Is the speed of gravity important to science?
Further measurements and confirmations are always useful. Unless of course it has been measured many times with more accuracy. Any new method to approach measuring is useful too. Because it shows the same result can be found by a different method, which lowers the chance that it is an artefact or repeated mistake or oversight in the first measurement. Not to mention it gives people another way to measure it if they need to. Or should I say, knowing more is never a bad thing, especially when it comes to gravity. According to wikipedia there isn’t a definite measurement of it.
