Recent content by Henri Garcia

Mea culpa. Thanks for the gentle reprimand. In hindsight I was bring a little lazy, But not completely, I was so surprised in reading this (in Ripples in Spacetime) that I thought others might benefit from a discussion. I have googled a derivation but have not yet worked through it all. I am...

So, I have heard that the deflection of starlight using Newtonian gravity is only half of the deflection predicted by Einstein. NE1 know where I can find an example of the former calculation? thanks

Apparently you have never seen a spherical chicken. :-) :-) And thanks for the answer. Can you (and/or Peter) recommend reading material (text?) for a PhD in physics who wants to understand GW and LIGO?

Thanks for the correction, PD and mfb. I am trying to ask a Physics question (i.e. spherical chickens) and I am getting engineering answers (hair in the form of vibrational noise). Assume no noise. The laser is solidly fixed. The mirror is either (a) totally unconstrained or (b) solidly fixed to...

Considering only motion induced by the GW, are you implying that the unconstrained mirror moves more than if it were fixed to the Earth? (Let's neglect noise for the sake of argument)

This discussion has helped me a lot. Thanks. And I think this next point is important. I originally thought that the stretching of spacetime affected the 4km distance to the mirror as well as the 4km pipe that surrounds it. Both would stretch by the same amount. I thought that the delicate...

Is it possible that Justin means "detector" and not "arm"? i.e., 2 LIGOs determine a plane for source location. 3 determine a line. and 4 are needed to pin down the direction?

Thanks for the reply, Mr. T. I am confused. Why should it matter if it is free to move or if it is rigidly held 4 km from the laser? I thought the suspension was solely to isolate the mirror. Please explain.

Thanks to you both!

You wouldn't. But I thought perhaps that the curvature effects in spacetime could be viewed *as if* they resulted from such a displacement. Clearly that is not the case. My original confusion with the stretching of LIGO was that I pictured two electrons, say in an antenna, being hit...

Thank you very much for the reply, Peter. This followup maybe inane, but please humor me and appreciate my confusion: Is the displacement for a GW completely within the 4 spacetime axes, or are the effects in spacetime, but the displacement is in a non-existent 5th dimension?

LIGO is most sensitive to a GW from directly above/below. As a transverse wave hits an arm why don't the laser source and the mirror move in unison -- thereby covering up the distorted motion?