible. The cause, however, would still precede effect.
No, for at least some moving observers you do wind up with the effect preceeding the cause. It's all part of relativity. Two observers moving in opposit directions can dissagree about the order of two events. If anything exceeds the speed of light one of the observers will see the effect preceed the cause on the time line.
There is no such thing as "simultaneous", it's all relative.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
What do you base this on????
... dimension, when i can clearly see that there are only 4, and no evidence has yet supported any other claims. (though when the LHC at CERN is turned on we might get it)
What is so preposterous about the idea of space and matter interacting?
Why is this more or less preposterous than other gravity theories?
Do you find it less preposterous that string theory has 11 or 20 or
>>Stop wasting time on those silly calculations: Gravitational waves do not exist.
Do you have any idea of how science works???
It is impossible to prove a theory, fx GR, but when thousands of scientist all over the world create one experiment after another that has the possibillity of disproving the theory and none of them manages to do so. Your confidence in the theory is greatly increased. Science therefore needs people to test and re-test any theory.
GR has now been tested since it was born almost a 100 years ago, and has been found to fit to observed phenomenae(how do you spell this) with great accuracy (at least in the weak field approximation).
If you have any links or articles about experiments that make GR break down i would very much like to see them?
QC_DK
(studying physics at NBI)
Let's blow up the moon and check how low it takes for the tides to be affected! Then we will know for sure the speed of gravity
As written up at the back of Wired mag a few years back.
http://www.geo600.uni-hannover.de/
Picture two tubes, each exactly 600m long and at 90 degrees to one another in the horizontal plane. Bounce a laser beam off a mirror at the end of each one. The time should be identical. Unless there is a gravitational pulse, in which case one would appear shorter than the other.
Or maybe this is something completely different =)
No, I did not read the f***ing article!
Well folks, there you have it. Anonymous Coward has declared it so. No need for further discussion.
Stop all funding for gravity experiments and go back to making some more of those wonderful bobble-head dolls. I can't get enough of them!
Sounds fine to me.
Feeling the effect before seeing the cause doesn't mean effect came before cause at the point of origin. If the cause particles (photons) take longer to reach me than the effect particles (gravitons), so what?
No, I did not read the f***ing article!
If we can send a faster-than-light signal, we can exploit relativity to send signals into the past.
First, we need to realise that 'simultaneous' is a relative concept. Consider three evenly spaced spacecraft flying past you in a line. The centre ship fires lasers at the front and back ships, and when the beam reaches them they explode. Simultaneously? No: the lead ship is flying directly away from the beam, while the tail ship is flying towards it, so the ship at the back blows up first, and the ship at the front blows up later. But from the point of view of the captain of the centre ship? Both the other ships are stationary relative to him, so the beams reach them simultaneously.
In general, events that are simultaneous for one observer will not be simultaneous for an observer in relative motion.
Let us now suppose that we wish to cheat on the Alpha Centauri state lottery. At time t=0 in the frame of reference of Alpha Centauri the draw is made, and an instantaneous signal is sent to Earth with the result. The signal arrives at time t=0 (Earth is in the same reference frame, because it's not moving at any significant speed relative to Alpha.)
So, from the perspective of observers on Earth or Alpha, event A (signal sent from Alpha) is simultaneous with event B (signal received on Earth).
However, simultaniety is relative. Let us post an agent in a spacecraft moving at high speed relative to Earth and Alpha, such that from his point of view event A takes place after event B. This is quite possible, as we saw above in the example of the simultaneous shootings. Now when we receive our signal on Earth we relay it - instantaneously - to our agent, who then relays it - again instantaneously - to Alpha Centauri, allowing us to know the result of the lottery ahead of time and buy a guaranteed winning ticket.
Conclusion: instantaneous signalling buggers up causality.
Real Daleks don't climb stairs - they level the building.
1 Lovelace = the gravitational pull that would be needed to suck a golf ball through a garden hose.
Just another day in Paradise
Relativity hurts my head. Well, not exactly but I find there is enough ambiguity in every discussion of it that I never really gain significant understanding of the principle.
