# How to discern something about gravity waves?

1. Dec 12, 2006

### jammieg

I had an idea on how to possibly get some idea of what gravity waves are, I couldn't find confirmation data on google but to be honest I don't really care and only spent 15minutes looking for it, anyway here it is:
If gravity waves are a particle of some sort on the electromagnetic spectrum then they should have a penetrating power, like visible light doesn't go nearly as deep as x-rays, so I'm wondering if during an ecclipse of the sun by the moon do the tides not go as high? Do you see what I'm getting at? The results of that data might hint on something about gravity waves if anyone cares or is curious.

2. Dec 13, 2006

### Danger

Hmmm....
There is no such thing as a 'particle on the electromagnetic spectrum' other than photons. Secondly, a wave and a particle are not the same thing, although photons display the characteristics of both. Thirdly, if gravity is indeed simply space-time curvature, there are no particles involved. Should the existence of the theoretical 'graviton' be proven, then physics will have entered a new age.
I might add that if you gave up after 'Googling' for 15 minutes, you're looking for an easy way out. Until I got on the net a couple of years ago (whenever I joined here), I spent hundreds upon hundreds of hours in libraries looking for this kind of stuff.

3. Dec 13, 2006

### Claude Bile

Data on tides has nowhere near the kind of accuracy you need to detect even the most powerful of gravity waves.

Claude.

4. Dec 14, 2006

### Jheriko

Maybe not individual waves, but the entire tidal effect is the sum of the effects of lots of individual waves. So the data should be sufficient to test this hypothesis, at least for large amounts of graviton absorbtion, and during a solar eclipse we should feel the effects of the Sun's gravity less if the Moon is capable of blocking gravitational waves, it may be an unobservably small effect. I could easily imagine such an effect being there since ultimately the Moon /might/ need to be able to absorb some gravitational waves to remain in orbit of the Earth.

On the other hand, is it possible that gravitons can pass through matter whilst interacting with it at the same time?

I don't really know enough to give an answer.

5. Dec 14, 2006

### vanesch

Staff Emeritus
If you mean somehow that the sun's gravity be "shielded" by the presence of the moon, then no, gravity cannot be "shielded" against, at least as long as the equivalence principle is valid, because it would be a means to distinguish gravity from acceleration.

6. Dec 14, 2006

### cesiumfrog

Wouldn't gravitational waves be slightly weaker on the far side of the moon, having converted some fraction of energy into heat?

7. Dec 14, 2006

### billiards

The gravitational pull (away from the earth) will be strongest during an ecclipse because the pull of both the sun and the moon will be combined.

Last edited: Dec 14, 2006
8. Dec 14, 2006

### vanesch

Staff Emeritus
I have no idea about that, but the sun's gravity here is not in the form of gravity waves...

9. Dec 14, 2006

### cesiumfrog

Sure (not "much" of it anyway), but gravitational waves are the topic of the question. Analogously, the fact photons may be shielded does not allow us to shield a bulk electric charge.

Think metal box (not dielectric medium): information about the internal charge distribution, or any wave describing changes thereof, is blocked. An external test charge is still attracted nonetheless.

10. Dec 14, 2006

### NoTime

While this has nothing to do with gravity waves, the sun and moon together affect tides.
Keywords you can look up are neep tide or syzygy.

For research on gravity waves try LIGO.

11. Dec 17, 2006

### Claude Bile

No, even the cumulative effect would be undetectable. There is simply too much 'noise' present in the measurements to extract the kind of sensitivity required to detect gravity waves.

Our best bet in detecting gravity waves would be from a cataclysmic collision between two black holes or something like that. Electromagnetically-speaking it is much easier to detect a supernova than the cumulative light of a billion white dwarves - same goes for gravity waves.

One final point, you are assuming that graviton/matter interaction is strong, where there is no real data to test this hypothesis. Given that gravity waves are barely-detectable-stretchings in space, I would venture that graviton/matter interaction is probably very weak - though I have absolutely no references to back up that statement .

Claude.

12. Dec 17, 2006

### Danger

Well, my understanding of that is that gravity is far and away the weakest of all natural forces. That's pretty easily demonstrated by picking something up with a little magnet while the whole planet is pulling against it. The only reason that it holds the universe together is that it doesn't have a counter-agent. The other forces have positive and negative natures that cancel each other out.