Certainly not enough measurements exist, and certainly we can't outright reject the possibility that gravitational waves can travel faster than light. However, any possibility of moving energy (or information) faster than light does seem unlikely to me - according to the current ideas about simultaneity, this possibility would be equivalent to the possibility of travelling to the past (or sending information to the past). If you ever read science fiction, you are probably aware that this might lead to all sorts of contradictory situations.
>Hi,
> This link disputes the findings
http://www.space.com/scienceastronomy/gravity_speed_030116.html>
> As noted in the article Japanese physicist Hideki Asada published a paper, also in the Astrophysical Journal Letters, about a year ago arguing that Fomalont and Kopeikin would actually be measuring the speed of light, not gravity.
>
> I think this link is nearer the mark and sets the speed at approx 20 times the speed of light.
http://www.ldolphin.org/vanFlandern/gravityspeed.html>
> The observations are of objects much closer to us, and would given much greater accuracy to the calcs.
>
> It is early days yet, but I am seeing a general trend from many sources which point to gravity or whatever causes it being the main binding/driving force behind everything. Reality is starting to look stranger than fiction.
>
>Regards N Mc Donald
>
>>Here is a recent piece of news about the speed of gravitation; PhysicsWeb seems a reputable source to me:
http://www.physicsweb.org/article/news/7/1/2. According to this, the speed of gravitation is equal to the speed of light (within experimental error).
>>
>>>Hi Hilmar,
>>> Due to some of the latest research being done large cracks are starting to appear in the currently held beliefs, i.e. Gravity's effect travells at greater than the speed of light, possibly by a factor of 20 fold. Check this link out
ftp://rock.helsinki.fi/pub/misc/matpitka/padtgd/Zanom.pdf
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