Slashdot striped out the disclaimer on the first line of my post - I dropped out of Physics after year two.
No, I did not read the f***ing article!
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I'm one of the true alpha-geeks that read and enjoyed this book:
"Einstein's Unifinished Symphony" which covers this topic in staggering (stupifying) detail.
One thing you'll note, is that the power required to create a detectable gravitational wave is on the scale of supernovae -- so creating enough waves in a sequence which could be interpreted and read would be a pretty remarkable undertaking.
Imagine 1 supernova per bit of communication.
http://www.amazon.com/exec/obidos/tg/detail/-/0
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
For a while I worked as a research programmer for one of the General Relative Groups working on the GEO600 Gravitational Wave Detector in both the UK and Germany. GEO600 is a UK and Germany co-project.
The interferometer is a typical Michaelson interferemoter using lasers with two orthogonal branches 600 metres in length. These gravitation events are small. Movements are ~10-E24 metres. It is expected that only one or two events a year will be detected. So it must run 24/7, 365 days a year.
Naturally you have to remove as much of the noise from the data as possible to detect an event. Mirrors are hung on glass threads as they are thermally inert. It runs in a vacuum. It is temperature controlled. Everything is monitored from air pressure to sisemology. The amount of data being produced is incredible. I assume LIGO is the same hence the distributed analysis.
GE0600 uses a microwave link to transmit data from the site to Hanover where it is backed up and fat pipes pass it on to partner universities. The 'head end' on site uses triple redundancy and enough bufferage for 24 hours back-up on site.
You are talking many gigabytes a day and many terabytes a year and some where in this lot will be an event. This is truely the domain of super computing or distributed processing.
Of course, even LIGO which is larger, is unlikely to spot many events if any and we will probably have to wait until LISA, the NASA/JPL/ESA spaced based interferometry project is up and running to get decent results.
The signal to noise ratio is suprisingly not bad here in /. on this so people must have some interest in it.
4 25 186202/qid=1089891363/sr=1-1/ref=sr_1_1/102-823243 2-3201747?v=glance&s=books
r av ity_waves_000727.html
There's a great book called "Einstein's Unifinished Symphony" that covers all this in great detail.
http://www.amazon.com/exec/obidos/tg/detail/-/0
The most likely thing to actually catch one is the proposed space based interferometer:
http://www.space.com/missionlaunches/missions/g
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
Let us post an agent in a spacecraft moving at high speed relative to Earth and Alpha, such that from his point of view event A takes place after event B. This is quite possible, as we saw above in the example of the simultaneous shootings.
I do realize that relativity tends to contradict common sense and that most arguments like this tend to turn out OK when all the details are considered, but I'm not sure about this one.
You're suggesting that if I draw a lottery (A) and then broadcast the result (B), somebody might get the result before the lottery is drawn?
In your spaceship analogy that would be like having a ship blow up before the initial laser is even fired - that would seem impossible to me. I certainly see how order of events can be skewed by frame of reference, but I'm not sure that two events that occur in one order in one frame would appear out of order in another frame. I can see how their relative timing might differ - but not how they could pass each other.
In any case, if this could happen (B preceeding A) then clearly this would let you predict the future. And of course cause causality loops like deciding you don't like the outcome and trying to change it...
As you'd know if you read the book:
r av ity_waves_000727.html
http://www.space.com/missionlaunches/missions/g
(no, I'm not affilliated with the book in any way other than owning it)
LIGO is built near the site of a SUPERFUND site -- one of the worst as I recall. The waste site predates LIGO which is basically just a couple of long hallways and a control center -- just very very carefully built hallways which are then superheated and purged of air. Toss in some fancy mirrors and suspected mirrors and you've got a site. Not toxic at all.
Now, the fact that we've spent enough on gravitational waves to have fed and medicated every starving, aids infected person on the planet is another matter -- and not one I'm likely to understand.
