They monitor the intensity of light from the star as a function of time. They saw the star dim a little bit just when predicted by the group who discovered the planet. If correct, it will transit (pass in front of the star) again today and people will be looking to confirm this.
I didn't mean to imply LIGO was a bad idea. I'm glad LIGO is being funded, and hope LISA will be funded similarly. I'm not involved with either, but I've heard people who are say the pricetag on LISA might actually be less than for LIGO. I suspect that is due in large part to the fact that LIGO has already developed lots of the technology they would need for LISA. Personally, I'm skepitcal that LISA would be as cheap as advertised, but the scientific possibilities more than make up for that.
GR is a non-linear theory. Most often the equations are linearized when discussing gravity waves. (It has been shown that gravity waves exist in the full non-linear equations, but that was a significant accomplishment.)
Any theory which when linearized gives the same equations will "predict" gravitational waves. (I don't know if any alternatives have been shown to support gravity waves in their non-linear equations.) However, different theories would predict different this in the non-linear regime, presumablely where these gravity waves are being created. Studying the waveforms may allow you to gain some insight about the non-linearities in the equations, thus supporting one theory or another.
This what I was refering to. I don't know of a (possiblely valid) theory that works and doesn't imply some sort of gravity waves. But I'm no expert.
Well, your point of view is one reason to do the experiment. A small minority of scientists still don't beleive in gravity waves. Therefore we look and see who is right. Michelson-Morley had much lower sensitivities.
However, a humougous majority of scientists beleive that space time itself is being distorted in a quaesi periodic way and that this is at least theoretically observable.
Indeed. Tell your congresspeople to support LISA, a similar experiment, but to be done in space. The improved sensitivy (mainly from being off the earth) will allow many more scientific discoveries and very interesting astrophysics.
There are many different predictions of general relativity. That's one reason it's so nice. A relatively simples model makes lots of predictions. Many of these predictions have been verified. Others have not.
Also, several different theories (mostly GR variations) can explain nearly all observed gravitational phenomena. Therefore doing new experiments may allow scientists to distinguish these theories.
These observations are indirect in the sense, that if you beleive GR, then the increased binding energy of the binary implies gravity waves. However, if you don't beleive GR, then the inference that there are gravity waves does not stand up. Since multiple different theories (mostly variations on GR) can accurately explain all previously observed gravitational phenomena, it makes sense to do new experiments trying to distinguish between the theories.
A gravity wave refers to a "packet" of basically periodic warping of space. The warping of space affects the "distance" which the photons must travel before reaching the detectors. Thus, the phase of the photons will be different if there is a significant warping of space time along the path of the photons. The experiment will measure relative phase shifts of the photons to detect the gravity waves.
Actually, there are "second order" effects which allow one high energy photons to interact (indirectly) with each other. But this is a very small effect.
No, the gravity waves from a passing bus or 747 are actually very small, even by LIGO's standards. However, the shaking of the earth due to seismic activity or a bus (passing very close to a detector) will be detectable. Fortunately, it's easy to model a passing bus, seismic activity can be characterized, and there is a small but significant range in which gravity waves from coallscing compact objects could be detected.
My old dorm (Random Hall at MIT) has long had it's washing machines and driers connected to the internet (http://spleen.mit.edu/LAUNDRY/index.html). Earlier this year we started connecting the bathrooms to the internet (http://bathroom.mit.edu/). We never had any problems.
Try to turn out the lights while someone's in the bathroom (without being to Random Hall. That would be cheating, Boris.) You won't suceed. (Taking down the server != Turning out lights in bathroom, so please don't. My friends use those computers.) Of course, the systems were designed by competant people so that there was no chance for any significant damage to be done. I suppose that can't be said for everything.
Yes, if you added every peripherial imaginable, a palm would no longer be a palm, but a laptop. However, that doesn't mean the ability to add things isn't valuable. I don't think most people want their palm to do everything, but I do think that most people would like their palm to be able to do one thing that it doesn't. Everybody can choose to add the one or two things that are important to them (maybe an HD, maybe a barcode reader, maybe a cell phone, etc.). Then the palm is just what each user wants and still not as big, heavey, or expensive as a laptop.
The key that some people seem to be ignoring is that this is only for self-similar phenomena. This gives rise to the asymmetry and emphasis for rare events as compared to the gaussian distribution. The assertion is not that a Gaussian is incorrect, but that it does not accurately model certain self-similar phenomena.