If we took a couple of years of research money, used it to feed, educate, and medicate the 3rd world (like most of Mississippi) we might just find our world economy in good enough shape to more than make up for the difference with increased science funding for a long time to come.
Ah well. Lasers are cool, Half dead poor people are not cool -- especially if they look different from us and have no oil. I get it.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
It is more probable that gravity propogates at the speed of light. See here.
The Moore-Murphy Law: The number of things that will go wrong will double every 2 years.
If A and B are simultaneous in your frame of reference, then A will be before B in frames of reference moving in one direction, and B will be before A in frames of reference moving in the opposite direction. So if you broadcast the result using an instantaneous communication device, then the recipient will get the result before the lottery is drawn - at least from some perspectives.
In your spaceship analogy that would be like having a ship blow up before the initial laser is even fired - that would seem impossible to me. I certainly see how order of events can be skewed by frame of reference, but I'm not sure that two events that occur in one order in one frame would appear out of order in another frame. I can see how their relative timing might differ - but not how they could pass each other.
The critical thing here is that the speed of light is the same in all reference frames.
So, in the frame of reference of the centre ship, beam A heads forwards at 300,000 km/s, and beam B heads backwards at 300,000 km/s. Since both ships are stationary, both ships are struck at the same time and explode simultaneously.
In the frame of reference of a stationary observer, in which the ships are cruising past at speed v, both beams are sent out at 300,000 km/s. The rear ship moves towards beam B at v and the front ship moves away, also at v, so the rear ship is struck first.
And in the frame of reference of a spy-ship flying at twice the speed of our warring convoy in the same direction, the three ships are moving backwards at speed v. Hence the front ship reverses onto the beam and the rear ship reverses away from it - and the front ship explodes first.
The wonderful part is that all three are correct. If two events are such that no signal travelling at lightspeed or slower can get from one to the other, then the order in which they take place is entirely dependent upon your point of view. That's why faster-than-light communication leads to madness...
Real Daleks don't climb stairs - they level the building.
"Free your mind..." so it goes. If your brain is a quantum computer then it probably acts like a quantum/non-local antenna as well.
They have been broadcasting for quite some time..... and they are waiting patiently for us to collectively tune in. Clarity will come in steps as resolution increases with coherence.
.
-shpoffo
That said, looking at the LIGO facility , it seems like somewhat of a harsh scar on the Louisiana forest. Could they not have been a little 'greener' in their construction of the site? One of their daily secondary missions, after all, is educating students.
In a bit of my research into gravity in general, the discovery and eventual understanding of gravity (waves or whatever they are) would me the most momentous discovery of science in the last 500 years. The eventual ability to alter and manipulate this natural force could mean a lot to science and everyday life. Some suggest that gravity, unlike light, is INSTANTANEOUS. Meaning that its effect is not time measurable, its force propagates throughout the universe everywhere instantaneously. Imagine the possibilites for communications, travel etc... is this proved to be true...
I agree with the fact that the jury is still out on the speed of gravitational waves, however most (including myself) expect it to be the speed of light. One can hope that LISA will not experience "budget troubles" as it will measure the arrival times of light and gravity from the same source, settling this question.
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Is a generic science DC client. Volunteers would be able to go to a web site and see what kind of projects are being worked on but some sort of governing scientitifc body would be allowed to allocate the amount of processing any given project would get. You could even allow for processing on multiple projects by the same clients. If you make sure that each project has a well designed web site explaining what it is they are researching and have the client app point to this information the owner of the donated cycles might become more aware of the impact his donation is having. Perhaps you could give the client the option to choose what project 50% of the donated cycles will be working on.
I could go for that. Sometimes the hardest part of participating in a DC project is deciding on which one to support.
Check out the definitive list here. Anything from testing anti-cancer drugs to simulating designs for particle accelerators to hardcore prime number searching!
The most likely thing to actually catch one is the proposed space based interferometer: http://www.space.com/missionlaunches/missions/grav ity_waves_000727.html
I've read about this before. How the hell do they plan on keeping that system calibrated?