Slashdot Mirror
They monitor the intensity of light from the star as a function of time. They saw the star dim a little bit just when predicted by the group who discovered the planet. If correct, it will transit (pass in front of the star) again today and people will be looking to confirm this.
I didn't mean to imply LIGO was a bad idea. I'm glad LIGO is being funded, and hope LISA will be funded similarly. I'm not involved with either, but I've heard people who are say the pricetag on LISA might actually be less than for LIGO. I suspect that is due in large part to the fact that LIGO has already developed lots of the technology they would need for LISA. Personally, I'm skepitcal that LISA would be as cheap as advertised, but the scientific possibilities more than make up for that.
GR is a non-linear theory. Most often the equations are linearized when discussing gravity waves. (It has been shown that gravity waves exist in the full non-linear equations, but that was a significant accomplishment.)
Any theory which when linearized gives the same equations will "predict" gravitational waves. (I don't know if any alternatives have been shown to support gravity waves in their non-linear equations.) However, different theories would predict different this in the non-linear regime, presumablely where these gravity waves are being created. Studying the waveforms may allow you to gain some insight about the non-linearities in the equations, thus supporting one theory or another.
This what I was refering to. I don't know of a (possiblely valid) theory that works and doesn't imply some sort of gravity waves. But I'm no expert.
Well, your point of view is one reason to do the experiment. A small minority of scientists still don't beleive in gravity waves. Therefore we look and see who is right. Michelson-Morley had much lower sensitivities.
However, a humougous majority of scientists beleive that space time itself is being distorted in a quaesi periodic way and that this is at least theoretically observable.
Indeed. Tell your congresspeople to support LISA, a similar experiment, but to be done in space. The improved sensitivy (mainly from being off the earth) will allow many more scientific discoveries and very interesting astrophysics.
There are many different predictions of general relativity. That's one reason it's so nice. A relatively simples model makes lots of predictions. Many of these predictions have been verified. Others have not.
Also, several different theories (mostly GR variations) can explain nearly all observed gravitational phenomena. Therefore doing new experiments may allow scientists to distinguish these theories.
These observations are indirect in the sense, that if you beleive GR, then the increased binding energy of the binary implies gravity waves. However, if you don't beleive GR, then the inference that there are gravity waves does not stand up. Since multiple different theories (mostly variations on GR) can accurately explain all previously observed gravitational phenomena, it makes sense to do new experiments trying to distinguish between the theories.
A gravity wave refers to a "packet" of basically periodic warping of space. The warping of space affects the "distance" which the photons must travel before reaching the detectors. Thus, the phase of the photons will be different if there is a significant warping of space time along the path of the photons. The experiment will measure relative phase shifts of the photons to detect the gravity waves.
Actually, there are "second order" effects which allow one high energy photons to interact (indirectly) with each other. But this is a very small effect.
No, the gravity waves from a passing bus or 747 are actually very small, even by LIGO's standards. However, the shaking of the earth due to seismic activity or a bus (passing very close to a detector) will be detectable. Fortunately, it's easy to model a passing bus, seismic activity can be characterized, and there is a small but significant range in which gravity waves from coallscing compact objects could be detected.
My old dorm (Random Hall at MIT) has long had it's washing machines and driers connected to the internet (http://spleen.mit.edu/LAUNDRY/index.html). Earlier this year we started connecting the bathrooms to the internet (http://bathroom.mit.edu/). We never had any problems.
Try to turn out the lights while someone's in the bathroom (without being to Random Hall. That would be cheating, Boris.) You won't suceed. (Taking down the server != Turning out lights in bathroom, so please don't. My friends use those computers.) Of course, the systems were designed by competant people so that there was no chance for any significant damage to be done. I suppose that can't be said for everything.
Have tons of windows, top should should it using more memory than it has and uptime should be years.
Yes, if you added every peripherial imaginable, a palm would no longer be a palm, but a laptop. However, that doesn't mean the ability to add things isn't valuable. I don't think most people want their palm to do everything, but I do think that most people would like their palm to be able to do one thing that it doesn't. Everybody can choose to add the one or two things that are important to them (maybe an HD, maybe a barcode reader, maybe a cell phone, etc.). Then the palm is just what each user wants and still not as big, heavey, or expensive as a laptop.
The key that some people seem to be ignoring is that this is only for self-similar phenomena. This gives rise to the asymmetry and emphasis for rare events as compared to the gaussian distribution. The assertion is not that a Gaussian is incorrect, but that it does not accurately model certain self-similar phenomena.