The three [spacecraft] are designed to detect gravity waves by measuring subtle changes in the spacecrafts' position. Aboard are instruments sensitive enough to notice positional changes as small as one-fiftieth the width of a human hair.
Sounds near impossible to me. Anyone know more about this?
Aw crap, ninjas!
It has to do with putting them in specific places where they'll tend to be fairly stable (not quite LaGrange points, but similar in idea) and then using really good gyroscopes. As I understand it, extremely tiny bursts of hyrdogen do the fine tuning -- but I may be mistaken. That's just from my memory of reading about it.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
For communications ..
Does this mean they will finally get to replace their aging psychic monkeys, which they currently use, with gravity wave communication ?
I'm curious, how do they produce the gravity waves - create a micro black hole and wiggle it ?!
And will they give up their former scheme of detonating nukes whose shockwaves can be detected to alert their subs that a nuclear war has started ?
I'm still trying to figure out what people mean by 'social skills' here.
I'd really like to see BOINC implement some economic principals in their code. By acting as a gateway to multiple distributed projects, they have the perfect framework to implement the concept of comparative advantage in distributed computing. By efficiently allocating projects to users while still allowing users to choose which projects make progress, more work will get done in less time.
Well, let's look at this another way...
Suppose that an instant signal is sent from Alpha to the ship, as well as from Earth. We've agreed that {Earth receives signal} and {Alpha sends signal} are simultaneous in the Earth / Alpha frame, and that observers in relative motion may legitimately disagree about the order of these two events.
Therefore the ship will receive two notifications of the lottery result - one from Alpha, one from Earth. Because of their perspective on things, even though the two signals are sent simultaneously (in Earth / Alpha frame) and travel instantaneously, the crew of the ship get Earth's signal first.
Now, in this time between receiving Earth's signal and receiving Alpha's signal, the crew of the ship are in the enviable position of knowing the lottery numbers before the draw. They have an instant communicator of their own - so they can signal someone on Alpha, which in their reference frame has not yet held the lottery draw, and they can buy a ticket.
I suspect I'm going to have to draw out the spacetime diagram for this one, though... it's never quite as convincing without the mathematics.
Real Daleks don't climb stairs - they level the building.
I have read that some of the corrections to Newtonian gravity that arise from General Relativity can be accounted for in a Newtonian Framework by accounting for the finite propgation speed of gravity but I have not worked my way through those calculations.
If gravity travelled instantaneously there would be a preferred frame in which to do physics, since it would give us a universal clock, and that would break the principle of equivalence.
Squirrel!
The same thing we'll DO when we have motion machines that ARE PERPETUAL -- modify the theory. Until then...
if the communication really is 'instant' - it is instant, for all frames of reference - so the ship would get the alpha cent signal at the same time as earth at the same time as all other points... if not, then it isn't 'instant' :)
Saying that the transmission and receipt of a signal are simultaneous, for all frames of reference, would break some basic assumptions. Going back to the three warring ships, suppose the losers sent instantaneous signals exactly when they exploded. According to your definition of instantaneous signals, both the assailant and earth would receive the same sequence of signals. If both signals arrive simultaneously for both observers, the earth observer must conclude that the laser went faster than c to hit the front ship and slower than c to hit the rear one. If the same signal arrives before the other for both observers, then the observer on the attacking ship must conclude that light travels at different speeds. The very basis of relativity is that all observers measure the same speed of light.
Spacetime diagram doesn't work out for this one, unfortunately... Think of a light-cone centered on Earth and another one centered on Alpha - they cross at a point a few years in the future (and physically at the midpoint between the two systems). So, yes, if Alpha draws a lottery, and sends the info to Earth instantaneously, the Earthlings have it a couple years before the light of the lottery-drawing event reaches Earth.
However, they turn around and beam the message back to Alpha Centauri. Time has still passed (even a miniscule amount of time, if they had an auto-receive/reply machine on Earth that takes the beam from A and turns it around immediately to send back). When the message is received at Alpha Centauri, it's received *after* the drawing took place, and *after* they sent the message to Earth. However, they're receiving it several years before they would know that the Earthlings would normally know about the result - so it seems like the Earthlings are "predicting" the lottery, but they're always telling the answer just a little too late.
In any case, the spacetime diagram in this instance works better if you take it as a generic... The 45-degree lines in an ordinary diagram represent light-speed. However, if you're including infinite-speed gravity waves as a method of transmitting data, then your "cone" has to open up to 180-degrees: every event, no matter how distant, that happens simultaneously can be known to everyone, no matter how distant. And no problem with causality, just that light is too slow to keep up with "real-time".
Highly unlikely, though - there are bigger problems than causality in relativity that constrain information (not just light) to travel no faster than light.
-T
The LIGO site in Livingston is the the middle of a forest used specifically for logging. As a matter of fact, this logging can cause problems for the vibrations that LIGO feels.
finally! ^_^
:-)
*remembers that Dr. Zefram Cochrane (ST) was born in 2030
The 1993 Nobel Prize was given to researchers who proved that gravitational waves DO exist by showing that two starts that rapidly revolve around each other are losing exactly the same amount of energy that gravitational waves predict.
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Unfunny, OK I can live with that, +1 funny is better, but hey, a lot of people here probably weren't alive in the 70's.
Modding me as troll was a waste of mod points. Like all things that strive to be funny but fail, they should be ignored.
Sheesh, wait until Oscar Goldman hears about this, you will be so sorry. Now Jamie called, and I got to pick up some dog food for are dog. You would think a dog that is mostly electronic wouldn't eats so much.
That reminds of the time I met Bigfoot...
The Kruger Dunning explains most post on
>
Tom van Flandern is a well-known crank. He has done some good science in other areas, but his conclusions regarding the speed of gravity are just plain wrong. For corrections of van Flandern's mistakes, see this paper, and also this discussion.
The speed of gravity has been indirectly measured to be equal to the speed of light within about 1% accuracy, by observing a binary pulsar system (whose rate of inspiral due to loss of energy from gravitational radiation depends on the speed of that radiation); the 1993 Nobel Prize in physics was awarded to Taylor and Hulse for this work. Direct measurements will become possible once LIGO or one of its peer or successor experiments detect gravitational waves.
Did you take into account multiple spaceships traveling at different speeds that could bounce the information around between them? Did you include ships going slower than the earth / alpha centari pair?
-- The act of censorship is always worse than whatever is being censored. Always.
That would not change anything, would it? You will still not be able to buy the lottery ticket before the winning numbers have been announced. What good would bouncing the information around do?
in GNUin GNUin GNUin GNUin GNUin GNUin GNUin GNUSegmentation fault
Spacetime diagram doesn't work out for this one, unfortunately...
It works out well if you parse merenguid's use of simultaneity in different frames. The situation is as follows: Alpha Centauri sends a signal to Earth, and this is bounced to the ship. This all happens in the spacelike slice for which Alpha Centauri is motionless and at the time the outcome of the lottery is announced. The ship is traveling rapidly away from Alpha Centauri, so the spacelike slice for which the ship is motionless passes through Alpha Centauri well in the past. Thus, if the ship sends a signal to Alpha Centauri that is instantaneous in the ship's frame, it will arrive before the outcome is announced.
"Your notation sucks!" -- Serge Lang (1927-2005)
Sounds interesting. Seems from the site it only works as a screensaver, though. At work we have 3 powerful dual cpu workstations (always on, not always logged in, almost never in screensaver mode) that could contribute if only the distributed program functioned a service. My FreeBSD server at home doesn't even have X, but still have lots of spare cycles that a 'nice -19' gravitational wave daemon could use.
Just a thought.
Are you a grammar Nazi? I'm trying to improve my English; please correct my errors!
To have a right to do a thing is not at all the same as to be right in doing it